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23 U.S. Department of Agriculture Ensuring the future of the forests
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U.S. Department of Agriculture
Ensuring the future of the forests
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Welcome to the Kane Experimental Forest
SITE CLASSIFICATIONThe Kane Experimental Forest is located within
the Northern Unglaciated Allegheny PlateauSection of the Laurentian Mixed Forest Province inBailey’s (1994) ecological classification system forthe United States. The Allegheny hardwood orcherry-maple forest is a subtype of the northernhardwood or beech-birch-maple forest that spansthe northern portion of the eastern United Statesfrom New England to the Lake States.
The Kane Experimental Forest ranges inelevation from approximately 1,800 to 2,100 feetabove sea level, primarily on flat to gently slopingland. The Mill Creek, Wolf Run, and AckermanRun drainages cross the KEF as do the Mill Creekand Twin Lakes trails.
The climate of the Kane Experimental Forest ishumid-temperate. Annual rainfall is about 45inches, of which an average of 4 inches per monthfalls during the growing season. The averageannual temperature is 43 degrees Fahrenheit.
The Kane Experimental Forest soils on thePlateau are derived from shales and sandstones.In general, they are extremely stony loams andsandy loams. They are strongly acidic. The majorsoils are the well-drained Hazelton series, themoderately well-drained to somewhat poorly-drained Cookport series, and the somewhatpoorly-drained Cavode series.
The 1,737 acres of forest land that comprise theKane Experimental Forest (KEF), were originally
part of the Allegheny National Forest. On March23, 1932, the land was formally dedicated toresearch use for the Allegheny Forest ExperimentStation (now the Northeastern Research Station).The KEF was established to promote the study ofthe unglaciated portion of the beech-birch-maple-hemlock forest type that made up such a large partof the Station’s territory. Today, the ExperimentalForest serves as the field laboratory for the re-search project “Understanding and ManagingForest Ecosystems of the Allegheny PlateauRegion,” which is headquartered at the ForestrySciences Laboratory in Irvine, Pennsylvania.
The headquarters of the Kane ExperimentalForest provide offices for Experimental Forestpersonnel, a conference building for meetings andtraining sessions, and temporary quarters forvisiting scientists and students working on theforest. The office facilities are open year-round,while living accommodations are generally availableMay through October. The residential facilitiesprovide rustic accommodations for college classesfor a field trip, or longer term quarters for up tofive residents.
View of the original office and garage. The bunkhouse as it is now called accomodates summer students and visiting college classes.
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COMMUNITIESMost stands on the Experimental Forest are
typical Allegheny Plateau second- and third-growthforest. They resulted from a series of cuttingsmade in the original beech-birch-maple-hemlockforest. The first cutting, made in the mid- to late-1800s, removed the hemlock and the best hard-wood trees to supply local tanneries and sawmills.Most of the remaining hardwoods were cut be-tween 1890 and 1925, but a few stands wereclearcut as late as 1937. These later cuttings werecomplete clearcuts to supply the local chemicalwood plants with wood of all species and sizeclasses. Today, the Kane Experimental Forestcontains second-growth stands ranging from 50 to100 years of age, a few third-growth stands from10 to 40 years old, and one tract containingremnant old growth. Most stands are even-aged incharacter, although they may contain trees ofseveral age classes because of the previoussequence of cuttings. The most common treespecies are black cherry, sugar and red maple,and American beech; but many other species arepresent, including yellow and sweet birch, easternhemlock, cucumbertree, yellow-poplar, white ash,and others. Several species of ferns, grasses,goldenrod, and aster occur in abundance asground covers. Common spring ephemeralsinclude trout lily, dwarf ginseng, and springbeauties. The wildlife communities found on theforest are typical of those found in managed andunmanaged forests of the Allegheny Plateauregion. At least 26 species of amphibians andreptiles, 95 bird species, and 45 mammalianspecies have been known to occur in the areathroughout the year.
HISTORY AND PAST RESEARCHON THE KANE EXPERIMENTAL FOREST
The main emphasis of research at the time theKane Experimental Forest was established, was todevelop silvicultural methods for improving qualityand yield of forests on the Allegheny Plateau.Various timber stand improvement projects set upin the 1930s, looked at such things as stumptreatments of black cherry to reduce sproutingafter clearcutting, pruning of hardwoods to facili-tate growth, and weeding of hardwood stands toimprove their value and composition. Fourweather stations were established on the Experi-mental Forest in 1932, each in a different location.Air temperature, precipitation and other climaticdata were recorded and compared to vegetativegrowth at the same site to determine the influenceof environmental factors on tree development.Much of the labor for the field work of thesestudies came from Civilian Conservation Corps(CCC) camps located in the vicinity. The KEF was
closed during World War II, and after the war, asmall silviculture research program was main-tained both here at Kane and at the PoconoExperimental Forest, Gouldsboro, Pennsylvania.A long period of reduced activity followed thatlasted until the late 1950s. It was only due to theperseverance of a few dedicated scientists thatmany studies were maintained and remeasuredduring this lull. In 1959, the Kane Experi-mental Forest was revitalized by combining thestaffs of the Kane and the Pocono ExperimentalForests and the establishment of the ForestrySciences Laboratory in Irvine, PA. The researchstaff was expanded in 1970 and this combinedwith the reopening of 1930s studies provided forthe rapid accumulation of scientific knowledge onthe ecology and management of Allegheny hard-woods. A sampling of this research is listed belowwith more detailed descriptions of other activestudies found in the Self-Guided Tour section:
1) Regeneration studies: Studies of the envi-ronmental factors affecting the natural regenera-tion of Allegheny hardwoods began in 1971. Theeffects of light, heat, and moisture were investi-gated to evaluate the contribution of each to theestablishment and growth of tree seedlings,shrubs, ferns, and grasses. Techniques includedcutting, roto-tilling, irrigation, bending overstorytrees, trenching, soil heating, fertilization, andshading. These studies led to detailed guidelinesfor the use of shelter-wood cutting to developadvance regeneration in Allegheny hardwoodforests. Other regeneration studies showed thathay-scented and New York fern interfered with thedevelopment of seedlings of desirable hardwoodspecies and led to the development of herbicide/shelterwood prescriptions.
