"The More Ecosystems Services, The Greater The Biodiversity Needed to Underpin Those Services"
11 Jul, 2007 07:01 pm
Andy Hector is a specialist on biodiversity. According to his study published today in Nature, biodiversity plays a more important role in ecosystem functioning or services than previously thought.
What does the report mean?
Studies to date, including previous work by myself, have tried to look at the relationship between biodiversity- numbers and types of species- and ecosystem functioning, or more popularly these days following the millennium ecosystem assessment, known as ecosystem services. Humans derive certain benefits from the natural environment and the ecosystem services. Previous research has found a positive relationship between biodiversity and ecosystem services, but one that saturates off if you like, that is some of the biodiversity appears to be redundant.
What we wanted to ask was, ‘Does this result depend on the fact that previous research has looked on one ecosystem process at a time?’. What we wanted to do was to try and take into account all the ecosystem services at the same time. So, we devised a new analysis, which enabled us to do that. Once we did that we found that the more ecosystems that we considered in the analysis the greater the biodiversity needed to underpin those services.
How did you conduct your study?
We published the data online a couple of years ago. The data are based on 7 ecosystem processes or services from European grasslands. We collected the data as part of a European Commission funded project that was under the acronym ‘Biodepth’. Once we published this data online we thought, ‘Well this is all well and good, but we’ve gone through one ecosystem service at a time. Can we now look at them all together?’. We came up with a new analysis that enabled us to do that. The key part of it was identifying the groups of species that identify each ecosystem service. Once we had done that we looked at the degree of overlap within the groups of species that include each pair of processes. Perhaps the key result was that we found the proportional degree of overlap was 0.2 to 0.5. In other words, when we looked at a pair of ecosystem processes and the groups of species that were important for those processes, and found that there was at most half of the species shared in common. To put it simply, different ecosystem services require different species.
To what degree do you believe the loss of biodiversity is underestimated?
It’s very hard to say at this stage, because our study is really the first of its type. In a way it’s partly important to just to bring the idea to peoples attention and alert them that they need to take this into account.
Inteview by: Christopher Le Coq
Andy Hector is a professor at the Institute of Environmental Studies at the University of Zurich in Switzerland.