Limitations and Connections

Thursday, August 20, 2009

Today I saw a thought-provoking talk about the efficacy of restoration projects.  Margaret Palmer recounted that restoration projects have increased significantly in the last 20 yrs in the U.S. In her review of published studies, she examined whether stream restoration projects were actually improving biodiversity and found that in the majority of cases they had not.  Similarly, wetland restoration projects had not improved biodiversity.  This led Palmer to ask what was the problem with these restoration projects?  She concluded that restoring streams and wetlands are complex problems that may require a different approach than that which is used predominantly today.  She cited a case study of the Chesapeake Bay where lowering nitrogen was identified as a major concern.  Instead of restoring the stream to an earlier reference condition, a completely new design was implemented to accomplish lower nitrogen runoff to the bay.  The novel design with a series of holding ponds did reduce nitrogen, but at a high cost.  She estimated that 1 kg of nitrogen removed from the system cost $14,000.  Yet there was 300 million kg of N input to the system.   She noted that asking people to stop fertilizing their lawns would probably go farther to reduce nitrogen in the stream for less money.  She noted that the idea that restoration can fix all problems may actually not be true.  We may have to accept the limitations of our scientific knowledge and our ability to restore degraded systems, plus each person may have to increase individual conservation efforts. 

This talk tied back to another plenary talk by Peter Vitousek, who showed an example of Ju et al (2009) which demonstrated that farmers in their study were applying twice the amount of nitrogen to their crops than was required.  He rightly pointed out that demonstrating this was one thing, which changing the behavior and beliefs of the farmers was yet another. 

These two talks link to some of my current interests in connecting fragments of pine rocklands. The concerns that Palmer and Vitousek raise about changing human attitudes are also relevant to our local Miami project.  Can we change the perception that beauty isn’t always a green lawn? 

Here in Brisbane there is an interesting architectural tool for creating connectivity right in the busy district near the convention center and our hotel.  Below is a beautiful picture of the lovely South Bank boardwalk area.  I like the fluid architecture of this walkway and the way it successfully creates a friendly ambience connecting the South Bank. 


Tonight we head to a discussion about carbon emissions trading.  It should be a stimulating discussion about the commercial value of nature and whether this scheme will reverse negative trends in biodiversity loss.