Can Australia afford the dingo fence?

18 05 2012

I wrote this last night with Euan Ritchie of Deakin University in response to some pretty shoddy journalism that misrepresented my comments (and Euan’s work). Our article appeared first in The Conversation this morning (see original article).

We feel we have to set the record straight after some of our (Bradshaw’s) comments were taken grossly out of context, or not considered at all (Ritchie’s). A bubbling kerfuffle in the media over the last week compels us to establish some facts about dingoes in Australia, and more importantly, about how we as a nation choose to manage them.

A small article in the News Ltd. Adelaide Advertiser appeared on 11 May in which one of us (Bradshaw) was quoted as advocating the removal of the dingo fence because it was not “cost effective” (sic). Despite nearly 20 minutes on the telephone explaining to the paper the complexities of feral animal management, the role of dingoes in suppressing feral predators, and the “costs” associated with biodiversity enhancement and feral control, there wasn’t a single mention of any of this background or justification.

Another News Ltd. article denouncing Ritchie’s work on the role of predators in Australian ecosystems appeared in The Weekly Times the day before, to which Ritchie responded in full.

So it’s damage control, and mainly because we want to state categorically that our opinion is ours alone, and not that of our respective universities, schools, institutes or even Biosecurity SA (which some have claimed or insinuated, falsely, that we represent). Biosecurity SA is responsible for, inter alia, the dingo fence in South Australia. Although our opinions differ on its role, we are deeply impressed, grateful and supportive of their work in defending us from biological problems. Read the rest of this entry »





Conservation value of paddy wagon currency: civil disobedience by scientists

12 05 2012

A couple of years ago, James Hansen visited Adelaide and I was fortunate enough to attend dinner with him and his lovely wife Anniek. A truly inspiring scientist in all respects. His academic track record is unbeatable, and he puts his money where his mouth is in terms of climate change activism.

In a similar vein, but something I’m not used to publishing on Conservation Bytes, my colleague Alejandro Frid requested I publish his essay here. I’m a firm advocate for standing up for evidence-based policy, and Alejandro (inspired by James Hansen), shows us how it’s done.

I am addressing this letter to colleagues with research careers because I am compelled to share what I learned recently by crossing a new threshold. For years I have been talking and writing about the climate change crisis. As intellectually rewarding and therapeutic as it has been, these letters to government, meetings with Members of [the Canadian] Parliament, and articles for conservation-minded audiences have accomplished nothing of substance.

Others feel similarly. Prominent academics, fed up with governments that ignore science and heed the priorities of corporations, have turned to civil disobedience. James Hansen, a senior climate scientist with NASA’s Goddard Institute for Space Studies, led by example last year when he got himself arrested in front of the USA’s Whitehouse to protest the proposed Keystone Pipeline that would carry oil from the Alberta Tar Sands to the USA. That was his third arrest in three years; the previous two involved civil disobedience against the mining of coal, a huge contributor to greenhouse gases.

In the wake of Hansen’s arrests, on 05 May 2012, Mark Jaccard—a prominent economist, IPCC member, and professor at the Energy and Materials Research Group of Simon Fraser University—got himself arrested in White Rock, British Columbia, for blocking a coal train carrying US coal for export to China via British Columbia ports. There were 12 others with Jaccard, among them a man in his 80s, several men in their 60s and 70s, and a few youngsters like myself and my good friend Lynne Quarmby. Lynne happens to be chair of the Department of Molecular Biology at Simon Fraser University.

Shortly before the arrest, as we sat on the tracks, I told Jaccard that I had been teetering on the decision to come, but his announcement to participate sealed my decision. Jaccard replied that, given what he knew about the climate crisis and the consequences of inaction, it was impossible for him to not be here. He was echoing sentiments shared by all 13 of us on the tracks. Later, as we were released from jail, Jaccard wondered out loud whether the arrest would affect his ability to travel for work. Then he said something to the effect that, “You can forever come up with excuses, or you can get real and just do it.”

