by , 16 October 2010
There’s been a whole lot of interesting stuff coming out this week related the Conference of the Parties (COP 10) for the Convention on Biological Diversity (CBD) going on in Nagoya, Japan right now. CBD’s goal was to slow the loss of biodiversity loss by 2010, but that goal was not achieved, and nations are hammering out how to revive the CBD with new goals for 2020.
At a prepatory meeting in May, governments agreed on 20 more specific draft targets, which aim to be “SMART” - specific, measurable, ambitious, realistic, and time-bound. A piece in this week’s Science, by some of the world’s biodiversity experts raised some issues that the current draft targets fail to address. Here are my thoughts on a couple:
Functional diversity is a new advance in recent years in how we quantify biodiversity science. It refers the mix of traits and functions present in an ecosystem. For an ecosystem to function properly it needs the right mix of species that perform different tasks, like pollinators, decomposers, and soil stabilizers. This measure of diversity is potentially much more important than a simple count of species. The authors argue that this concept should be explicitly integrated into the targets for 2020. The one draft target that awknowledges that biodiversity exists at different scales is #13, which says:
By 2020, the loss of genetic diversity of cultivated plants and domestic farm animals in agricultural ecosystems and of wild relatives is halted and strategies have been developed and implemented for safeguarding the genetic diversity of other priority socio-economically valuable species as well as selected wild species of plants and animals.
Genetic diversity is an important component of functional diversity, but I think this statement reflects an underappreciation of the role genetic diversity plays in ecosystems. I think it comes out of a notion that genetic diversity is neccessary for survivial of species, and thus we should ensure that our crops and a few cherished or very important species have enough genetic diversity to persist. However, genetic diversity itself often underlies the functions that species have in ecosystems. I think this should refer to something like “the genetic diversity across species in ecosystems.”
The other issue the authors raise that I’d like to comment on is uncertainty. They write:
How much diversity it is critical to maintain depends on the range of environmental conditions expected. The greater the expected variation in environmental conditions, the greater the required diversity within groups providing particular functions. Ecological functioning may change as environmental conditions change. Targets for diversity within functional groups of species should adjust with changes in expectations about the state of the environment.
It’s not that ecological functioning “may” change - it WILL change. We live in a world changing faster than anytime in history or what we know of pre-history. To me, this is the biggest thing missing from these goals - an awknowledgement that we no longer have a “baseline scenario” to return to, and no matter what we do, the world and its biodiversity will look very different in 2020 or beyond.
Perrings, C., Naeem, S., Ahrestani, F., Bunker, D., Burkill, P., Canziani, G., Elmqvist, T., Ferrati, R., Fuhrman, J., Jaksic, F., Kawabata, Z., Kinzig, A., Mace, G., Milano, F., Mooney, H., Prieur-Richard, A., Tschirhart, J., & Weisser, W. (2010). Ecosystem Services for 2020 Science, 330 (6002), 323-324 DOI: 10.1126/science.1196431