Species distributions and climate change:current patterns and future scenarios for biodiversity

Christian Hof

Species distributions and climate change:current patterns and future scenarios for biodiversity

Christian Hof

Ecology and Evolution

555 Downloads (Pure)

Abstract

Hvordan påvirkes biodiversiteten af klimaforandringerne? - At besvare dette

spørgsmål er en af de vigtigste opgaver for økologisk forskning i dag. Jorden er blevet

0,7 °C varmere over de sidste 100 år, og konsekvenserne for biologiske systemer er

allerede tydelige. For eksempel reagerer arter med forandringer i deres udbredelse,

hvilket forandrer de rumlige mønstre i artsrigdom. Globale temperaturer forventes at

stige med endnu 1,8 - 4 °C i løbet af dette århundrede; det er derfor sandsynligt at

klimaforandringer vil påvirke arter og økosystemer yderligere. Denne ph.d.-afhandling

sigter mod at bidrage til en bedre forståelse af klimaforandringernes indvirkning på

arters udbredelse og på rumlige mønstre i artsrigdom.

De nuværende klimaforandringer formodes at blive en de største fremtidige trusler

mod biodiversiteten, da man har ment at forandringen sker hurtigere end nogensinde

før. Dog viser nyere studier at klimaforandringerne under og efter Pleistocæn muligvis

er sket hurtigere end hidtil antaget. Da hurtige klimaforandringer ikke dengang

udryddede mange arter, må man gå ud fra at de fleste arter også vil være i stand til at

håndtere de nuværende klimaforandringer. Dog er nutidens økosystemer stærkt

påvirkede af mennesker. Både habitat-ødelæggelse og landskabs-fragmentering, skabt af

menneskers brug af jorden, har en negativ indvirkning på arters strategier til at håndtere

klimaforandringer. Selv om vi er nødt til at gentænke arters evne til at klare hurtige

klimaforandringer, udgør interaktionerne mellem forskellige trusler altså stadig en

alvorlig udfordring for biodiversiteten. I en global undersøgelse af fremtidige trusler for

diversiteten af padder undersøger jeg geografien af klimaforandringer,

jordbrugsændringer og den patogene svamp Batrachochytrium dendrobatidis (Bd). Der

var et stort sammenfald mellem de områder hvor påvirkningen fra klimaforandringer og

jordbrugsændringer var størst, men kun et lille overlap med områder hvor Bd var

almindelig. Alt i alt kan op mod to tredjedele af de områder i verden der har den rigeste

padde-fauna blive stærkt berørt af en af de tre vigtige trusler inden 2080.

Stabiliteten af arters klimatiske niche afgør hvor nødvendigt det er for dem at følge

klimaforandringer ved at sprede sig, og deres mulighed for at tilpasse sig nye klimatiske

forhold. Jeg undersøger derfor det fylogenetiske signal i de klimatiske nicher for alle

verdens padder, hvilket er en måde at kvantificere nichernes stabilitet. Resultaterne

indikerer at der generelt er et fylogenetisk signal i arternes realiserede klimatiske nicher,

men at styrken af signalet varierer på tværs af biogeografiske områder og mellem

forskellige ordener af padder.

Evnen til at følge klimaet afhænger af spredningsevnen, som igen afhænger af

økologiske tilpasninger såsom tilknytning til en bestemt habitattype. En udbredt

hypotese er at arter der er knyttet til mindre varige habitater har udviklet en større evne

til spredning. To studier i denne afhandling støtter denne hypotese: (1) den geografiske

udbredelse af guldsmede som er knyttet til mindre varige habitater er i højere grad i

ligevægt med de klimatiske forhold; (2) der er stor forskel på de rumlige mønstre i

artsrigdom og turnover hos europæiske ferskvandsarter fra forskellige habitattyper,

hvilket tyder på at arter der er tilpasset mindre varige habitater har genkoloniseret

Europa hurtigere efter sidste istid.