2) Regeneration cutting methods: A study ofcutting methods and their effects on the survivaland growth of advance regeneration and newseedlings was established in 1973. The methodsincluded a two-cut shelterwood (6 acres),clearcutting alternate strips (66 feet wide), andblock clearcutting (26 acres). The regenerationresponse was evaluated on the number of stemsper acre by species, the percent stocking, and thesurvival and growth of both advance regenerationand new seedlings.
3) Thinning plots: In 1974, an experimentdesigned to test the effects of both the density andstructure left after thinning in even-aged standswas installed on the KEF. Three blocks arelocated here, containing more than thirty 2-acretreatment plots. From this study, we havelearned a great deal about how thinning responsevaries with density, structure and species compo-sition. The responses we have studied include
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Phil E. Ackerman, first superintendent of the Kane Experimental Forest, and family in front of office building, April 1937.
Civilian Conservation Corps camps located in the vicinity of theKEF provided field crews for many early studies.
Mowing, a type of stand improvement cutting, was utilized in the1930s to improve value and composition of hardwood stands.
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overstory tree growth as well as regeneration andother understory responses.
4) Atmospheric monitoring: In 1978, one ofthe first National Atmospheric Deposition Programmonitoring stations was set up at the Kane Experi-mental Forest. This site (PA29), located near theKEF headquarters, has been monitoring atmo-spheric data on a 24-hour-basis up to the presenttime.
PRESENT RESEARCHBesides continuing with already established
studies, current research at the Kane Experi-mental Forest focuses on understanding the
complex interrelationships of all thecomponents affecting Alleghenyhardwood forests today. To this end,research on the Kane ExperimentalForest focuses on three topics:
1) Regeneration and forestrenewal: Second-growth forestsacross the region have high eco-nomic value and harvesting rates.However, managers are encounteringmajor problems in establishing adiverse third-growth forest. A keyfactor is the high density of white-tailed deer in the region, not onlynow, but for at least 50 years. Deerhave altered the species compositionof forest understories, changedhabitat conditions for forest wildlife,and interfered with the establish-ment and development of tree regen-eration. Studies on the Kane Experi-mental Forest have led to the devel-opment of techniques that allow forsuccessful regeneration of foreststands in spite of high deer densi-ties. These include: control ofinterfering vegetation, shelterwoodseed cutting, fertilization of develop-ing young stands, and fencing toexclude deer.
2) Stand dynamics andsilviculture: Forest managementgoals are a lot more complex thanthey were in the past. Today, forestsare managed for wildlife, recreation,water resources and aesthetic beautyin addition to timber. Studies atKane are designed to integrate all ofthese resources and help managersgrow forests with the most social andeconomic benefits. The facilities atKane serve as the summer base forwildlife research done in conjunction
with current studies. Data are collected to assessthe responses of songbird, small mammal, andamphibian communities to forest management instudies across the Allegheny Plateau.
3) Sugar maple decline: Since the 1980s,forest health problems have greatly impactedforests across the Plateau. Moderate to severedroughts have occurred in 1988, 1991, and1995, stressing trees across the AlleghenyNational Forest. Since 1991, native defoliators,including elm spanworm, cherry scallop shellmoth, and forest tent caterpillar, have producedmoderate to serious defoliation on 385,000acres of the Allegheny National Forest, including
Early attempts to control black cherry stump sprouting included girdling,peeling, and manual removal of new sprouts.
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the Kane Experimental Forest. Twoexotic defoliators, gypsy moth andpear thrips, and one exotic diseasecomplex, beech bark disease, haveaffected 317,000 acres of the Allegh-eny National Forest since 1985.Finally, sugar maple is suffering adecline across the unglaciated sec-tions of the Plateau. In 1992, a foresthealth monitoring system was imple-mented on the KEF to documentinsect, disease, and environmentalconditions on the forest. A visit toeach active study site is conductedannually and observations are takenon stand and tree health. Weatherdamage, crown dieback, defoliations,seedling mortality, and browsingdamage are some of the conditionsthat are recorded. This information isanalyzed in conjunction with thestudy data so that forest healthimpacts can be separated from treat-ment impacts.
SELF-GUIDED TOURThe following are descriptions of
seven current research studies. Thesesites are set up to facilitate a self-guided 1-day tour. The locations ofeach are highlighted on the mapfound in the center of the brochure.Several sites have trails runningthrough them and include signs thatdescribe the research conducted at
Sugar maple is suffering a decline across the unglaciated sections of the Allegheny Plateau. Scientistsbelieve that a number of factors including drought, disease, and mineral deficiencies are responsible.
that location.Although themarked stopscover only asmall portion ofthe researchcurrently takingplace, they arefairly represen-tative of theimportantstudies beingconductedthroughout theKane Experi-mental Forest.
Ice storms hit the Kane Experimental Forest Area in 1936 and 1950. These stormsprovided the means to study how such damage affected tree growth and quality.
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1) Clearcutting of second growth: This areashows how today’s forest can be influenced byseemingly unimportant events of years ago. Theoriginal stand of trees here was partially harvestedone or more times during the latter half of the 19thcentury, then first clearcut in about 1895.
