If biodiversity is so important, why is Europe not languishing?

17 03 2014

collapseI don’t often respond to many comments on this blog unless they are really, really good questions (and if I think I have the answers). Even rarer is devoting an entire post to answering a question. The other day, I received a real cracker, and so I think it deserves a highlighted response.

Two days ago, a certain ‘P. Basu’ asked this in response to my last blog post (Lose biodiversity and you’ll get sick):

I am an Indian who lived in Germany for quite a long period. Now, if I am not grossly mistaken, once upon a time Germany and other west european countries had large tracts of “real” forests with bears, wolves, foxes and other animals (both carnivore and herbivore). Bear has completely disappeared from these countries with the advent of industrialization. A few wolves have been kept in more or less artificially created forests. Foxes, deer and hares, fortunately, do still exist. My question is, how come these countries are still so well off – not only from the point of view of economy but also from the angle of public health despite the loss of large tracts of natural forests? Or is it that modern science and a health conscious society can compensate the loss of biodiversity.

“Well”, I thought to myself, “Bloody good question”.

I have come across this genre of question before, but usually under more hostile circumstances when an overtly right-wing respondent (hell, let’s call a spade a spade – a ‘completely selfish arsehole’) has challenged me on the ‘value of nature’ logic (I’m not for a moment suggesting that P. Basu is this sort of person; on the contrary, he politely asked an extremely important question that requires an answer). The comeback generally goes something like this: “If biodiversity is so important, why aren’t super-developed countries wallowing in economic and social ruin because they’ve degraded their own life-support systems? Clearly you must be wrong, Sir.”

There have been discussions in the ecological and sustainability literature that have attempted to answer this, but I’ll give it a shot here for the benefit of CB.com readers. Read the rest of this entry »





Cleaning up the rubbish: Australian megafauna extinctions

15 11 2013

diprotodonA few weeks ago I wrote a post about how to run the perfect scientific workshop, which most of you thought was a good set of tips (bizarrely, one person was quite upset with the message; I saved him the embarrassment of looking stupid online and refrained from publishing his comment).

As I mentioned at the end of post, the stimulus for the topic was a particularly wonderful workshop 12 of us attended at beautiful Linnaeus Estate on the northern coast of New South Wales (see Point 5 in the ‘workshop tips’ post).

But why did a group of ecological modellers (me, Barry Brook, Salvador Herrando-Pérez, Fréd Saltré, Chris Johnson, Nick Beeton), ancient DNA specialists (Alan Cooper), palaeontologists (Gav Prideaux), fossil dating specialists (Dizzy Gillespie, Bert Roberts, Zenobia Jacobs) and palaeo-climatologists (Michael Bird, Chris Turney [in absentia]) get together in the first place? Hint: it wasn’t just the for the beautiful beach and good wine.

I hate to say it – mainly because it deserves as little attention as possible – but the main reason is that we needed to clean up a bit of rubbish. The rubbish in question being the latest bit of excrescence growing on that accumulating heap produced by a certain team of palaeontologists promulgating their ‘it’s all about the climate or nothing’ broken record.

Read the rest of this entry »





Learning from danger

13 05 2013
Guanaco fleeing
Study vehicle, a group of vicuñas and a guanaco in San Guillermo National Park (San Juan, Argentina) [courtesy of Marco Escudero]. Guanacos and vicuñas are native to South America, and are the ancestors of domesticated llamas and alpacas – which are exploited for their meat, milk and wool. Both species form monotypic genera. They have discontinuous distributions in Argentina, Bolivia, Chile and Peru, with introduced populations in Paraguay (guanaco) and Ecuador (vicuña). Population estimates are > 500,000 (guanaco) and > 300,000 (vicuña), the latter restricted to high-altitude ecosystems. They are ‘Least Concern’ for the IUCN but, given their low population growth rates (fertility = 1 offspring/female/yr), guanacos and vicuñas are targeted by conservation programs in all their native countries.

Many of us might have stumbled twice on the same stone, yet learnt to be wary of future situations of similar risk. Likewise, wild animals can be predisposed to flee when faced with already known predators (or threats in general). The type and magnitude of their evasive response depends on predator distance, speed and body size (1). Regardless, prey need to assess predation risk in a matter of seconds (or even shorter than that), i.e., balancing the benefits and costs of fleeing.