Originalsprog	Engelsk

Udgivelsessted	Biologisk Institut
Forlag	Museum Tusculanum
Antal sider	220
Status	Udgivet - jan. 2010

FN’s Verdensmål

Dette resultat bidrager til følgende verdensmål

Adgang til dokumentet

Christian 20HofForlagets udgivne version, 19,8 MB

Citationsformater

@phdthesis{dd7431b089c011df928f000ea68e967b,

title = "Species distributions and climate change:current patterns and future scenarios for biodiversity",

abstract = "How does climate change affect biodiversity? - Answering this question is one ofthe most important tasks in current ecological research. Earth has been warming by0.7°C during the last 100 years, and the consequences are already apparent in bioticsystems. For example, species are responding by shifts of their distributional ranges,which affects the spatial patterns of species richness and turnover. Global temperaturesare projected to rise by 1.8 - 4°C until the end of the century; hence climate change willmost likely leave further imprints on species and ecosystems. This PhD thesis aims tocontribute to a better understanding of the impacts of climate change on speciesdistributions and spatial patterns of biodiversity.Contemporary climate change is assumed to be one of the major future threats forbiodiversity, due to its supposedly unprecedented velocity. On the contrary, recentstudies suggest that climatic changes during and after the Pleistocene may have beenmuch faster than commonly assumed. In one of the studies of this thesis I discuss theconsequences of these findings for species and ecosystems. Since these rapid climatechange events did not cause a broad-spectrum mass extinction, one might assume thatmost species may also be able to successfully cope with contemporary climate change.However, current ecosystems are heavily modified by humans. Among other factors,habitat destruction and fragmentation caused by anthropogenic land-use changesnegatively affect species' strategies to cope with climate change. Therefore, althoughwe need to rethink species' abilities to cope with rapid climate change, the interactionsof different threats impose severe challenges for biodiversity. In a global assessment offuture threats for amphibian diversity, I investigate the geography of climate change,land-use change and the fungal pathogen Batrachochytrium dendrobatidis (Bd). Resultsindicated that the regions with highest projected climate and land-use change impactsshow a strong tendency of congruence, but show little overlap with regions of high Bdprevalence. Overall, two-thirds of the areas harboring the richest amphibian faunas maybe heavily impacted by at least one of the major threats by 2080.The stability of the climatic niche influences the need for a species to track climatechange via dispersal, or its potential to adapt to novel climatic conditions. I thereforeexplore the phylogenetic signal in climatic niches of the world's amphibians, whichserves as a surrogate quantification of niche stability. Results indicate an overalltendency of phylogenetic signal to be present in realised climatic niches, but signalstrength varies across biogeographical regions and among amphibian orders.The ability to successfully track climatic changes depends on dispersal, which is inturn influenced by ecological adaptations, such as the affiliation with a certain habitattype. A common hypothesis is that species adapted to less persistent habitats haveevolved stronger dispersal abilities. Two studies of my thesis provide evidence for thishypothesis: (1) geographical distributions of dragonflies adapted to less persistenthabitats show higher degrees of equilibrium with climatic conditions; (2) spatialpatterns of European freshwater species richness and turnover differ strongly amonghabitats, indicating a faster post-glacial re-colonization of northern Europe by speciesadapted to habitats of lower persistence.",

author = "Christian Hof",

note = "Supervisor: Carsten Rahbek",

year = "2010",

month = jan,

language = "English",

publisher = "Museum Tusculanum",

}

TY - BOOK

T1 - Species distributions and climate change:current patterns and future scenarios for biodiversity

AU - Hof, Christian

N1 - Supervisor: Carsten Rahbek

PY - 2010/1

Y1 - 2010/1

N2 - How does climate change affect biodiversity? - Answering this question is one ofthe most important tasks in current ecological research. Earth has been warming by0.7°C during the last 100 years, and the consequences are already apparent in bioticsystems. For example, species are responding by shifts of their distributional ranges,which affects the spatial patterns of species richness and turnover. Global temperaturesare projected to rise by 1.8 - 4°C until the end of the century; hence climate change willmost likely leave further imprints on species and ecosystems. This PhD thesis aims tocontribute to a better understanding of the impacts of climate change on speciesdistributions and spatial patterns of biodiversity.Contemporary climate change is assumed to be one of the major future threats forbiodiversity, due to its supposedly unprecedented velocity. On the contrary, recentstudies suggest that climatic changes during and after the Pleistocene may have beenmuch faster than commonly assumed. In one of the studies of this thesis I discuss theconsequences of these findings for species and ecosystems. Since these rapid climatechange events did not cause a broad-spectrum mass extinction, one might assume thatmost species may also be able to successfully cope with contemporary climate change.However, current ecosystems are heavily modified by humans. Among other factors,habitat destruction and fragmentation caused by anthropogenic land-use changesnegatively affect species' strategies to cope with climate change. Therefore, althoughwe need to rethink species' abilities to cope with rapid climate change, the interactionsof different threats impose severe challenges for biodiversity. In a global assessment offuture threats for amphibian diversity, I investigate the geography of climate change,land-use change and the fungal pathogen Batrachochytrium dendrobatidis (Bd). Resultsindicated that the regions with highest projected climate and land-use change impactsshow a strong tendency of congruence, but show little overlap with regions of high Bdprevalence. Overall, two-thirds of the areas harboring the richest amphibian faunas maybe heavily impacted by at least one of the major threats by 2080.The stability of the climatic niche influences the need for a species to track climatechange via dispersal, or its potential to adapt to novel climatic conditions. I thereforeexplore the phylogenetic signal in climatic niches of the world's amphibians, whichserves as a surrogate quantification of niche stability. Results indicate an overalltendency of phylogenetic signal to be present in realised climatic niches, but signalstrength varies across biogeographical regions and among amphibian orders.The ability to successfully track climatic changes depends on dispersal, which is inturn influenced by ecological adaptations, such as the affiliation with a certain habitattype. A common hypothesis is that species adapted to less persistent habitats haveevolved stronger dispersal abilities. Two studies of my thesis provide evidence for thishypothesis: (1) geographical distributions of dragonflies adapted to less persistenthabitats show higher degrees of equilibrium with climatic conditions; (2) spatialpatterns of European freshwater species richness and turnover differ strongly amonghabitats, indicating a faster post-glacial re-colonization of northern Europe by speciesadapted to habitats of lower persistence.

