Journal of Ecology (1981), 69, 1017-1059 A COMPARATIVE STUDY OF GERMINATION CHARACTERISTICS IN A LOCAL FLORA J. P. GRIME, G. MASON, A. V. CURTIS, J. RODMAN, S. R. BAND, M. A. G. MOWFORTH, A. M. NEAL AND S. SHAW Natural Environment Research Council Unit ofComparative Plant Ecology, Department of Botany, The University, Sheffield S 10 2TN SUMMARY (1) Using a standardized procedure, a laboratory study was made of thegermination characteristics of seeds collected from a wide rangeof habitats in the Sheffield region. Measurements were conducted on freshly-collected seedsand on samples subjected to dry storage, chilling and scarification. Responses to temperature and light fluxwere also examined. (2) The data have beenused to compare thegermination biology ofgroups of species classifiedwith respect to various criteriaincluding life-form, family, geographical distribution, ecology, and seed shape, weight and colour. (3) Marked differences were observed in the capacity of freshly-collected seeds for immediategermination. Of the 403 species examined, 158 failed to exceed 10% germination but 128 attained values greater than 80%. Germination was highin the majority of grassesand low in manyannualforbs and woody species.Withrespect to initialgerminability, major families could be arrangedin the series Gramineae > Compositae> Leguminosae = Cyperaceae > Umbelliferae. Many small-seeded species wereable to germinate immediately after collection and seeds of these specieswere often elongatedor conical and had antrorse hairs or teethon the dispersule. High initial germinability was conspicuous amongthespeciesof greatest abundancein theSheffield flora. (4) In the majority of species, germination percentage increased during drystorage; this effect was most markedin small-seeded species. Among the seventy-five species whichresponded to chilling, some germinated at low temperature in darknesswhilst others weredependent upon subsequent exposure to light or to higher temperature or to both.Responsesto chilling werecharacteristic oftheUmbelliferae. In all ofthelegumes examined, rapidgermination to a high percentage was brought aboutby scarification. (5) Undertheexperimental conditions, all of theannualgrassesshowed thepotential forrapid germination. High rateswerealso observed in manyof the annual forbs and perennial grasses.Low ratesof germination occurred in themajority of sedges, shrubs and trees, and were particularly commonin speciesof northern distribution in Britain. Rapid germination was characteristic ofthespeciesofgreatest abundance intheSheffield flora. Rate ofgermination showed a progressive decline with increasing seed weight, and, with some exceptions, there was a positive correlation between rateof germination and the relative growth rate oftheseedling. (6) In sixteenspecies, germination in the lightwas foundto be dependent upon exposure to diurnal fluctuations in temperature. Underconstant temperature conditions, the majority of grasses, legumesand compositesgerminated over a wide range of temperature, and the same feature was evident in species of ubiquitous or southern distribution in the British Isles. A requirement for relatively high temperature was apparent in sedges,in plantsof northern distribution and in a majority of the marsh plants. The rangeof constant temperatures conducive to germination tended to be wider in grassland plantsthan in woodlandspecies. Rapid germination over a wide rangeof temperature occurredin many of the species whichattaingreatest abundance in the Sheffield flora. 0022-0477/81/1100-1017 $02.00 (?1981 Blackwell Scientific Publications 1017 This content downloaded from 69.167.65.194 on Mon, 2 Dec 2013 13:19:33 PM All use subject to JSTOR Terms and Conditions
Transcript
Journal of Ecology (1981), 69, 1017-1059
A COMPARATIVE STUDY OF GERMINATION CHARACTERISTICS IN A LOCAL FLORA
J. P. GRIME, G. MASON, A. V. CURTIS, J. RODMAN, S. R. BAND, M. A. G. MOWFORTH, A. M. NEAL AND S. SHAW
Natural Environment Research Council Unit of Comparative Plant Ecology, Department of Botany, The University, Sheffield S 10 2TN
SUMMARY
(1) Using a standardized procedure, a laboratory study was made of the germination characteristics of seeds collected from a wide range of habitats in the Sheffield region. Measurements were conducted on freshly-collected seeds and on samples subjected to dry storage, chilling and scarification. Responses to temperature and light flux were also examined.
(2) The data have been used to compare the germination biology of groups of species classified with respect to various criteria including life-form, family, geographical distribution, ecology, and seed shape, weight and colour.
(3) Marked differences were observed in the capacity of freshly-collected seeds for immediate germination. Of the 403 species examined, 158 failed to exceed 10% germination but 128 attained values greater than 80%. Germination was high in the majority of grasses and low in many annual forbs and woody species. With respect to initial germinability, major families could be arranged in the series Gramineae > Compositae > Leguminosae = Cyperaceae > Umbelliferae. Many small-seeded species were able to germinate immediately after collection and seeds of these species were often elongated or conical and had antrorse hairs or teeth on the dispersule. High initial germinability was conspicuous among the species of greatest abundance in the Sheffield flora.
(4) In the majority of species, germination percentage increased during dry storage; this effect was most marked in small-seeded species. Among the seventy-five species which responded to chilling, some germinated at low temperature in darkness whilst others were dependent upon subsequent exposure to light or to higher temperature or to both. Responses to chilling were characteristic of the Umbelliferae. In all of the legumes examined, rapid germination to a high percentage was brought about by scarification.
(5) Under the experimental conditions, all of the annual grasses showed the potential for rapid germination. High rates were also observed in many of the annual forbs and perennial grasses. Low rates of germination occurred in the majority of sedges, shrubs and trees, and were particularly common in species of northern distribution in Britain. Rapid germination was characteristic of the species of greatest abundance in the Sheffield flora. Rate of germination showed a progressive decline with increasing seed weight, and, with some exceptions, there was a positive correlation between rate of germination and the relative growth rate of the seedling.
(6) In sixteen species, germination in the light was found to be dependent upon exposure to diurnal fluctuations in temperature. Under constant temperature conditions, the majority of grasses, legumes and composites germinated over a wide range of temperature, and the same feature was evident in species of ubiquitous or southern distribution in the British Isles. A requirement for relatively high temperature was apparent in sedges, in plants of northern distribution and in a majority of the marsh plants. The range of constant temperatures conducive to germination tended to be wider in grassland plants than in woodland species. Rapid germination over a wide range of temperature occurred in many of the species which attain greatest abundance in the Sheffield flora.
(7) Although germination in most species was promoted by light, some were inhibited under relatively high light flux. In 104 species a marked reduction in germination occurred if seeds were kept in the dark, and in many species this inhibitory effect could be intensified by either or both excluding temperature fluctuations and abandoning the use of a green 'safety' light. The capacity for germination in darkness was observed in all of the legumes and many of the grasses. Dark germination did not occur in the Cyperaceae and was uncommon in the Compositae. The inhibitory effect of darkness was characteristic of many of the species known to form reserves of buried seeds, but it occurred also in certain species with more transient seed banks.
(8) There were recurrent associations between features of seed morphology and of germination, several of which coincided with particular ecological characteristics.
(9) The functional significance of some of the germination characteristics observed in this study leads us to the conclusion that certain regenerative mechanisms in the field may be predicted from the laboratory characteristics of the seed.
INTRODUCTION
The results of many comprehensive studies (Ridley 1930; Salisbury 1942; Isely 1947; Ross-Craig 1948-74; Baker 1972; van der Pijl 1972; Hubbard 1976; Lhotska & Chrtkova 1978) show clearly that flowering plants differ considerably with respect to the number, size, shape and dispersal mechanisms of their seeds and fruits. Although such information is of considerable interest to plant ecologists (Salisbury 1942; Harper, Lovell & Moore 1970; Stebbins 1971; Baker 1972), its value is severely limited by ignorance of other aspects of the regenerative process. In particular, there is a shortage of data concerning the germination biology of flowering plants. The objective of the study described in this paper is to describe some of the germination characteristics of a range of flowering plants drawn from a local flora in northern England. Using a standardized procedure, a series of germination tests was conducted, to assess germinability immediately following seed collection, after storage, and under various conditions of temperature and light flux.
The results have been used to compare the germination requirements of groups of species of contrasted ecology, and an attempt has been made to relate germination characteristics in the laboratory to the mechanisms which control the time and place at which germination occurs under natural conditions.
MATERIALS AND METHODS
Seed* collections
Seeds of 403 species were taken from natural populations during the period 23 May 1972 to 4 August 1976. Each species was collected in bulk from plants established in a relatively small area (10-20 m2). Considerable effort was made to collect only ripe seed, to sample both large and small inflorescences, and, as far as possible, to include seeds representative of the full range in size and morphology present at each site.
Details of the collection sites are given in Appendix 2. With the exception of fifty-six species of southern, montane or coastal distribution, all collections were made within an area of 2400 km2 around Sheffield.
* Here and subsequently the term 'seed' refers to the germinating structure that in some cases would be more accurately described as a fruit.
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The experiments described in this study provide an opportunity to relate germination characteristics to other attributes of the seed. Accordingly, a standardized series of measurements was conducted on each seed collection, and the results are recorded in Appendix 2. In addition to information relating to size and structure, a description of seed colour is included (based upon matching with Munsell colours (Munsell 1954) under a binocular microscope). The seeds of certain species were found to be multicoloured or variable in colour or both; data for these species are not included in Appendix 2.
Seed storage Immediately following collection, the seeds of fleshy fruits were extracted and washed
by hand in tap water. Seeds of all species were then allowed to dry at laboratory temperature for 1 or 2 days, mixed thoroughly, and placed in dry storage in plastic containers in darkness at a temperature of 5 ?C.
Germination experiments Initial tests
Before placing the seeds in dry storage the capacity of the freshly-collected seeds for immediate germination was tested. Fifty unsterilized seeds were placed on Whatman No. 1 filter paper in each of two Petri-dishes. The filter paper was moistened with distilled water and the dishes were transferred to a growth room providing visible radiation at a flux of 40 W m-2 ('Warm-white' fluorescent tubes + tungsten bulbs), over a 15-h day at 20 ?C and a night temperature of 15 OC. Each dish was inspected daily, and germinated seeds were counted and removed. The seed was considered to have germinated when the radicle first emerged. The minimum duration of a test was 30 days and counting continued until no germination occurred for 5 successive days. Further tests were conducted on subsamples removed from dry storage 3, 6 and 12 months after collection.
Dormancy breaking In the initial tests many species exhibited low germination percentages or low rates of
germination or both. Where this occurred, subsamples of seeds were subjected to various additional treatments in an attempt to facilitate germination. Because of the large scale of the investigation it was impracticable to examine the response of each species to a wide range of treatments. Three main treatments were adopted (dry storage, chilling and scarification), and these were applied in a series, progression through which depended upon continued failure to induce rapid germination to a high percentage.
It should be emphasized that these procedures were not designed to provide an exhaustive study of dormancy. The purpose was to identify major types of dormancy associated with particular ecological groups, and to obtain seeds in a condition suitable for later studies (see below) of the effects of temperature and light upon germination.
In the dry-storage treatment, a subsample of the seeds was removed from cold storage (usually within 6 months of collection) and placed in darkness in dry conditions at laboratory temperature (about 20 OC). After a minimum of 5 weeks, 100 seeds were tested for germination as described above.
In the scarification treatment, 100 seeds were removed from dry storage and the testa of each was perforated using a small scalpel or mounted needle. The germinability of the seeds was then measured as before.
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In the chilling treatment, a large subsample was immersed in moist sand in a refrigerator maintaining a temperature of 5 OC + 1 OC. Each subsample occupied a separate box of sand and the seeds were placed between two layers of terylene cloth. At intervals of approximately 45 days, seeds were removed from the sand and tested for germinability.
In a small number of species the effect upon the imbibed seed of incubation at room temperature was assessed. The procedure was identical to that for chilling except that the seeds were stored at about 20 0C.
Response to temperature The influence of temperature upon germination percentage and rate was studied at thirty
constant temperatures over the range 5-40 OC, using temperature-gradient bars closely similar in design to those described by Mason (1976).
Each bar was covered with a single layer of Whatman 3MM chromatography paper. Before sowing, the paper was thoroughly saturated with water and rolled to remove air bubbles and to ensure close contact with the bar. The edges of the paper dipped below the sides of the bar into a water reservoir and acted as a wick transporting water to the germination area. At the hot end of the bar an additional source of moisture was provided by three fine plastic tubes through which water was delivered to the paper by means of a peristaltic pump.
Only species showing high germinability (greater than 75% after 14 days incubation) and rapid rates of germination in the initial tests were considered for experiments on the bars. Preparation of the seed for sowing usually involved removal of the outer investing structures, as far as possible, without damaging the seed. Where seeds were known to possess a testa impermeable to water they were scarified and allowed to imbibe water for a short period before sowing.
The seeds were sown in groups of 30 at intervals of 2.2 cm along the bar. Each group was sown in a line transversely across the bar and spanning a width of about 0.5 cm (about 0. 13 OC). Thirty groups of seeds were accommodated on each bar. Infrequently, the number of seeds in each group was reduced to 20 if the seed was especially large or was available only in limited quantity. Each group of seeds was covered by a miniature transparent cloche, designed to restrict evaporative water loss from the seeds and the surface of the bar.
