Tropical rock outcrops (inselbergs): their importance as habitat islands
Stefan Porembski, University of Rostock, Stefan Porembski, University of Rostock, Institute of Institute of BiosciencesBiosciences, , DeptDept. of . of BotanyBotany, Wismarsche Str. 8, , Wismarsche Str. 8,
DD--18051 Rostock, Germany18051 Rostock, Germany
-- EnvironmentalEnvironmental conditionsconditions-- Plant Plant communitiescommunities on inselbergson inselbergs-- Adaptive Adaptive strategiesstrategies
Habitat Habitat islandsislands as as modelmodel systemssystemsforfor biodiversitybiodiversity researchresearch
OceanicOceanic islandsislandsTheThe evolutionevolution of of speciesspecies (Darwin 1859)(Darwin 1859)TheoryTheory of of islandisland biogeographybiogeography ((MacArthurMacArthur & Wilson 1967)& Wilson 1967)
TerrestrialTerrestrial habitathabitat islandsislandsForestForest fragmentsfragments (e.g. BDFFP (e.g. BDFFP nearnear Manaus)Manaus)Rock Rock outcropsoutcrops
Inselbergs Inselbergs areare oldold habitathabitat islandsislands
Geomorphol. bekannt
Biologie unbekannt
-- GeomorphologyGeomorphologywell well knownknown
-- BiologyBiologylargelylargely neglectedneglected
ShieldShield inselberginselberg Bornhardt
KoppjeKoppjeKoppje
Inselberg typesInselberg types
StudyStudy sitessites: : pantropicalpantropical
Inselbergs: Inselbergs: terrestrialterrestrial habitathabitat islandsislands
to to squaresquare kilometerskilometers
fromfrom squaresquare metersmeters
- Size spectrum
Granitic and Granitic and GneissicGneissic InselbergsInselbergs- Environmental conditions extreme
EdaphicallyEdaphically drydry: lack of : lack of soilsoil covercover
MicroclimaticallyMicroclimatically extreme: extreme: elevatedelevatedtemperaturestemperatures and high and high insolationinsolationratesrates
100100
8080
6060
4040
2020
00
100100
8080
6060
4040
2020
0000 5050 100100 200200 250250150150 300300 350350 400 m400 m
Air Air TemperatureTemperature ((°°C)C) rel. rel. HumidityHumidity (%)(%)
Granitic and Granitic and gneissicgneissic inselbergsinselbergs-- Habitat Habitat typestypes
Lichens and cyanobacteria on inselbergsLichensLichens and cyanobacteria on inselbergsand cyanobacteria on inselbergs
Lichen-inselbergLichenLichen--inselberginselberg
Cyanobacteria-inselbergCyanobacteriaCyanobacteria--inselberginselberg
PeltulaPeltulaPeltula
Lichens and cyanobacteria on inselbergsLichensLichens and cyanobacteria on inselbergsand cyanobacteria on inselbergs
Lichen-inselbergLichenLichen--inselberginselberg
Cyanobacteria-inselbergCyanobacteriaCyanobacteria--inselberginselberg
PeltulaPeltulaPeltula
Drainage channelsDrainage channels
Wet flush vegetationWet flush vegetation• on exposed rock in seasonal streams
colonizing cyanobacterial mats• on exposed rock in seasonal streams
colonizing cyanobacterial mats
Wet flush vegetationWet flush vegetation• dominant families
Lentibulariaceae, Xyridaceae, Eriocaulaceae• dominant families
Lentibulariaceae, Xyridaceae, Eriocaulaceae
Utricularia subulataUtriculariaUtricularia subulatasubulataUtricularia rigidaUtriculariaUtricularia rigidarigida
Utricularia striatulaUtriculariaUtricularia striatulastriatula
Seasonally water-filled rock poolsSeasonallySeasonally waterwater--filledfilled rock rock poolspools
Seasonally water-filled rock poolsSeasonallySeasonally waterwater--filledfilled rock rock poolspools
Dopatrium longidensDopatrium Dopatrium longidenslongidens
Rock pools– „grinding holes“Rock Rock poolspools–– „„grindinggrinding holesholes““
- Spatial species turnover in rock pools-- SpatialSpatial speciesspecies turnoverturnover in rock in rock poolspools
Inselbergs: Inselbergs: habitathabitat typestypes
MonocotyledonousMonocotyledonous matsmats
West Africa
Afrotrilepis pilosa
Inselbergs: Inselbergs: habitathabitat typestypes
MonocotyledonousMonocotyledonous matsmats
East Africa/Madagascar
Xerophyta spp.Myrothamnus flabellifolius/moschatus
Coleochloa setifera
Inselbergs: Inselbergs: habitathabitat typestypes
MonocotyledonousMonocotyledonous matsmats
Neotropics
Pitcairnia geyskesii Encholirium spec.
