Functional biotic homogenization of bird communities in disturbed landscapes
Article first published online: 22 NOV 2007
© 2007 The Authors
Global Ecology and Biogeography
Volume 17, Issue 2, pages 252–261, March 2008
How to Cite
Devictor, V., Julliard, R., Clavel, J., Jiguet, F., Lee, A. and Couvet, D. (2008), Functional biotic homogenization of bird communities in disturbed landscapes. Global Ecology and Biogeography, 17: 252–261. doi: 10.1111/j.1466-8238.2007.00364.x
- Issue published online: 22 NOV 2007
- Article first published online: 22 NOV 2007
- Biodiversity indicator;
- breeding bird survey;
- biotic homogenization;
- landscape fragmentation;
- landscape disturbance;
- 2010 target
Aim Worldwide, functional homogenization is now considered to be one of the most prominent forms of biotic impoverishment induced by current global changes. Yet this process has hardly been quantified on a large scale through simple indices, and the connection between landscape disturbance and functional homogenization has hardly been established. Here we test whether changes in land use and landscape fragmentation are associated with functional homogenization of bird communities at a national scale.
Methods We estimated functional homogenization of a community as the average specialization of the species present in that community. We studied the spatial variation of this community specialization index (CSI) using 1028 replicates from the French Breeding Bird Survey along spatial gradients of landscape fragmentation and recent landscape disturbance, measured independently, and accounting for spatial autocorrelation.
Results The CSI was very sensitive to both measures of environmental degradation: on average, 23% of the difference in the CSI values between two sample sites was attributed to the difference in fragmentation and the disturbance between sites. This negative correlation between CSI and sources of landscape degradation was consistent over various habitats and biogeographical zones.
Main conclusions We demonstrate that the functional homogenization of bird communities is strongly positively correlated to landscape disturbance and fragmentation. We suggest that the CSI is particularly effective for measuring functional homogenization on both local and global scales for any sort of organism and with abundance or presence–absence data.