Read the rest of this entry »





No more ecology

9 05 2012

To all ecology people who read this blog (students, post-docs, academics), this is an intriguing, provocative and slightly worrying title. As ecology has matured into a full-fledged, hard-core, mathematical science on par with physics, chemistry and genetics (and is arguably today one of the most important sciences given how badly we’ve trashed our own home), its sophistication now threatens to render many of the traditional aspects of ecology redundant.

Let me explain.

As a person who cut his teeth in field ecology (with all the associated dirt, dangers, bites, stings, discomfort, thrills, headaches and disasters), I’ve had my fair share of fun and excitement collecting ecological data. There’s something quaintly Victorian (no, I am not referring to the state next door) about the romantic and obsessive naturalist collecting data to the exclusion of nearly all other aspects of civilised life; the intrepid adventurer in some of us takes over (likely influenced by the likes of David Attenborough) and we convince ourselves that our quest for the lonely datum will heal all of the Earth’s ailments.

Bollocks.

As I’ve matured in ecology and embraced its mathematical complexity and beauty, the recurring dilemma is that there are never enough data to answer the really big questions. We have sampled only a fraction of extant species, we know embarrassingly little about how ecosystems respond to disturbance, and we know next to nothing about the complexities of ecosystem services. And let’s not forget our infancy in understanding the synergies of extinctions in the past and projections into the future. Multiply this uncertainty by several orders of magnitude for ocean ecosystems.

Read the rest of this entry »





Sharks: the world’s custodians of fisheries

5 05 2012

Today’s post comes from Salvador Herrando-Pérez (who, incidentally, recently submitted his excellent PhD thesis).

Three species co-occurring in the Gulf of Mexico and involved in the trophic cascade examined by Myers et al. (8). [1] Black-tips (Carcharhinus limbatus) are pelagic sharks in warm and tropical waters worldwide; they reach < 3 m in length, 125 kg in weight, with a maximum longevity in the wild of ~ 12 years; a viviparous species, with females delivering up to 10 offspring per parturition. [2] The cownose ray (Rhinoptera bonasus) is a tropical species from the western Atlantic (USA to Brazil); up to 2 m wide, 50 kg in weight, and 18 years of age; gregarious, migratory and viviparous, with one single offspring per litter. [3] The bay scallop (Agropecten irradians) is a protandric (hermaphrodite) mollusc, with sperm being released a few days before the (> 1 million) eggs; commonly associated with seagrasses in the north-western Atlantic; shells can reach up to 10 cm and individuals live for < 2 years. In the photos, a black-tip angled in a bottom long-line off Alabama (USA), a school of cownose rays swimming along Fort Walton Beach (Florida, USA), and a bay scallop among fronds of turtle grass (Thalassia testudinum) off Hernando County (Florida, USA). Photos by Marcus Drymon, Dorothy Birch and Janessa Cobb, respectively.

The hips of John Travolta, the sword of Luke Skywalker, and the teeth of Jaws marked an era. I still get goose pimples with the movie soundtrack (bass, tuba, orchestra… silence) solemnizing each of the big shark’s attacks. The media and cinema have created the myth of man’s worst friend. This partly explains why shark fishing does not trigger the same societal rejection as the hunting of other colossuses such as whales or elephants. Some authors contend that we currently live in the sixth massive extinction event of planet Earth (1) 75 % of which is strongly driven by one species, humans, and characterized by the systematic disappearance of mega-animals in general (e.g., mammoths, Steller’s seacow), and predators in particular, e.g., sharks (2, 3).

The selective extirpation of apex predators, recently coined as ‘trophic downgrading’, is transforming habitat structure and species composition of many ecosystems worldwide (4). In the marine realm, over the last half a century, the main target of the world’s fisheries has turned from (oft-large body-sized) piscivorous to planctivorous fish and invertebrates, indicating that fishery fleets are exploiting a trophic level down to collapse, then harvesting the next lower trophic level (5-7).