Germinated seeds were counted daily and removed. The minimum duration of an experiment was 14 days, and counting was extended considerably in species which continued to germinate. Where seeds remained on the bars for a protracted period we sometimes had to replace the chromatography paper in order to avoid heavy bacterial infection.
Response to light Only the effect of light flux upon germination was studied. Earlier studies on the effects
of both flux and spectral composition have been reported elsewhere (Grime & Jarvis 1975).
In Experiment 1, seeds were exposed to three treatments ('light', 'shade' and 'dark'). In the 'light' treatment, five replicate transparent dishes, each containing 20 seeds, were placed in a growth room with a visible light flux of 40 W cm-2 ('Warm-white' fluorescent tubes supplemented by tungsten bulbs), a daylength of 15 h, and a temperature regime of 20 OC (day) and 15 OC (night). Seeds were sown on Whatman No. 1 filter paper moistened with distilled water, and germinated seeds were counted and removed daily.
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Conditions and procedure in the 'shade' treatment were identical to that in the 'light', except that the flux of radiation was reduced to 97 ,uW cm-2 (2.4% of the 'light' treatment) by means of a neutral filter. In the 'dark' treatment the dishes containing the seeds were placed in a light-proof box within the growth room; in order to record germination the box was opened briefly each day under a low-intensity green light. The experiment was continued until no germination was observed for five consecutive days in any of the three treatments.
Brief illumination of seeds by low-intensity green light may eventually cause germination in certain species (Grime & Jarvis 1975; Blom 1978). Furthermore, Experiment 1 involved a diurnal fluctuation in temperature (20/15 IC), a condition known to stimulate the germination of certain species even in continuous darkness (K. Thompson, Grime & Mason 1977). Accordingly, a second experiment (Experiment 2) was conducted on selected species. Seeds were subjected to three treatments. The first treatment reproduced the conditions in the 'light' treatment of Experiment 1. The remaining seeds were in continuous darkness. In one treatment a diurnal temperature fluctuation of 20/15 IC was applied, whilst in the other the dishes of seeds were maintained at a temperature of 20 + 0*1 OC within a water-bath. Germinated seeds could not be removed from the dark treatments, but daily counts were made in the 'light' treatment, and the experiment was terminated when germination there declined to a low rate.
Standardization Practical work extended over 6 years, and involved daily germination counts on a wide
variety of species. In order to standardize procedures, and in particular the recognition of germinated seeds, one author (JPG) was responsible for germination counting on at least 2 days in each week throughout the investigation.
Data analysis andpresentation The results of all tests are presented as final germination percentage and as the time
required for 50% of the final germination percentage to be attained ('half-time', P5O). Analysis of the data from the temperature-gradient bar experiment followed the
procedure described by P. A. Thompson (1970a, b). For each species a graph was drawn showing the time taken at each temperature to attain 50% of the maximum germination percentage. Each successive day, plots were made of the maximum and minimum temperature at which a germination percentage equal to or exceeding 50% of the final germination percentage attained at the most favourable temperature was achieved. The points were connected by a smooth curve, fitted by eye. Thus a large quantity of data is summarized in one diagram. Specimen curves are shown in Fig. 1, and the essential characteristics of the curve for each species are described in Appendix 2.
RESULTS
The large body of data accumulated in this investigation provides many opportunities for analysis and interpretation. The original data collected for particular species are available on request. Here we attempt to classify the species with respect to a variety of criteria, including seed characteristics, life-forms and field ecology, and to examine variation in germination characteristics both within and between the resulting groups of species. A summary of the results of the germination experiments conducted on each species is included in Appendix 2, and a synopsis of the classifications used to analyse the results is presented in Appendix 3.
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5 10 IS 20 25 30 35 5 10 IS 20 25 30 35 40 Temperature (IC)
FIG. 1. The main types of germination response to temperature. Each curve has been constructed by plotting for successive days after sowing the maximum and minimum temperatures at which 50% maximum germination is attained. (a) Ballota nigra (Type I), (b) Koeleria cristata (Type
Capacity for immediate germination Distributions of initial germinability in selected types of plants are shown in Fig. 2, and
a more comprehensive statistical comparison in Table 1. Species differed considerably with respect to the capacity of freshly-collected seeds to germinate under the experimental conditions, and the distribution of final germination percentages within the 403 species showed a strongly bimodal pattern. At one extreme were 158 species (39%) in which fewer than 10% of seeds germinated, whilst at the other were 128 species (32%) the seeds of which showed more than 80% germination. Just over half the species investigated failed to achieve 50% germination, and in approximately one-quarter none of the seeds was capable of immediate germination.
Differences in germinability were associated with life-form. A high proportion of the annual and perennial grasses was capable of germinating immediately after collection, in marked contrast to both the annual forbs and the woody species. The five major families represented in the seed collections formed a series declining in germinability as follows: Gramineae > Compositae > Leguminosae and Cyperaceae > Umbelliferae.
An extensive literature (Brenchley & Warington 1930; Chippindale & Milton 1934; Milton 1939; Champness & Morris 1948; Chancellor 1968; Wesson & Wareing 1969a; Watkinson 1978; K. Thompson & Grime 1979) suggests that under field conditions the seeds of many British grasses germinate soon after release in the late summer and autumn. However, it is also clear from these studies that among the species which exhibited high initial germinability in the present study there are some (e.g. Agrostis tenuis*, Deschampsia cespitosa, Holcus lanatus, Poa annua, P. trivialis) in which a proportion of the seeds do not germinate immediately and may remain live, in the soil, for an extended period. Most of the grasses in this category have seeds which are small and compact and
* Nomenclature follows that of Clapham, Tutin & Warburg (1962).
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TABLE 1. Number of species, grouped in various classes, with ?50% and >50% germination of seeds immediately after collection and after dry storage, and time (t50) required for half the final germination to be reached. The values in the '>50%' columns are based upon the maximum percentage attained in any of the four tests on dry-stored seeds. The significance levels between the '?50%' and '>50%' columns refer to the probability with which the ratio of low- (<50%) to high- (>50%) germinating species in the class departs from the ratio expected from that observed for all 403 species (chi-squared test). The significance levels between fresh and dry-stored seed columns are based upon a comparison within each class between the ratios obtained for fresh seeds and dry-stored seeds. The significance levels between the two 't50' columns refer to the probability with which the ratio of rapid (t50 < 1-4-days) to more slowly (P0 > 4 days) germinating species departs from the ratio expected from that observed for all 267 species. Significance con- ventions in this and other tables: * P < 0.05, ** P < 0 01, *** P < 0.1, - numbers
too small for reliable test. Where no indication is given, P > 0.05. Germination (%) Germination rate,
tend to be without appendages and large hairs-a suite of characteristics which appears to be conducive to burial in the soil.
No obvious correlations were detected between initial germinability and patterns of species-distribution within the British Isles. There were, however, indications of a positive
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relationship between the capacity for immediate germination and species-abundance in the local flora. Of the fifteen most commonly-recorded species in the Sheffield area, only one (Rubus fruticosus agg.) failed to exceed 50% germination in the initial test. By contrast, more than half of the species in the two rarest classes had germination percentages below 50%.
There was also an unusually high proportion of woodland species with low initial germinability; this was evident in both woody plants and in many of the woodland herbs.
No consistent relationship was apparent between the capacity of freshly-collected seeds to germinate and the average height of the inflorescences of the species. There was a tendency, however, for plants with explosive mechanisms of dehiscence to include an unusually high proportion of species in which the seeds were incapable of immediate germination.
The majority of the species with small seeds (less than 0. 1 mg) attained a high germina- tion percentage in the initial test. Conspicuous within this group were species such as Calluna vulgaris, Hypericum perforatum, Juncus articulatus, J. effusus, J. inflexus, Origanum vulgare and Thymus drucei, all of which are known to accumulate large and persistent reservoirs of seeds in the soil (K. Thompson & Grime 1979).
Three categories of seed shape (cylinders, 'tadpoles' and cones) were strongly associated with the capacity for immediate germination. Cylindrical and tadpole-shaped seeds are particularly common in the Gramineae, whilst cones are characteristic of many genera in the Compositae. The high initial germinability of the majority of the species from these two families can be related to further correlations evident in the results: the presence of hygroscopic appendages (Gramineae), pappus (Compositae) and antrorse (i.e. backwardly-projected relative to the direction of radicle extension) hairs or teeth (Gramineae and Compositae). In experimental studies with both composites (Sheldon 1974) and grasses (Peart 1979, 1981) it has been established that these types of seed structure are characteristic of species in which germination normally occurs in seeds lodged on the soil surface. Radicle penetration and early seedling establishment in these species appears to benefit from the combined effects of the seed shape and the antrorse hairs or teeth, both of which tend to anchor the seed in a relatively upright position in loose soil, litter or bryophyte mats, thus bringing the point of imbibition and radicle emergence into close contact with the soil.
It is interesting to note that none of the eleven species with black seeds, and comparatively few of those with dark red (Munsell hues 5R-10R) seeds, achieved a high germination percentage. A high proportion of the species which were polymorphic with respect to seed colour (most of them legumes) failed to exceed 50% germination.
Response to dry storage Appendix 2 gives, for most species, estimates of change in germination percentage and
rate during dry storage for 12 months in air at 5 'C and for about 5 weeks at about 20 'C. In a large number of species, storage was associated with a progressive increase in
germination percentage and rate. Germinability in some species remained unaffected, however, and in a minority there was a decline in germination percentage. In this last category two groups can be distinguished. The first contains five species (Hedera helix, Petasites hybridus, Quercus petraea, Tussilago farfara and Ulmus glabra) in which high initial germinability was followed by desiccation and shrivelling of the embryo. The second and larger group was composed mainly of legumes and species within the Geraniaceae;
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here, increasing dormancy of viable seeds was associated with progressive drying and hardening of the seed coat.
Comparison of freshly-collected and stored seeds with respect to final germination percentage (Fig. 2) reveals a marked increase in germinability with storage. Although the distribution of germination percentages in the 403 species remained bimodal, 66 (31%) of the 211 species which failed to achieve 50% germination as freshly-collected seed exceeded this value after storage. The same calculation has been made for each of the classes of species recognized in Table 1. In certain classes the effect of storage was to increase germination (>50%) in a proportion either greater or smaller than would be expected from the value of 31% obtained for all species. Conspicuously different was the response of the seeds of shrubs and trees, in which only 4.2% of the species that failed to attain 50% germination as fresh seed were induced to exceed this percentage after storage. A similar value of 7.3% was obtained for all the woodland species of initially low (<50%) germinability.
These results are in contrast to the high proportion (63%) of the low-germinating (<50%) species from skeletal habitats in which germination exceeded 50% after storage. Strong beneficial effects of storage upon species with little germination when fresh occurred in the Compositae (67%) and Gramineae (56%), but not in the Umbelliferae (5.9%) and Leguminosae (0%). A very consistent relationship is apparent between seed weight and the response to storage of seeds that did not attain 50% germination as fresh seeds. The declining effect of storage with increasing seed weight is maintained throughout the four classes of seed weight: <0 1 mg, 67%; 0 1-0-99 mg, 38%; 1 00-9 99 mg, 22%; >9.99 mg, 0%. There are indications in the results that dry storage exerted maximal effects upon seeds released from low (<20 cm) inflorescences (40%). The failure of storage to increase substantially the germinability of seeds which were spherical (7.7%), subject to explosive dehiscence (10%) or either or both multicoloured and variable in colour (< 10%) is correlated with the high representation of legumes in these categories.
Several differences are apparent in the responses of individual species to particular storage treatments. In the 5 IC treatment rapid ripening and germination occurred in certain annual species (e.g. Aira praecox, Draba muralis, Lapsana communis and Solanum nigrum) and some perennials (e.g. Hypericum hirsutum, Rumex crispus, Thlaspi alpestre and Veronica officinalis), but was comparatively slow in species such as Ballota nigra, Carexflacca, Plantago lanceolata, Senecio viscosus and Veronica persica.
In Table 2, lists are provided for three groups of species which responded anomalously to dry storage: eighteen species in which germinability increased at 5 IC but showed no increase at 20 IC; twenty-six species in which the effect of storage was much more pronounced at 20 ?C than at 5 IC; and seventeen species in which germination varied erratically between tests. Over half of the last group were marsh plants, which are known (K. Thompson, Grime & Mason 1977, Appendix I) either to germinate only at relatively high temperatures or to require diurnal fluctuations in temperature (or both) to achieve high germination percentages.
Germination rate In most species and tests, germination was discontinuous (sensu Salisbury 1942), i.e.
when the numbers of seeds germinating on successive days is plotted a bell-shaped distribution is obtained, with the majority of seeds germinating within a relatively short period. Continuous germination, involving radicle emergence in a small proportion of the seeds each day over a long period, sometimes occurred in tests on freshly-collected seeds
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and often coincided with low final germination percentage. Continuous germination was also associated with the consistently low rates of germination of many legumes and of certain species of Geranium, in several of which continuous and more rapid germination was obtainable if the testa was scarified. A second group exhibiting continuous germination included species such as Potentilla erecta, P. tabernaemontani, Ranunculus acris, R. flammula and R. repens, in which maturation of the embryo occurs during incubation in moist warm conditions.