DesiccationDesiccation--toleranttolerant vascularvascular plantsplants- Adaptations to unpredictable water scarcity
Drying without dying:Desiccation-tolerant vascularplants: „resurrection plants“
Microdracoides squamosus
Myrothamnus moschatus
dry wet dry
dry wet dry
-- Habitat Habitat typestypes
Granitic and Granitic and GneissicGneissic InselbergsInselbergs
EphemeralEphemeral flushflush vegetationvegetation
EphemeralEphemeral flushflush vegetationvegetation
• Downslope fringes of monocot-mats
Floristically exceptionally rich with 25-30 spp./m2
Ecological attributes of EFV•• HighlyHighly seasonalseasonal plant plant
communitycommunity•• Small Small habitathabitat sizesize•• AnnualsAnnuals dominatingdominating•• Small Small sizesize of of plantsplants•• High High speciesspecies richnessrichness•• ShallowShallow substratesubstrate•• Lack of Lack of nutrientsnutrients•• High High percentagepercentage of of
carnivorouscarnivorous plantsplants
dry season aspect
Burmannia spp. Utricularia spp.Xyris spp.
FloristicFloristic compositioncomposition of EFVof EFV
•• TypicalTypical throughoutthroughoutmostmost regionsregions::
CyperaceaeCyperaceaePoaceaePoaceaeLentibulariaceaeLentibulariaceaeEriocaulaceaeEriocaulaceaeXyridaceaeXyridaceaeGentianaceaeGentianaceaeDroseraceaeDroseraceae
IndiaIndia
AustraliaAustralia
Phylogeny and ecology of Lentibulariaceae
Lamiales/Lentibulariaceae: Pinguicula, Genlisea, Utricularia
Pinguicula Genlisea Utricularia
TropicalTropical rock rock outcropsoutcrops
-- InselbergsInselbergs-- SandstoneSandstone tabletable mountainsmountains-- FerricretesFerricretes
Eisenlateritkrusten (ferricretes, cuirasses ferralitiques)
WesternGhats
Eisenlateritkrusten (ferricretes, cuirasses ferralitiques)
Mass flowering of terrestrial Utricularia-species
UtriculariaUtricularia purpurascenspurpurascens
Eisenlateritkrusten (ferricretes, cuirasses ferralitiques)
Xyris spec. Drosera indica Eriocaulon eurypeplon
Inselbergs and ManInselbergs and Man
TourismTourism......
...and ...and LeisureLeisure
InvasiveInvasive speciesspecies on inselbergson inselbergs
-- Inselbergs Inselbergs areare evolutionaryevolutionaryspringboardsspringboards of of invasiveinvasive speciesspecies
-- Habitat Habitat fragmentationfragmentation increasesincreases thethepercentagepercentage of of exoticexotic weedsweeds on on inselbergsinselbergs
Granitic and Granitic and GneissicGneissic InselbergsInselbergs-- Inselbergs as Inselbergs as refugiarefugia forfor maintaingmaintaing biodiversitybiodiversity
Rio de JaneiroRio de Janeiro
18421842 20002000
A threatened paradise of rare plants:vegetation of tropical inselbergs
• Conclusions:- Rock outcrops form centers
of diversity for plants typicalfor nutrient poor and seasonally wet sites
- Habitat specialists dominate(e.g. carnivorous species, resurrection plants)
• Major risks: quarrying, firegrazing, outdoor activities(e.g. rock climbing)
AcknowledgementsAcknowledgements-- FundingFunding:: DAAD, DFG, ECOFAC, DAAD, DFG, ECOFAC, SmithonianSmithonianInstitution, Studienstiftung des deutschen VolkesInstitution, Studienstiftung des deutschen Volkes
-- CooperationCooperation:: L. L. AkAkéé AssiAssi (Abidjan), W. Barthlott (Abidjan), W. Barthlott (Bonn), F. Franca ((Bonn), F. Franca (FeiraFeira de Santana), P. de Santana), P. GoetgheGoetghe--beurbeur (Gent), S. D. Hopper (Perth), J. Lejoly (Gent), S. D. Hopper (Perth), J. Lejoly ((BruxellesBruxelles), G. Martinelli (Rio de Janeiro), M. F. ), G. Martinelli (Rio de Janeiro), M. F. de Sales (Recife), F. R. Scarano (Rio de Janeiro), de Sales (Recife), F. R. Scarano (Rio de Janeiro), B. B. SinsinSinsin ((CotonouCotonou), M. ), M. NdanghaNdangha ((LimbeLimbe), Z. ), Z. Tuba (Tuba (GGööddööllllöö), A. Watve (), A. Watve (PunePune))