This blog is the summary of a presentation that I presented on 10 March at the Fenner Conference on the Environment titled "The Art and Science of Good Decision Making". I will prepare a journal article on this subject later this year.
“The question is not which refuge system contains more total species, but which contains more species that would be doomed to extinction in the absence of refuges.” Jared Diamond (1976)
Many metrics currently used to prioritise expenditure for conservation simply rank sites according to their habitat quality. That is, higher quality habitat are afforded higher scores.
This is not only a waste of money, but can be detrimental to conservation.
By prioritising funding based on habitat quality alone we may be funding sites in which additional investment makes little practical difference to conservation. For example, what is the point of investing in a remnant that is in good quality, is resilient, can't be cleared because of stronger land clearing laws and has poor capability for permitted land uses (e.g. stock grazing, logging)? This site will have the same conservation value whether it is funded for conservation or not.
The corollary of this strategy is that poor quality sites, which are often under considerable threat, remain unfunded for conservation, and thus continue to degrade over time.
I will demonstrate this with an example.
In a study I am currently preparing for publication with Anthony Weinberg and Stephen Bonser, 46% of remnants in an agricultural landscape contained no eucalypt regeneration. These are typically the smaller remnants on privately owned farmland that are grazed continuously. They are doomed to further degradation and loss under the status quo. Larger remnants and remnants on public land (regardless of tenure) typically supported regeneration.
A "conservation" strategy that prioritises funding to larger, high quality remnants in this landscape will result in the eventual loss of about half of all remnants (i.e. all the smaller remnants in which regeneration is not occurring).
The best conservation outcomes in this landscape will be achieved by funding a change to grazing regimes in the smaller remnants on private land - provided only sites are selected for investment if they are likely to respond to the change of management.
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Nice blog! Certainly the best (and only) one I've ever checked out. It needs some comments though, so here goes…
ReplyDeleteI agree with your point and think you can make a very strong case to support this argument. I do think it would be a good idea to define the conservation context in which it applies. There are many places in the world where rapid destruction of high quality habitat is the major ecological problem. In such cases, protection of high quality habitat that would otherwise be lost is clearly a priority. In the situation you describe, we are presumably looking at a negligible net loss of habitat area but a gradual deterioration of habitat quality. As you’ve said, within this context, protection of areas that are already relatively ‘safe’ achieves little in the long term.
Having just written all this, it’s pretty obvious and you’re probably thinking “Duh…”. However, an important ‘universal’ message that could come out of your argument is that conservation strategies must identify and address the major threatening processes relevant to that environment. There’s nothing revolutionary in saying that, but it’s alarming how often it doesn’t seem to happen.