Published online by Cambridge University Press: 17 September 2009
SUMMARY
Empirical and theoretical evidence suggests that the rate and magnitude of below-ground ecosystem processes depend on the architecture of the detrital food web. Although some species have an indisputable keystone role in determining soil processes, there is little evidence suggesting that species diversity per se has any major influence at a system level.
We review studies that shed light on the degree of functional redundancy in decomposer food webs – from microbes to soil fauna. As well as emphasising the need to define accurately functional redundancy (using both ‘Hutchinsonian ecological niche’ and ‘functional niche’ concepts), we also focus on features specific to soils and their communities that may affect the levels at which functional redundancy exists in detrital food webs.
We also explore the levels of ecological hierarchy (from species to trophic levels) at which diversity differences manifest themselves as altered ecosystem-level processes.
We conclude that the high degree of generalism – even omnivory – in resource-use among decomposer organisms, and the highly heterogeneous environment of soil organisms (reducing competition between species, thus allowing taxa with similar feeding preferences/environmental tolerances to co-exist), play major roles in explaining the high degree of functional complementarity found in decomposer communities.
Introduction
The accelerating loss of biodiversity in various global ecosystems (Lawton & May 1995; Lawton 2000; Schmid et al. 2002) and recent findings emphasising the close linkage between the above- and below-ground components of ecosystems (Wardle 2002) have led many ecologists to direct their interest to soil ecology and processes.
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.