In 1936, the new stand was heavily damagedby an ice storm. Foresters decided to regeneratethe stand again, rather than allow the ice-damagedtrees to continue to grow. Logging was done byteams consisting of two loggers and a horse, eachassigned to a strip of forest about 60-feet wide.The loggers would cut the trees so that they fellwith their tops toward the edges of the strip. Theywould then cut off the main stems and have thehorse pull them out to the road through the centerof the strip. In the center of the strip, all trees,down to those only an inch or so in diameter, werecut. But near the edges, loggers did not want towade through the brush from fallen tree tops to getsuch small trees. Therefore, in these brush piles,small trees of the slower growing species like sugarmaple and American beech were left, while in thecenter, only stumps and new seedlings were left.
Today, in the center of the strips, the only largetrees are black cherry, the fastest growing speciesin the new stand. The sugar maple and beechtrees left in the strip-edge brush piles are the onlytrees of those species that are as large as thelargest black cherry trees. Foresters often describestands by the number of complete harvests thathave occurred since the original forest. Thus, thisstand, with two cuttings since the original forest, iscalled third growth.
2) Older growth tract: This area is approxi-mately 74 acres and is dominated by Americanbeech and sugar maple. Two trails, the Twin Lakeand Mill Creek, run through the area. The trailscan be followed as they wind through the forest.The stand boundaries are marked with whitepaint, so you will know when you exit the stand.As you walk along the trails, notice the high per-cent of large sugar maple and younger blackcherry trees. Historically, old-growth tracts on theAllegheny Plateau did not contain such a highpercent of sugar maple or black cherry, but weremostly eastern hemlock and American beech. It isbelieved that this area of the Kane ExperimentalForest has a unique disturbance history includingwindstorms, fire, and cutting. Such disturbances,especially over the past 100 years, resulted in theunique characteristics we see today.
This area, although never clearcut, has hadthree partial cuts, the first one early in the 1900s,the second between 1941-1951, and the third in1951-1956. In each cut, individual trees were
selected and harvested. At the turn-of-the-century cut, hemlock was selectively removedfrom throughout the area. In many of the placescreated by this hemlock removal, we find patchesof 100-year-old black cherry trees.
As you walk through the stand, notice thebeech trees. The white “dust” you observe onthem is the first stage in the beech bark diseasecomplex. A tiny insect, the beech scale, boresinto the bark and secretes the wool-like waxsubstance. The second stage occurs when theNectria fungus, using the holes created by thebeech scale, invades the tree. The fungus ischaracterized by its reddish-orange fruitingbodies. The fungus kills patches of the tree’scambium. As these patches coalesce overtime,the fungus girdles the tree.
Also, notice that many of the sugar mapletrees are dying. This tends to happen from thetop down. You can see how many of the treeshave no crowns and some only have a few livebranches very low on the tree. Scientists believethat several factors are responsible for this de-cline, including: drought, insect defoliations,disease, and mineral deficiencies (magnesium andcalcium).
3) Thinning plots: Nature handles crowdingamong trees in a forest through the death of smalltrees and the slow growth of large ones. In acrowded forest, there is little food or cover forwildlife near the forest floor, as there is notenough light for tree seedlings or small plantgrowth. Foresters may want to interrupt nature’shandling of crowding for a variety of reasons.These include growing wood products moreefficiently, changing the habitat conditions forwildlife, or changing the scenic conditions forforest recreation.
On this stop, you will walk through an experi-ment to determine the level of crowding that ismost efficient for growing high value wood prod-ucts. Crowding is measured as the percentrelative density for a stand. This percent is anestimate of the crowding in the stand compared toa 100-percent standard representative of anundisturbed stand of the same species composi-tion and average tree size. Experimentalthinnings were conducted on treatment plots ofthis experiment in the early to mid-1970s andagain in the early 1990s. On the south side of theroad, the trail goes through four plots at differentcrowding levels. Signs are posted at each plot andyou can refer to the map in the center of thisguide to see their location along the trail.
The first, or 100-percent plot has never beenthinned. Notice the number of dead trees in this
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plot and look up to see the small size of thecrowns of surviving trees.
The second plot was cut to 80 percent relativedensity in 1974 and 1991. This light thinningtreatment opens the canopy for only a short periodof time, as the growth of residual trees fills in theopenings quite quickly. Notice that the understoryplants in this treatment, mostly striped maple, areconsiderably higher and denser than the under-story in the control plot. Even though these lightthinnings increased light levels reaching theseunderstory plants for only a short period, theyresponded with increased growth. Large trees didnot develop new low branches under this treat-ment, and increases in tree growth rate are minor.
The third plot, which was cut to 60-percentrelative density in 1974 and 1991, is intermediatebetween the 40-percent and 80-percent thinningtreatments in crown size, rate of tree growth,development of forest floor plants and in develop-ment of low branches on large trees. This60-percent treatment is the one that we recom-mend to forest managers who want to grow high
Tree heights are one of the many measurements periodicallytaken on study sites.
value wood products in stands with high propor-tions of red maple, sugar maple, or oak.
In 1974 and 1991, the last tour plot on thisside of the road was cut until 40-percent relativedensity remained. Especially in the first cut,trees of all sizes were removed, but the majorityof trees cut were from the smaller size classes.Large trees were cut only if they were in poorhealth or of poor quality, or to create room for thecrowns of the very best trees to expand. After thefirst cut, the residual trees even in this heavythinning eventually closed the canopy completelyagain. This has not, however, happened sincethe second thinning. In that thinning, we wereforced to cut more large trees to achieve theresidual density that the experiment required.Notice how large the crowns of the tallest treeshave become as a result of the thinning. Notice,too, the low branches on the trunks of these treesas a result of increased growing space. Finally,notice that the understory here is very dense andcomplex, consisting of American beech, blackbirch and a few scattered trees of other species.The 40-percent treatment had created a two-agedstand with the seedlings that started after thefirst thinning occupying a significant portion ofthe stand’s growing space.
Continue your tour on the north side of theroad. Here, you go through three more plots thatare part of the same experiment. In these plots,which were cut in 1975 and again in 1991, thelevel of crowding was kept the same, but differentgroups of trees were removed from each plot; thatis, the structure of the forest was altered.