Myers et al. (8) illustrate the problem with the fisheries of apex-predator sharks in the northeastern coast of the USA. Those Atlantic waters are rife with many species of shark (> 2 m), whose main prey are smaller chondrichthyans (skates, rays, catsharks, sharks), which in turn prey on bottom fishes and bivalves. Myers et al. (8) found that, over the last three decades, the abundance of seven species of large sharks declined by ~ 90 %, coinciding with the crash of a centenary fishery of bay scallops (Agropecten irradians). Conversely, the abundance of 12 smaller chondrichthyes increased dramatically over the same period of time. In particular, the cownose ray (Rhinoptera bonasus), the principal predator of bay scallops, might today exceed > 40 million individuals in some bays, and consume up to ~ 840,000 tonnes of scallops annually. The obvious hypothesis is that the reduction of apex sharks triggers the boom of small chondrichthyans, hence leading to the break-down of scallop stocks. Read the rest of this entry »





If a tree falls… preventing deforestation with insurance

3 05 2012

As CB readers will know, I’ve reported a few times on our iREDD idea, and it got a little pick-up overseas. Here’s a great article by Rachel Nuwer covering the concept, published in Ecoimagination.com.

Almost everything we own – our houses and cars and our very health – is insured. It works on a simple principal: the higher the risk, the higher the premium. It’s an age-old concept that ecological modelers have decided to apply to a new area: forest preservation.

A new proposal, published in the journal Conservation Letters, would create forest insurance to make the U.N. forest preservation program Reduced Emissions from Deforestation and forest Degradation, or REDD, more effective. REDD is generally supposed to function by paying developing countries to protect their forests in exchange for carbon pollution credits. Currently the program has 42 partner countries across the globe. The program is crucial to the fight against climate change since deforestation and forest degradation accounts for about 20 percent of global greenhouse gas emissions and threatens biodiversity.

“REDD is a fantastic idea,” said Corey Bradshaw, director of ecological modeling at the University of Adelaide and co-author of the study. “You get a carbon advantage and biodiversity doesn’t get wiped out at the same time, it seems perfect.”

But it has a few major flaws that the insurance scheme, called iREDD, seeks to remedy.

REDD only works if the parties are honest and stick to the agreement. Bradshaw doesn’t have much faith that will happen. “If there’s a way to cheat, people will cheat. That’s the nature of all life, not just humans, but we excel at it,” he said. If, for example, a country is paid to conserve one forest but moves its deforestation efforts to an adjacent forest in order to get both money and timber, in terms of carbon offsets, that transaction was a failure. This phenomenon is called “leakage.”

Carbon-capture also only works if it’s maintained indefinitely. If a country accepts money for ten years and then cuts its forest the day after the agreement expires, then all of that conservation was for naught. This issue is called “permanence,” usually translated into an arbitrarily defined period of time set by countries in terms of decades or centuries. Read the rest of this entry »





We only have decades…

26 04 2012

… not centuries.

Here’s a little video production The Environment Institute put together that explains some of our lab‘s work and future directions.


CJA Bradshaw





To corridor, or not to corridor: size is the question

24 04 2012

I’ve just read a really interesting post by David Pannell from the University of Western Australia discussing the benefits (or lack thereof) of wildlife ‘corridors’. I’d like to elaborate on a few key issues, and introduce the most important aspect that really hasn’t been mentioned.

Some of you might be aware that the Australian Commonwealth Government has just released its Draft National Wildlife Corridors Plan for public comment, but many of you might not really know what a ‘corridor’ constitutes.

Wildlife or biodiversity ‘corridors’ have been around for a long time, at least in terms of proposals. The idea is fairly simple to conceive, but very difficult to implement in practice.