The benefits all boil down to survival, but the costs might include moving away from offspring, loss of access to fresh and abundant food, or spending precious metabolic energy (2). The methods ecologists use to study animal flight behaviour in the wild are rife with nuisances (3), yet they represent a tool for quantifying wildlife stress resulting from a variety of human activities.

Equipped with our modern technological kit (weapons, vehicles, GPS, etc.), humans behave like genuine predators and can trigger the range of flight behaviours displayed by their potential prey. In that context, Emiliano Donadio and Steve Burskirk (4) studied flight behaviour of guanacos (Lama guanicoe) and vicuñas (Vicugna vicugna) in the Argentinean open plains (‘llanos’). They monitored 2 protected areas under weak surveillance and subject to illegal hunting: the Laguna Brava Provincial Reserve and the San Guillermo Biosphere Reserve (treatment = H); and one area free of hunting and only exposed to guided visits with strict entry/exit times: the San Guillermo National Park (treatment = NH). The ecologists did 3 transects per study area. When they encountered a group of camelids, they classified three types of flight behaviour (alert without fleeing, walking away, galloping away), and measured flight time (between vehicle detection and initiation of flight behaviour) and flight distance (between the vehicle and the individuals when initiating flight behaviour). Read the rest of this entry »





Tropical protected areas still in trouble

8 10 2012

© P. Harris

There’s nothing like a bit of good, intelligent and respectful debate in science.

After the publication in Nature of our paper on tropical protected areas (Averting biodiversity collapse in tropical forest protected areas), some interesting discussion has ensued regarding some of our assumptions and validations.

As is their wont, Nature declined to publish these comments (and our responses) in the journal itself, but the new commenting feature at Nature.com allowed the exchange to be published online with the paper. Cognisant that probably few people will read this exchange, Bill Laurance and I decided to reproduce them here in full for your intellectual pleasure. Any further comments? We’d be keen to hear them.

COMMENT #1 (by Hari Sridhar of the Centre for Ecological Sciences at the Indian Institute of Science in Bangalore)

In this paper, Laurance and co-authors have tapped the expert opinions of ‘veteran field biologists and environmental scientists’ to understand the health of protected areas in the tropics worldwide. This is a novel and interesting approach and the dataset they have gathered is very impressive. Given that expert opinion can be subject to all kinds of biases and errors, it is crucial to demonstrate that expert opinion matches empirical reality. While the authors have tried to do this by comparing their results with empirical time-series datasets, I argue that their comparison does not serve the purpose of an independent validation.

Using 59 available time-series datasets from 37 sources (journal papers, books, reports etc.), the authors find a fairly good match between expert opinion and empirical data (in 51/59 cases, expert opinion matched empirically-derived trend). For this comparison to serve as an independent validation, it is crucial that the experts were unaware of the empirical trends at the time of the interviews. However, this is unlikely to be true because, in most cases, the experts themselves were involved in the collection of the time-series datasets (at least 43/59 to my knowledge, from a scan of references in Supplementary Table 1). In other words, the same experts whose opinions were being validated were involved in collection of the data used for validation.

OUR RESPONSE (William F. Laurance, Corey J. A. Bradshaw, Susan G. Laurance)

Sridhar raises a relevant point but one that, on careful examination, does not weaken our validation analysis. Read the rest of this entry »





Threats to biodiversity insurance from protected areas

26 07 2012

A red-eyed tree frog (Agalychnis callidryas) from Barro Colorado Island in Panama. This small island, just 1500 ha (3700 acres) in area, is one of the tropical protected areas evaluated in this study (photo © Christian Ziegler <zieglerphoto@yahoo.co>, Smithsonian Tropical Research Institute). Note: It is prohibited for any third party or agency to use or license this image; any use other then described above shall be subject to usage fees as determined solely by the photographer.

Much of conservation science boils down to good decision making: when, where and how we ‘set aside’ terrestrial or marine areas for specific protection against the ravages of human endeavour. This is the basis for the entire sub-discipline of conservation planning and prioritisation, and features prominantly in most aspects of applied conservation and restoration.

In other words, we do all this science to determine where we should emplace protected areas, lobby for getting more land and sea set aside so that we have ‘representative’ amounts (i.e., to prevent extinctions), and argue over the best way to manage these areas once established.

But what if this pinnacle of conservation achievement is itself under threat? What if many of our protected areas are struggling to insure biodiversity against human consumption? Well, it’d be a scary prospect, to say the least.

