When weeds are wanted

31 01 2011

And in keeping with the topic of bees

© Flowergardengirl

I’ve just read a very, very cool paper in Ecology Letters about something I’ve wanted to do myself for some time. It’s a fairly specific piece of work, so it could easily be reproduced elsewhere with different species. My point though is that a hell of a lot more of these types of studies are required.

The study by Carvalheiro and colleagues entitled Natural and within-farmland biodiversity enhances crop productivity examined the role of weedy (ruderal) vegetation in supporting pollinator communities. Using sunflowers as a model crop, they showed rather convincingly how native vegetation patches interspersed amongst crop species can enhance a host of crop production measures, even when larger areas of natural habitats were far away from the crops themselves.

Based on a series of plot experiments, they tested four main hypotheses:

  1. The distance to natural habitat affects pollination visitor abundance and diversity.
  2. Plots surrounding or interspersed with ruderal vegetation affect pollinator abundance and diversity.
  3. The diversity of pollinators visiting sunflowers affects honeybee (the principal pollinators) behaviour.
  4. The diversity of pollinators affects sunflower production.

Read the rest of this entry »





A wee ditty about the bee

29 01 2011

I liked this. Another quick and entertaining look at why bees are important, why they’re crashing, and what people can do about it (at least, on a very fine scale). And it’s all done in Scottish.





Condoms instead of nature reserves

24 01 2011

Rob Dietz over at the Centre for the Advancement of the Steady State Economy thought ConservationBytes.com readers would be interested in the following post by Tim Murray (the original post was entitled What if we stopped fighting for preservation and fought economic growth instead?). There are some interesting ideas here, and I concur that because we have failed to curtail extinctions, and there’s really no evidence that conservation biology alone will be enough to save what remains (despite 50 + years of development), big ideas like these are needed. I’d be interested to read your comments.

Each time environmentalists rally to defend an endangered habitat, and finally win the battle to designate it as a park “forever,” as Nature Conservancy puts it, the economic growth machine turns to surrounding lands and exploits them ever more intensively, causing more species loss than ever before, putting even more lands under threat. For each acre of land that comes under protection, two acres are developed, and 40% of all species lie outside of parks. Nature Conservancy Canada may indeed have “saved” – at least for now – two million acres [my addendum: that's 809371 hectares], but many more millions have been ruined. And the ruin continues, until, once more, on a dozen other fronts, development comes knocking at the door of a forest, or a marsh or a valley that many hold sacred. Once again, environmentalists, fresh from an earlier conflict, drop everything to rally its defence, and once again, if they are lucky, yet another section of land is declared off-limits to logging, mining and exploration. They are like a fire brigade that never rests, running about, exhausted, trying to extinguish one brush fire after another, year after year, decade after decade, winning battles but losing the war.

Despite occasional setbacks, the growth machine continues more furiously, and finally, even lands which had been set aside “forever” come under pressure. As development gets closer, the protected land becomes more valuable, and more costly to protect. Then government, under the duress of energy and resource shortages and the dire need for royalties and revenue, caves in to allow industry a foothold, then a chunk, then another. Yosemite Park, Hamber Provincial Park, Steve Irwin Park [my addendum - even the mention of this man is an insult to biodiversity conservation]… the list goes on. There is no durable sanctuary from economic growth. Any park that is made by legislation can be unmade by legislation. Governments change and so do circumstances. But growth continues and natural capital [my addendum: see my post on this term and others] shrinks. And things are not even desperate yet. Read the rest of this entry »





Biodiversity begins at home

20 01 2011

A few months ago I was involved in a panel discussion entitled ‘Biodiversity begins at home’ held at the Royal Institution of Australia in Adelaide and sponsored by the Don Dunstan Foundation.

The main thrust of the evening was to have both academic (me & Andy Lowe) and on-the-ground, local conservationists (Sarah Lance, Craig Gillespie and Matt Turner) talk about what people can do to stem the tide of biodiversity loss. The video is now available, so I thought I’d reproduce it here. We talked about a lot of issues (from global to local scale), so if you have a spare hour, you might get something out of this. I did, but it certainly wasn’t long enough to discuss such big issues.

Warning – this was supposed to be more of a discussion and less of a talkfest; unfortunately, many of the panel members seemed to forget this and instead dominated the session. We really needed 4 hours to do this properly (but then, who would have watched the video?).

Read the rest of this entry »





Deforestation partly to blame for Queensland floods

17 01 2011

© recoverling

Last week I sent a fairly random Tweet about deforestation in south-eastern Queensland being partially responsible for the record floods there. It went more or less unnoticed, but I thought the comment deserved a proper explanation.

As many of you might know, my colleagues and I wrote an article a few years ago about the global-scale evidence for deforestation leading to a higher incidence and severity of floods in the developing world. This was fairly controversial, but it was nonetheless the first broad-scale evidence for the fabled deforestation-flood link yet published (in my not-so-humble opinion). Subsequent comment reiterated the point with new data.

Now, I will begin by saying I have no data yet to back up my Queensland-specific hypothesis, but I am contemplating a time-series paper on floods in Australia, especially after the events of the last month. This post is therefore merely a reasoned hypothesis.

The hypothesis itself is rather simple. Testing is not. I submit that the recent flooding in Australia has been exacerbated (not caused) by the rapid loss of forest cover over the last 40 years. We know that this is a particularly intense La Niña in Australia and our unusually high rainfall arises from this meteorological phenomenon, but I hypothesise that it wouldn’t have been as bad if this part of Australia hadn’t been so careless with its forest cover since the 1970s. Read the rest of this entry »





Cartoon guide to biodiversity loss X

14 01 2011

The latest batch of six cartoons…

See also full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here.

Read the rest of this entry »





S.A.F.E. = Species Ability to Forestall Extinction

8 01 2011

Note: I’ve just rehashed this post (30/03/2011) because the paper is now available online (see comment stream). Stay tuned for the media release next week. – CJAB

I’ve been more or less underground for the last 3 weeks. It has been a wonderful break (mostly) from the normally hectic pace of academic life. Thanks for all those who remain despite the recent silence.

© Ezprezzo.com

But I’m back now with a post about a paper we’ve just had accepted in Frontiers in Ecology and Environment. In my opinion it’s a leap forward in how we measure relative threat risk among species, despite some criticism.

I’ve written in past posts about the ‘magic’ minimum number of individuals that should be in a population to reduce the chance of extinction from random events. The so-called ‘minimum viable population (MVP) size’ is basically the abundance of a (connected) population below which random events take over from factors causing sustained declines (Caughley’s distinction between the ‘declining’ and ‘small’ population paradigms).

Up until the last few years, the MVP size was considered to be a population- or species-specific value, and it required very detailed demographic, genetic and biogeographical data to estimate – not something that biologists tend to have at their fingertips for most high-risk species. However, several papers published by our group (Minimum viable population size and global extinction risk are unrelated, Minimum viable population size: a meta-analysis of 30 years of published estimates and Pragmatic population viability targets in a rapidly changing world) have shown that there is in fact little variation in this number among the best-studied species; both demographic and genetic data support a number of around 5000 to avoid crossing the deadly threshold.

Now the fourth paper in this series has just been accepted (sorry, no link yet, but I’ll let you all know as soon as it is available), and it was organised and led by Reuben Clements, and co-written by me, Barry Brook and Bill Laurance.

The idea is fairly simple and it somewhat amazes me that it hasn’t been implemented before. The SAFE (Species Ability to Forestall Extinction) index is simply the distance a population is (in terms of abundance) from its MVP. In the absence of a species-specific value, we used the 5000-individual threshold. Thus, Read the rest of this entry »








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