His main point (as is mine, and that of a growing number of conservation scientists) is that we’ve already failed biodiversity, so it’s time to move into the next phase of disaster mitigation. By ‘failing’ I mean that, love it or loathe it, extinction rates are higher now than they have been for millennia, and we have very little to blame but ourselves. Apart from killing 9 out of 10 people on the planet (something no war or disease will ever be able to do), we’re stuck with the rude realism that it’s going to get a lot worse before it gets better.

This post acts mostly an introduction to Peter Kareiva & collaborators’ latest essay on the future of conservation science published in the Breakthrough Institute‘s new journal. While I cannot say I agree with all components (especially the cherry-picked resilience examples), I fundamentally support the central tenet that we have to move on with a new state of play.

In other words, humans aren’t going to go away, ‘pristine’ is as unattainable as ‘infinity’, and reserves alone just aren’t going to cut it.

Let me elaborate. It is plainly naïve, overly simplistic, unrealistic and ultimately criminal even to contemplate the notion that all extant species can be saved from extinction. Not only does this go against everything we know about the turnover of species on the geological time scale (i.e., 99 % of all species that have ever existed are now extinct), it erroneously overestimates our ability to solve the complex interaction between biology, governance, socio-economics, religion and politics (i.e., ‘conservation’).

And I use the word ‘criminal’ with sincerity. If you are naïve enough to embrace the outlook that conservation triage is unnecessary or even offensive, I’ve got news for you – you are (inadvertently or ignorantly) consigning many more species to extinction by wasting precious resources on the doomed. I have little time for climate-change deniers, religious zealots or alternative-’medicine’ quacks, soI have just as little time for so-called conservationists that choose to ignore reality.

But acceptance of the ongoing negative fate of biodiversity is insufficient to move us forward. While I agree with Kareiva and colleagues that a semi-religious attachment to the ideal of ‘pristine’ nature is helping no one (not least of which, biodiversity), we can go a lot further than just accepting the ‘new’ paradigm.

As we discussed in a recent post here on ConservationBytes.com, the greatest strides forward in this matured (but doggedly viscous) discipline will be to:

1. Accept that the biology is more or less well-developed. We can further fine-tune our estimates of loss or minimisations of gain, but the concepts defining how and why species go extinct are firmly established;
2. Get extremely practical about what to save. Adolescent idealism about saving everything on the planet will get us nowhere. Part of this is to determine WHICH species are the most important components of ecosystem resilience (ecosystem function), and part is being hard-core about designing algorithms that quantify this importance.
3. Focus on quantifying ecosystem services – which species complexes provide the highest benefits to humanity. Social revolution thus far (and, I argue, will continue to) eludes us, so convincing the blatantly humanist section of society will require some very well-established relationships between biodiversity and human health, wealth and welfare.
4. Accept that technical fixes are the (perhaps largest) areas of potential gain. Without solving our lust for energy at the expense of dwindling and finite resources, biodiversity will continue down the toilet.

So to all those dedicated and well-meaning environmentalist types out there, if you cannot accept these suggestions, then I have to put you in the same group as the self-interested, myopic, greed hounds that oppose any form of conservation. Get out of the way because you have become part of the problem.

I have some hope, but I remain profoundly pessimistic about our own future as a result of biodiversity erosion. We do not appear, after all, to possess a very strong sense of (long-term) self-preservation.

CJA Bradshaw

Another workshop; another productive week.

As many readers will know, I’ve spent the last week in the mountains north of Madrid working on a series of conservation ecology papers with host Miguel Araújo (of the Integrative Biology and Global Change Group at the Spanish National Museum of Natural Sciences), my lab colleagues, Barry Brook, Damien Fordham and Salvador Herrando-Pérez, and Miguel’s post-doc, Regan Early.

Let me tell you, staying in the craggy granite Sierra de Guadarrama mountains at a well-known health spa eating explosively flavourful Spanish food and drinking an immodest selection of the region’s delicious wines, is particularly conducive to scientific productivity (yes, I AM a jammy tart). Although unlikely to be followed by many (even if they have the means), I highly recommend the experience for those suffering from writer’s block.

