The invisible hand of ecosystem services

4 08 2012

I’ve just spent nearly an entire week trying to get my head around ecosystem services (ES).

You’d think that would have been a given based on my experience, my research, my writings and the fact that I’ve just spent the last week with 400 ES specialists from around the world at the 5th international Ecosystem Services Partnership (ESP) Conference in Portland, Oregon, USA.

Well, prior to this week I thought I knew what ES were, but now I think I’m just a little more confused.

Of course, I’m not talking about the concept of ES or what they are (hell, I’ve written enough about them on this blog and in my papers); my problem is understanding how we as society end up valuing them in a practical, sensible and feasible way.

So I’m going to describe the ESP Conference as I saw it, and not necessarily in chronological order.

First up is the term ‘ecosystem services’ itself – horrible name, and something rammed home again after attending the conference. Most people on the planet that are not scientists (that would be nearly everyone) just might have the most tenuous and ethereal of grasps of ‘ecosystem’ in the first place, and I’d bet that 99 % of most undergraduate students couldn’t provide a comprehensive description. This is because ecosystems are mind-bogglingly, chaotically and awesomely complex. Just ask any ecosystem ecologist.

The second part of the term – services – is particularly offensive in its presumption and arrogance. It’s not like you ring up an ecosystem and get it to clean your carpets, or fill your water tank or gas cylinder. No, the natural world did not evolve to pamper humanity; we are merely part of it (and bloody efficient at modifying it, I might add).

So try to sell this ‘incredibly complex thingy’ that is ‘there to do some (intangible) shit for us’ to the public, policy makers and politicians, and you mostly get a dog’s regurgitated breakfast and some blank, slack-jawed stares. Read the rest of this entry »





Different is better

6 03 2012

I found a nice complement to my More is Better post from January where I reported the results of a new meta-analysis demonstrating how higher species evenness and diversity engendered greater forest productivity – great empirical evidence for the so-called diversity-productivity relationship.

The latest paper adding convincing evidence regarding the important role of species diversity in maintaining ecosystem function comes from Marc Cadotte and colleagues published online early in Ecology. The paper, Phylogenetic diversity promotes ecosystem stability, looks at the problem from a slightly different angle.

If you recall from Zhang and colleagues, forest plots composed of many different species were more productive than single-species stands, and more ‘even’ (i.e., a metric which includes relative abundance of each species in system) stands were more productive, and better at explaining the variance in productivity than species richness alone.

Of course, species richness is considered only a blunt instrument to measure ‘biodiversity’, with evenness providing only a slight improvement. Ideally, we should be talking about genetic diversity considering this is the fundamental unit on which most of evolutionary processes operate (i.e., genes and gene complexes).

So Cadotte and colleagues measured genetic diversity within experimental plots of grassland savanna species established in Minnesota, USA (i.e., consisting of C3 grasses, C4 grasses, legumes, non-legume herbaceous forbs and two woody species) and compared this to ecosystem ‘stability’ (i.e., above-ground biomass divided by inter-annual standard deviation). They measured genetic diversity using four different metrics:

  1. the sum of the phylogenetic branch lengths represented by a set of co-occurring species
  2. the mean nearest taxon distance = the average of the shortest phylogenetic distance for each species to its closest relative
  3. the mean pairwise distance = the average of all phylogenetic distances connecting species in the sample; and
  4. an entropic measure based on the relative distribution of evolutionary distinctiveness, measured as the amount of a species’ evolutionary history that is not shared with other species Read the rest of this entry »




More is better

18 01 2012

In one of those rare moments of perusing the latest ecological literature, I stumbled across an absolute gem, and one that has huge conservation implications. Now, I’m really no expert in this particular area of ecology, but I dare say the paper I’m about to introduce should have been published in Nature or Science (I suspect it was submitted to at least one of these journals first). It was still published in an extremely high-impact journal in ecology though – the Journal of Ecology produced by the British Ecological Society (and one in which I too have had the honour of publishing an article).

Before I get into specifics, I have to say that one thing we conservation biologists tend to bang on about is that MORE SPECIES = BETTER, regardless of the ecosystem in question. We tend to value species richness as the gold standard of ecosystem ‘health’ and ‘resilience’, whether or not there is strong empirical evidence in support. It’s as if the more-is-better mantra strikes an intuitive chord and must, by all that’s ecologically right in the world, be true.