In the thin-from-below plot, loggers beganwith the smallest tree in the stand and keptselecting the next smallest until 60-percentrelative density was reached. Most of the treesthat were removed were too small for any use andthe large trees that were left, have not grownfaster than they would have if the cutting wasnever done.
In the thin-from-the-middle plot, loggersbegan with the smallest trees large enough to sellto paper pulp producers and kept selecting thenext largest until 60-percent relative density wasreached. Much of the growth benefit of thistreatment has gone to trees that will not growlarge enough to sell for many decades. And inthe largest trees, many low branches remain,reducing future lumber quality.
In the thin-from-above treatment, also called“diameter limit cut,” loggers began with thelargest trees in this stand and kept selecting thenext smallest until 60-percent relative density
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Extensive studies have shown that thinning a stand to 60- to 75-percent relative density is ideal for growing high value wood products.
was reached. The smallest trees that were left werenot prepared for full sunlight and many of thetrees died in the first 5 years after the first cuttingtreatment in 1975. This treatment also tends toresult in a decrease in final timber values.
The thinning plots that you have visited hereare part of a larger experiment, consisting of morethan 60 plots in northwestern Pennsylvania andsouthwestern New York. Forest stands of manyages and species compositions are represented.The diversity of plots within this experiment hasallowed us to refine our thinning guidelines re-cently. We suggest that target residual densityshould vary by species composition. In standsdominated by shade-tolerant species, lower re-sidual densities are better, while in stands domi-nated by less shade-tolerant species like blackcherry, white ash, and yellow-poplar, higher re-sidual densities are preferred. Our research showsthat for the production of high quality woodproducts, thinning to 60- to 75-percent relativedensity by removing mostly smaller trees andenough larger trees to provide room for crownexpansion of the residual trees is best.
4) Herbicide/shelterwood treatment andbiodiversity: The goal of any regeneration cutting
is to ensure the establishment of the next stand.This can only occur if there is enough regenerationpresent to allow this to happen and interferingplants are not hindering growth and developmentof trees. Herbicide/shelterwood is the cuttingmethod employed when not enough advanceseedlings are present and interfering plants are aproblem. Herbicide use is required to removeunderstories of ferns, grasses and sedges, stripedmaple, and beech that interfere with regeneration.Herbicides are applied first, followed by theshelterwood cut, which reduces the overstory to60-percent relative density. This allows additionalsunlight, moisture, and nutrients to be availablefor the establishment of new seedlings. In 1994,the Allegheny National Forest and the NortheasternResearch Station began a 10-year cooperativestudy to determine the short- and long-termchanges in species diversity of herbaceous andwoody vegetation, small mammals, songbirds, andamphibians resulting from a single commercialapplication of a herbicide mix, [glyphosate andsulfometuron methyl, or Roundup (TM) plus Oust(TM)] combined with a shelterwood cut. This arearepresents one of 10 approximately 20-acre standsthat are being studied. Each stand is split in halfwith one-half receiving the herbicide treatment andthe other half serving as the control. These areaswere treated in the fall of 1994.
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To achieve the goals of this study, we gatherdata on all five of the communities of interest everyother summer. We measure the ground cover ofnon-woody plants on 30 sample plots twice eachseason; once in spring, when spring wildflowersare in bloom, and once in midsummer, when fernsare fully expressed. We count tree seedlings on adifferent set of plots during each summer, identify-ing them by species and several height classes.Twice each summer, we place 100 live traps on agrid throughout the stand, visit the traps daily for4 days and identify the small mammals caught.
Small mammal trapping is one technique used to assess the response of wildlifeto different silvicultural treatments.
Board complexes are used to survey salamander populations.
To assist in the capture of shrewand amphibian species, we placepitfall traps at planned locationsthroughout the stand. Thesetraps are below the level of theground surface and both smallmammal and amphibian speciesfall in and can be censusedwhen we visit the live trap grids.In addition, sets of 12 hemlockboards placed in a 4 x 3 patternalong the trapping grids are“run” periodically throughoutthe summer by lifting them andrecording information on anycaptured salamanders. Song-bird surveys are done threetimes each season. A skilled
5) Crop tree plots: This is an example ofthinning with careful consideration of crop trees.We have chosen as crop trees those with thecharacteristics that make them valuable for timberproduction. These are mostly black cherry treeswith large diameters, straight trunks, and maxi-mum length of stem to their first branches. Wealso tried to choose trees that were evenly spacedthroughout the area. This same treatment couldbe done using wildlife or aesthetic values as thedeciding criteria instead of timber productionvalue.
observer visits eightmarked spots through-out the stand in theearly morning hoursand for 5 minutesrecords all birds seen orheard within a radius of100 feet.
The boundary ofthis site is painted inwhite and the midlineseparating the two sidesis painted with whitestripes. A successfulherbicide applicationallows for regenerationgrowth before interfer-ing species can comeback and take over thestand again. As youwalk through the site,observe how the struc-ture and composition ofthe vegetation changesbetween the treated anduntreated sides. Pleasefeel free to observe, butnot disturb, data collec-tion sites.
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At each plot in this experiment, we havemarked the crop trees with a ring of white paint.This includes the plot where we have done nocutting, so that we can compare the growth of croptrees in an uncut stand with the various treat-ments. The cutting in these stands was doneduring the winter of 1989. A trail winds its waythrough the five different treatment stands.
In the first plot, we removed all trees whosecrowns were touching those of the 60 crop treesthat we designated per acre, unless the touchingcrown belonged to another crop tree. Notice thespacing between the trees. This seems to be idealfor growing big trees quickly.
The second plot is an uncut plot. Notice howmuch more crowded it feels and how much smallerthe crop trees are.