Think of it this way. We buy insurance policies to buffer our investments against tragedy; this applies to everything from our houses, worldly possessions, cars, livestock, health, to forest carbon stores. We buy the policies to give us peace of mind that in the event of a disaster, we’ll be bailed out of the mess with a much-needed cash injection. But what if following the disaster we learn that the policy is no good? What if there isn’t enough pay-out to fix the mess?

In biodiversity conservation, our ‘insurance’ is largely provided by protected areas. We believe that come what may, at least in these (relatively) rare places, biodiversity will persist despite our relentless consumerism.

Unfortunately, what we believe isn’t necessarily true.

Today I’m both proud and alarmed to present our latest research on the performance of tropical protected areas around the world. Published online in Nature this morning (evening, for you Europeans) is the 216-author (yes, that is correct – 216 of us) paper entitled “Averting biodiversity collapse in tropical forest protected areas” led by Bill Laurance. Read the rest of this entry »





The seeds of tropical forest destruction

22 01 2012

Bill Laurance asked me to reproduce his latest piece originally published at Yale University‘s Environment 360 website.

We live in an era of unprecedented road and highway expansion — an era in which many of the world’s last tropical wildernesses, from the Amazon to Borneo to the Congo Basin, have been penetrated by roads. This surge in road building is being driven not only by national plans for infrastructure expansion, but by industrial timber, oil, gas, and mineral projects in the tropics.

Few areas are unaffected. Brazil is currently building 7,500 km of new paved highways that crisscross the Amazon basin. Three major new highways are cutting across the towering Andes mountains, providing a direct link for timber and agricultural exports from the Amazon to resource-hungry Pacific Rim nations, such as China. And in the Congo basin, a recent satellite study found a burgeoning network of more than 50,000 km of new logging roads. These are but a small sample of the vast number of new tropical roads, which inevitably open up previously intact tropical forests to a host of extractive and economic activities.

“Roads,” said the eminent ecologist Thomas Lovejoy, “are the seeds of tropical forest destruction.”

Despite their environmental costs, the economic incentives to drive roads into tropical wilderness are strong. Governments view roads as a cost-effective means to promote economic development and access natural No other region can match the tropics for the sheer scale and pace of road expansion. resources. Local communities in remote areas often demand new roads to improve access to markets and medical services. And geopolitically, new roads can be used to help secure resource-rich frontier regions. India, for instance, is currently constructing and upgrading roads to tighten its hold on Arunachal Pradesh state, over which it and China formerly fought a war.

Read the rest of this entry »





No substitute for primary forest

15 09 2011

© Romulo Fotos http://goo.gl/CrAsE

A little over five years ago, a controversial and spectacularly erroneous paper appeared in the tropical ecology journal Biotropica, the flagship journal of the Association for Tropical Biology and Conservation. Now, I’m normally a fan of Biotropica (I have both published there several times and acted as a Subject Editor for several years), but we couldn’t let that paper’s conclusions go unchallenged.

That paper was ‘The future of tropical forest species‘ by Joseph Wright and Helene Muller-Landau, which essentially concluded that the severe deforestation and degradation of tropical forests was not as big a deal as nearly all the rest of the conservation biology community had concluded (remind you of climate change at all?), and that regenerating, degraded and secondary forests would suffice to preserve the enormity and majority of dependent tropical biodiversity.

What rubbish.

Our response, and those of many others (including from Toby Gardner and colleagues and William Laurance), were fast and furious, essentially destroying the argument so utterly that I think most people merely moved on. We know for a fact that tropical biodiversity is waning rapidly, and in many parts of the world, it is absolutely [insert expletive here]. However, the argument has reared its ugly head again and again over the intervening years, so it’s high time we bury this particular nonsense once and for all.

In fact, a few anecdotes are worthy of mention here. Navjot once told me one story about the time when both he and Wright were invited to the same symposium around the time of the initial dust-up in Biotropica. Being Navjot, he tore off strips from Wright in public for his outrageous and unsubstantiated claims – something to which Wright didn’t take too kindly.  On the way home, the two shared the same flight, and apparently Wright refused to acknowledge Navjot’s existence and only glared looks that could kill (hang on – maybe that had something to do with Navjot’s recent and untimely death? Who knows?). Similar public stoushes have been chronicled between Wright and Bill Laurance.

