Global rates of forest loss – everyone’s a bastard

29 04 2010

© A. Hesse

I’ve written rather a lot about rates of forest loss around the world, including accumulated estimates of tropical forest loss and increasing fragmentation/loss in the boreal forest (see Bradshaw et al. 2009 Front Ecol Evol & Bradshaw et al. 2009 Trends Ecol Evol). For the tropics in particular, we used the index that an area of rain forest about the size of Bangladesh (> 15 million hectares) was disappearing each year, and in Russia alone, annual decline in forest area averaged 1.1 million hectares between 1988 and 1993. Mind boggling, really.

But some of these estimates were a bit old, relied on some imprecise satellite data, and didn’t differentiate forest types well. In addition, many have questioned whether the rates are continuing and which countries are being naughty or nice with respect to forest conservation.

It was great therefore when I came across a new paper in PNAS by Hansen & colleagues entitled Quantification of global gross forest cover loss because it answered many of the latter questions.

Part of the problem in assessing worldwide forest cover loss in the past was the expense of satellite imagery, access problems, data storage and processing issues. Happily, new satellite streams and easing of access has rectified many of these limitations. Hansen & colleagues took advantage of data from the MODIS sensor to create a stratification for forest cover loss. They then used the Landsat ETM+ sensor as the primary data for quantifying gross forest cover loss for the entire planet from 2000 to 2005. They defined ‘forest cover’ as “… 25% or greater canopy closure at the Landsat pixel scale (30-m × 30-m spatial resolution) for trees > 5 m in height”.

For your reading pleasure (and conservation horror), the salient features were: Read the rest of this entry »





Make your conservation PhD relevant

23 04 2010

The other day I was approached by two PhD candidates from James Cook University in the ARC Centre of Excellence for Coral Reef Studies who requested I publish a short article they put together on making conservation PhDs relevant while achieving academic excellence. I’m delighted to say that I found the article very well written and topical, so I am pleased to present it in full here.

© J. Cham

Make your conservation PhD relevant – bridging the research-implementation gap

Duan Biggs & Tom Brewer

ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia

A recent paper, in Biotropica’s special issue on bridging the research-implementation gap (Duchelle et al. 2009) included examples of postgraduate students in the University of Florida’s Tropical Conservation and Development Program contributing to knowledge exchange with local stakeholders. The authors argue that this experience, during training, enables postgraduate students to develop their skills to confront the elaborate set of management and policy issues that will be present through their careers. We agree with Duchelle and her co-authors’ arguments, but believe that further discussion is required on finding the balance between the requirements of academic training and knowledge sharing with conservation stakeholders at the PhD level specifically.

Earning a PhD requires a novel theoretical contribution to a specific field of knowledge, and the practical value or contribution of that knowledge is of secondary importance, or irrelevant. Therefore, finding synergies between the requirements of academia and knowledge sharing can be particularly challenging at the PhD level. Yet, we believe that in an applied science like conservation, the quality of research and training will be enhanced through being more explicit about how to synergise a scientific contribution worthy of a PhD degree with related practical skills like knowledge sharing. In support of our argument, we propose the following six questions that PhD candidates, together with their academic supervisors, can consider during research design to enhance their contribution to knowledge exchange whilst meeting the requirements of academic training: Read the rest of this entry »





New April Issue of Conservation Letters out now

22 04 2010

Low intensity fire in a longleaf pine-wiregrass system

Another great line up of papers has just come out in the April Issue of Conservation Letters:

CJA Bradshaw

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A world of hurt

21 04 2010

Given it’s only a little under 3 weeks away, I thought I’d advertise an upcoming free public lecture I’m giving for the University of Adelaide‘s highly popular Research Tuesdays programme.

The Research Tuesdays team have done a fantastic job of putting together the associated promotional material, so I’m more or less going to reproduce it here.

The topic is about the global-scale evidence for declining human health from environmental degradation – it’s new research that I haven’t yet published, and so it’ll be exciting to start disseminating the amazing results my colleagues and I have found in a public forum.