In a very large number of species, dry storage at 5 IC brought about a progressive increase in speed of germination. Although this effect of seed-ripening often coincided with
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an increase in number of seeds germinating, it was also observed in species which attained uniformly high germination throughout the storage period. Many of the species in which 5 OC storage caused an acceleration in germination rate showed an even more pro- nounced response to short-term storage at about 20 OC. This effect is well exemplified by some winter annuals (e.g. Cerastium semidecandrum, Erophila verna, Myosotis ramosissima) and perennial forbs such as Carex echinata and Serratula tinctoria.
Caution must be applied in judging the validity and significance of the comparatively low (i.e. t50 <4 days) rates of germination observed in certain species. In plants such as Caltha palustris, Conium maculatum and Molinea caerulea, slow germination coincided with very low germination percentage, and almost certainly reflected, at least in part, the failure to provide suitable germination conditions or pre-treatment. Seventy-nine species are identified in Appendix 2, however, in which consistently low germination rate in the dry-stored seeds is associated with high germination percentage. This group almost certainly includes some species in which an invariably low rate of germination is genetically determined; but for some species, greater rates of germination were achieved under conditions different from those applied in the initial tests. In forty-three species (twenty of them marsh plants) a greater rate of germination was observed in the temperature-gradient bar experiment (Appendix 2). In fourteen species (including nine marsh plants), the optimal temperature was higher than that used in the initial tests, and in four species (three of them woodland plants) maximum germination rates occurred at temperatures lower than the mean daily temperature applied in the initial tests.
Thus it is apparent that the potential germination rate of certain species was under-estimated in the initial tests. Despite this limitation, the tests provide a substantial body of comparative data which allows a preliminary analysis of among-species variation in germination rate and some ecological inferences. In Fig. 3 the distribution of maximum germination rates in the initial tests in various classes of species is presented. The distribution for all species is skewed to the left, with a maximum t50 at 3-4 days. All the annual grasses and a high proportion of the annual forbs and perennial grasses germinated rapidly. A wide range of germination rates occurred in the perennial forbs, but there was a clear bias towards low rates in the shrubs and trees. Germination rates were high in many Compositae, but low in all the Cyperaceae and many of the Leguminosae. The distributions in Fig. 3 also provide several correlations between germination rate and field distribution (Table 1, last two columns). There was a well-defined tendency for species of northern distribution in the British Isles to germinate relatively slowly. Rapid germination was characteristic of the majority of the species of fertile disturbed habitats. Marshland and woodland plants included a high proportion of slow-germinating species.
Several correlations between seed characteristics and germination rate (t50) are apparent in Table 1 (last two columns). With increasing seed weight there is a progressive decline in representation of rapidly-germinating species. Slow germination was common among species in which the seeds were spherical, multicoloured, variable in colour, or mucilaginous. Rapid germination was correlated with the presence of a pappus, conical seed shape (Compositae), hygroscopic awns (Gramineae) and antrorse hairs or teeth (Compositae and Gramineae).
From a previous investigation (Grime & Hunt 1975), estimates are available for the maximum rate of dry-matter production (Rmax) during the seedling phase of ninety-nine of the species investigated here. In Fig. 4 these species have been classified according to Rmax, and the classes have been compared with respect to the proportion of rapidly-germinating species. A very clear positive correlation is evident between rate of germination and rate of
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FIG. 4. The contribution of rapidly-germinating (t50 ? 1- days) and slow-germinating (t50 > 4 days) species to groups classified with respect to estimates of the maximum potential rate of
seedling dry-matter production (Rmax).
seedling dry-matter production. It is not unreasonable to propose that in many species the two attributes will show parallel responses to natural selection, which in some cases may be linked physiologically. Need for caution is suggested, however, by species such as Helianthemum chamaecistus, Lotus corniculatus and several other tap-rooted forbs of infertile soils, in which the capacity of scarified seeds to germinate rapidly is associated with an inherently low rate of seedling growth.
Dormancy Of the 403 species examined in the initial tests, 137 failed to attain a final germination
percentage of 50%, and in many other species germination was incomplete. Low germination in some species was due to unusual light and temperature requirements. In Urtica urens, for example, the results of the light-flux test reveal that germination was almost completely inhibited by the irradiance used in the initial tests. In Ballota nigra, Bidens tripartita, Carex capillaris, C. demissa, C. nigra, Molinia caerulea, Nardus stricta, Thiaspi arvense and Verbascum virgatum, low germination percentages in the initial tests may have been related to a requirement for rather high temperature. Seven of the species exhibiting low germination (Bidens tripartita, Linaria vulgaris, Lycopus europaeus, Mentha arvensis, Molinia caerulea, Sonchus arvensis and Stachys sylvatica) are capable of responding in the light to amplitudes of diurnal temperature change greater than the 5 ?C fluctuation used in the initial tests (K. Thompson 1977).
The present investigation was not designed to provide a thorough analysis of the causes of seed dormancy in each species. Seeds from the same population of plants or even from the same individual may differ in germination requirements, and in order to investigate their responses fully it would be necessary to apply various procedures in factorial combination to seeds subjected to a range of pretreatments (Steinbauer & Grigsby 1957; Toole 1973; Vincent & Roberts 1977; Bostock 1978; P. A. Thompson 1981). Several procedures were applied, however, in an attempt to stimulate germination in many of the
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species which failed to attain high percentages in the initial tests, and a summary of the results is presented in Appendix 1.
There is evidence of a positive response to chilling in 75 of the 107 species tested. The list includes 7 woody plants, 16 woodland herbs, Umbelliferae and 3 annual hemiparasites (Euphrasia officinalis, Odontites verna, Rhinanthus minor). Of the three grasses which responded to chilling, one was a woodland species (Bromus ramosus), whilst the other two (Molinia caerulea and Nardus stricta) had seeds which before chilling germinated only at relatively high temperature. A pattern of response similar to that observed in Molinia caerulea and Nardus stricta was recognizable also in Carex nigra, Mentha arvensis, Sonchus arvensis, Stachys sylvatica and Solanum dulcamara, in each of which germination prior to chilling was dependent upon exposure to high temperature or to large diurnal fluctuations in temperature.
Among the species which responded to chilling, there were marked differences not only with respect to the length of treatment required but also to the capacity for germination at the chilling temperature (5 IC). At one extreme were species in which satisfaction of the chilling requirement was associated with the capacity for rapid germination at low temperature. This group contained 10 species in the Umbelliferae, and included a high proportion of species with comparatively large seeds.
In 24 species no germination was observed during the chilling treatment, but a high percentage of the seeds germinated following transfer to light and higher temperature. This group of plants included arable weeds and marsh plants with relatively small seeds.
Scarification was applied to 27 species, and resulted in a marked stimulation of germination in 19 species (12 legumes).
Response to temperature The need for caution in extrapolation from laboratory to field is especially clear with
respect to the results of the temperature gradient bar experiments. In order to summarize a large volume of results, the germination response has been described mainly by reference to the upper and lower limits of the range of temperatures over which high (>50% of maximum) germination percentages occurred. This form of presentation obscures the fact that the percentage germination was less outside this range. It should be remembered also that the results are for constant temperature, and that in many species the germination range (particularly at its lower extremity) may be extended under fluctuating temperature regimes.
Despite these qualifications the data show several consistent patterns of predictive value. Results for 272 species are presented in Appendix 2. The majority of results were for
seeds tested after dry storage in the laboratory. In some species the measurements were conducted on pre-chilled or scarified seeds, and in two species (Ranunculus acris, R. repens) seeds were incubated in darkness at 20 IC prior to use in the experiment.
In 16 of the species investigated, germination did not occur or was restricted to a very small number of seeds. Under similar light flux, all these species had attained higher percentages in the initial tests, and it seems likely that failure to germinate on the temperature-gradient bars was related to a requirement for fluctuating temperature.
Among the 256 species which germinated on the bars, there were considerable differences in response to temperature, some of which are summarized in Fig. 5.
In Table 3 comparisons of temperature-response have been drawn between various classes of plants. Among annual and perennial grasses a high proportion of species was capable of germinating over a wide (>20 OC) range of temperature. This feature is
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FIG. 5. Distributions of (a) upper and (b) lower limits of temperature and of (c) range of temperature over which 50% maximum germination was attained in 256 species. The classes in
(a) are not of equal width.
particularly evident in species of dry habitats and of southern distribution, and suggests that relative insensitivity to temperature is characteristic of seeds in which water supply acts as the primary determinant of the timing of germination in the field.
Several sources of variation in temperature-response appeared to be associated with taxonomic differences. Scarified seeds of legumes tended to germinate over a very wide range of temperatures. In both the Leguminosae and the Gramineae, wide germination range was related to the capacity for germination at high and low temperature, but in the Compositae wide germination range was mainly due to high germinability at higher
TABLE 3. Number of species, grouped in various classes with respect to the range of constant temperature over which germination in light exceeds 50% of that attained at the optimal temperature, and of germination percentage in the dark treatment of Experiment 1. The significance levels refer to the probability with which the ratio for a particular class departs from the ratio expected from the results obtained for all species. Significance conventions as in Table 1. Superscript
's' = scarified. Dark treatment of
Temperature Experiment 1; Lower limit Upper limit Range (IC) germination
temperature. A quite distinct pattern of response was characteristic of the Cyperaceae, in which germination was restricted to a narrow range of relatively high temperatures.
When groups of species belonging to various geographical elements within the British flora were compared, several features were apparent. The most striking of these was the failure of the majority of plants of northern distribution to germinate at low (<7 IC) temperature. This result is in agreement with earlier studies (Billings & Mooney 1968; P. A. Thompson 1968, 1970b; Wein & Maclean 1973), and is consistent with the hypothesis that the high temperature-requirement in these plants is the result of natural selection at high latitudes for a germination-response restricting the appearance of seedlings to the short but relatively favourable summer.
Species concentrated in southern Britain included a high proportion capable of germinating at low temperature, and tended to have a temperature range exceeding that of the northern species. Species germinating over a wide range of temperature reached their highest frequency among plants which are ubiquitous in the British Isles. A wide temperature range for germination is also characteristic of plants occurring in the highest frequency-class (> 10% of records) in the Sheffield flora (Table 3).
Relationships between temperature response and habitat are suggested by the results. Marshland and disturbed habitats accounted for a large proportion of the species which did not germinate at low (<70C) temperature. Some of these species are also unusually responsive to diurnal fluctuations in temperature (K. Thompson 1977). In temperate localities, seedling establishment in marshes and at the margins of lakes, rivers, ponds and ditches is usually restricted to the late spring, when the water-table recedes and the surface layers of mud became exposed and aerobic. It seems likely, therefore, that the requirement for high or fluctuating temperature in these marsh plants provides a mechanism delaying spring germination until such time as the declining water-table no longer insulates the soil from the increasing radiation load (K. Thompson, Grime & Mason 1977).
Germination over a wide range of temperature was particularly common in grassland plants and species from skeletal habitats. In the woodland plants investigated, by contrast, germination was often restricted to a narrow range of intermediate temperatures.
Response to light
Experiment 1 Figure 6 describes the distribution of germination percentages attained by 271 species
in the 'light', 'shade' and 'dark' treatments. In both 'light' and 'shade', percentages were high in the majority of the species, although there was a tendency for germination percent- age and rate to be slightly lower in the 'light'. Germination was much reduced by the 'dark' treatment, and failed to exceed 10% in 104 species.
Despite these general trends, interspecific differences occurred in response to the 'light' treatments. At one extreme were species such as Lycopus europaeus, Mentha arvensis, Polemonium caeruleum, and Urtica urens in which germination percentages in the 'light' fell below those in 'shade', whilst, at the other, were plants such as Bidens tripartita, Carex flacca, Juncus conglomeratus and Scirpus sylvaticus, where germination in 'shade' was inferior to that in the 'light'.
These results confirm those of the comprehensive screening experiment of Kinzel (1920), who found that plants differed considerably in their germination responses to light. In Kinzel's investigation, as in our study, germination in the majority of species was promoted in the light. In both studies there was a smaller number of species in which
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FIG. 6. Distribution with respect to germination of 271 species subjected to (a) 'light' (b) 'shade' and (c) 'dark' treatments. For details of treatments see text.
germination in the dark was superior to that in the light. The inhibitory effects of light were less pronounced in our study, however, and this can be related to the lower light flux and smaller proportion of far-red radiation in our experiments compared with the natural daylight used in Kinzel's investigation.
The tendency of certain species to be inhibited from germinating in 'light' has been observed in numerous species in earlier investigations (Toole 1973). The inhibitory effect is most severe under prolonged high light flux (Black & Wareing 1960; Schulz & Klein 1963; Chen & Thimann 1964; Rollin & Maignan 1967; Kendrick & Frankland 1969) and also at high temperature (Black & Wareing 1960; Chen & Thimann 1964). This suggests that under field conditions the inhibitory effects of high light flux will usually coincide with strongly desiccating conditions, which may pose a severe threat to seedling establishment. It seems possible, therefore, that sensitivity to high irradiance provides a safeguard reducing the risk of seedling death caused by drought.