Back to the story. I recall a particular coffee discussion at the National University of Singapore between Navjot Sodhi (may his legacy endure), Barry Brook and me some time later where we planned the idea of a large meta-analysis to compare degraded and ‘primary’ (not overly disturbed) forests. The ideas were fairly fuzzy back then, but Navjot didn’t drop the ball for a moment. He immediately went out and got Tien Ming Lee and his new PhD student, Luke Gibson, to start compiling the necessary studies. It was a thankless job that took several years.

However, the fruits of that labour have now just been published in Nature: ‘Primary forests are irreplaceable for sustaining tropical biodiversity‘, led by Luke and Tien Ming, along with Lian Pin Koh, Barry Brook, Toby Gardner, Jos Barlow, Carlos Peres, me, Bill Laurance, Tom Lovejoy and of course, Navjot Sodhi [side note: Navjot died during the review and didn't survive to hear the good news that the paper was finally accepted].

Using data from 138 studies from Asia, South America and Africa comprising 2220 pair-wise comparisons of biodiversity ‘values’ between forests that had undergone some sort of disturbance (everything from selective logging through to regenerating pasture) and adjacent primary forests, we can now hammer the final nails into the coffin containing the putrid remains of Wright and Muller-Landau’s assertion – there is no substitute for primary forest. Read the rest of this entry »





Party with future conservation leaders

11 07 2010

I’ve just come back from the 2010 International Congress for Conservation Biology in Edmonton, Canada. I thought it would be good to tweet and blog my way through on topics that catch my attention. This is my third post from the conference, and a full conference ‘assessment’ post will follow in a few days.

I haven’t been a member of the Society for Conservation Biology for a very long time, and I’ve only now attended three annual meetings of the Society. I’ve been somewhat lukewarm about the social events at these conferences in the past, but this time I had much better experience.

After a less-than-inspiring barbecue meal and a general under-abundance of ethanol-based social lubricant, someone in our group whispered that we should ‘crash’ a party being held ‘secretly’ back at the conference venue. I had heard around the traps that the Conservation Leadership Programme (CLP) bashes were good, but I hadn’t attended one before. Well, not only was it a bloody good party, I’ve learned a little more about the programme and the kinds of people it promotes. Read the rest of this entry »





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 »





Bill Laurance coming to Adelaide

13 03 2010

We’ve got a real treat for biodiversity buffs scheduled for the end of March. Eminent (Distinguished, Famous, Respected… the list goes on) Professor William (Bill) Laurance is briefly leaving his tropical world and coming south to the temperate climes of Adelaide to regale us with his fascinating biodiversity research career.

Bill is a leading conservation biologist who has worked internationally on many high-profile threats to tropical forests—in the Amazon, Central America, Africa, and Australasia. A highly prolific scientist, to date he has published five books and over 300 scientific articles. Bill has recently commenced a position as Distinguished Research Professor at James Cook University and is involved with the Smithsonian Tropical Research Institute in Panama. He also happens to be the bloke that blew the lid open on the devastating effects of tropical fragmentation in the Amazon with some of the best long-term experiments ever done in conservation biology.

I’m personally very pleased for several reasons: (1) Although I have never met Bill in person yet, I’ve recently co-authored two papers with him (Wash and spin cycle threats to tropical biodiversity and Improving the performance of the Roundtable on Sustainable Palm Oil for nature conservation) and I’m keen to meet the man behind the pen; (2) we have had many email discussions (some of them rather heated!), so I’m keen to flesh some of these out over a nice glass of South Australian Shiraz; (3) he’s been a keen supporter of my work for years, and has given me many opportunities to get my research noticed; and (4) it’s high time to met one of ConservationBytes.com Conservation Scholars.

Bill has recently shifted shop from Panama (Smithsonian Tropical Research Institute) to Australia’s own James Cook University, and so we at the Environment Institute thought we should take advantage of his geographical disorientation and bring him down south for a while. But he’s going to have to sing for his supper, so he’s kindly agreed to give three talks in 3 days from 29-31 March 2010.

His first talk (on Monday 29 March) will be an in-house Environment Institute seminar, but the second two will be public events that I urge anyone remotely interested in biodiversity conservation research to attend. In fact, his Tuesday 30 March presentation (18.00-20.00 Napier G03, University of Adelaide) is even more generic than that, and word on the street is it is highly entertaining and extremely well attended wherever Bill’s is gracious enough to give it:

Amplify Your Voice: Keys to Having a Prolific Scientific Career (and Bill would know).

