You are not currently logged in.
Access JSTOR through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Interactive Effects of Grazing and Enrichment on Diversity; Conceptual Implications of a Rocky Intertidal Experiment
Anne D. Guerry
Vol. 117, No. 8 (Aug., 2008), pp. 1185-1196
Stable URL: http://www.jstor.org/stable/40235511
Page Count: 12
You can always find the topics here!Topics: Algae, Productivity, Invertebrates, Nutrient nutrient interactions, Grazing, Coastal ecology, Macroalgae, Marine ecology, Synecology, Species
Were these topics helpful?See something inaccurate? Let us know!
Select the topics that are inaccurate.
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
Understanding the ways in which consumers and productivity act and interact to yield differences in diversity is of primary conceptual and pragmatic importance in a world in which humans are simultaneously changing ecological communities and substantially altering the availability of nutrients. Here, I used macroalgal communities on rocky reefs to examine the effects of both limpet grazing and nutrient enrichment on algal diversity throughout almost two years of succession. The experimental design included three levels each of grazing and nutrients, with unglazed terracotta pots attached to the rock as replicate plots in a high intertidal limpet-macroalgal community. Grazing effects varied by year. During the first year, grazing effects were context-dependent with limpets resulting in lower species richness, especially at the highest level of limpet density. However, at this highest level of limpet density, high enrichment counteracted the negative effect of limpets such that diversity was similar to that in treatments with lower limpet densities. In the second year, grazing generally decreased richness, regardless of enrichment. The results of this experiment are partially consistent with the grazer-reversal hypothesis-grazing decreased richness in low nutrient conditions and this effect was neutralized (rather than reversed) under high enrichment. Inconsistencies with model predictions may be explained by the apparent unresponsiveness of algal productivity to experimental enrichment, the unique substrate-scraping feeding mechanisms of limpets, and potentially limited propagule supply.
Oikos © 2008 Nordic Society Oikos