In the third plot, we used the results from ourthinning study and cut the stand to 60-percentrelative density. This traditional treatment inwhich we remove trees predominately of the small-est sizes and some large trees to create room forthe crowns of residual trees to expand, does notrequire formal identification of crop trees. But wedid designate 60 crop trees per acre after we
Selecting crop trees allows forest managers to monitor trees with the characteristics they deem the most valuable.
the growth of crop trees in treatments that specifi-cally released them from competition.
In the fourth plot, the treatment was to removeall trees whose crowns touched those of the 40 croptrees per acre that we chose. Here, you can seethat much of the growth since the cutting has beenin forest floor plants__ferns, raspberry, and sometree seedlings, instead of in the selected crop trees.
In the fifth plot you enter, the treatment was toremove all trees that were merchantable as forestproducts, except the 60 crop trees per acre. Here,too, trees are not using all the growing space.
In addition to these plots, there are two othergroups of crop tree plots elsewhere on theAllegheny National Forest. One is in an oak standand the other is in a young third growth forest.
Results from this study indicate that goodthinning techniques, whether or not we focus oncrop trees or use more traditional area-wide tech-niques, produces the same positive result.Efficiency of high value wood production wasincreased and understory development was kept
thinned here, so that we could compare theirgrowth in a plot treated in the traditional way with
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low except where too many trees were removed, asin the fourth and fifth plots.
6) Residual tree cutting: Remember stop 1,from which we learned that leaving small, slow-growing trees like sugar maple and beech at thetime of a clearcut would ensure their presence aslarge trees of seed-bearing size in the new forestthat developed? This site is an experiment to testthat method in today’s forest.
In 1982, this stand was clearcut. Before thecutting, foresters selected 31 sugar maple andbeech trees per acre with good crowns and straightstems with no low branches. These residuals weremarked with a ring of white paint and protectedduring the final harvest.
In 1985, this stand was fertilized with nitrogenand phosphorous dropped from a helicopter. Thistreatment allows the young seedlings to rapidlygrow out of the reach of browsing white-taileddeer. Notice that the young cherry stems arecatching up to the residual sugar maple. Ourresearch suggests that the cherry will catch upwith the maple in height sometime around 2020.
The residual trees suffered from the stresses ofdrought and late spring frosts in the first yearsafter cutting and by 1987, about 10 percent ofthem had died. Then, in the early 1990s, the treesunderwent several years of elm spanworm defolia-tions and more drought. Nonetheless, many aregrowing and surviving and a close look at theyounger stems will show that the residual trees arethe only maple, beech, and hemlock in the newstand.
We recommend this treatment, even though apercentage of the residual trees have died, becauseit is the surest way of maintaining diversity in astand. Diverse stands are less vulnerable to insectattack, have better nutrient cycling regimes,
produce higher quality timber, are better for wild-life, and ensure seed source for diverse stands inthe future.
7) Management strategies plots: You will needto walk down the gated old logging road about ahalf mile to a sign that starts this tour. The hikemay take about an hour, depending on how fre-quently you stop. At the center of the trail’s paththrough each treatment plot, there is a sign thatwill help you recognize the stops on this tour.Each sign (after the introductory one where thetrail turns off the logging road) has the name of thetreatment on it.
The purpose of this study was to explore theresults associated with several different manage-ment strategies in Allegheny Plateau forests. Eachstrategy involves a pattern of forest developmentand an associated pattern of management actions,and each has benefits and drawbacks. By applyingeach of these strategies several times within asmall (about 100 acres) area of similar forest, wecan learn about these benefits and drawbacks inmuch more detail. We chose this stand because itincludes trees of at least two distinct age classes.The first age class resulted from the partial har-vests conducted in this stand during the 1860-1880 era, when partial cuts were common. Thenaround 1900, a very heavy partial cut was com-pleted in this stand. So, prior to the start of ourexperiment in 1980, this stand contained sometrees that were about 80 years old and some thatwere at least 100 to 120 years old. As you walkdown the trail to the start of the experiment, youcan see patches of nearly pure black cherry thatprobably developed where the turn-of-the-centurycutting was particularly complete, and patches ofhemlock that were probably left when the partialcutting was made in 1900. There are four repli-cates of the treatments here and one other repli-cate located in an oak stand elsewhere on the
Since the early 1990s, a series of native and exotic defoliators, like the elmspanworm, have impacted thousands of acres of KEF and surroundingNational Forest land.
Allegheny National Forest. The plotson the trail were last treated in 1980.During the 1990s, this stand has beenheavily influenced by sugar mapledecline. Mortality of sugar maple hasbeen so high that none of the plots areready for second treatments as sched-uled in the year 2000. Studies con-ducted elsewhere by our unit haveindicated that sugar maple declineoccurs when trees with low levels ofsome key nutrients are exposed tostresses like defoliations and droughtsseveral times within the same decade.
The first plot you visit is beingmanaged with classic even-age silvicul-tural techniques. These techniques aredesigned for managing a group 11
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A clearcut area, eight growing seasons after cutting, 1959.
The same clearcut area 40 years later, 1996.
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of trees of a very narrow range of ages (a stand inwhich all trees regenerated at essentially the sametime, either through a natural disturbance or atimber harvest). This stand was thinned in 1980 toa 60-percent relative density. The trees that wereremoved were generally from the smaller merchant-able size classes, but some large trees were removedto allow residual tree crowns to expand. The big-gest and best trees will grow until perhaps 2020,and then the stand will be clearcut. The benefits ofthis strategy include rapid growth of valuable, largetrees like black cherry, that thrive in high sunlightconditions created by this management strategy.The drawbacks of this technique are the unpleasantappearance of even-age stands in the first few yearsafter clearcuts or shelterwood removal cuts. In thisolder stand, crown closure did not occur afterthinning. Sugar maple decline also reduced relativedensity. As a result, a new age class dominated byblack birch developed in the understory.
