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))