At least for as long as I’ve been in the conservation biology biz, ‘corridors’ have been proffered as one really good way to make broad-scale landscape restoration plausible and effective for (mainly) forest-dwelling species which have copped the worst of deforestation trends around Australia and the world. The idea is that because of intense habitat fragmentation, isolated patches of primary (or at least, reasonably intact secondary) forest can be linked by planting some sort of long corridor of similar habitat between them. Then, all the little creatures can merrily make their way back and forth between the patches, thus rescuing each other from extinction via migration. Read the rest of this entry »





Take a leaf from insurance industry’s book

18 04 2012

Just a quick one rehashing today’s media release on the iREDD paper I blogged about a while back. The full, online version is available upon request. Stay tuned for media coverage.

A group of environmental scientists say a problem-ridden economic model designed to slow deforestation can be improved by applying key concepts from the insurance industry.

REDD (Reduced Emissions from Deforestation and forest Degradation) is a UN-promoted scheme that allows countries to trade in carbon credits to keep forests intact. It is mainly targeted at developing nations where deforestation and exploitation are a major threat.

In a paper published online in the journal Conservation Letters, ecology researchers from Australia and South Africa argue that REDD projects can suffer from three major problems. They have proposed strengthening the scheme by using insurance policies and premiums, creating a new scheme known as iREDD.

“The idea of paying a nation to protect its forests in exchange for carbon pollution offsets can potentially reduce overall emissions by keeping the trees alive, and ensure a lot of associated biodiversity gets caught up in the conservation process,” says Professor Corey Bradshaw,, Director of Ecological Modelling at the University of Adelaide’s Environment Institute and a senior author of the paper.

“However, there are three main problems with REDD: these are known as leakage, permanence and additionality.” Read the rest of this entry »





The wounded soldiers of biodiversity

10 04 2012

Here’s another great post from Salvador Herrando-Pérez. It is interesting that he’s chosen an example species that was once (a long, long time ago in a galaxy far, far away) of great interest to me (caribou – see ancient papers a, b, c, d). But that is another story. Take it away, Salva.

 

Figure 1. Caribou (reindeer) are ungulates weighing up to ~ 100 kg. They live in tundra and taiga in Finland, Greenland, Finland, Norway, Mongolia, Russia, Canada and USA (extinct in Sweden). The species is globally stable (‘Least Concern’, IUCN Red List), but the subspecies of woodland caribou (Rangifer tarandus caribou) is threatened in North America. Schneider and colleagues’ 7 study encompasses ~ 3,000 individuals in 12 herds (75 to 450 individuals per herd), occupying ~ 100.000 km2 of conifer forest and peatland (3,000 to 19,000 km2 per herd). Two ecotypes are recognized regionally22, namely migratory mountain herds (mostly from mountains and foothills in west-central Alberta), and non-migratory boreal herds (mostly from peatlands in central and northern Alberta). The photo shows a group of caribous grazing on subalpine vegetation from Tonquin Valley, Jasper National Park (Alberta, Canada). Photo courtesy of Saakje Hazenberg.

As conservation biology keeps incorporating management and economical principles from other disciplines, it stumbles with paradoxes such that investing on the most threatened components of biodiversity might in turn jeopardize the entire assets of biodiversity.

At the end of 2011, newspapers and TVs echoed an IUCN report cataloguing as ‘extinct’ or ‘near extinct’ several subspecies of rhinos in Asia and Africa. To many, such news might have invoked the topic: “how badly governments do to protect the environment”. However if, to avoid those extinctions, politicians had to deviate funds from other activities, what thoughts would come to the mind of workers whose salaries had to be frozen, school directors whose classroom-roof leakages could not be repaired (e.g., last winter at my niece’s school in Spain), colonels whose last acquisition of ultramodern tanks had to be delayed, or our city council’s department who had to cancel Sting’s next performance.

Thus, there are three unquestionable facts regarding species conservation:

  1. the protection of species costs money;
  2. governments and environmental organisations have limited budgets for a range of activities they deem necessary; and
  3. our way of conserving nature is failing because, despite increasing public/private support and awareness, the rate of destruction of biodiversity is not decelerating1,2.

