Previous Article |
Table of Contents
| Next Article 
BIOLOGICAL SCIENCES / ECOLOGY
Functional consequences of realistic biodiversity changes in a marine ecosystem
,
*Marine Science Center, Northeastern University, 430 Nahant Road, Nahant, MA 01908; Bodega Marine Laboratory, University of California at Davis, PO Box 247, Bodega Bay, CA 94923; Department of Biology, New Mexico Institute of Mining and Technology, Socorro, NM 87801; and ¶Department of Biology, Duke University, Durham, NC 27708
Edited by Peter Vitousek, Stanford University, Stanford, CA, and approved November 21, 2007 (received for review May 2, 2007)
Declines in biodiversity have prompted concern over the consequences of species loss for the goods and services provided by natural ecosystems. However, relatively few studies have evaluated the functional consequences of realistic, nonrandom changes in biodiversity. Instead, most designs have used randomly selected assemblages from a local species pool to construct diversity gradients. It is therefore difficult, based on current evidence, to predict the functional consequences of realistic declines in biodiversity. In this study, we used tide pool microcosms to demonstrate that the effects of real-world changes in biodiversity may be very different from those of random diversity changes. Specifically, we measured the relationship between the diversity of a seaweed assemblage and its ability to use nitrogen, a key limiting nutrient in nearshore marine systems. We quantified nitrogen uptake using both experimental and model seaweed assemblages and found that natural increases in diversity resulted in enhanced rates of nitrogen use, whereas random diversity changes had no effect on nitrogen uptake. Our results suggest that understanding the real-world consequences of declining biodiversity will require addressing changes in species performance along natural diversity gradients and understanding the relationships between species' susceptibility to loss and their contributions to ecosystem functioning.
ammonium | diversity | ecosystem function | nitrogen | species identity
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at www.pnas.org/cgi/content/full/0704103105/DC1.
To whom correspondence should be addressed. E-mail: m.bracken{at}neu.edu
© 2008 by The National Academy of Sciences of the USA
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg What's this?
