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16 Cards in this Set
- Front
- Back
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4 ways species respond to change |
extinction, movement, adaptation, persistence |
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species response to change accumulate in communities |
change in community-level attributes leads to change in ecosystem-level attributes |
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Non-Random Extinction Risk |
- habitat loss -habitat fragmentation -altered habitat quality -climate change |
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Extinction Risk in Top Predators |
- larger body size -high trophic position -low fecundity -small population abundance |
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Habitat Loss |
- not just habitat loss, but also: -fragmentation (isolation) -degradation (edge effects) |
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The SLOSS Debate |
(Single Large Or Several Small) Single Large: Island Biogeography Theory - species area relationships (S=cA^z) Several Small: - small patches cumulatively have more species -habitat heterogeneity -asynchronous dynamics |
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pros and cons of single large |
Single large: - pro:better protection for endemic species -pro:better for gene flow -con:expensive and inconvenient for human activity |
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pros and cons of several small |
pro: protects against catastrophic events pro: cheaper, and balances human needs con:limits gene flow con:more edge habitat |
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multiple drivers of habitat loss |
Edges--> habitat degradation: a decline in habitat quality edges increase as patch sze decreases |
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How can habitat connectivity ameliorate the effects of fragmentation |
-promoting the movement or dispersal of individuals -reduce rates of extinction and increase probability of population persistence -maintain local and regional diversity |
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habitat loss and isolation |
- species richness decreases with habitat loss - non-random loss of top predators -trophic cascade (prey increase) following predator decline |
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Climate change as a stressor -systematic and progressive changes in climate include |
increased temperature increased atmospheric CO2 levels changes in precipitation increased climate variability |
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Climate change as a stressor: -summary of community changes |
-phenological changes (timing of life history events)ex. plants and pollinators out of synch -species range shifts -changes in competitive outcomes -community reorganisation -->top-down or bottom-up cascades -increasing complexity through feedbacks -->uncertainty |
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climate change restructures communities - experiment |
warming altered the competitive outcomes of boreal peatland plant communities -decline in Sphagnum mosses -corresponding increases in Carex sedges |
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climate change restructures communities - experiment results
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temperature decreased bryophyte biomass and increased graminoid abundance |
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interactive of climate change effects of multiple stressors |
-land use change -biological disturbance -natural resource extraction -pollution/nutrient loading -invasive species and disease |