But this post isn’t about the scenery, food, wine, hydrothermal treatment or even the content of the workshop at all (I just prefaced it as such to gloat); it’s about a particularly sore point for me and hundreds of thousands of other scientists the world over – our slavery to the scientific publishing industry.

And ‘slavery’ is definitely the most appropriate term here, for how else would you describe a business where the product is produced by others for free¹ (scientific results), is assessed for quality by others for free (reviewing), is commissioned, overviewed and selected by yet others for free (editing), and then sold back to the very same scientists and the rest of the world’s consumers at exorbitant prices.

This isn’t just a whinge about a specialised and economically irrelevant sector of the economy, we’re talking about an industry worth hundreds of billions of dollars annually. In fact, Elsevier (agreed by many to be the leader in the greed-pack – see how some scientists are staging their protest; also here) made US$1.1 billion in 2010!

Apart from rectifying some dodgy business practices, I thought we were well and truly enslaved to this model because of the one thing science must uphold beyond all else – integrity. Any other model involving payment for services would, I thought, jeopardise the quest for subjetivity reduction (a.k.a. objectivity²). Imagine if we had to sell our science to highest bidder – speciali-interest groups could conceivably highjack the system to their advantage (sound like American politics at all?). I’d certainly give up the baton if that happened.

But after discussing the issue this week in between bouts of R programming, Miguel mentioned an idea of his³ that I think has immense merit. Sure, there are plenty of alternative models out there to credit reviews in a meaningful way (e.g., The Peerage of Science experiment), but none seem to get at the core of the issue. How do we get remunerated for our time, effort and expertise without sacrificing our scientific integrity.

Miguel’s answer³ is the simplest and most elegant of them all.

Suppose for moment that ALL journals paid a standard sum for each review they commissioned. Let’s say the price was somthing in the vicinity of €100 (an amount that Miguel and apparently many others deemed would be a reasonable request for a review – I concur). Now, I get something like 2-3 review requests per week, and I refuse probably 80 % of them for time-commitment reasons. So let’s say I agree to do 20 reviews per year. Under Miguel’s modified scheme, I’d earn an extra €2000 (~ AU$2484) per year. Not a lot, but it’s certainly enough to take my wife out to dinner a few more times than usual, perhaps buy some nice wine, or even (partially) finance a trip to Spain! The point is that I wouldn’t be getting rich, but I’d feel remunerated for my hard work.

Now let’s look at it from the perspective of the journal. An average journal in ecology probably publishes between 10-20 papers per issue, with 6-12 issues per year. Let’s go with an average of 15 × 8 = 120 papers per year. Of course, the journal would have to pay for the reviews for rejected papers too, so let’s use a rather conservative 50 % rejection rate⁴ to make our point. At an average of 2 reviews per paper, that’s 240 × 2 × €100 = €48,000 paid to reviewers each year per journal. For the big scientific publishing companies, let’s say they manage about 2000 journals each (Elsevier has 2632, Wiley has 1500 and Springer has 2400) – that’s €96,000,000 per year. That seems like a whopping number, but when put into perspective, it’s only about 10% of the $1.1 billion Elsevier earned in 2010.

I think profiteering from slavery is wrong (call me a crazy, liberal do-gooder), so I’d feel perfectly justified in asking for such a modest proportion of these over-the-top profits for the work I now do for free.

There are other advantages to such a scheme beyond the improved economic fairness. As an editor, I’d make damn sure I chose REALLY GOOD reviewers if the journal I was editing had to pay €100 a pop for each review. As a reviewer, I’d probably provide a much more in-depth, insightful review if I was getting paid, and I’d bloody well do it in time (or probably have to forfeit my fee). You could also have a review scoring system within each journal such that those reviewers who consistenly provided high-quality reviews would get solicited more often, thus gaining a little more than the lazier and less-dedicated types.

