Biodiversity is rapidly declining worldwide, and this may lead to subsequent declines in ecosystem functioning and stability. Here I consider whether: (i) stabilizing species interactions, such as niche partitioning and facilitation, promote biodiversity, ecosystem functioning, and stability, and (ii) global ecosystem changes influence biodiversity, ecosystem functioning, and stability by destabilizing species interactions.
In Chapters 2 and 3, I report results from studies that used long-term data from a grassland biodiversity experiment to identify the mechanisms that promoted biodiversity, productivity, and the temporal stability of productivity. Stabilizing species interactions that favored rare species promoted productivity and temporal stability. Stabilizing species interactions that favored unproductive species promoted biodiversity and temporal stability.
In Chapters 4 and 5, I report results from a new experiment that tested whether intense grazing influenced biodiversity, ecosystem functioning, and stability by favoring common and productive species, especially in exotic species mixtures. Stabilizing species interactions maintained biodiversity and promoted ecosystem functioning in ungrazed native species mixtures. However, species interactions were destabilized, and ecosystem functioning was decreased, in both exotic and intensely grazed mixtures.
In conclusion, these results suggest that: (i) stabilizing species interactions that favor rare and unproductive species can simultaneously promote biodiversity, ecosystem functioning, and temporal stability in grasslands; and (ii) changing from native grasslands to exotic grasslands or pastures can decrease ecosystem services by destabilizing species interactions.
|Advisor:||Wilsey, Brian J.|
|Commitee:||Fairbanks, W. Sue, Harpole, W. Stan, Liebman, Matt, Moloney, Kirk|
|School:||Iowa State University|
|Department:||Ecology, Evolution, and Organismal Biology|
|School Location:||United States -- Iowa|
|Source:||DAI-B 71/09, Dissertation Abstracts International|
|Keywords:||Biodiversity, Ecosystem functioning, Grasslands, Grazing, Niche partitioning|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be