This will include (1) How to be more prolific: strategies for writing and publishing scientific papers and (2) Further ways to maximise your scientific impact – interacting with the popular media and how to promote yourself. Each topic will run for 50 minutes and will include 10 minutes for audience questions. A tea and coffee break will be held between sessions. Book here.

His second public talk on Wednesday 31 March (18.00-19.30 Napier 102, University of Adelaide) will be:

Diagnosis Critical | The lungs of our Planet

Here he will be discussing how the forests of our world are in crisis. Our drive for continued economic growth has had devastating consequences for the world’s ecosystems that provide critical human services. Our forests are a haven for countless plant and animal species that form the basis of ecological services, these services are the biological mechanisms that make the world our home. Book here.

So, if you have a couple of free nights at the end of the month and are in Adelaide, I strongly recommend you come out and see Bill do his thing.

CJA Bradshaw

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Celebrities actually doing something positive for conservation?

7 05 2009

When I first saw this on the BBC I thought to myself, “Well, just another toothless celebrity ego-stroke to make rich people feel better about the environmental mess we’re in” (well, I am a cynic by nature). I have blogged before on the general irrelevancy of celebrity conservation. But then I looked closer and saw that this was more than just an ‘awareness’ campaign (which alone is unlikely to change anything of substance). The good Prince of Wales and his mates/offspring have put forward The Prince’s Rainforest Project, which (thankfully) not only endeavours to raise awareness about the true value of rain forests, it actually proposes a mechanism to do so. It took a bit to find, but the 52-page report on the PRP website outlines from very sensible approaches. In essence, it all comes down to money (doesn’t everything?).

Their proposed plan to the United Nations Framework Convention on Climate Change (UNFCCC) details some of the following required changes:

  1. Payments to rain forest nations for not deforesting (establish transaction costs and setting short-term ‘conservation aid’ programmes)

  2. Multi-year service agreements (countries sign up for multi-year targets based on easily monitored performance indicators)

  3. Fund alternative, low-carbon economic development plans (fundamental shifts in development targets that explicitly avoid deforestation)

  4. Multi-stakeholder disbursement mechanisms (using funds equitably and minimising corruption)

  5. Tropical Forests Facility (a World Bank equivalent with the express purpose of organising, disbursing and monitoring anti-deforestation money flow)

  6. Country financing from public and private sources (funding initially derived from developed nations in form of ‘aid’)

  7. Rain forest bonds in private capital markets (value country-level ‘income’ as interest payments and incentives within a trade framework)

  8. Nations participate when ready (giving countries the option to advance at the pace dictated by internal politics and existing development rates)

  9. Accelerating long-term UNFCCC agreement on forests (transition to independence post-package)

  10. Global action to address drivers of deforestation (e.g., taxing/banning products grown on deforested land; ‘sustainability’ certification; consumer pressure; national procurement policies)

Now, I’m no economist, nor do I understand all the market nuances of the proposal, but it seems they are certainly on the right track. The value of tropical (well, ALL) forests to humanity are undeniable, and we’re currently in a state of crisis. Let’s hope the Prince and his mob can get the ball rolling.

For what it’s worth, here’s the video promoting the PRP. I could really care less what Harrison Ford and Pele have to say about this issue because I just don’t believe celebrities have any net effect on public behaviour (perceptions, yes, but not behaviour). But look beyond the superficiality and the cute computer-generated frog to the seriousness underneath. Despite my characteristically cynical tone, I give the PRP full support.

more about “Rainforest film brings out stars“, posted with vodpod


CJA Bradshaw

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Tropical Turmoil II

8 03 2009

In August last year I covered a paper my colleagues (Navjot Sodhi and Barry Brook) and I had in press in Frontiers in Ecology and the Environment entitled Tropical turmoil – a biodiversity tragedy in progress. The paper is now available in the March 2009 issue of the journal (click here to access). We were also fortunate enough to grab the front cover (shown here) and have a dedicated podcast that you can listen to by clicking here about the paper and its findings. I encourage ConservationBytes.com readers to have a listen if they’re interested in learning more about the woeful state of tropical biotas worldwide, and maybe some ways to rectify the problems. The intro to the podcast can be viewed by clicking here.

CJA Bradshaw





Conservation Scholars: Mark Cochrane

22 10 2008

This series on ConservationBytes.com takes a page out of our book Tropical Conservation Biology (Sodhi, Brook & Bradshaw) – therein we produced a series of ‘Spotlights’ describing the contributions of great thinkers to conservation science. Each highlight of a Conservation Scholar includes a small biography, a list of major scientific publications and a Q & A on the person’s particular area of expertise.