One of the modern debates among conservationists pivots around how to use resources efficiently3-6. Schneider and colleagues7 have dealt with this question for woodland caribou (Rangifer tarandus) in Canada. A total of 18 populations of this ungulate persist in the Canadian province of Alberta, all undergoing demographic declines due to mining extractions (oil, gas and bitumen), logging and wolf predation. The species is listed as ‘threatened’ regionally and nationally. The Alberta Caribou Recovery Plan (2004-2014) is attempting to protect all herds. Under such a framework, Schneider et al.7 predicted that woodland caribou would be regionally extirpated in less than a century.

Furthermore, they estimated the costs of making each herd viable (Fig. 1), with a triple revelation. To save all herds from extinction would need ~ CA$150,000 million (beyond the available budget). The most threatened herds are among the most expensive to protect (within present management approach). Some herds would be secured through modest investment for two decades. Overall, their study suggests that Alberta’s woodland caribou would be eligible for triage, i.e., at the subpopulation level8. Read the rest of this entry »





Tentacles of destruction

5 04 2012

This last post before Easter is something I’ve thought more and more about over the last few years. I wouldn’t have given it much time in the past, but I’m now convinced roads are one of the humanity’s most destructive devices. Let me explain.

Before I had a good grasp of extinction dynamics, I wouldn’t have attributed much import to the role of roads in conservation. I mean, really, a little road here and there (ok, even a major motorway) couldn’t possibly be a problem? It’s mostly habitat destruction itself, right?

Not exactly. With our work on extinction synergies, I eventually came to realise that roads are some of the first portals to the devastation to come. Read the rest of this entry »





Humans suddenly become intelligent

1 04 2012

Some described it as the “eco-topia”; some believed they had died in the night and awoken in a different universe. Some just stood there gaping stupidly.

Yet the events of 01 April 2012 are real*. Humans suddenly became intelligent.

In an unprecedented emergency UN session this morning, all the world’s countries pledged to an immediate wind-down of the fossil-fuel economy and promised to invest in a rational combination of nuclear and renewable energy sources. Some experts believe the pledge would see a carbon-neutral planet by 2020.

Additionally, the session saw a world-wide pledge to halt all deforestation by 2013, with intensive reforestation programmes implemented immediately.

Family planning would be embraced worldwide, with a concerted effort to see the human population plateau by 2070, and begin declining to a stable 2 billion by 2300. Read the rest of this entry »





Eat a feral a week

22 03 2012

© Y. Sugiura

Just a quick post this week about something I’ve been contemplating for a while.

What if every Australian pledged to eat a feral animal a week?

Yes, I know that it’s a bit out of the pitch, and I’m sure not everyone would do it. Nor would it be physically possible for one person to eat an entire camel, buffalo or deer in a week – but hopefully you get the picture.

Why propose this? Australia is quite over-run with feral animals. Some quick stats:

Now we have, of course, many other ferals (cats, rats, foxes, mice), but I don’t think too many people would want to eat them. I have personally eaten feral pigs, camels, buffalo, goats, and red, fallow and sambar deer, mostly from my own research trips or from friends who hunt. Read the rest of this entry »





Bill Laurance wins Heineken Prize

16 03 2012

I’ve just learnt some fantastic news about my good friend and colleague, Professor Bill Laurance of James Cook University.

Bill has the distinction of being named this year’s recipient of the most-prestigious Heineken Prize for Environmental Sciences. Probably only second in prestige to the Crafoord Prize, the Heineken Prize has sent many recipients in the fields of medicine, biochemistry and biophysics on to win Nobel Prizes.

While there is still no Nobel category in ecology, conservation or the environment (there bloody well should be, in my not-so-humble opinion), this is a huge recognition of Bill’s amazing scientific track record, environmental portfolio, advocacy and expertise.

Read the rest of this entry »





Worlds collide: greenwashed development to kill biodiversity

15 03 2012

Another development fiasco that, if it goes ahead, will devastate a Biodiversity Hotspot and ultimately, reduce the livelihood prospects of millions of West Africans.