AB - How does climate change affect biodiversity? - Answering this question is one ofthe most important tasks in current ecological research. Earth has been warming by0.7°C during the last 100 years, and the consequences are already apparent in bioticsystems. For example, species are responding by shifts of their distributional ranges,which affects the spatial patterns of species richness and turnover. Global temperaturesare projected to rise by 1.8 - 4°C until the end of the century; hence climate change willmost likely leave further imprints on species and ecosystems. This PhD thesis aims tocontribute to a better understanding of the impacts of climate change on speciesdistributions and spatial patterns of biodiversity.Contemporary climate change is assumed to be one of the major future threats forbiodiversity, due to its supposedly unprecedented velocity. On the contrary, recentstudies suggest that climatic changes during and after the Pleistocene may have beenmuch faster than commonly assumed. In one of the studies of this thesis I discuss theconsequences of these findings for species and ecosystems. Since these rapid climatechange events did not cause a broad-spectrum mass extinction, one might assume thatmost species may also be able to successfully cope with contemporary climate change.However, current ecosystems are heavily modified by humans. Among other factors,habitat destruction and fragmentation caused by anthropogenic land-use changesnegatively affect species' strategies to cope with climate change. Therefore, althoughwe need to rethink species' abilities to cope with rapid climate change, the interactionsof different threats impose severe challenges for biodiversity. In a global assessment offuture threats for amphibian diversity, I investigate the geography of climate change,land-use change and the fungal pathogen Batrachochytrium dendrobatidis (Bd). Resultsindicated that the regions with highest projected climate and land-use change impactsshow a strong tendency of congruence, but show little overlap with regions of high Bdprevalence. Overall, two-thirds of the areas harboring the richest amphibian faunas maybe heavily impacted by at least one of the major threats by 2080.The stability of the climatic niche influences the need for a species to track climatechange via dispersal, or its potential to adapt to novel climatic conditions. I thereforeexplore the phylogenetic signal in climatic niches of the world's amphibians, whichserves as a surrogate quantification of niche stability. Results indicate an overalltendency of phylogenetic signal to be present in realised climatic niches, but signalstrength varies across biogeographical regions and among amphibian orders.The ability to successfully track climatic changes depends on dispersal, which is inturn influenced by ecological adaptations, such as the affiliation with a certain habitattype. A common hypothesis is that species adapted to less persistent habitats haveevolved stronger dispersal abilities. Two studies of my thesis provide evidence for thishypothesis: (1) geographical distributions of dragonflies adapted to less persistenthabitats show higher degrees of equilibrium with climatic conditions; (2) spatialpatterns of European freshwater species richness and turnover differ strongly amonghabitats, indicating a faster post-glacial re-colonization of northern Europe by speciesadapted to habitats of lower persistence.

M3 - Ph.D. thesis

BT - Species distributions and climate change:current patterns and future scenarios for biodiversity

PB - Museum Tusculanum

CY - Biologisk Institut

ER -

Species distributions and climate change:current patterns and future scenarios for biodiversity

Abstract

FN’s Verdensmål

Adgang til dokumentet

Fingeraftryk

Citationsformater