Striking differences in response occurred in the 'dark' treatment (Table 4, last two columns). The proportion of species exceeding 50% germination in the 'dark' treatment was considerably higher in the grasses than it was in the annual and perennial forbs. After scarification, all of the Leguminosae germinated rapidly to a high percentage in the 'dark'
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treatment, in marked contrast with the Cyperaceae and Compositae. Species with the capacity to germinate to a high percentage in the 'dark' treatment were especially common among plants which are ubiquitous or of widespread occurrence in the British Isles, and also formed a high proportion of the species of common occurrence in the Sheffield flora. When the species were broadly classified with respect to habitat, they could be arranged in a series through which the proportion of species attaining 50% germination in darkness declines as follows: grassland > skeletal habitats > woodland > disturbed habitats > marshland.
No consistent relationship was detected between the capacity of seeds to germinate in the 'dark' treatment and their average height of release. With one exception (Viola palustris), species with explosive dehiscence (mainly legumes) germinated to a high percentage in darkness. Small-seeded species (<0.1 mg) included many which failed to germinate in darkness, and the incidence of species with a dependence upon light declined progressively with increasing seed size.
Experiment 2 The results of the second experiment clarify those obtained in the 'dark' treatment of
Experiment 1. When germination in the two dark treatments of Experiment 2 was compared with that
measured in Experiment 1, a variety of responses was apparent among the 70 species examined. In Table 4 five main types of response have been recognized, and these have been identified as Types (a)-(e).
TABLE 4. The effect of a diurnal fluctuation in temperature and brief daily exposure to green light upon the germination in darkness of selected species. In each column germination is expressed as a percentage of that recorded in a concurrent test conducted in the light at 20/15 IC; the significance levels refer to this comparison.
Significance conventions as in Table 1. Superscripts: 's' = scarified,'c' = chilled. Response
type Experiment 1 Experiment 2 Experiment 2 (see text)
Exposure to green 'safety' light + - - Temperature regime (OC) 20/15 20/15 20/20
Annual grasses Aira praecox 91** 97 98 b Bromus pseudothominii 100 101 100 b Bromus sterilis 100 100 100 b Catapodium rigidum 94 102 99 b Hordeum murinum 100 98 100 b Vulpia bromoides 103 104 104 b
Annual forbs Aphanes arvensis 29*** 12*** 2*** c Arabidopsis thaliana 23*** 3*** 0*** c Atriplexpatulac 57*** 41*** 26*** d Blackstonia perfoliata 16*** 0*** 0*** c Cerastium semidecandrum 98 65*** 56*** d Chaenorrhinum minusc 59*** 66*** 67*** b Chenopodium album 8*** 8*** 3*** a Draba muralis 95 43*** 31*** d Galium aparine 91 83 31*** e Lapsana communis 57*** 0*** 7*** c Medicago lupulinas 100 99 99 b Moehringia trinervia 82*** 53*** 56*** d
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In Type (a), represented by nine species, germination remained uniformly low in all the dark treatments, indicating low responsiveness to both green light and fluctuating temperature. Type (b) species have a high percentage germination in all treatments, and include the annual grasses and the legumes, together with four perennial grasses (Alo- pecurus pratensis, Arrhenatherum elatius, Cynosurus cristatus and Lolium perenne) and three perennial forbs (Luzula multiflora, Rumex acetosa and Silene nutans). It seems reasonable to conclude that in these species no evidence of a light requirement was obtained. Response-type (c) was that in which considerable germination in the dark treatment of Experiment 1 was associated with a value at or near to zero in both dark treatments of Experiment 2. This effect was clearly related to the exclusion of green light, and was observed in seven annual forbs, nine perennial forbs and one undershrub (Vaccinium myrtillus). A similar but less dramatic effect of light (Type (d)) was evident in 15 species, where a proportion of the seeds continued to germinate in the absence of green light. This type of response, indicating heterogeneity within the seed population in respect to light requirement, occurred in all life-form classes except the annual grasses.
In a fifth pattern of response (Type (e)) dark germination was unaffected by the exclusion of green light, but declined markedly at constant temperature. This dependence of germination in darkness upon diurnal fluctuations in temperature was apparent in nine species, two of which (Filipendula ulmaria and Silene dioica) also showed evidence of a response to exposure to green light.
The results confirm the need for caution in interpreting the results obtained in the dark treatment of Experiment 1, and suggest that in order to detect all the species which may be incapable of germination in darkness it is necessary to devise experimental treatments which exclude both visible radiation and fluctuations in temperature.
The capacity of the seeds of certain species to germinate in darkness in response to diurnal fluctuations in temperature appears to be relevant to an understanding of the mechanisms of depth-sensing and gap-detection by buried seeds. Measurements in grassland (K. Thompson, Grime & Mason 1977) and scrub (Panetta 1979) have confirmed that the amplitude of diurnal fluctuations in temperature within the soil is greatest near to the soil surface and in local- situations where removal of the insulating layers of foliage and litter admits a higher flux of radiation.
DISCUSSION
The measurements in each row of Appendix 2 refer to seeds from a single population, and further studies are required in order to establish the e%tent to which these results are definitive for the species. This applies particularly with respect to responses to light and temperature, as it has been established (Koller 1962, McCullough & Shropshire 1970; Junttila 1973; Gutterman 1974; Cresswell & Grime 1981) that these may be influenced by the conditions experienced during seed maturation.
The experimental conditions used throughout this study were extremely simple compared to the complex fluctuations of many factors experienced by seeds in natural environments. The screening approach adopted rests upon three assumptions: (a) that little may be achieved by transferring to the laboratory complexities which have already defied analysis in the field; (b) that the prospects for reliable extrapolation to the field depend upon examination of an adequate range of species and recognition of the causes of differential response, rather than the use of experimental conditions which closely approximate to those occurring in nature; and (c) that differences of ecological importance
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are often detectable in the responses of groups of plants of contrasted ecology to standardized experimental conditions.
The results in this paper reveal numerous instances where the same group of seed-characteristics recurs in association with species of similar ecology, and the information has already been used (Grime 1979) to consider the role of morphological and physiological attributes of seeds in particular regenerative strategies. The most satisfactory analysis, however, is that in which the laboratory results are complemented by studies of the production and fate of seeds under natural conditions. This approach is adopted in the sequel to this paper (Grime & Hillier, unpublished) in which seed-bank models are used to assess the functional significance of some of the recurrent groupings of seed-characteristics emerging from the present study. As a preliminary to this analysis, the remainder of this discussion considers some problems of interpretation associated with particular aspects of the data.
Capacityfor immediate germination With the exception of species such as Petasites hybridus and Tussilago farfara, whose
seeds are exceptionally short-lived, it would be unwise to assume that the ability of freshly-collected seeds to germinate in the laboratory is a reliable indication that under field conditions germination occurs soon after seed release. Many of the species which showed the capacity for immediate germination had other characteristics (e.g. specialized temperature requirements) which suggest that germination of freshly-dispersed seeds may be prevented by the intervention of limiting factors operating in the field but excluded from the initial germination test. This hypothesis is supported by the fact that many of the species which displayed high initial germinability are known to accumulate large and persistent buried seed banks in the field.
Response to dry storage Beneficial effects of dxy storage upon germination percentage and rate were most
conspicuous among winter annuals of shallow or sandy soils (e.g. Aira praecox, Arabidopsis thaliana, Draba muralis, Erophila verna, Myosotis ramosissima and Saxifraga tridactylites). Seeds of these species are shed during the early summer. From field studies (Ratcliffe 1961; Newman 1963) it seems likely that the after-ripening functions as a mechanism preventing premature germination in the dry habitats exploited by these plants. The same explanation may be applied to the characteristic but less pronounced responses to dry storage evident in certain of the autumn-germinating perennial grasses such as Festuca ovina, Koeleria cristata and Poa compressa.
Of the perennial species which displayed a marked improvement in germinability during dry storage, the majority are small-seeded and many are known to form persistent seed banks in the soil. The possibility must be considered, therefore, that in certain species a major effect of delayed ripening and germination is to facilitate seed burial.
Germination rate Success in seedling establishment almost invariably depends upon rapid exploitation of
temporarily favourable conditions, and the prospects for survival and reproduction during later stages of the life-history may be strongly affected by the speed of germination and the rate of seedling development. Thus it is tempting to propose that all species will be capable of rapid germination in their natural environments, and that where low rates of germination were observed in the present study they arose from the failure to provide
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appropriate germination conditions or pretreatments. The rates recorded in the initial tests and in most of the studies of response to temperature and light were based upon experiments in which germination was initiated by hydration of air-dried seeds. This procedure reproduces the common circumstance in which the germination of many grasses, members of the Compositae and winter annuals at the end of the summer coincides with the onset of wet conditions, but it is scarecly relevant to the variety of instances in which fully-imbibed seeds are induced to germinate by environmental stimuli such as changes in temperature or illumination.
The rates of germination reported in this paper may thus prove to be of doubtful value as an index of the germination rates achieved in the field.
Response to chilling The results suggest that the species which responded to chilling treatment fall into two
categories, in the first of which the seeds are comparatively large and after chilling are capable of rapid germination at low temperature and in darkness. This group includes a variety of plants of widespread occurrence in northern Europe. In Britain the majority of these species are known to produce large even-aged populations of seedlings in the early spring. There is no evidence to suggest that any of these plants maintain persistent seed banks in the soil, and the most probable explantion for this peculiar germination biology is that it allows spring colonization of gaps in perennial vegetation. It seems likely that the large seeds and capacity for early germination allow seedlings of these species to compete effectively with neighbouring established perennials.
A different significance may be attached to the chilling responses noted in some of the smaller-seeded arable weeds and marsh plants. Here the requirement for chilling is allied to a need for subsequent exposure to light or higher temperature or both. As several of the species in this second category are known to form reserves of buried seeds (Brenchley 1918; Chippendale & Milton 1934; Champness & Morris 1948), we may suspect that the chilling requirements are involved in mechanisms of delayed germination and seed burial.
Response to scarification Although the role of impermeable seed coats under field conditions is still uncertain
(Ballard 1973), there can be little doubt that this characteristic is often conducive to delayed germination and incorporation into persistent seed banks. A further insight into the possible ecological significance of the hard seed coats of legumes is provided by studies such as those of Hamly (1932) and Hagon & Ballard (1969) and Hagon (1971), which have shown that permeability depends upon the condition of the strophiole, the only point of entry of water into the unscarified seeds of many legumes. More suggestive still are the results of Quinlivan (1961, 1968) and Quinlivan & Millington (1962), which have established that in some Australian legumes permeability of the strophiole can be increased under field conditions by diurnal temperature fluctuations of the magnitude commonly experienced by buried seeds lying on or close to a soil surface devoid of vegetation. From these sources, therefore, there is circumstantial evidence to suggest that seed-coat impermeability in the legumes, and perhaps also in other species examined in this study, facilitates the persistence of seed reserves in the habitat and may also provide a mechanism of gap-detection (K. Thompson, Grime & Mason 1977; Grime 1979) by surface-lying or buried seeds.
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Response to temperature The time-course of the germination response to temperature in each species has been
described in Appendix 2 by reference to the classification of curve-types illustrated in Fig. 1. The most common type of curve (Type I) was that in which the upper limit of the temperature range became constant soon after the commencement of germination, and there was a progressive extension, with time, of the lower limit. Type I curves were particularly characteristic of grasses and legumes. In the second most commonly- occurring type of response (Type II) both the upper and lower limits of the curve became fixed after the initial burst of germination. This compact form of response often coincided with germination over a narrow range of relatively high temperatures, and was more frequent in forbs than in grasses. It would appear (K. Thompson 1977) that in many of the species exhibiting this response, the lower temperature limit may be extended by exposure to diurnal fluctuations in temperature. Although further work is required to clarify the significance of the Type II response to temperature, we suspect that in many species it is associated with the capacity to form persistent seed banks and with a tendency for germination to occur in the spring and early summer.
The temperature responses classified as Types III and IV, together with two intermediate types (Types I-Ill, 11-111), are characterized by delayed germination of some seeds at moderate temperature. The group of species in which this pehnomenon was observed is rather heterogeneous. It includes many members of the Compositae and a number of species in which the seed is large or has a surface texture likely to impair the conduction of water from the surface of the temperature-gradient bar to the seed. In a number of elegant experimental studies (Harper et al. 1965; Harper & Benton 1966; Sheldon 1974; Peart 1979), it has been shown that the contact established between seed and substrate is often a critical factor determining imbibition and germination. Thus it is not immediately obvious why some seeds should have a structure which impairs moisture uptake. However, under warm summer conditions rapid evaporation of moisture from the soil surface is a severe hazard to those seedlings which appear in response to temporary moistening of the soil, and a selective advantage may be expected for mechanisms which restrict germination to circumstances where more constant moisture supply or lower evaporative losses, or both, are propitious for seedling survival.
Response to light The presence of a light-requirement in the freshly-collected seeds of many of the species
included in this investigation poses several interesting problems. Why is this behaviour found in some species but not in others? In many species the difference applies to seeds within the same seed collection, and it is known (Cavers & Harper 1966) that seeds removed from the same inflorescence may exhibit marked differences in light-requirement. It is also necessary to consider the influence which a light-requirement may exert upon the subsequent fate of the seed.