Our fourth Conservation Scholar is Mark Cochrane

Biography

I am a Professor at the Geographic Information Science Center of Excellence at South Dakota State University and am jointly appointed with the Department of Biology and Microbiology and the Department of Geography. I conduct interdisciplinary work that combines remote sensing, ecology and other fields of study to provide a landscape perspective of the dynamic processes involved in land-cover change. I first became interested in ecology through coursework while I was completing my baccalaureate in Environmental Engineering at the Massachusetts Institute of Technology. I then spent a year working on a variety of research projects in Antarctica, furthering my interest in science. Having had enough of cold-weather environments, I chose to do my postgraduate research in the Brazilian Amazon and, in 1998, received a doctoral degree in Ecology from The Pennsylvania State University. I am among the world’s leading experts on wildfire in tropical ecosystems. I am renowned for documenting wildfire characteristics, behaviour and severe effects in tropical forests, as well as how current systems of human land-use foster wildfires. My research focuses on understanding spatial patterns, interactions and synergisms between the multiple physical and biological factors that affect ecosystems. Recently published work emphasizes human dimensions of land-cover change and the potential for sustainable development. My collaborative research with the Brazilian NGO IMAZON (The Amazon Institute of Man and the Environment) has been instrumental in the Brazilian government’s recent (2003) program to expand its national forest system in the Amazon to 50 million hectares. In my ongoing research programs, I continue to investigate the drivers and effects of disturbance regime changes resulting from various forms of forest degradation, including fire, fragmentation and logging.

Major Publications

Questions and Answers

1. Are fires in tropical landscapes more frequent now than in the past?

Yes. Fires are much more prevalent in the tropics than in the past. The issues with fire in tropical landscapes do not centre on the presence of fire in these landscapes, but with the frequency with which they are burning. In many regions of the tropics, current land-use practices result in surviving forest fragments being subjected to fire so often that they are rapidly being degraded by a fire regime that they cannot withstand. Fire is the primary tool for clearing and maintaining agricultural land. Forests are slashed and allowed to dry before being burned to release their nutrients to the soils. Many lands are subsequently turned into pastures, which also are burnt frequently in order to keep trees from regrowing. Most land use is fire-dependent. Forests are also subjected to selective logging, which removes only the valuable trees and leaves the remaining forests susceptible to escaped fires. Having fire-dependent agriculture embedded in fire-susceptible forests quickly leads to forest fires. Once this occurs, the landscape is quickly converted from one of a few flammable islands (e.g., pastures) within a near fire-immune sea of vegetation (i.e., rain forests), to one where a fire at any location can permeate an entire region, forests and agricultural lands alike.

2. Will global climate change be important in altering future fire regimes?

Yes. Global climate change will likely result in important changes in regional fire regimes. Global climate models (GCMs) do not all agree on what the future climates will be like, but it is fairly certain that temperatures will increase substantially, especially in interior regions such as the upper Amazon. Most models show a concomitant increase in rainfall for these regions, but it is uncertain whether or not these increases will be enough to offset the drought stress from rising temperatures. Rainfall reductions from ongoing deforestation, however, will probably be greater than any projected increases due to global climate change, leading to a net increase in drought stress and fire behaviour, further stressing these important ecosystems.

3. How important are the adverse effects of fire on tropical biotas relative to other drivers such as habitat loss and land use change?

Fire is what integrates tropical landscapes. Habitat loss is primarily seen as a function of deforestation, but forest degradation through logging and fire causes substantial changes in forest structure and composition that affect habitability. The key aspect of wildfire is that once it has damaged a region’s forests, it effectively changes the ‘rules of the game’ for land management. What was once a highly fire-resistant ecosystem becomes a highly fire-susceptible forest. A positive feedback of increasing fire frequency, fire intensity and fire severity can become established. Instead of burning once every thousand years or more, these forests may burn once every 10 years or less. These forests cannot withstand such a fire regime and several fires can effectively deforest an area. As the landscape becomes more permeable to fire, even diligent landowners have difficulty protecting their lands from fires. Uncontrolled fires destroy large-investment, high-return perennial crops such as rubber tree, pepper and fruit plantations, making cattle ranching the most viable land use. Pasture grass is the most flammable land cover possible and only exacerbates a region’s fire problems.

