Login | Request Account (DAF staff only)

Do constrained immigration rates and high β diversity explain contrasting productivity–diversity patterns measured at different scales?

View Altmetrics

Connolly, N. M. and Pearson, R. G. (2020) Do constrained immigration rates and high β diversity explain contrasting productivity–diversity patterns measured at different scales? Oecologia . ISSN 1432-1939

[img]
Preview
PDF
1MB

Article Link(s): https://doi.org/10.1007/s00442-020-04766-x

Abstract

The relationship between productivity and diversity is controversial because of disparity between unimodal and monotonic patterns, especially when occurring simultaneously at different scales. We used stream-side artificial channels to investigate how the availability of a major resource (leaf litter) affected stream invertebrate abundance and diversity at leaf-pack and whole-channel scales. At the larger scale, invertebrate diversity increased monotonically with increasing litter resource density, whereas at the smaller scale the relationship was hump-shaped, in keeping with reports in the literature. This divergence at higher resource levels suggests that multiple mechanisms may be operating. Our results indicate that consistently high species turnover (β diversity) caused the monotonic pattern because of a species-area or “sampling effect” in which new species accumulate with increasing number of samples. The hump-shaped pattern was due to constrained immigration because of a “dilution effect” in which a limited number of immigrants is spread out among the increasing number of available patches. We propose that the relationship between productivity or resource availability and α diversity is generally hump-shaped and the scale-dependent contrast in the relationship only arises where the species pool is large and β diversity is high. Differences in β diversity may, therefore, explain some of the contrasting patterns in the productivity–diversity relationship previously reported.We suggest that continuing immigration by rare taxa is important in sustaining species diversity when productivity is high. The hump-shaped pattern has implications for the impact of anthropogenic ecosystem enrichment on species diversity.

Item Type:Article
Business groups:Agriculture
Additional Information:Open access
Keywords:Sampling effect Dilution effect Monotonic pattern Humped pattern Stream assemblage
Subjects:Agriculture > Agriculture (General) > Agricultural economics
Science > Statistics > Mathematical statistics
Deposited On:06 Oct 2020 01:33
Last Modified:06 Oct 2020 01:33

Repository Staff Only: item control page

Downloads

Downloads per month over past year

View more statistics