In yet another move to expose and shame the greedy developers behind another massive (and superlatively greenwashed) oil palm development in the tropics (see our previous Open Letter), Bill Laurance and Josh Linder have organised another Open Letter from some of the world’s top conservation scientists (again, I count myself fortunate to be included in that group) denouncing the project. The press release is below, followed by the letter itself:

Eleven of the world’s top scientists have produced an open letter to the public urging the Cameroon government to stop a giant oil palm plantation that they say will threaten some of Africa’s most important protected areas.

The project, sponsored by a subsidiary of U.S. agribusiness giant Herakles Farms in collaboration with a U.S. nonprofit organization, All for Africa, would span 70,000 hectares (154,000 acres), an area nearly the size of New York City.

“It’s simply frightening in scope,” said Thomas Struhsaker, a leading expert on African primates and rainforest ecology at Duke University in North Carolina, USA, who has worked in the region for nearly a half-century.

The project would destroy a critical forested area that currently links five national parks or protected areas in Cameroon, say the scientists.

“These forests are vital for wildlife, including the African elephant, chimpanzee and drill, all threatened or endangered species,” said anthropologist Joshua Linder of James Madison University in Virginia, USA, who has helped coordinate the protest. “These animals rely on the forests that would be destroyed to survive and move among the parks.”

“This area is a biodiversity hotspot, some of the world’s most biologically important real estate,” said tropical ecologist William Laurance of James Cook University in Australia, who studies threats to wildlife in the Congo Basin.

“There’s no way a project like this would be allowed in most countries, because the price for biodiversity is just too high,” said Laurance.

The project has been promoted in Cameroon as environmentally sustainable, but the scientists heatedly disagree. “Those promoting this project are misleading everyone—especially the people and government of Cameroon,” said Linder. “They claim the forests they want to clear are mostly logged and degraded, but we’ve shown clearly that they include lots of tall, dense forest that’s vital for wildlife and nature conservation.” Read the rest of this entry »





Unholy trinity of leakage, permanence and additionality

13 03 2012

I begin with the proverbial WTF? The title of this post sounds a little like the legalese accompanying a witchcraft trial, but it’s jargon that’s all the rage in the ‘trading-carbon-for-biodiversity’ circles.

I’m sure that most of my readers will have come across the term ‘REDD‘ (Reduced Emissions from Deforestation and forest Degradation), which is the clever idea of trading carbon credits to keep forests intact. As we know, living forests can suck up a lot of carbon from the atmosphere (remember your high school biology lesson on photosynthesis? Carbon dioxide in. Oxygen out), even though climate change is threatening this invaluable ecosystem service. So the idea of paying a nation (usual a developing country) to protect its forests in exchange for carbon pollution offsets can potentially save two birds with one feeder – reducing overall emissions by keeping the trees alive, and ensuring a lot of associated biodiversity gets caught up in the conservation process.

The problem with REDD though is that it’s a helluva thing to bank on given a few niggly problems essentially revolving around trust. Ah yes, the bugbear of any business transaction. As the carbon credit ‘buyer’ (the company/nation/individual who wishes to offset its carbon output by ‘buying’ the carbon uptake services provided by the intact forest), you’d want to make damn sure that all the money you spend to offset your carbon actually does just that, and that it doesn’t just end up in the hands of some corrupt official, or even worse, used to generate industry that results in even higher emissions! As the buyer, of course you want to entice investors to give you lots of money, and if you bugger up the transaction (by losing the resource you are providing), you’re not likely to have any more investors coming knocking on your door.

Enter the unholy trinity of leakage, permanence and additionality.

This horrible jargon essentially describes the REDD investment problem:

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 »




Sink to source – the loss of biodiversity’s greatest ecosystem service

29 02 2012

I’ve mentioned this idea before, but it’s nice when some real data support a prediction (no matter how gloomy that prediction might have been). It’s what drives scientists toward discovery (or at least, it’s what I find particularly appealing about my job).