The second plot you visit is being managed withtechniques called economic selection. The intent isto develop a stand in which trees of many differentage classes, each about 20 years apart, coexist nextto each other. In this treatment and the next two,we divided the growing space among the trees ofdifferent size classes using our growth factors todetermine how many trees of each size class we hadroom for, and removed the excess. In this particu-lar treatment, we tried to do this without removingany trees too small to be used for sawtimber (saw-mills require trees with a diameter chest height ofabout 12 inches for sawtimber products). We hopethat this management strategy will be useful onsmall forested properties, where marketing smalltrees might be difficult, but where landowners wantto manage for a diversity of forest resource benefits.Cutting stimulates the growth of the plants on theforest floor providing food for wildlife and carefullymanaged cutting ensures that the best trees are notremoved all at once. The benefits of this manage-ment strategy include the easy marketability of itsproducts and the avoidance of clearcut appearance.But for it to succeed, species that can germinateand grow in the partial shade of a forest canopythat includes trees of all sizes and heights mustgrow past the reach of the deer. So far, the new ageclass is sparse; instead there are many ferns, nottree species. Species that are very valuable fortimber production and wildlife food production, likethe oaks and cherry, do not grow well in thesepartially shaded conditions, even though cherry isless preferred by deer. The heavy browsing of treeseedlings by deer is a pervasive feature of theseforests and a substantial threat to their re-generation.
The third plot you visit is being managed withtechniques called group selection. Trees that weremerchantable for both timber and paper pulp
production were removed from the stand. As inthe previous plot, trees were designated for re-moval when there were too many trees of a givensize on the plot. In addition, we purposely createdopenings up to a half-acre in size throughout thestand. In this opening, we are having some suc-cess where the tops of trees cut in the 1980 har-vest have denied deer access to valuable treeseedlings. This management strategy may offersome of the best benefits, if the deer do not eat allthe valuable sun-loving species in the openingsand all the more shade-loving species that growbetween the openings. So far, we don’t observethis happening.
The fourth plot you visit is being managed withtechniques called single-tree selection. This isanother technique in which trees of all ages willcoexist in one stand. In this variant of the tech-nique, only openings resulting from single-treeremovals have been created. Trees merchantablefor both paper pulp and timber products wereremoved in this treatment. The residual density inthis stand has been reduced to 60 percent, al-though the sizes of the trees removed is quitedifferent from those removed in even-agedthinnings. It is hard to believe that there was atimber sale here in 1980, which is perhaps thegreatest benefit of this strategy. But despitehaving all the right species for seed source in theoriginal stand (sugar maple, beech, hemlock andother shade-loving species that should prosperunder this strategy) there is little regeneration.The regeneration that is occurring is of Americanbeech, often growing as root suckers off of existingtrees. Not only does beech have a very low valuefor wood products, it is the victim of beech barkdisease that is rapidly spreading into this area.Once again, deer are a primary reason for the lackof regeneration. The beech sucker plants seemmore resistant to deer browsing probably becausethey have access to the energy stored in the rootsof mature trees.
The final plot on this stop demonstrates a two-age management strategy. This strategy is a crossbetween the strategies that maintain severaldifferent age groups of trees on the site at any timeand even-age strategies that replace one single-agecrop of trees with another. We will remove morethan two-thirds of the mature trees on this plot atthe next treatment, creating conditions of abun-dant light almost like a clearcut, but withoutremoving the overstory completely. We would liketo keep the trees from the original stand for per-haps 40 years after that, until the new age class oftrees has the appearance of a young foreststand. Then we will harvest the oldest treesand thin the new age class, creating conditionsthat will allow seedlings of sun-loving speciesto grow again. This strategy may be the only 15
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Since 1976, SILVAH (SILViculture of Allegheny Hardwoods) training sessions have been held every year on the KEF.These courses provide participants with the opportunity to apply silvicultural guidelines to actual stands.
way that we will be able to maintain the presenceof a high proportion of seedlings of sun-loving,high-value species while still avoiding the appear-ance of fresh clearcuts. In this stand, however,beech present as small root suckers at the time ofthe 1980 thinning have been the main beneficia-ries of that treatment.
TECHNOLOGY TRANSFERScientists at the Irvine laboratory emphasize
the need to bring research results to the public.Our technology transfer programs are created tohelp resource professionals, landowners, and thegeneral public appreciate the importance of sus-tainable forest communities through the applica-tion of research results. Annual programs on theKane Experimental Forest include:
1) Training for future foresters: Scientists atthe laboratory host numerous college forestry andbiology courses throughout the year at the KaneExperimental Forest. Abundant study and demon-stration sites across the Experimental Forestprovide excellent opportunities to teach studentsthe basics of forest management in Alleghenyhardwood stands.
2) Environmental education and tours: Vari-ous programs at the Kane Experimental Forestgive local school groups an opportunity to learneverything from tree identification and foresthealth to wildlife habitat requirements. Informa-tion on careers in forestry, wildlife biology, andresearch are also shared. In addition, guidedtours and slide shows are offered, by priorarrangement, for any interested group.
3) SILVAH Training sessions: Since its incep-tion in 1932, studies on the Kane ExperimentalForest have provided for the rapid accumulation ofscientific knowledge on the ecology and manage-ment of hardwoods on the Allegheny Plateau re-gion. Even early on, special efforts were made toorganize that knowledge into a coordinated set ofmanagement guidelines. Initial guidelines includedprocedures to obtain satisfactory regeneration afterharvest cutting and to control stand density andstructure during thinning. These guidelines havesince been expanded into a complete system ofstand evaluation and silvicultural prescriptionsthat cover the full range of forest conditions andmanagement alternatives in the region. Researchresults developed to date by the research project atIrvine have been incorporated into a systematicapproach to silviculture called SILVAH(SILViculture of Allegheny Hardwoods), which aidsforesters in managing Allegheny hardwood stands.Since 1976, this system for stand inventory, analy-sis, and prescription writing has been presented toresource professionals during week-long workshopsheld two to four times each year at the Kane Ex-perimental Forest’s conference building. Sessionsare conducted by staff from the Irvine laboratory incooperation with The Pennsylvania State Univer-sity. This intensive course gives participants boththe theoretical background information and activefield experience in applying silvicultural guidelinesto actual stands for both timber and non-timbervalues. The sessions are updated periodically asnew research information becomes available. Inaddition, the SILVAH approach has been developedinto a computerized decision model, also calledSILVAH (version 5.0 is currently available).