Since the studies of Flint & McAlister (1935, 1937) and Borthwick et al. (1952), it has been established that the responsiveness of seeds to changes in illumination is mediated by the presence in the seed of phytochrome (P), a compound which exists in two interconvertible forms, one of which (P650) absorbs light in the red region whilst the other (P730) absorbs in the far-red region. Provided that other factors such as water supply and temperature are not limiting, germination appears to be induced when the concentration of P730 in the seed rises above a critical threshold. In these circumstances germinability
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depends upon the ratio of red: far-red in the light impinging upon the seed. From laboratory studies and experiments with natural leaf canopies (Pigott 1971; Gorski 1975; Grime & Jarvis 1975; King 1975; Panetta 1979; Fenner 1979, 1980; Silvertown 1980), it has been demonstrated that sunlight which has been filtered through a leaf canopy may be depleted in red light to an extent that causes germination to be inhibited. In view of this evidence of post-dispersal effects of leaf canopies upon germinability, it seems likely that similar effects could occur at an earlier stage during the maturation of the seeds on the parent plant. Recent studies (Cresswell & Grime 1981) suggest that induction of a light requirement in developing seeds occurs not only in inflorescences shaded by neighbouring plants but also in circumstances where seed maturation is completed within green parental structures. It seems, therefore, that the most likely explanation for the light requirement noted in many of the freshly-collected seeds examined in this study is to be found in the light-filtering properties of the tissues which surround the developing seeds of these species.
Failure to germinate in darkness was most commonly observed in small-seeded species of disturbed habitats and marshland. Many of these species are known to develop large and persistent seed reserves in the soil. This suggests that the light-requirement of the freshly-dispersed seed (perhaps in some cases reinforced by the influence of leaf-canopies prior to burial) prevents the germination of the buried seed and initiates germination when the seed is eventually unearthed by some form of disturbance.
ACKNOWLEDGMENTS
We are grateful to many past and present members of the Unit of Comparative Plant Ecology who assisted in this project. In particular we thank Dr J. C. Hodgson for his help in collecting seeds; A. H. Lumb, W. Hall and W. Ross-Fraser who constructed the temperature-gradient bars; and Mrs N. Ruttle, Miss S. H. Hillier and R. F. Grime for their skilled assistance in the preparation of the manuscript. This research was conducted with the support of the Natural Environment Research Council.
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(Received 1 May 198 1)
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Effects of chilling and scarification upon germination percentage and rate; the control percentage refers to the maximum obtained for fresh or dry-stored seeds. For the species subjected to chilling, the values in parentheses after the name of the species indicate the duration in months of the chilling treatment (5 IC, moist storage). Where chilling was preceded by moist incubation at 15 IC, an additional number has been inserted to indicate the length of this pre-treatment. For the species subjected to scarification, the value in parentheses refers to the duration of the period of dry storage prior to scarification. The significance values are based upon comparison of the germination percentage of the treated seeds with that of the controls. Germination percentages in brackets are estimates (to 5%) for species in which substantial germination occurred prior to removal of seed from the chilling treatment. Significance conventions: NS, P > 0.05; * P < 0 05, ** P < 0-01,
Species-characteristics and germination data for 403 seed collections. Key to parenthetic notes: (1) Based upon Perring & Walters (1962): u = ubiquitous, w = widespread, 1 =
localized, s = southern, n = northern. (2) Values refer to the % occurrence in 2748 1-M2 quadrats distributed within the
major terrestrial habitats occurring in an area of 2400 km2 (J. P. Grime & J. G. Hodgson, unpublished results).
(3) s = skeletal habitats (rock outcrops, screes, cliffs, walls), d = disturbed fertile habitats (arable, paths, soil heaps, manure and sewage waste, etc.), m = marshland, g = grassland, w = woodland (including plantations, scrub and hedgerows).
(4) Based upon Clapham, Tutin & Warburg (1962). (5) 1 = nearly spherical, 2 = ovoid, rhomboidal or turbinate, 3 = trigonous or
triquetrous, 4 = lenticular, reniform or subulate, 5 = cylindrical or ligulate, 6 = clavate, 7 = winged, 8 = tadpole-shaped, 9 = conical (including all seeds with a pappus).
(6) 1 = absent, 2 = straight awn(s) or spine(s) only, 3 = hygroscopic awn or spine, 4 = pappus or persistent calyx, 5 = large hook(s) or barbed spine(s), 6 = eliasome, 7 = wing.
(7) 1 = absent or inconspicuous, 2 = radial or irregular, 3 = antrorse. (8) 1 = smooth, 2 = rugose, tuberculate, muricate or reticulate, 3 = striate, 4 =
hairy, 5 = striate and hairy, 6 = mucilaginous. (9) Seed colours are described using the Munsell System (Munsell 1954).
(10) Germination is expressed as the final % germination and as t5O (the time in days required for 50% of the seeds to germinate).
(11) * = % germination significantly (P < 0.01) different from that of freshly- collected seeds.
(12) Pre-treatments (p): d = dry storage at 20 IC, c = chilling at 5 IC, s scarification, w = moist storage at 20 OC in darkness, f = freshly-collected seed.
(13) Range is described in terms of the lowest and highest temperatures at which germination attained 50% of maximum.
(14) A key to curve types I-IV is included in the legend to Fig. 1 (p. 1022). (15) * = % germination significantly (P < 0.01) different from that of seeds in the
light, t = additional measurements of germination in darkness are presented for this species in Table 4 (pp. 1037-1038).
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1050 Germination characteristics in a localfiora APPENDix 2-continued
E~~~~~~~~~~~~~~~~~~~ - ~~~~~~~~~~~~~~SeedcollectioE E
National Weight
(a) Annalgrase 1. -A tr crvphivea r 0.2 2.18.74 Old colier~y spoil heap SK 555685 20 p 1 55 0.40 8 3 3 0.09 2A tr praecocGr 0.8 3.7.73 Old stone quarry heap SK 248803 10 p 2-20 0.80 8 3 3 0.18 3 Avena faw,aGr <0-.1 d 4.8.76 Fallow arble SK 522861 60 p 24.10 2.10 8 3 3 14.13 4Brmspsuohonii Gra <0.1 g 14.8 73 Disturbed road veg SK 291838 40 p 11.65 1.90 8 2 3 3-15 5. Briu trh r s 0-8 d 10.8.73 Heap of minera soil SK 293984 65 p 37.-55 1.100 8 2 3 8.37 6Ca pdti iidi r s 0.4 20.7.73 Deeitlmsoeqar flo 5K 505826 10 p 1.80 0.50 4 1 3 0-19 7. Hodii niiii r 0 3 d 20.7.73 Urbarn. brick rubble SK 349863 45 p 3 775 2 70 9 2 3 6.55 8 Poaaiu r 12.2 d I 7 73 Cultivated garden soil SK 333874 15 p 2.60 0.85 2 1 1 0.26 9V lt boioie r s 0.3 2 1.6 73 Rock outcrop in limestonequary SK 555678 15 p 13-70 1.00 8 2 3 0.30
10 A tis ciati Umb s 0.4 d 5 10 73 Ditre odiebn SK 342752 40 p 2-85 2 05 4 1 1 1.06 11A iigli rvni r 0 9 d 24.8.73 Flor fdisusd snd quary SK 564819 15 p 1.45 1.05 3 1 1 0.40 12. A phaies nensis Rs 13 15.6 73 Sandyradsidebank SK 670918 10 p 2 30 1. 10 4 1 1 0 18 13A raiopi thalina ru 0-5 22 6.72 Derelict limestone quary heap SK 165661 25 p 0 50 0.50 4 1 1 0.02 14 A eai eriIioi Car 1.9 10 8.73 Old cide heap SK 293985 10 p 0.50 0.50 4 1 1 0.06 IS A triple hastaa Che 1 3 d 8.10.73 Hollow subject to flood1ing SF 595000 60 p 2.00 1 85 4 1 1 0.86 16. A triple.cpawula Che 3 0 d 7.8 73 Trampled wstegroud SK 375750 60 p 1.80 1.55 4 1 I 1.33 17 Bidens trprl Com s 0.2 m 4 10.73 Lakeside marhhand SK 455644 35 p 9 05 2.40 5 5 3 2.72 1 8Blcslii perdoial Gn 0.3 24.8 73 Floor o diue lietn quarr SK 555827 30 p 0.35 0.30 4 1 1 0.01 19 Capsella btrapsoi Car 2.6 d 1.8.73 Urban wateground SK 355835 25 p I .00 0-50 4 I 1 0.11 20 Cadiin isl r 0.8 s 22 672 Deeitlmson uryha SK 165661 20 e 1.00 1.00 4 1 I 0.09 21. Ceiarui rire e 0 7 8.10.73 Ditre atgon SF 598028 20 p 0.35 0.30 1 1 I 0.01 22 Ceattmsindcnri Car 0.3 12 673 Dereictli,metoequaryheap SK 555678 10 p 0.50 0 50 1 1 I 0.03 23. Chaenor, un iu Scr 0.3 20.9.73 D,ereict railway cinders SK 261655 15 p 1.10 0.65 2 1 1 0.07 24 Cheiiopodiui alu Che IS11 d 7.8 73 Urban watgon SK 375750 50 p 1.50 1.35 4 1 1 0.77 25. Cheiiopodiui rubru,ni Che 0 7 d 8.10 73 Hollow subject toflooding SE 596008 40 p 0.60 0.55 4 1 1 0.09 26 Coi'zacana~denss Cms <0. I d 8.10.73 Refusetip SF 593014 50 p 3.55 0.50 5 4 3 0.05 27. Crepis cailat Com u 2.0 s 10.8.73 Cinder and slag heap SK 293985 55 p 5.75 0-50 9 4 1 0.21 28. Draba Inrls r 0.2 s 22.6.72 Derelict limeston quarr heap SK 165661 20 p I 00 0. 