It’s time we had a change.

CJA Bradshaw

–

¹Believe it or not, but many journals (mainly American ones – see an example here) actually CHARGE scientists for the ‘privilege’ of publishing in them. F$%#ing insane.

²Humans can only ever pursue subjectivity reduction because absolute objectivity is beyond our capacity. Errare humanum est.

³Miguel isn’t really the progenitor of the idea of paying for reviews – see a paper by Christopher Lortie here on the subject.

⁴Remember, we’re not counting the papers that were rejected by the Editor without review.

By weird coincidence, Salvador Herrando-Pérez (student blogger extra-ordinaire – see his previous posts on evolution, pollination, bird losses, taxonomic inflation, niche conservatism, historical biogeography, ecological traps and ocean giants) has produced a post this week expanding on the problem of roads. Also weirdly coincidental is that both Salva and I are in his home country of Spain this week.

–

Australia’s > 800,000-km road network would go 60 times around the equator of our planet. Confined to the boundaries of any one country, roads are a conspicuous component of the landscape, and shape the dispersion, survival and reproduction of many plants and animals in urban and remote areas.

Those who drive (or are driven by) will be familiar with the image of a crushed kangaroo on the roadside (a hedgehog in Europe), or the sticky mosaic of insects smashed against the windscreen after a high-speed run. Mortality by collision is one of the many effects that roads can have on the demography of organisms – including humans. Those effects encompass

• physical alteration of terrestrial and aquatic habitats,
• chemical pollution leakage during road construction and maintenance, and from asphalt compounds during storms,
• alteration of animal behaviour (e.g., change in home range, or in patterns of flight or vocalisation),
• access to remote areas by hunters, fishermen and gatherers in general, and
• intense habitat fragmentation^1-3.

However, some species get around those negative impacts by using the roads as pathways to new territories, thereby eluding barriers like seas, mountains, rivers, dense vegetation, or competition for vital resources with other species.

Figure 1: Road use by cane toads in the Northern Territory, Australia (2). Top panel: frequency of radio-tracked individuals recorded at different distances to the nearest dirt road (25 to 975 m in 50 m intervals). Bottom panel: frequency of toads with body axis aligned at different angles with the main axis of the Arnhem Highway (0º for toads facing the main axis of the road, to |90|º for toads facing perpendicular to the right or left of the road). Most toads were found within 25 m of dirt roads, and facing -10º to 10º to the highway axis.

Brown and colleagues⁴ illustrate the latter scenario with cane toads (formerly Bufo marinus; now Rhinella marina) in Australia. This species was introduced to Queensland in the 1930s to control (unsuccessfully) insect pests in sugar cane fields⁵. Nowadays, Aussie cane toads outnumber the human population in China, occupy a surface equivalent to 100 million soccer stadia, and only in 2009 crossed the border of Western Australia, > 2,500 km from the release point⁶ [see Rick Shine’s cane toad lab research]. For over 300 nights, Brown et al. radio-tracked 49 adult toads in farmland and eucalyptus forest in the Northern Territory. They found that these animals adjusted their movements to the local network of roads. In half of the records, toads were seen on or near dirt roads, mainly following those portions of the roads in the Northwest direction of progression of the invading front (Figure 1).

With an independent sample, they observed that the body axis of most individuals found near a highway was aligned with the principal axis of the road (Figure 1), giving evidence that the animals were moving relative to the trajectory of the highway. Undoubtedly, roads confer demographic benefits that compensate the > 200 tonnes of toads killed on the roads in (only) Queensland every year.

The invader’s backpack

Among the panoply of exotic species that are detrimental globally outside their native ranges⁷, the fungus Phytophthora lateralis is another self-explanatory example of road-loving biological invasion⁸. Rivers disperse the spores of this fungus. The spores then parasitise the roots of tree species along riverbanks and beyond (i.e., during floods), resulting in fulminating rot of the entire root system. In Oregon and California, spores have spread in most rivers in the mud stuck to vehicles and people’s shoes walking along local dirt roads. The disease was first recorded in the 1920s in Seattle in a plantation of Port Orford cedars (Chamaecyparis lawsoniana). It has since caused massive mortality of juvenile to centenary cedars in the conifer forests of Western USA, and has ruined a multi-million-dollar export of wood and ornamental trees (by means of which the fungus has already reached, at least, Asia and Europe).

