Litter decomposition in highly urbanized rivers: influence of restoration on ecosystem function
Smith, Benjamin; Chadwick, Michael A.
published: Oct 1, 2014
ArtNo. ESP141018501002, Price: 29.00 €
This study examined ecosystem function via measures of litter decomposition in restored and unrestored reaches in a range of urban rivers in Greater London. Land use at the study rivers was 47–93 % urban cover, while restorations comprised activities that improved flow conditions and remeandered channels. Using standard litter bag techniques, we found rates of decomposition ranged from 0.001 to 0.012 per degree day. However, no differences in litter decomposition rates or associated macroinvertebrate community structure were found between restored and unrestored reaches. These findings illustrate that river restoration may not necessarily lead to ecological enhancement even if there are highly valued aesthetic improvements. We suggest the lack of an ecological response in our study reinforces the need for a better understanding of the outcomes expected from restoration activities in urban rivers. Further, our research highlights the need for a better understanding of the goals of river restoration, and the potential role that stochastic events play in regulating both the potential for restoration and the basic ecology of urban rivers.