Are biodiverse ecosystems more stable? Early work: Yes MacArthur - PowerPoint PPT Presentation

Are biodiverse ecosystems more stable? Early work: Yes MacArthur 1955, Elton 1958, Hutchinson 1959, Margalef 1969. Anecdotal evidence. Reviewed in McCann 2000

Are biodiverse ecosystems more stable? Early work: Yes MacArthur 1955, Elton 1958, Hutchinson 1959, Margalef 1969. Anecdotal evidence. May 1974: No May 1974: No. Mathematical models suggested that communities with more species were less stable. with more species were less stable. Reviewed in McCann 2000

Are biodiverse ecosystems more stable? Early work: Yes MacArthur 1955, Elton 1958, Hutchinson 1959, Margalef 1969. Anecdotal evidence. May 1974: No May 1974: No. Mathematical models suggested that communities with more species were less stable. with more species were less stable. Collective response: Huh? That’s weird. Pimm 1984: Our vocabulary is deficient. We’re t lki talking about different things. b t diff t thi Reviewed in McCann 2000

Are biodiverse ecosystems more stable? 1990s – 2000s: Tilman: Experimental approaches. “Random community assembly”. photo courtesy Cedar Creek LTER, U Minnesota

Are biodiverse ecosystems more stable? 1990s – 2000s: Tilman: Experimental approaches. “Random community assembly”. 2005: Hooper et al: “Effects of biodiversity on ecosystem functioning: A consensus of current ecosystem functioning: A consensus of current knowledge” (ESA Report)

Are biodiverse ecosystems more stable? Hooper et al 2005 (ESA Report): “Based on our review of the scientific literature, we are certain of the following conclusions: … (5) More species are needed to insure a stable supply of ecosystem goods and services as spatial supply of ecosystem goods and services as spatial and temporal variability increases, which typically occurs as longer time periods and larger areas are considered.”

Are biodiverse ecosystems more stable? Hooper et al 2005 (ESA Report): “We have high confidence in the following conclusions: … (3) Having a range of species that respond differently to different environmental perturbations differently to different environmental perturbations can stabilize ecosystem process rates in response to disturbances and variation in abiotic conditions.”

Are biodiverse ecosystems more stable? Hooper et al 2005 (ESA Report): “Uncertainties remain and further research is necessary in the following areas: … (3) Theoretical work on stability has outpaced experimental work, especially field research. We experimental work, especially field research. We need long ‐ term experiments to be able to assess temporal stability, as well as experimental perturbations to assess response to and recovery from a variety of disturbances.”