So join us on 11 May at the University of Adelaide for what I promise will be an interesting (if not frightening) public lecture. Details below. Read the rest of this entry »





The spillover effect

18 04 2010

© everlessaday

The so-called ‘spillover effect’ is a long-standing debate in conservation ecology. The idea is relatively simple – put in a marine reserve (or, no-take zone, park, whatever you wish to call it as long as it restricts blanket over-fishing) and the area around the reserve eventually profits from the nearby over-production of fish (and other taxa). The idea is very attractive because even if you’re thick enough not to understand the absolute necessity of marine reserves in our age of mass, global over-exploitation, at least you might have enough grey matter to appreciate the value of more fish ‘spilling over’ into your favourite fishing area. More proposed marine reserves have been sold to the more Luddite ‘stakeholder’ this way than I care to count.

However, as attractive an idea it was, early on in the marine reserve literature (i.e., the early Devonian 1990s), there was limited (Rowley 1994; Willis et al. 2003) or only circumstantial evidence (Russ & Alcala 1996; Roberts et al. 2005) for the effect. Indeed, many have suggested that the spillover benefit, if present, depends entirely on the size of the reserve and whether adjacent areas are managed at all (Allison et al. 1996; McClanahan & Mangi 2000). Others have even suggested that marine reserves can displace fishing effort into smaller areas and change local community structure enough to facilitate invasion by exotic species (Kellner & Hastings 2009).

It is happier time now that we have more than ample evidence that marine reserves do in fact result in species spillover (e.g.,Roberts et al. 2001; Russ et al. 2004; Abesamis & Russ 2005). So it is not with any great claims of novelty that I highlight Garry Russ & Angel Alcala’s latest paper, Enhanced biodiversity beyond marine reserve boundaries: the cup spilleth-over; rather, it’s how they quantify the long-term evidence, the mechanisms for how spillover occurs and how the community changes that they deserve a mention. Read the rest of this entry »





Conservation jobs at the University of Adelaide

13 04 2010

I’m posting the advertisements for two new conservation jobs in the Global Ecology Group at the University of Adelaide.

This Australian Research Council-funded Discovery Project seeks to determine whether functional forms of spatially explicit population dynamics are generalisable across taxa with similar attributes and range limiting factors. By considering the effects of multiple interacting factors (biotic and abiotic) on the demographic determinants of species’ habitat suitability and geographic distributional limits, the research will provide a foundation on which to develop adaptive conservation strategies in response to the anticipated impacts of global change; examine the complexities and potentially irreducible uncertainties in forecasting and managing biodiversity; and identify limitations associated with different modelling approaches. Read the rest of this entry »





The maggot of the plant world – mangroves

12 04 2010

I don’t know how many of my readers have waded through a mangrove swamp before – if you have, you’ll know it’s no ‘walk in the park’. They are generally mosquito-infested with waist-deep mud, have more creepy-crawlies than you can poke a stick at, and in some places (such as my former stomping ground, the Northern Territory of Australia) are down-right dangerous due to lovelies such as saltwater crocodiles.

But, most people probably don’t know just how important mangroves are. Just like the maggot who can sicken the hardiest of individual, under-appreciated mangroves provide major ecosystem services.

For example, did you know that mangroves:

  1. Protect inland human communities from damage caused by coastal erosion and storms?
  2. Provide critical habitat for a variety of terrestrial, estuarine and marine species? Indeed, it has been estimated that ~80 % of fish catches globally depend directly or indirectly  on mangroves.
  3. Are a source and sink for nutrients and sediments for other inshore marine habitats including seagrass beds and coral reefs?
  4. Protect coasts from floods?
  5. Process nutrient and organic matter?
  6. Control sediment?
  7. Provide at least US$1.6 billion per year in ecosystem services worldwide?
  8. Sequester up to 25.5 million tonnes of carbon per year?
  9. Provide more than 10% of essential organic carbon to the global oceans?
  10. Occupy only 0.12% of the world’s total land area?

Pretty staggering, no?

So, even if you don’t like them, it’s difficult to deny that they’re important.

But, like almost every other habitats worldwide, mangroves are on the big downward slide. In a new paper in PLoS One by Polidoro & colleagues entitled The loss of species: mangrove extinction risk and geographic areas of global concern, the authors not only highlight the above benefits, they quantify just how badly the 70 mangrove species around the world are faring. Read the rest of this entry »