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RESEARCH RESULTS APPLIEDThe area occupied by Allegheny hardwoods is a
heavily forested region. It is one of the majorcontiguous blocks of commercial forest land in theNortheast. Forests in the Allegheny Plateau regioninclude the half-million-acre Allegheny NationalForest, several districts from Pennsylvania’s2.1-million-acre State Forest System, severalgamelands managed by the Pennsylvania GameCommission, municipal watersheds, hundreds ofthousands of acres of industrially owned forest,and a similar acreage of non-industrial privateforest. All of these forests are used for a variety ofpurposes, including timber production, wildlifehabitat, outdoor recreation, and watershed man-agement. They are important for conservation ofbiological diversity, for safeguarding the region’swater supply, and for providing people with theexperience of large blocks of contiguous workingforest.
Research conducted on the Kane ExperimentalForest and by USDA Forest Service researchersassociated with the KEF has influenced the man-agement of these forests for several decades.Inventory procedures and management guidelinesdeveloped by Irvine Laboratory researchers arestandard practice on public lands throughout the
The Allegheny hardwood forest covers approximately 16 million acres of the Allegheny Plateau and Allegheny Mountainsections of Pennsylvania, New York, Maryland, West Virginia, and Ohio.
region, through use of the SILVAH computerprogram and participation of professionals inSilvicultural Training Sessions. When white-taileddeer browsing created a regeneration crisis inthe region during the late 1960s and early 1970s,guidelines developed by Forest Service researchersenabled managers to improve their rate of success-ful regeneration after final timber harvests from 50percent to more than 90 percent. These guidelinesincluded inventory procedures for formal assess-ment of advance regeneration, the first suchguidelines widely used in the eastern hardwoodregion. These procedures were later adapted foruse by the USDA Forest Service, Forest Inventoryand Analysis group for their 1989 inventory ofPennsylvania’s forest resources. Guidelines devel-oped by Forest Service researchers for herbicidetreatment of plants that interfere with the estab-lishment of diverse regeneration in Plateau forestsare used annually by a variety of forest manage-ment organizations on several thousand acres.The on-going thinning studies on the Kane Experi-mental Forest have led to major advances in ourunderstanding of forest growth and development inhardwood stands of mixed species composition,and guidelines based on this understanding areused throughout the eastern United States.
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Guidelines developed by Forest Serviceresearchers are mentioned as standards againstwhich forest management practices were com-pared in assessments of both industrial andPennsylvania State Bureau of Forestry manage-ment practices by Scientific Certification Systems,Inc.1 during the 1990s. These ownerships, total-ing more than 2 million acres, were among thefirst and largest forests in the eastern UnitedStates to receive certification as well managed byorganizations approved1 by the InternationalForest Stewardship Council.
1 The use of trade, firm, or corporation names in thispublication is for the information and convenience ofthe reader. Such use does not constitute an officialendorsement or approval by the U.S. Department ofAgriculture or the Forest Service of any product orservice to the exclusion of others that may be suitable.
Cooperators and Partners
■ Audubon Society■ Clarion University■ Forest Investment Associates (FIA)■ Hammermill Paper Company■ International Paper Company■ Kane Hardwood, a Division of Collins Pine■ Marshall University■ National Biological Service■ Nature Conservancy■ New York Department of Environmental
Conservation■ New York State Parks■ Northeastern Area State & Private Forestry■ Pennsylvania Bureau of Forestry■ Pennsylvania Game Commission■ Pennsylvania State Parks (Department of
Conservation and Natural Resources)■ Region 9’s Research Natural Areas Program■ Shippensburg University■ Society of American Foresters (SAF) Deer/
Forest/Farm Committee■ SUNY - College of Environmental
Science and Forestry■ The Pennsylvania State University■ The University of Pennsylvania■ Western PA Conservancy■ Wildlife Society■ Wolf Run Forest Resource Partnership
This publication reports research involving pesticides. It does not contain recommendations for their use, nor does it implythat the uses discussed here have been registered. All uses of pesticides must be registered by appropriate State and/orFederal agencies before they can be recommended.
CAUTION: Pesticides can be injurious to humans, domestic animals, desirable plants, and fish or other wildlife__if they are nothandled or applied properly. Use all pesticides selectively and carefully. Follow recommended practices for the disposal ofsurplus pesticides and pesticide container.
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List of Publications from Research on the Kane Experimental Forest
deCalesta, David S. 1994. Effect of white-taileddeer on songbirds within managed forests inPennsylvania. Journal of Wildlife Management.58(4): 711-718.
Horsley, Stephen B. 1991. Using Roundup andOust to control interfering understories inAllegheny hardwood stands. In: McCormick,Larry H., Gottschalk, Kurt W.; eds. Proceedings8th Central Hardwood Forest Conference 1991March 4-6. Gen. Tech. Rep. NE-148. Radnor,PA: U.S. Department of Agriculture, ForestService, Northeastern Forest ExperimentStation. 281-290.
Hough, Ashbel F. 1937. A study of natural treereproduction in the beech-birch-maple-hemlock type. Journal of Forestry.35: 376-378.