4. Is there a theory in fire ecology, and if yes, what is it?

The short answer is no. To my knowledge there is no accepted theory underlying fire ecology.

CJA Bradshaw

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(with thanks to Navjot Sodhi, Barry Brook, Ward Cooper, Wiley-Blackwell and Mark Cochrane for permission to reproduce the text – buy your copy of Tropical Conservation Biology here)





Conservation Scholars: William Laurance

7 10 2008

This series on ConservationBytes.com takes a page out of our book Tropical Conservation Biology (Sodhi, Brook & Bradshaw) – therein we produced a series of ‘Spotlights’ describing the contributions of great thinkers to conservation science. Each highlight of a Conservation Scholar includes a small biography, a list of major scientific publications and a Q & A on the person’s particular area of expertise.

Our third Conservation Scholar is William Laurance

Biography

I am a conservation biologist, and am especially interested in assessing the impacts of intensive land uses such as habitat fragmentation, fires, and logging on tropical ecosystems. My team also studies global-change phenomena, such as the effects of global warming on tropical biotas, and I’m broadly interested in conservation policy. Over the past two decades I’ve worked in the Amazon, Central Africa, tropical Australia, and Central America. Why do I work and live in the tropics? I have long been interested in nature conservation, and tropical forests are among the most biologically diverse and imperilled ecosystems on Earth. I was raised far from any rain forest – in the western USA – but I worked in several zoos in my youth and in that way became intrigued by tropical species and communities. When it came time to do my PhD at the University of California, Berkeley, I decided to study the impacts of forest fragmentation on tropical mammals. Later, I started working on tropical trees, and also used remote sensing and geographic information systems to study deforestation and land-use change. Today, I pretty much work on anything – trees, vines, mammals, birds, amphibians – but the one common theme is that my research has a strong conservation focus. I am very much a believer that conservation biologists have to be active conservationists as well. This is especially so in the tropics, where biologists have led international efforts for nature conservation. As president of the Association for Tropical Biology and Conservation, the world’s largest scientific society devoted to the study and protection of tropical ecosystems, I’ve tried to ensure that our organisation plays a leading role in promoting conservation. Our main weapon is our scientific credibility, and the fact that we have a lot of expertise among our members. We’ve fought a number of important conservation battles, and won some of them. Sometimes we feel like the little Dutch boy with his finger in the dike, but if we biologists don’t strive to slow rampant forest destruction, who will?

Major Publications

Questions and Answers

1. Is fragmentation always bad for tropical biodiversity?

It depends what you mean by biodiversity. Whenever there is an environmental change, there are winners and losers. If you fragment a forest, edge-adapted, generalist and exotic species proliferate, whereas old-growth specialists and area-demanding species (such as predators and large-bodied species that are vulnerable to hunting) decline. The reason we worry so much about habitat fragmentation is that the world has plenty of generalist and exotic species; we don’t need to conserve them. The old-growth and area-demanding species, however, are a different story. In a fragmented landscape, their populations often collapse and vanish. So if our goal is to maximise the long-term survival of species – especially those that are most vulnerable to extinction – then habitat fragmentation is almost universally a bad thing. A final consideration is that fragmented landscapes tend to be far more vulnerable to fires, logging, and over-hunting than are intact forests. In the Amazon, for example, fire frequency increases drastically within a few kilometres of forest edges relative to forest interiors. In times-series imagery from satellites, you can see the fragments imploding over time, because rain forests just can’t survive this withering recurrence of destructive fires. Thus, fragmentation is bad from lots of different perspectives.

2. Do you think it is timber logging, agricultural expansion, or global change phenomena that poses the biggest threat to Amazonia this century?

I’d have to say agricultural expansion is the biggest threat, especially for cattle ranching and industrial soy farming, simply because it’s so apparent that it’s devastating vast expanses of forest. Cattle ranching has exploded – the number of cattle in Brazilian Amazonia rose from about 20 million to 60 million head over the last decade – while soy farms have also grown exponentially. Soy farmers not only clear forest themselves, they also buy up a lot of recently cleared land, thereby force ranchers and slash-and-burn farmers to push ever further into the frontier and destroy even more forest. The soy farmers are also a powerful political lobby that is pushing for a massive expansion of highways, roads, and other transportation infrastructure in the Amazon. These new projects are criss-crossing the Amazon and are greatly increasing the pace of forest loss and fragmentation. It’s far harder to predict the effects of global-change phenomena. Some models suggest that increasing deforestation (which reduces evapo-transpiration and hence rainfall) and global warming could both have major impacts on the Amazonian climate. But the different models vary a lot, and the bottom line is that there is still much we don’t understand. The threat from global change might be relatively limited, or it might be massive.

