Climate-induced temporal variation in the productivity�diversity relationship

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Category: Ecological Research

Title: Climate-induced temporal variation in the productivity diversity relationship

Author: * Laughlin, D.C. , Moore, M.M.

Subject: Climate, Bunchgrass, Ponderosa pine (Pinus ponderosa)

Abstract: Spatial scales are known to influence the form of the productivitydiversity relationship, but less attention has been given to the influence of temporal scales. Interannual climatic variation in semi-arid ponderosa pinebunchgrass ecosystems causes significant year-to-year differences in herbaceous production. We hypothesized that unimodal (or ‘hump-backed’) relationships would be detected between herbaceous production and species richness in wet years, whereas positive logarithmic relationships would be detected in dry years. We analyzed nine years of herbaceous production and species richness data and used Akaike’s information criterion (AICc) to determine the weight of evidence for each model in each year. As predicted, species richness exhibited a unimodal relationship to herbaceous production in wet years; however, richness exhibited a logarithmic relationship with herbaceous production in dry years. These results suggest that competitive exclusion occurred within this semi-arid plant community in years of high production when enough moisture was available to drive abundant plant growth. Thus, just as it is important to sample broad spatial variation in production to detect the full unimodal productivitydiversity relationship, it is also important to recognize that the full unimodal curve may be undetectable in less productive dry years in semi-arid ecosystems.

Date: 2009

Type: Journal

Source: OIKOS

Identifier: 10.1111/j.1600-0706.2009.17514.x

Publisher: Blackwell Science Ltd.,

Format: PDF

Language: English