Of course, measuring what is ‘better’ is a difficult task, especially when we are talking about complex ecosystems comprising thousands, if not millions, of species. Does ‘better’ refer to the most temporally stable, the most genetically diverse, the most resilient to perturbation, or the provider of the greatest number of functions and hence, ecosystem services?

It’s up to you, but all these things tend to be difficult to measure for a large number of species and over time scales of sufficient duration to measure change. So the default for plants (i.e., the structural framework of almost all ecosystems) I guess has come down to a simpler measure of success – ‘productivity’. This essentially means how much biomass is produced per unit area/volume per time step. It’s not a great metric, but it’s probably one of the more readily quantifiable indices.

Enter the so-called ‘diversity-productivity relationship’, or ‘DPR’, which predicts that higher plant species diversity should engender higher net productivity (otherwise known as the ‘net biodiversity effect’). Read the rest of this entry »





The balancing act of conservation

1 10 2010

Image via Wikipedia

Navjot Sodhi & Paul Ehrlich‘s book, Conservation Biology for All, has just been reviewed in Trends in Ecology and Evolution. I’ve blogged about the book before and our contributing chapter (The conservation biologist’s toolbox), so I’ll just copy the very supportive review here by Rosie Trevelyan.

Conservation Biology for All is a textbook that aims to be a one-stop shop for conservation education. The book is packed with information, is wide ranging, and includes most emerging issues that come under the umbrella of conservation biology today. Sodhi and Ehrlich have brought together a total of 75 experts from many disciplines to provide a smorgasbord of up-to-date conservation concepts and case studies. Leading conservation biologists contribute to every chapter either as authors of the main text or of the boxes that give real life examples of the conservation issue being covered. The boxes add hugely to the information included in each chapter, and many are well worth returning to on their own. Read the rest of this entry »





The lost world – freshwater biodiversity conservation

6 09 2010

Even the most obtuse, right-wing, head-in-the-sand, consumption-driven, anti-environment yob would at least admit that they’ve heard of forest conservation, the plight of whales (more on that little waste of conservation resources later) and climate change. Whether or not they believe these issues are important (or even occurring) is beside the point – the fact that this particular auto-sodomist I’ve described is aware of the issues is at least testament to growing concern among the general populace.

But so many issues in conservation science go unnoticed even by the most environmentally aware. Today’s post covers just one topic (I’ve covered others, such as mangroves and kelp forests) – freshwater biodiversity.

The issue is brought to light by a paper recently published online in Conservation Letters by Thieme and colleagues entitled Exposure of Africa’s freshwater biodiversity to a changing climate.

Sure, many people are starting to get very worried about freshwater availability for human consumption (and this couldn’t be more of an issue in Australia at the moment) – and I fully agree that we should be worried. However, let’s not forget that so many species other than humans depend on healthy freshwater ecosystems to persist, which feed back in turn to human benefits through freshwater filtering, fisheries production and arable soil accumulation.

Just like for the provision of human uses (irrigation, direct water consumption, etc.), a freshwater system’s flow regime is paramount for maintaining its biodiversity. If you stuff up the flow regime too much, then regardless of the amount of total water available, biodiversity will suffer accordingly.

Glen Canyon Dam

Image by James Marvin Phelps (mandj98) via Flickr

Thieme and colleagues focus specifically on African freshwater systems, but the same problems are being seen worldwide (e.g., Australia’s Murray-Darling system, North America’s Colorado River system). And this is only going to get worse as climate change robs certain areas of historical rainfall. To address the gap in knowledge, the authors used modelled changes in mean annual runoff and discharge to determine fish species affected by 2050.

The discharge/runoff results were: Read the rest of this entry »





Simple educational tool to explain biodiversity

26 08 2010

I just came across this little educational video explaining what biodiversity is, what it does, and what we’re doing to it. If you’re looking to explain biodiversity and its importance to someone, this is a good place to start. Not a bad tool for school children either.




CJA Bradshaw





100 actions to slow biodiversity loss

19 08 2010

I received an email a few days ago from Guillaume Chapron of the Swedish University of Agricultural Sciences (Sveriges lantbruksuniversitet) asking me to promote his ‘Biodiversity 100‘ campaign on ConservationBytes.com. I think it’s an interesting initiative, and so I’ll gladly spread the word.

Teaming up with George Monbiot of The Guardian, the Biodiversity 100 campaign seeks to encourage scientists and others to compile a list of 100 tasks that G20 governments should undertake to prove their commitment to tackling the biodiversity crisis.

Dr. Chapron writes: Read the rest of this entry »