Long, Robert P.; Horsley, Stephen B.; Lilja, Paul R.1997. Impact of forest liming on growthand crown vigor of sugar maple andassociated hardwoods. Canadian Journalof Forest Research. 27: 1560-1573.
Marquis, David A. 1975. The Allegheny hardwoodforests of Pennsylvania. Gen. Tech. Rep. NE-15. Upper Darby, PA: U.S. Department ofAgriculture, Forest Service, NortheasternForest Experiment Station. 32 p.
Marquis, David A. 1975. Seed storage andgermination under northern hardwood forests.Canadian Journal of Forest Research.5: 478-484.
Marquis, David A. 1981. Removal or retention ofunmerchantable saplings in Alleghenyhardwoods: Effect on regeneration afterclearcutting. Journal of Forestry. 79: 280-283.
Marquis, David A.; Bjorkbom, John C. 1982.Guidelines for evaluating regeneration beforeand after clearcutting Allegheny hardwoods.Res. Note NE-307. Broomall, PA: U.S.Department of Agriculture, Forest Service,Northeastern Forest Experiment Station. 4 p.
Marquis, David A.; Ernst, Richard L. 1992. User’sguide to SILVAH. Gen. Tech. Rep. NE-162.Radnor, PA: U.S. Department of Agriculture,Forest Service, Northeastern Forest ExperimentStation. 130 p.
Marquis, David A.; Ernst, Richard L.; Stout,Susan L. 1992. Prescribing silviculturaltreatments in hardwood stands of theAlleghenies (revised). Gen. Tech. Rep. NE-96.Radnor, PA: U.S. Department of Agriculture,Forest Service, Northeastern Forest ExperimentStation. 101 p.
Nowak, Christopher A. 1996. Wood volumeincrement in thinned, 50- to 55-year-old,mixed-species Allegheny hardwoods. CanadianJournal of Forest Research. 26: 819-835.
Ostrom, C. E.; Hough, Ashbel F. 1944. Earlyweeding in northern hardwoods. Journal ofForestry. 42: 138-140.
Roach, Benjamin A. 1977. A stocking guide forAllegheny hardwoods and its use in controllingintermediate cuttings. Res. Pap. NE-373.Upper Darby, PA: U.S. Department ofAgriculture, Forest Service, Northeastern ForestExperiment Station. 30 p.
Stout, Susan L., Redding, James A.; DeMarco,Lois A. 1995. Technology transfer at the heartof a research/management partnership. In:Silviculture: From the Cradle of Forestry toecosystem management, Proceedings of theNational Silviculture Workshop, Foley, LouiseH., comp.; 1993 November 1-4; Hendersonville,NC. Gen. Tech. Rep. SE-88. Asheville, NC: U.S.Department of Agriculture, Forest Service,Southeastern Forest Experiment Station.188-193.
Tilghman, Nancy G. 1989. Impacts of white-taileddeer on forest regeneration in northwesternPennsylvania. Journal of WildlifeManagement. 53 (3): 524-532.
Yanai, Ruth D.; Twery, Mark J.; Stout, Susan L.1998. Woody understory response to changesin overstory density: thinning in Alleghenyhardwoods. Forest Ecology and Management,102: 45-60.
For copies of these publications and others,contact the Publications Group: USDA Forest Service,359 Main Road, Delaware, OH 43015;(PHONE) (740-368-0123); (FAX) (740-368-0152);e-mail: afrancis/[email protected] 19
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Glossary
Clearcutting -- A method of regenerating an even-aged stand in which anew age class develops in a fully-exposed microclimate after removal,in a single cutting, of all trees in the previous stand. Regeneration isfrom natural seeding, direct seeding, planted seedlings and/or advancereproduction.
Crop Tree -- Any tree that is selected to become a component of afuture commercial harvest.
Crown -- The part of a tree or woody plant bearing live branches andfoliage.
Even-Aged Stand -- A stand of trees containing a single age class inwhich the range of tree ages is usually less than 20 percent of rotation.
Herbaceous -- Fleshy, nonwoody plants. Does not include trees andshrubs.
Interference -- Any form of vegetation that prohibits desired speciesfrom growing.
Mowing -- A release treatment in stands at the saplings stage thateliminates or suppress undesirable vegetation regardless of crownposition.
Regeneration -- Seedlings or saplings existing in a stand; or the act ofestablishing young trees naturally or artificially.
Silviculture -- The art and science of controlling the establishment,growth, composition, health and quality of forests and woodlands tomeet the diverse needs and values of landowners and society on asustainable basis.
Shelterwood Seed Cutting -- A method of regenerating an even-agedstand in which a new age class develops beneath the moderated micro-environment provided by the residual trees.
Stand -- A contiguous group of trees sufficiently uniform in age-classdistribution, composition and structure, and growing on a site ofsufficiently uniform quality, to be a distinguishable unit.
Thinning -- A cultural treatment made to reduce stand density of treesprimarily to improve growth, enhance forest health, or to recoverpotential mortality.
Two-age -- A stand composed of two distinct age classes that areseparated in age by more than 20 percent of rotation.
Weeding -- A release treatment in stands not past the sapling stagethat eliminates or suppresses undesirable vegetation regardless ofcrown position.
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Julie Smithbauerhas been abiological sciencetechnician with theNortheasternResearch Stationat the KaneExperimentalForest since 1992.She has a B.S.from Penn StateUniversity inAnimal Bioscience,with a minor inWildlife Science.She serves assuperintendent ofthe KaneExperimentalForest andoversees thesummer wildliferesearch program.
22 Printed on Recycled PaperNE-INF-137-99 eU.S. Government Printing Office:704-946/1999
For further information contact: Northeastern Research StationForestry Sciences Laboratory, P.O. 267, Irvine, PA 16329-0267or call: (814) 563-1040; FAX (814) 563-1048;e-mail: sstout/[email protected]
PREPARED BY: CommunicationsNortheastern Research Station, Radnor, PA
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