Several years ago, my colleagues (Navjot Sodhi† and Ian Warkentin) and I wrote a major review in TREE about the fate of the world’s ‘second’ lung of the planet, the great boreal forests of Russia, Canada & Scandinavia. We discussed how fragmentation was increasing at an alarming rate, and that although most species there are still relatively intact, we stand to lose a lot of its biodiversity if we don’t halt the fragmenting processes soon. We wrote more on the subject in a paper to appear imminently in Biological Conservation.

Another component though that we raised in the TREE paper was the boreal forests were very much in danger of turning into a net carbon producer. You see, the ‘lung’ analogy is very pertinent because on average, the growth of the massive expanse of the vegetation in the forest generally takes up much more atmospheric carbon that it exudes through decay and burning (for as we all know, plants take up carbon dioxide to produce sugars during photosynthesis, and produce oxygen as a ‘waste’ product). However, as we fragment, cut down and burn the forest, it can end up producing more than it takes up (i.e., turning from a ‘sink’ to a ‘source’). We highlighted several studies indicating how insect outbreaks and human-exacerbated fire intensities and frequencies could conceivably do this.

Now Zhihai Ma and colleagues have just compiled a paper in PNAS indicating that the danger is well on the way to becoming reality in Canada. The paper entitled Regional drought-induced reduction in the biomass carbon sink of Canada’s boreal forests reports the results from 96 long-term permanent sampling plots spread right across southern Canada – from British Columbia in the far west, to Newfoundland in the far east. Read the rest of this entry »





Conservation catastrophes

22 02 2012

David Reed

The title of this post serves two functions: (1) to introduce the concept of ecological catastrophes in population viability modelling, and (2) to acknowledge the passing of the bloke who came up with a clever way of dealing with that uncertainty.

I’ll start with latter first. It came to my attention late last year that a fellow conservation biologist colleague, Dr. David Reed, died unexpectedly from congestive heart failure. I did not really mourn his passing, for I had never met him in person (I believe it is disingenuous, discourteous, and slightly egocentric to mourn someone who you do not really know personally – but that’s just my opinion), but I did think at the time that the conservation community had lost another clever progenitor of good conservation science. As many CB readers already know, we lost a great conservation thinker and doer last year, Professor Navjot Sodhi (and that, I did take personally). Coincidentally, both Navjot and David died at about the same age (49 and 48, respectively). I hope that the being in one’s late 40s isn’t particularly presaged for people in my line of business!

My friend, colleague and lab co-director, Professor Barry Brook, did, however, work a little with David, and together they published some pretty cool stuff (see References below). David was particularly good at looking for cross-taxa generalities in conservation phenomena, such as minimum viable population sizes, effects of inbreeding depression, applications of population viability analysis and extinction risk. But more on some of that below. Read the rest of this entry »





Parts a whole do not make

17 02 2012

I’m particularly proud of our latest paper for three main reasons:  (1) Salva Herrando-Pérez, lead author and contributor-extraordinaire to CB, has worked extremely hard to get this one out; (2) it is published in a really good journal; and most importantly, (3) it’s the very first empirical demonstration over hundreds of species that just because you have a density effect on some vital rate (e.g., survival, fertility, dispersal), this in no way means you have any evidence at all for density dependence at the population level. Let us explain.

Quantifying variation in population size is an important element for explaining and predicting population dynamics. In models where a vital (demographic) rate responds to change in population size, those ‘density-dependent’ relationships are ecologically understood as being demographic signals of trophic and social interactions, such as parasitism, predation or competition for shelter, because the intensity of those interactions varies with population size.

In fact, density-dependent effects reflect the theoretical capacity of populations to adjust growth and rebound from low or high numbers – and so this concept has become an important metric in population management and conservation  (Eberhardt et al. 2008). Read the rest of this entry »





Cartoon guide to biodiversity loss XV

13 02 2012

I’m in the field at the moment, so here are the latest six cartoons to pass the time (see full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here). Enjoy.

Read the rest of this entry »