Roads also contribute to the spread of insect and plant pests and human diseases^1,3. In the case of cane toads, dirt roads in the Northern Territory might be assisting in the dispersal of their toxicity (arguably the toad’s worst ecological impact⁶), present in all developmental stages (egg, tadpole, toadlet, and adult), especially for adults because toxicity increases with size. Up to 27 species of vertebrates have been reported to die from ingestion of cane toads⁵ – thus, at a population level, it is predictable that the worst ravages will occur in apex predators able to catch larger (and more toxic) toads, such as elapid snakes, varanid lizards, the freshwater crocodile (Crocodylus johnstoni) and quolls (Dasyurus spp.)⁶.

Surely we all want roads that are safe and (as much as possible) benign for biodiversity. Taylor and Goldingay² have recently reviewed the state of the art of published research into roads and wildlife worldwide, with the following highlights:

• studies on large ungulates and carnivores predominate, partly due to rocketing insurance and medical costs after collisions;
• road-crossing structures for wild animals are being widely applied, although population benefits remain poorly understood;
• behavioural avoidance with genetic and metapopulation implications occurs in some species, calling for landscape road planning;
• focused management actions are needed for globally threatened species like amphibians (surely not cane toads),
• poor experimental designs across the board.

It caught my eye that the three reviews I cite^1-3 did not encompass road impacts on subterranean ecosystems⁹ – a dark oasis of living wonders¹⁰ and reservoir of > 30 % (98 % along with glaciers) of available freshwater globally¹¹. Clearly, to those who build roads (from the politician to the engineer), environmental impact assessment should take into account their multiple ecological impacts, and not only along the route itself^2,3.

Next time you hit the road, be aware; you are never alone.

—

1. S. C. Trombulak and C. A. Frissell, Conserv Biol 14 (1), 18 (2000) doi:10.1046/j.1523-1739.2000.99084.x
2. B. D. Taylor and R. L. Goldingay, Wildl Res 37 (4), 320 (2010) doi:10.1071/WR09171
3. W. F. Laurance, M. Goosem, and S. G. W. Laurance, Trends Ecol Evol 24 (12), 659 (2009) doi:10.1016/j.tree.2009.06.009
4. G. P. Brown, B. L. Phillips, J. K. Webb et al., Biol Conserv 133 (1), 88 (2006) doi:10.1016/j.biocon.2006.05.020
5. C. Lever, The Cane Toad. The History and Ecology of a Successful Colonist. (Westbury Academic and Scientific Publishing, Otley, UK, 2001)
6. R. Shine, Quart Rev Biol 85 (3), 253 (2010) doi:10.1086/655116
7. S. Lowe, M. Browne, and S. Boudjelas, Aliens 12, S1 (2000)
8. E. M. Hansen, Boreal Environ Res 13, 33 (2008); E. M. Hansen, D. J. Goheen, E. S. Jules et al., Plant Disease 84 (1), 4 (2000) doi:10.1094/PDIS.2000.84.1.4; E. S. Jules, M. J. Kauffman, W. D. Ritts et al., Ecology 83 (11), 3167 (2002)
9. M. Knez and T. Slabe, in Encyclopedia of Caves and Karst Science, edited by J. Gunn (Palgrave Macmillan, London, UK, 2004), pp. 419
10. J. Gibert and L. Deharveng, BioScience 52 (6), 473 (2002) doi:10.1641/0006-3568(2002)052[0473:SEATFB]2.0.CO;2; D. C. Culver and B. Sket, J Cave Karst Stud 62 (1), 11 (2000)
11. D. L. Danielopol, C. Griebler, A. Gunatilaka et al., Environmental Conservation 30 (2), 104 (2003) doi:10.1017/S0376892903000109
12. B. L. Phillips, G. P. Brown, J. K. Webb et al., Nature 439 (7078), 803 (2006) doi:10.1038/439803a
13. N. Sallam, Aust J Entomol 50 (3), 300 (2011) doi:10.1111/j.1440-6055.2010.00807.x

www.sumatranforest.org

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

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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.