3. Has the Biological Dynamics of Forest Fragment Project (BDFFP) delivered practical conservation outcomes, and can its principles be applied to other tropical regions?

Yes, I think so. We’ve demonstrated, for example, that even remarkably small clearings, such as a powerline corridor or highway, can dramatically inhibit the movements of many rain forest species. We’ve shown that smaller (< 100-hectare) forest fragments rapidly lose many species and exhibit striking changes in their ecology. We’ve also found that edge effects drive many changes in fragmented rain forests, and this has implications for reserve and buffer-zone management, and for the design of wildlife corridors. These are all quite practical conservation outcomes. In general, I think that many of these principles can be applied to other tropical regions, though of course that’s not to suggest that all forests behave similarly. For example, the importance of edge effects may vary quite a lot among different tropical regions.

CJA Bradshaw

(with thanks to Navjot Sodhi, Barry Brook, Ward Cooper, Wiley-Blackwell and Bill Laurance for permission to reproduce the text – buy your copy of Tropical Conservation Biology here)

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Tropical Conservation Biology

8 09 2008

An obvious personal plug – but I’m allowed to do that on my own blog ;-)

I’d like to introduce a (relatively) new textbook that my colleagues, Navjot Sodhi and Barry Brook, and I wrote and published last year with Blackwell (now Wiley-Blackwell) Scientific Publishing – Tropical Conservation Biology.

We’re rather proud of this book because it was a timely summary and assessment of the scientific evidence for the degree of devastation facing tropical biodiversity today and in the future. I’ve summarised some of the main issues in a previous post covering a paper we have ‘in press’ that was born of the text book, but obviously the book is a far more detailed account of the problems facing the tropics.

This introductory textbook examines diminishing terrestrial and aquatic habitats in the tropics, covering a broad range of topics including the fate of the coral reefs; the impact of agriculture, urbanisation, and logging on habitat depletion; and the effects of fire on plants and animal survival.

One of the highlights of the book is that each chapter (see below) Includes case studies and interviews with prominent conservation scientists to help situate key concepts in a real world context: Norman Myers (Chapter 1), Gretchen Daily (Chapter 2), William Laurance (Chapter 3), Mark Cochrane (Chapter 4), Daniel Simberloff (Chapter 5), Bruce Campbell (Chapter 6), Daniel Pauly (Chapter 7), Stephen Schneider (Chapter 8), Stuart Pimm (Chapter 9) and Peter Raven (Chapter 10). These biographies are followed by a brief set of questions and answers that focus on some of the most pertinent and pressing issues in tropical conservation biology today. It is our intention that readers of Tropical Conservation Biology will benefit from the knowledge and be inspired by the passion of these renowned conservation experts.

TABLE OF CONTENTS

  1. Chapter 1: Diminishing habitats in regions of high biodiversity. We report on the loss of tropical habitats across the tropics (e.g., deforestation rates). We also highlight the drivers of habitat loss such as human population expansion. Finally, we identify the areas in immediate need of conservation action by elucidating the concept of biodiversity hotspots. Read the rest of this entry »




Tropical turmoil – a biodiversity tragedy in progress

18 08 2008
© Mongabay.com

We recently published (online) a major review showing that the world is losing the battle over tropical habitat loss with potentially disastrous implications for biodiversity and human well-being.

Published online in the Ecological Society of America’s journal Frontiers in Ecology and the Environment, our review Tropical turmoil – a biodiversity crisis in progress concludes that we are “on a trajectory towards disaster” and calls for an immediate global, multi-pronged conservation approach to avert the worst outcomes.

Tropical forests support more than 60 % of all known species, but represent only about 7 % of the Earth’s land surface. But up to 15 million hectares of tropical rainforest are being lost every year and species are being lost at a rate of up to 10000 times higher than would happen randomly without humans present.

This is not just a tragedy for tropical biodiversity, this is a crisis that will directly affect human livelihoods. This is not just about losing tiny species found in the canopies of big rain forest trees few people will ever see, this is about a complete change in ecosystem services that directly benefit human life. Read the rest of this entry »








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