55 4 1 1 0.05 29. Erige,ron acer Com s 0.6 8.9.73 Derelict ra~iway cidr SK 136733 20 p 6 40 0 45 9 4 3 0.1 I 30 Erdii iulrui e <0.1I s 8 10.73 Ditre snybn SF 598027 30 e 17.10 1.30 6 3 3 1.25 31. Erophilavra r 0.3 6.6.73 Shallow soi on limetone outcrop SK 184716 10 p 0.63 0.50 4 1 1 0.03 32. Etiphorbkapeplus Eup 0.2 d 7.8.73 Trmldwatgon SK 375750 20 p 1.70 1.00 2 6 I 0.48 33 Etprai o/Jkicinai Scr 1.4 5.10.74 Floor ofdereict limeston quarr SK 150612 15 p 0.95 0.60 2 1 1 0.13 34. Galeopsis letrahit Lab 1 i.3 d 16.8.73 Disturbed wasteland SK 436863 55 p 2.95 2.30 4 1 1 4.83 35 Gaisg prflr Com s <0.1I d 2.10.75 Ditre rasd SF 558034 40 p 2.50 0-55 9 4 3 0-18 36. Gaii aparine Rub 5.8 w 31.10.72 Hedgero SK 232748 65 p 2.33 2.00 1 1 2 7.25 37 Geaii iseti e <0.1I d 18.7.74 Soilepa deoito site SK 545913 35 e 2.00 1.60 2 1 2.47 38. Geaiunlcdi e 0.3 11. 7.74 Shallow soil onsae ietn SK 135825 25 e 2.15 1.35 2 1 1 1.09 39. Geaiii iol e 0.7 28.8.73 Distubedwateland loutcrop SF 615003 25 e 1.85 1.45 2 1 I 1.24 40 Geraiiiti roetaii Ger 4.7 3.10.73 Lietn ala als SK 145733 30 e 1.25 110 2 1 1 1.14 41. inpawiens glandulifera Bal 0.9 m 23.10.74 Stremside SK 527837 150 e 4.75 3.45 4 1 1 7.32 42. liptei atilr Bal I <0.1 S .10.73 Distubed wodlad SK 265565 65 e 4.45 2.15 4 1 I 6.91 43 inci biftiu Jun 1.0 m 5.10.73 Shallow pool in disturbed ground SK 362774 10 p 0.60 0.35 2 1 1 0.02 44 Lasn oiiui Com u 1.1 d 28.8.73 Ditre rasd SF 615002 55 p 4.50 1.35 5 I 1 1.27 45. Liuncthriui Lin 3.7 9.8.74 Raiwy embarnkment SF 603003 1 5 p 1.40 0.85 4 I I 0.15 46 Marcraia(iaiie Com u 4 7 d 7.8 73 Ditre atgon SK 523649 15 p 1 20 0 50 5 1 1 0 08 47. MeiaoIpln Leg 2.5 14 8.73 Lietn otcrops SK 156732 25 p 2.85 2.40 4 1 2 2.01 48 Mohigatii i a 0.8 w 19.6 73 Scrub indereict quary SK 554677 25 p 0.95 0.75 4 1 1 0.22 49 Mvo~sosavniBr 0.8 d 28.8.73 Wasteland SF 600009 20 p 1.75 0.95 4 1 I 0.29 50. Mrosolis cespilsaBo <0. I m 26.7.73 Pond margin SK 486790 30 p 1.55 1.30 4 1 1 0.24 51 Mrslsrioisii o 0.6 4.6.73 Limestonotcrops SK 183716 10 p 1 00 0.75 4 1 1 0.11 52. Odo,,itites en Scr <01 I g 5.10.73 Lightly trampled path magi SK 381660 25 p 1 65 0.95 2 1 1 0.IS 55. Papaver aiemone Pap s <0.1I d 29.7.74 Ditre rasd SK 633927 30 p 1.00 0.60 4 1 1 0.17 54 Papavrdbunla <0.1I d 8 10.73 Ditre snybn SK 658964 40 p 0.95 0.75 4 1 1 0.12 55 Papaverhoeas Pap s 0.7 d 5.10 73 Ditre odiebn SK 346745 40 p 0 90 0.65 4 1 I 0.09 56 Paae oinfri Pap <0.1I d 7.8 73 Riverbank SK 375749 65 p 1.00 0.90 4 1 1 0.25 57 Porou vclr Pol 6 1 d 7 8.73 Trmldwatgon SK 373750 10 p 3.75 2.10 3 1 1 1 45 58 Pol,hgonincovovuu Pol 2.0 d 7.8.73 Ditre wstelad SK 522649 75 p 4.00 2.35 3 1 1 1 28 59 Poli'gonum hvdropiper Pol 0.5 m 16 8.73 Lake margin SK435863 50 p 3.50 2 00 3 1 I 1.24 60 Polivgonui lapathifobhtti Pol 0 5 d 7.8 73 Fallow arable SK 508649 60 p 3.00 2.55 4 I I 2.25 61 Po'gni priai Pol 31i d 3 17 73 Ditre odiebn SK 495851 50 p 3.20 2 30 4 1 1 2.12 62. Rauciisselrtt a 0.6 m 7 873 Fecr SK 583578 40 p 2 20 1.23 4 I 1 0.16 63 Rh,nathiis innrScr 0.4 g 12.7.73 Floor ofderelct limestone qurr SK 142732 20 p 4-85 3.75 7 7 1 2.84 64 Roip sadc r 0.5 m 3 1.8 73 Pondmargin SK 453645 35 p 0.90 0.60 4 I 1 0 07 65 Sagina apewala Car 03 12 673 Derlictlimestoequaryheap SK 555678 10 p 0 36 0.26 4 1 I 0.001 66 Safrga U ridacQ,vifes Sax s 0 4 22 772 Deeitlmson uryha SK 164662 10 p 0.47 0 25 2 1 1 0.01 67 Sceaihsaiiu a <0.1I 15 673 Sarndytrack SK 669921 S p 3 90 1.35 9 I 1 1.16 68 Se,weci squalidii Com s 3.3 d 10 7 73 Disturbed wateland SK 332873 25 p 7.50 0.75 9 4 3 0.21 69 Seicw s'vIvaicus Com w 0.2 28.8.73 Disurbed grasslad SF 595011I 50 p 5 80 OSO0 9 4 3 0.23 70. Seei vsou Com w .0 28 873 Rala ine rc SF 603003 35 p 9.00 OSO0 9 4 3 0 60 71 Seei vlai Com u 3.9 d 7 6.73 Cutvtdgadnsi SK33l1870 20 p 4.10 0 50 9 4 3 0.25 72 Siai reni r 0 7 d 1.8.75 Margin ofarablefield SK 542802 SS p 1.85 I 25 I I I I. IS 73 Sivnru lisiii r I <0Ol d 810 73 Dereict rfuetip SF 593014 60 p 130 0-95 4 I I 0 25 74. Sivnru officinale Cu 0.3 d 31.7.73 Roadside SK 461845 60 p 1.20 0.95 4 I I 0.23 75,Sola u ngugin Sol <0. I d 8 10.73 Disturbed sandv barnk SK 658964 30 p 6.40 5.10 4 I I 0 76 76. Sonchusaper Com u 0 7 d 3l17.73 Roa~dside SK461845 8S p S 30 I IS 9 4 I 0.32 77 Socu oleraceus Com u 31i d 17 8.73 Roadside SK 3 11850 8S p 6S50 0-8S 9 4 1 0.27 78 Spruaavni a I S d 3 17 73 Disturbd rodside SK 495851 20 p I 45 1.30 4 I I 0.42 79. Siellari ,iwdiaCa 6.3 d 5.10.73 Margin ofarblefield SK 353738 IS p 1.30 100 4 I I 0 35 80 Thap res r <0 I d 15.8 75 Arablefield SE53l10l5 35 p 2 IS ISO0 4 I I 0.95 81 Toii aoic Umb u 0.7 d 19.9.73 Roadside SK 23976 1 65 p 4 00 2 40 4 5 2 I 98 82 Trflun res Leg <0 I 24.8.74 Floo ofad lvb SK 671918 IS p I 20 I 00 4 I I 0 31 83 Trifoliii camipesIre Leg <0OIl 14.8 73 Lietn uco SK 157732 IS p 1.40 0.90 4 1 I 0.36 84 Trperseiuniaiinii Com u 2S5 d 16.8 73 Lakemargin SK 435863 35 p 2 00 IlO0 S I I 0.29 85. Uria rn Urt 0 4 d 15.6 73 Floo ofsadyI ay-bv SK 671918 35 p 2 12 1.50 4 I I 0-50 86. Vaeinla aiil Val <0OIl 22 6.72 Deeitlmson uryha SK 164662 20 p 2.10 IS1 2 I I 0.66 87. Veoic avni Scr 0.8 22 6.72 Deeitlmsonuryha SKl164662 IS p 1.12 0.8l 4 I I OIl1 88 J etonc pe-s wa Scr 2.0 d 7 8.73 Trampled watelad SK 373750 2S p 1.50 0-75 4 I I 0S52 89. Vkciahirsula Leg <O.l d 2 874 Deeitcllevha SK 555683 2S 2.05 2.00 I I I 2l19 90. Vicia 5aiva ssp. anqs~oi Leg s Os- d 1 7.7 73 Wasteland SK 157732 55 2.70 2.30 I I I 1306 91 Vkiolaarensis Vio 0.9 d 15.6 73 Margin f sndvarblefield SK 6679l18 20 C ISS 1.00 2 I I 0.40
(c) Perenialgase 92. Agoirncniiii r 0.5 w 3.10.73 Shaded rodside bank SK 144734 65 p 10.45 2 00 5 I 3 4.04 93 Agropiron repe'ns Gra 9.2 d 5 10 73 Wasteland bewe aralefieds~ SK 356742 6S p 1290 1.80 5 2 3 2.02 94 Agotsciiiaspcnn Gra u) 3 g 288973 Dereictwtgrasslnd SE59501I 35 p 1.70 0 3S 2 1 I 0.OS 95. Agro,i icarnin sp iniai Gra n 36 7 1 174 Acidic heeppastur SK155741 3S p 250 0.50 2 I 3 0 06 96 Agotsggne Gra - d 0 10.74 SK 504923 60 p 2 3S 0 60 2 I I 0 09 97 A rsi tlnfr r 18.0 d 28 8.73 Hollow ubjet toflooding SF 605002 70 p 1 6S 0 46 2 I I 0.02
NI-irgmd on'aabl fied
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1052 Germination characteristics in a localfiora APPENDIX 2-continued
Dehiscene Dispersle
cr ~~~~~~~~~~~~~~~~~~Natiornal Wih Species U. Date Habitat Grid ref. (mg)
98. Agrostis tenuis Gra u 8.3 g 3 1.10.72 Acidic sheep pasture SK 223745 35 p 1.85 0.50 2 I 1 0.06 99. A lopecurus pratensis Gra 1.0 g 1.8.73 Semi-derelict pasture SK 178745 60 p 5.50 1.95 4 3 3 0.71 100. A nhxnthui odoratum Gra 6.7 g 1 1.8.72 Wasteland SK 356656 35 p 4.30 1.25 8 3 3 0.45 101. A rhenathe~rum elatius Gra 14.1 g 29.8.72 Derelict1limestone grassland SK 175655 90 p 10-75 1.80 5 3 3 2.39 I0 2. Brc ,oimpnau Gra 2.5 g 25 10.73 Derelict calcareous pasture SK 500666 45 p 12.25 1.85 5 2 3 2.85 103. Brcioims,iaiu Gra 3.3 w 16.10.72 Wasteland SK 153732 60 p 19.70 1.60 8 2 3 0.62 104. Briza inedia Gra 1.7 g 24.8.72 Derelict calcareous pasture SK 098714 35 p 2.95 1.75 4 1 1 0.23 lOS. Broms erectus Gra 1.0 g 24.8.73 Derelict limestone quarry SK 555825 80 p 17.45 1.80 8 2 3 4.23 106. Brmsriou Gra 2.0 w 16.10 72 Shaded roadside bank SK 153732 125 p 14-45 2.15 5 2 3 7.37 107. Caars autc Gra <0.1 m 26.6.75 Marsh SK 274590 35 p 2.75 1.15 2 1 3 0.46 108. Cinsrs rsau Gra 2.8 g 26.7.73 Dam,p cattle pasture SK 361775 45 p 3.45 0.75 5 2 3 0.70 109. Dat,i gonrt Gra 17.9 g 20.7 73 Wasteland SK 324810 65 p 6.70 1.35 3 2 3 0.51 110 Descha,inpsia cespitosa Gra 6.3 m~ 27.10.72 Margin of lake SK 435863 125 p 2.85 0.85 2 3 3 0.31 III Decansafeus Gra n 20.3 g 22.8.72 Acidic grasslnd SK 305832 30 p 3.50 1.25 2 3 3 0.43 112 Festuca aru,dinacea Gra 0.3 g 16.10.72 Wasteland SK 1 5573 2 130 p 7.80 1.60 5 1 3 1.26 113. Festuca giganuea Gra 3.4 w 16.10 72 Shaded rodside bank SK 155 732 100 p 19-50 1.50 8 2 3 3.-12 114 Festuca ovin Gra 11.2 g 3 1.7.72 Deeitlmstn rsln SK 17565 5 30 p 4.25 1.05 5 2 3 0.38 1 15 Festuwapratetisis Gra 0.7 g 7.8.75 Wasteland in derelict quarry SK 563795 60 p 7.45 1.45 5 1 3 1.53 116. Fetc ur Gra 19.4 g 11.8.72 Wasteland SK 356655 40 p 7.30 1.05 5 2 3 0.79 117. Gli'ceriafluitans Gra 1.6 nm 3 1.8.73 Floded cattle pasture SK 243578 55 p 6.90 1.55 5 1 3 1.20 118 Heittiho rtts Gra 2.0 g 14.8.73 Deeitclaeu rsln SK 155732 45 p 18.45 1.55 8 3 3 2.08 119. Helictotrichornpubhescens Gra 1.5 g 9.7.75 Roadside bank SK 493637 50 p 14.90 1.05 8 3 3 1.92 120 Hoilcus lanatus Gra 18.1 g 11.8.72 Wasteland SK 356655 40 p 4.80 1.95 4 3 3 0.32 121 Ko~eleri cisat Gra 2.7 g 23.7.73 Derelict calcareous grassland SK 223743 25 p 4.90 1.00 5 1 3 0.30 122. Loliiicn pere,ine Gra 7.8 g 16.8.73 Path margin near arable field SK 439863 35 p 6.60 1.80 5 1 3 1.79 123. Vfelica tiutns Gra n 0.3 23.7.73 Hazel scu SK 224742 30 p 2.65 1.35 4 1 1 1.96 124. Afiliu,,n effusu,'n Gra 1.4 3.7.73 Mix~ed deciduou wodland SK 323813 85 p 2.70 1.20 4 1 1 1.20 125. Afolinia caerulea Gra n 0.7 g 5.10.73 Heathland SK 295675 80 p 4.10 1.10 2 1 1 0.53 126 Nardus stricta Gra n 3.2 g 14.8.72 Acidic wasteland SK 546915 20 p 10.40 0.85 5 2 3 0.38 127 Phalartirudinacea Gra 1.2 nm 16.10.72 River terrace SK 150732 90 p 4.15 1.20 2 1 3 0.67 128. Phei rtts agg. Gra 2.1 g 12.10.74 Derelict arable field SK 366683 75 p 2.25 2.00 2 1 3 0.45 129. Po onpes Gra 0.2 20.9.73 Topof wall SK 284630 30 p 2.55 0.50 5 1 2 0.20 130. Po rtei ssp angustf/olia Gra 1.1 g 3 1.7.73 Derelict grassland SK 533912 45 p 3.00 0.75 3 1 2 0.19 13 1. Po rtni s.paeii Gra 15.0 g 23.7 73 Roadside bank SK 223743 45 p 3.50 0.95 3 1 2 0-25 132 Poatrivialis Gra 22.0 d 14.8.72 Hedgebank SF 512002 40 p 3.25 0.90 3 1 2 0.09 133. Piicci,iellia distans Gra I <0.1I d 8.10.73 Tram~pled limetnet quarry heap SF 600003 35 p 2.00 0.75 2 1 1 0.28 134. Sesleria albicans Gra I <0.1 g 24.7.75 Sheep pasture NZ 838283 25 p 4.45 1.20 2 1 3 0.32 135 Sieglingia decu,inbens Gra n 0.9 g 11.8.72 Wasteland SK 356655 25 p 3.20 2.05 4 6 3 0.87 136. Trisetinmifkaesce,ns Gra 5-3 g 7.7.75 Disused railway cutting SK 485755 35 p 5.70 0.65 8 3 3 0.18