Of course, roads are not just an environmental worry in the tropics. In forested areas of western North America, one of the best predictors of wildfire frequency is the density of roads. In Siberia, road expansion is promoting a sharp increase in logging and forest fires. And new roads in the Arctic could potentially alter epic mammal migrations.

But no other region can match the tropics for the sheer scale and pace of road expansion and the degree of environmental change roads bring. Road building has a range of direct impacts on rainforest ecology. In wet tropical environments, the cut-and-fill operations associated with road construction can impede streams, increase forest flooding, and drastically increase soil erosion. Roads also discharge chemical and nutrient pollutants into local waterways and provide avenues of invasion for many disturbance-loving exotic species.

Roads that cut through rainforests can also create barriers for sensitive wildlife, many of which are ecological specialists. Studies have shown that even narrow (30 m-wide), unpaved roads drastically reduce or halt local movements for scores of forest bird species. Many of these species prefer deep, dark forest interiors; they have large, light-sensitive eyes and avoid the vicinity of road verges, where conditions are much brighter, hotter, and drier. A variety of other tropical species — including certain insects, amphibians, reptiles, bats, and small and large mammals — have been shown to be similarly leery of roads and other clearings.

And by bringing naïve rainforest wildlife into close proximity with fast-moving vehicles, roads can also promote heavy animal mortality. For some creatures, especially those with low reproductive rates, roads could potentially become death zones that help propel the species toward local extinction.

Although the direct effects of roads are serious, they pale in comparison to the indirect impacts. In tropical frontier regions, new roads often open up a Pandora’s box of unplanned environmental maladies, including illegal land colonization, fires, hunting, gold mining, and forest clearing.

“The best thing you could do for the Amazon,” said the respected Brazilian scientist Eneas Salati, “is to bomb all the roads.”

In Brazilian Amazonia, my colleagues and I have done studies showing that around 95 % of all deforestation occurs within 50 km of highways or roads. Human-lit fires increase dramatically near Amazonian roads, even within many protected areas. In Suriname, most illegal gold mining occurs near roads, whereas in tropical Africa we have found hunting to be so intense near roads that it strongly affects the abundance and behaviour of forest elephants, buffalo, duikers, primates, and other exploited species. Roads can sharply increase trade in bushmeat and wildlife products; one study found that eight killed mammals were transported per hour along a single road in Sulawesi, Indonesia.

Paved highways are especially dangerous to forests. They provide year-round access to forest resources and reduce transportation costs, causing larger-scale impacts on forests and wildlife than do unpaved roads, which tend to become impassable in the wet season. The proposed routes of new highways often attract swarms of land speculators who rush in to buy up cheap forest land, which they then sell to the highest bidder.

Perhaps the most damaging aspect of paved highways is that they spawn networks of secondary roads, which spread further environmental destruction. For instance, the 2,000 km-long Belem-Brasília highway, completed in the early 1970s, has today evolved into a spider web of secondary roads and a 400 km-wide swath of forest destruction across the eastern Brazilian Amazon. As my colleagues and I showed in a 2001 study published in Science, large expanses of the Amazonian forest could be fragmented by the advance of new highways and roads in Brazil. According to our models, by the year 2020, rates of forest destruction would rise by up to 500,000 ha per year, and the area of forest that remained in large, unfragmented tracts — exceeding 100,000 km² — would decline by 36 %.