(d) Perennial forbs 137. Acilaiileoit Co 3.5 g 27.10.72 Wasteland SK 438863 25 p 2.05 1.05 5 1 1 0.16 138. A chillea ptar,nica Com, n 0.4 nm 15.9.75 Ditch in hay meadow NZ 862291 40 p 1.80 0.75 5 1 1 0.22 139. A doa nschatellina Ado 0.4 w 3.7.73 Scrub on riverbank SK 151731 10 p 10.00 8.00 1 1 1 0.63 140. Aegpodiumpodagraria Unmb u <0.1 g 3 1.8.73 Road verge SK 246577 70 p 3.90 1.40 4 1 1 2.73 14 1. Aginoi euaoi Ros <01 g 16.10.72 Wasteland SK 150733 45 p 7.90 5.70 2 5 2 23.78 142 Ajuga reptans Lab 0.2 w 23.7.73 Hazel scrub SK 224743 20 p 2.25 1.50 2 1 1 1.47 143. A lche,inillavstt Ros <0.1I 23.7.73 Hazel scrub SK 224743 20 p 3.00 1.10 2 1 1 0.47 144. A iiapatg-qitc Ali 1.0 nm 27.10.72 Marshland at nmargin oflake SK 437863 60 p 2.35 1.60 4 1 1 0-27 145. A lai eilt Cru 0.8 d 4.7.73 Shaded roadside bank SK 147734 70 e 3.15 1.00 5 1 1 2.25 146. A liuhnursnui Lil 1.9 w 20.7.72 Mix~ed deciduou wodland SK 531831 25 p 2.45 2.35 4 1 1 4.27 147. Anemone ne,inors Ran 3.7 w 10.6.74 Oak-birch wooxdland SK 325813 15 p 4.90 1.90 4 5 2 0.99 148. A ngelica sYvestris Um,b u 3.2 m~ 27.10.72 Dampwasteland SK 437863 115 p 4.55 3.40 7 7 1 1.15 149. A nthriscus s Nvestris Um,b u 3.9 g 23.7.73 Roadside SK 360774 80 p 3.40 1.35 6 1 1 5.18 ISO. A,ith 'llis vunrra Leg 0.4 g 24.8.72 Derelict limestone grassland SK 098715 15 p 3.90 2.40 4 1 1 2.76 151 A quilegia vulgaris Ran <0.1I 29.6.73 Mixed deciduous woodland SK 524784 70 p 2.55 1.30 4 1 1 0.78 152. A rabis cacasica Cru I 0.2 4.7.75 Roadside bank SK 295575 20 p 1.60 1.25 7 7 1 0.26 153. A rabis hirsula Cru 1.0 5.8.73 Derelict limestone pasture SK 175655 35 p 1.65 0.85 7 7 1 0.09 154. A chrelun ninus Comn u 0-5 d 20.9.73 Cinders in derelict railway siding SK 261653 90 p 11.45 3.70 1 5 1 11.47 155. A r,neria inaritima Plu I <0-I1 24.7.75 Derelict nmineral working NZ 756425 15 p 5-50 1.30 2 1 3 0.03 156. A rte,nisia absirnhiu,n Com s 0.5 d 8.10.73 Derelict refusetip SF 593014 60 p 1.17 0.70 4 1 1 0.10 157. A rfe,nisia vulgaris Com s 2.4 d 8.10.73 Derelict refuse tip SF 593014 90 p 1.34 0-45 4 1 1 0-12 158. A riniaclaun Ara 1.7 14.8.73 Mixed deciduous woodland SK 231748 40 p 8-10 5-85 1 1 1 4-54 159. Aster novibelgii Comn w <0- I d 7.11.74 Urban wasteground SK 349864 100 p 7.80 0.60 9 4 3 0.42 160. A rp elaon Sol <0- I 5.10.73 Wasteland SK 523650 90 p 16.50 16.50 1 1 1 0.08 161. Baldellia an,cukoides Ali <01 I nm 26.7.74 Pondnmargin SK 595195 10 p 2.10 1.30 2 1 1 0.45 162. Baillota igr Lab s 0.2 g 29.6.74 Hedgebank TF 6704 10 70 p 2.25 1.55 3 1 1 0.73 163. Bellis perenrnis Comn u 3.0 g 22.6.72 Cattle pasture SK 160662 10 p 1.70 0.75 4 1 1 0.09 164. Beil erecta Unmb s <0- I nm 23.10.74 Marshland at margin oflake SK 437863 65 p 2.00 1,50 1 1 1 0.49 165 Beto,,ica offici,tialis Lab s 0.6 g 31.10.72 Cattle pasture SK 224745 35 p 2.60 1-75 3 1 1 1-37 166. Brioiadiica Cuc <0- I 28 8.73 Hedgerow S 5F99010 250 p 9-00 9-00 1 1 1 13-37 167. Cailtha palu~stris Ran 0-6 nm 2.7 73 Marsh at riverside SK 243753 25 p 2-SO 1-30 2 1 1 0-99 168. Canaua aioi Can, w 0-2 w 18.11 74 Mixed deciduou wooxdland SK 530652 8S p 2-10 1-20 4 1 1 0.06 169 Canauartnioi Cam u .1 g 15.10.74 Limestone scree and grassland SK 155732 25 p IS1 0-50 2 1 1 0-07 170. Cadiiiifeus Cru 2.4 nm 22.6.73 Sha~ded roadside SK 175887 30 e 1.30 0-55 4 1 1 0.13 171. Cadiii rtni Cru 1.9 nm 4.7.75 Small marsh SK 285613 45 e 1.70 1-15 4 1 1 0.60 172. Carduus acanthoides Comn s <0- I d 3.10,73 Disturbed roadside SK 223743 75 p 5-15 1-75 9 4 1 2-49 173. Care.,c atifoi,-nis Gyp s 0.6 nm 3 1.8.73 Pond margin SK 454644 lOS p 3S50 1-65 3 1 1 I'll 174. Cae aplai Gyp n <o- I n 3 1.7.74 Montane grassland NY 839283 IS p 2-65 1-10 3 2 1 0.51 175. Carex de,nissa Cyp n 0.2 nm 26.7.73 Shallow pools in floor ofold quarry SK 490785 15 p 3-70 1-45 3 2 1 0.66 176. Care,cechi,iata Cyp n 0-1 nm 29.7.73 Streams~ide flush SK 18S810 25 p 3.70 1-60 3 2 1 0.83 177. Carer facca Cyp 2.3 g 15.8.73 Derelict pasture SK 289818 25 p 2.55 1.45 2 1 1 0-37 178. Car-er laev-igata Cyp 0-3 nm 26.7.73 Wet cattle p~sture SK 362774 65 p 3 -5 1-25 3 1 1 2.69 179. Car,er igra Cyp n 1.4 nm 15.873 Snmall Sphagnum~ bog in acidic SK 258777 40 p 2.65 1-95 2 1 1 0-81 180. Car,er tr-tbae Cyp <o-1 nm 16.8.73 Ditch [grassland SK 424880 75 p 4-65 2-10 6 2 1 1-28 181. Carer. ovalis Cyp n 0.3 nm 28.8.73 Damp grassland SE59501 SS5 p 4-SO 2.00 4 2 1 0-50 182. Cae aie Cyp n <O-1 nm 1.8.73 Damp limestone pastre SK 175745 25 p 1.55 0-8S 2 1 1 1188 183 Carerpaiculata Cyp s 0.2 nm 7.8.73 Carr SK 583579 105 p 3-SO 1.75 6 2 1 0,82 184. Cae, uiai Cyp n <0-1 nm 1.8.73 Dam,plimestone pasture SK 175745 20 p S-SO 0-75 4 1 1 1-46 185. Cae, sYihatica Cyp s 0-4 w 26.7.73 Wet cattle pasture SK 362774 35 p S.00 I-SO 3 2 I 1-65 186. Carlina vulgaris Co 0.3 1.10 75 Limestone otcrop at edgeof quarry SK 550789 35 p 3.20 1-20 5 4 3 1-53 187. Centaurea nigra ~ Co 3-7 g 19.9.73 Roadside SK 240758 SS p 3-85 1.70 2 4 1 2-55 188. Centaurea scabiotsa Co 0-9 g 6 10.72 Limestone wasteland SK 154732 60 p 10-25 2-40 9 4 1 7-46 189 Centrath,is ruber- Val <0- I 10.8.73 Cinder tip SK 293984 SS p 7S50 1-65 9 4 1 1-66 190 Ceatunfttiii Car 9.2 g 17.7.73 Limestone sheep pasture SK 135825 20 p 0.91 0-75 1 1 1 0-16 191. CheohIu tueti Unmb s 0.2 g 7.11.74 Disturbed roadside SK 223743 65 p 5-20 1-35 6 1 1 1,44 192 Chawnaenerion angusti/blhu,n Ona 12.6 d 10.8.73 Shaded roadside SK 297988 75 p 12.60 0.46 9 4 1 0-05 193. Chelidot,,iurn in'Pap <0-1I 30,8.74 Garden wall I F 660240 60 p 1-35 0-55 2 6 1 0-81 194. Chnpdunbn~hniu Che <0- I d 8.10.73 Derelict refuse tip SEFS93014 40 p 1-95 1-80 1 1 1 1-91 195. Chn,santhemum' leucanthe,nu,n Co 3.2 20.7.73 Derelict limestone quarry heap SK 505827 45 p 2-40 0-50 5 1 1 0-33 196. Chr,isanthemum,n,naxi,iiu, Co <0- I d 20.9,73 Cinders in derelict railway siding SK 261654 SS p 2-65 I-OS S I I 0-31 197. Chr,vsosplenium oppotsidtifliun Sax w 1-3 nm 15.6.73 Streanm nmargin SK 53 1831 10 p 0-66 0-46 2 1 1 0-04 198. Cir-siu'n acuo o <0- I g 24.8.73 Rough grassland in golfcourse SK 546828 15 p 25.00 1-75 9 4 1 3-71
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1054 Germination characteristics in a localfiora APPENDIX 2-continued
Dehiscene Dispersue
Seed cllection E ZNational - dh
Species U. Date Habitat Grid ref (rn~g)
199. Cirsim rvns Cm 6.8 d 28.8 73 Wasteland SE 610003 60 p 14.35 1.55 9 4 1 1.17 200 Cisu ausr o 1.8 m 15.8.73 Sml panm o naii SK 258777 90 p 12-65 1.55 9 4 1 2.00 201. Cirstum vugr o 3.0 d 10.8.73 Cinder tip Igra~ssand SK 293984 90 p 25-95 1.50 9 4 1 2.64 202. Clhnopodirum ugare Lab 0.3 g 16.10.72 Roadside bank SK 149734 55 p 1.50 1.10 2 1 1 0.49 203 Coheraofiiai r <0.1I 11.7.74 Dam,plim,estoe otcrop SK 135825 30 p 1.15 1.00 4 1 1 0.32 204. Coniummaultu Umb s 0.2 m 16.8.73 Lake margin SK 424880 125 p 3.40 1.60 6 1 1 2.25 205. Conopodium majus Umb u 1.7 g 15.8.73 Derelict pasture SK 152730 40 p 4.60 1.35 6 1 1 2.26 206. Covlai aai Lii 0.4 w 3.10.73 Screeitnhazel crub SK 224743 1 5 p 8.10 7.00 1 1 1 16.02 207 Covluu rvni o <0.1I d 23.10.74 Cinder tip SK 437862 50 p 5.05 1.50 3 1 1 34-69 208. Crepis paludos Cm <01I 23.8.74 Wet oerhanging cliff SK 119869 60 p 11.75 0.60 9 4 1 0.69 209. Daucuscarota Umb s 0.4 25.10.74 Railway cinders SK 577617 65 p 2.65 1.90 6 5 2 0.88 210. Digitalispurpurea c 1.3 w 10.8.73 Shaded rie bank SK 297990 00O p 1-00 0.50 2 1 1 0.07 211 Diplotaxis tenuifolia C <0.1I d 17.9.75 Colliery heap SK 261633 55 p 1.35 0.95 4 1 1 0.32 212. Discsflou Dip s 0.1 d 20.9.73 Deeitriwysdn SK 261654 125 p 4.50 1.40 5 1 3 2.26 213. Donicumpardalianches Com w <01I 4.7.75 River bank SK 261633 60 p 5.00 1.05 5 4 3 0.27 214 Droerartudifolia Dro n <01 I m 15.9.74 Bog near eservoir SK 259931 15 p 1.52 0.26 7 7 I 0.01 215. Echium vlgare Bor s <0.1I d 28.8.73 Railway embatnkment SE 605004 60 p 2-80 1.80 3 1 1 2.76 216. Elohrs auti Gyp 1.0 nm 16.8.73 Marsh m,arginal to ake SK 435863 35 p 2.40 1.45 4 1 1 0.96 217. End,mon nonscriptu~s Lili 9.1 20.7.73 Mix~ed deciduou wodland SK 324813 35 p 2.80 2.05 1 1 1 6.17 218. Epilobiuadencaulon Ona 1.6 d 7.8.73 Disturbed wasteland SK 375750 75 p 1.25 0.50 9 4 1 0.06 219 Epilobumhirsuhtumr Otna 3.2 m~ 3.10.73 Marsh at riverside SK 151731 115 p 4.05 0.50 9 4 1 0.05 220 Epilobiumr monta,num Ona 4.7 w 5.8.73 Edgeof deciduou wodland SK 176654 40 p 7.00 0.50 9 4 1 0.13 221. Epilobiumr nerterftoides Ona n <01 I m 3 1.8.73 Wet floor of disused stoequarry SK 209868 10 p 3.70 0.25 9 4 1 0.02 222. Epilobiumpalu~stre Ona 0.5 m~ 26.7.73 Snmall pond SK 487789 35 p 7.30 0.50 9 4 1 0.04 223 Erohrmanutflu Gyp n 1.0 m~ 2.7.73 Moorland SK 258777 40 p 60.50 1.35 9 4 1 0.44 224. Erio~phouvagintumn Gyp n 0.4 m~ 22.6.73 Moorland SK 260877 40 p 21.72 1.21 9 4 1 1.02 225. Eupatorium cannbinum ~ Com s 0.3 nm 20.9.73 Riverbank SK 260657 75 p 3.50 0.65 9 4 1 0.27
226. Filipendula lai o 1.5 m~ 16.10.72 River terrace SK 156731 90 p 4.20 1.90 6 1 3 0-99 227 Frgai esc~a Rs 0.8 22.6 73 Derelict stone quarry SK 209868 15 p 10.50 8.90 1 1 1 0.31 228. Gailega officinalis Leg I <0.1 d 2.10.75 Wasteland SF 560047 150 e 3.75 1.20 2 1 1 8.23 229. Gaeboonltu Lab 3.7 w 29 6.73 Mixed deciduou woodland SK 530832 40 p 3.50 1.85 3 1 1 1.98 230. Galiumr molugo Rub <01 g 15.10.75 Disued rail ballast SK 497553 70 p 1.50 1.25 1 1 1 0-67 231. Galiumpalustre Rub 1.5 nm 27.10.72 Marsh at m,argin of1ake SK 437863 20 p 1.65 1.50 1 1 1 0-91 232. Galiumr s~axatile Rub n 6.0 g 29.8.72 Derelict acidic grassland SK 176654 15 p 1-50 2.20 2 1 1 0.56 233 Galium sterneri Rub n 2.0 28.8.75 Outcrop of sgar limestone NZ 838283 25 p 1.10 1.00 I I 1 0.39 234 Galium rermRub 09 g 16.10.72 Derelict lineson grassland SK 149733 55 p 1.50 1.40 1 1 1 0.40 235 Gentianella amarella Gen 0.4 19.9.73 Broken turfon lietn outcrop SK 155732 15 p 0.70 0.60 1 1 1 0.12 236 Geaimpaes Ger 0.4 g 15.8.73 Road verge SK 259784 55 e 3.55 2.15 2 1 1 6.37 237 Geranium saguineumn Ger I <01 g 6.10.72 Derelict linmestone grassland and SK 155732 25 e 3.30 2.35 2 1 1 1.02 238 Geumrivale Rs n 02 m 23 7.73 Damp areain hazel crub scree SK 232748 40 p 10-50 1.35 8 5 3 1.22 239. Geum r banum os 1.4 w 23.7 73 Shaded roadside SK 223743 40 p 8-50 1.30 8 5 3 0.73 240. Glechoma hederacea Lab 1.7 19.6.73 Hedgerow SK 668918 20 p 1.90 1.10 2 1 1 0.69 241 Heracleumr mategazzianum Unmb w <01 d 15.8.75 Derelict garden SEF546007 250 p 11.90 7.70 4 1 1 5.73 242 Heracleusphondv'lium Unmb u 8.5 g 16.10.72 Roadside SK 149733 125 p 8 60 6.30 4 1 1 5.52 243 Hircun ioel Com u 4.5 25.7 72 Stabilied limestone sce SK 175655 15 p 7.65 0.50 9 4 1 0.15 244. Hi'pericum hirsutum Hyp 0.5 g 19.9.73 Derelict linestone grassland SK 155732 70 p 1.30 0.50 5 1 1 0.07 245 Hi'perncummntanumn Hyp 0.4 g 8.10.73 Derelict lim~estone grassland SF 595008 60 p 0.96 0.36 5 1 1 0-07 246. Hi.per,cumpetrforau Hyp 0.9 g 25.10.73 Deeitlmstn rsln SK 155732 60 p 1.30 0.55 5 1 1 0.10 247 Hipericumpulchru'n Hyp n 0.2 g 31.10.72 Senmi-derelict acidic pasture SK 224744 45 p 1.25 0.50 5 1 1 0.08 248. H'pericumtetrapterumr Hyp s <0.1 3.10.73 Marshland near river SK 241754 50 p 0.90 0.44 5 1 1 0.05 249. Hiohei radicata Comn u 2.8 g 24.8.72 Railway cutting SK 153629 40 p 13.70 0.75 9 4 3 0.96 250. Inula coni,a Com, s 0.8 26.9 74 Disued rail ballast SEF596004 75 p 13.80 0.50 9 4 3 0.26 251 Irspeuaou Irn <01 10.10.75 Silted pond SK 442697 95 p 8.40 5.80 3 1 1 46-67 252. Juncus ariculatu Jun 1.4 nm 5.10.73 Shallow pools in distrbed wasteland SK 262807 40 p 0.70 0.33 2 1 1 00 253 Jucuscoglomeratus Jun 0.3 nm 18.10.74 Wasteland SK472822 90 p 0.69 0.25 2 .2 254. Juncus effusus Jn 3.4 m 3 10.73 Streanmside SK 262807 90 p 0.52 0.25 2 1 1 00 255 Juncus infleus Jun 0.3 m 23.10.74 Marshland adjoining lake SK 437863 40 p 0.65 0.42 2 .3 256. Jucssurou Junn 0.5 g 3.10.73 Moorland SK 288819 30 p 0.80 0.50 2 .5 257. Lath',rus mntanu~s Leg 0.6 g 24.7.73 Railway cutting SK 390398 25 2.55 2.20 1 249 258. Lath 'rs pratensis Leg 2.3 g 10.8.73 Cinder tip SK 293985 75 3.25 2.75 1 285 259. Leontodon auntumnalis Com u 2.1 24.8.72 Derelictlimestone quarry heap SK 165662 30 p 9.75 0.80 9 4 3 0.7 260. Leontodon hispidus Comn s 4.0 g 24.8.72 Derelict limestone grassland SK 155732 35 p 12-45 0.95 9 4 3 0.85 261. Linaria vulgaris Scr s 0.7 d 8.10.73 Old refuse tip SF 593014 55 p 2.10 1.76 7 .4 262. Lou oniuau Leg 5.6 g 16.10.72 Derehict lim,estone grassland SK 155732 IS 1.85 1.50 1 .7 263. Lou liiou Leg 0.5 nm 8.10.73 Hollow in disturbed wasteland SK 682994 35 1.13 1.00 I I 1 0-4 264. Luul camrpestris Ju . g 5.7.73 Acidic cattle pasture SK 198797 10 p 1.65 1.05 I .4 265. L~uzul muliflraI~ Jun n J 14.8.72 Derelict grassland SK 548915 30 p 1.60 1.00 I .7 266. Luzla pilosa Jun 0.7 w 22.6.73 Oak woodland and scrub SK 209868 20 p 1.35 1.00 I I 1 08 267. Luuas'vvtc Jun n 0.3 w 20.7.73 Oak woodland SK 323813 55 p 1.70 1.05 1 .9 268. L 'chnis f1os-ecucli Car 0.1 nm 14.8.73 Marshland adjoining river SK 243754 50 p 0.88 0.75 4 1 2 0.21 269. L epseuoau Lab s 0.5 nm 4.10.73 Pondnmargin SK 473645 65 p 1.50 1.25 3 1 1 0.28 270. Litrmsaiai Lyt s <01 I nm 15.10.73 Edge of large ditch SF 713159 90 p 1.15 0.50 6 1 1 0.06 271. Mfelilotus altissima Leg s 0.2 d 18.10.74 Railway enmbanknment SK 468821 90 p 3.10 2.75 2 1 1 3.72 272 Mfentha aquatica Lab 1.4 nm 27.10.72 Marshland adjacent to lake SK 437863 50 p lOS5 0.60 2 1 1 0.14 273. Mfentha arensis Lab s 0.4 nm 8.10.73 Reed bed SF 596008 35 p 1.00 0.90 2 1 1 0.27 274. Mfercukialis perennis Eup 7.0 w 14.6.73 Mixed deciduos woodland SK 752731 30 p 2.70 2.60 1 1 1 2.15 275 Minatia erna Car I 1.0 31.10.72 Lead m,ine poil heap SK 223742 10 p 1.00 0.65 4 1 2 0.08 276. Mfycelis mra~~lis Conm s 1.1 15.8.73 Shaded limestone cliff SK 151731 60 p 8.90 0.90 9 4 3 0.34 277. Mfvsotis scorpioides Bor 1.5 nm 25.10.73 River bank SK 151731 30 p 1.95 1.20 4 1 1 0.28 278. Mf'vsostis s~'vIvtica Bor I 0-5 w 2.7.73 Hazel scrub SK 152731 30 p 2.00 1.40 4 1 1 0.56 279. M Vrrh is odorata Unmb n 0.5 g 10.8.73 Shaded roadside SK 295988 80 p 20.80 3.00 5 1 1 35.01 280. Oenotherapariflora Ona I 0.2 d 3.11.75 Disturbed wasteland SK 583864 75 p 1.80 1.30 3 1 1 0.56 281. Origanumr vulgare Lab 1.3 g 16.10.72 Derelict limestone grassland SK 155732 55 p 1.00 0.70 4 1 1 0.10 282. Oxalis acetosella Ox~a 3.5 3.7.73 Hazel scrub SK 152731 10 p 2.5 5 1.60 4 1 1 1.01 283. Parnassia palustris Par n <01 I nm 15.10.74 Derelict limestonegrassland SK 162728 20 p 1.60 0.60 7 1 1 0.31 284. Petasites hibridus Comn w 08 nm 29 573 Shaded river terrace SK 245754 25 p 11-50 0.55 9 4 1 0.26 285 Pimrpinellamajor Unmb s 0.2 g 17 873 Derelict limestone quarry heap SK 144731 85 p 3 55 1.45 6 1 1 2.12 286. Pimpinrella sairg Unmb S1. g 25.10.73 Broken turfon lim,estone outcrop SK 155732 65 p 2.65 1.65 2 1 1 1.19 287. Pigicl gradiflora Len I <01 I nm 23.8.74 Wet cliff SK 119870 IS5 p 0.85 0.37 5 I 1 0.03 288. Pinguicula vulgaris Len n <01 I nm 24.7.75 Derelict mineral working NZ 756425 10 p 0.85 0.30 5 1 1 0.02 289. Platagocoronpus Pla <01 2.8.74 Snmall letone outcrop SK 5 57682 10 p 1.15 0.65 2 1 1 0.15 290. Plantago laceolata Pla 9.6 g 27.10.72 Wasteland SK 435863 35 p 3.55 1.75 2 1 1 1.90 291. Platago maj.or Pla 5.6 d 27.10.72 Tranmpled wasteland SK 435863 15 p 3.09 1.82 2 1 1 0.24 292. PIatago media Pla 0.4 g 7.11.74 Floorof derelict limestone quarry SK 132733 25 p 2.60 1.95 2 1 1 0.40 293. Polemonium, caeruleum Pole I 0.1 g 24.8.72 Ungrazed lim,estone grassland SK 165660 60 p 3.00 1.20 3 1 1 0.77 294 Pol 'gala vlgaris Poly 0.8 g 3 1.7.75 Grazed limestone grassland SK 174745 20 p 2.50 1.50 2 6 2 1-72 295 Poaoeo olgnflu Pot 0.2 nm 8 1073 Ditch SE 594012 <10 p 2.25 1.55 2 1 1 1.12 296. Potentilla erectaRo 2.8 g 3.10.73 Acidic road verge SK 290819 20 p 1.55 1.05 2 1 1 0.58 207. PoterntiIa tabernemntan~i Ros I <01I 27.7.72 -im,estone ou~tcrop SK 088723 10 p 1.80 1.35 2 1 I 0.91 298. Poternumsaguisorba o 1.5 g 23.7 73 Deeitlmson he atr SK 223743 30 p 3.15 2.14 2 1 I 4.11 299 Primula veris Prn 0.5 g 17.8.73 Floor ofderelict limestone quarry SK 143731 20 p 1.65 1.35 3 I I 0.69 300. Primulat vulgaris Prn <01 24 7.74 Ash woodland SD 274740 5 p 1.75 1.35 3 1 1 - 301 Prunella vulgaris Lab 2.7 g 31.10.72 Disturbed wasteland SK 230748 IS5 p 2.00 1.00 3 1 1 0.73 302. Puiai i,etrc Com s <01 I nm 8.10.73 Marshland SE 59601 1 40 p 9.70 0.35 9 4 3 0.06
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1058 Germination characteristics in a localflora APPENDIX 3
Synopsis of the classifications used to analyse the experimental data. Classifications (a)-(g) refer to characteristics of the species, (h)-(m) refer to the seed. The four columns relate to different types of germination result. The values tabulated are the number of species for which results were obtained. For key to parenthetic notes, see Appendix 2, except that (*) = does not include sixteen species in which most of the
seeds failed to germinate at constant temperature (see Appendix 2)
Initial tests on freshly-collected Measurements Measurements Measurements and dry-stored of germination of response to of response to