Can the environmental impacts of tropical roads be minimized? In theory, the answer is “Yes, partially.” Frequent culverts can reduce the effects on streams and hydrology. Impacts on animal movements can be reduced by keeping road clearings narrow enough so that canopy cover is maintained overhead, providing a way for arboreal species to cross. In high-priority areas, such as certain national parks, rope-bridges are being used to facilitate road crossings of monkeys and possums. For small ground-dwelling species, culverts beneath roads can allow road-crossing movements, and even large animals such as Asian elephants will use highway underpasses that are designed to be wildlife-friendly.

Measures also exist to limit the devastating indirect impacts of roads, such as illegal land colonization and forest clearing. One of the most vital steps is to establish legally parks or reserves along road routes in advance of road construction. Such reserves often substantially reduce forest incursions, though they rarely halt them entirely. Another promising idea is to promote rail roads rather than highways in tropical wilderness regions. Because railroads stop only at fixed locations, the spatial patterns of forest exploitation and movement of forest products can be more easily controlled and monitored than with roads.

In practice, however, limiting the environmental impacts of roads in developing nations is expensive and risky. Tropical nations rarely have the institutional capacity, human capital, or financial resources to adequately manage development in their remote frontier regions, frequently leading to a “resource grab” revolving around illegal trade and outright theft of natural resources, which is greatly facilitated by road expansion.

When it comes to tropical roads, I believe three conclusions are inescapable. First, highways and roads are the single biggest factor determining the pattern and pace of tropical forest destruction. New roads that slice deep into intact forest tracts are especially devastating.

Second, among the many human drivers of environmental change, road building is one of the most readily amenable to policy modification. In practical terms, it is far easier to cancel or relocate a road project than it is to, say, reduce human overpopulation or halt harmful climate change.

Finally, if we hope to maintain intact tropical forests and their vital ecosystem services and biodiversity, then we simply must get serious about tropical roads. And there is only one real solution: carefully plan and limit frontier road expansion.

How can this be achieved? First, we need to sensitize political decision-makers, economists, infrastructure planners, and the general public about If we hope to maintain intact tropical forests, then we must get serious about tropical roads. the myriad environmental costs of road expansion, especially into intact forests. The biggest road projects are often being supported by international lenders — such as the Asian, African, and Inter-American development banks — and by foreign aid doled out by China, the U.S., and the European Union. Educating such decision-makers needs to be done both generally and on a project-by-project basis.

When I was president of the Association for Tropical Biology and Conservation, one of my key goals was to use the organization’s scientific expertise and credibility to combat some of the most environmentally risky plans for frontier road expansion. We were especially active in critiquing plans to punch new roads into the cores of national parks, such as Yasuní in Ecuador, Kerinci Seblat in Indonesia, and the Serengeti in Tanzania.

Another key priority should be better frontier law enforcement and forest monitoring, given that much road building in tropical nations is illegal or unplanned. Special attention should be focused on the more-aggressive timber, oil, gas, and mineral corporations, many of which are known to engage in bribery and collusion in their efforts to gain unbridled access to forest resources.

There is also a dire need to improve environmental impact assessments (EIAs) for planned roads. In Brazil, for instance, EIAs for several major Amazonian highways focused only on a narrow strip along the road route itself, while completely ignoring the devastating indirect effects of roads. Similarly, EIAs for major development projects, such as large mines and hydroelectric dams, often ignore the impacts of road proliferation that such projects inevitably promote.

Finally, given that tropical deforestation is a massive source of greenhouse gas emissions, international carbon-trading funds should be used to better plan and mitigate road projects, to establish new protected areas in advance of road construction, and to halt the most ill-advised road projects altogether. In the end, the easiest and most cost-effective way to limit the manifold pressures from roads may be simply not to open Pandora’s box in the first place.

William F. Laurance

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’).

Nice idea, and one that is especially attractive in this day of carbon accounting (forest carbon sequestration as offsets to industrial and transport greenhouse gas production). If true, the net biodiversity effect is adequate justification for maximising species diversity in carbon plantings such that both carbon sequestration and biodiversity value are maximised – the best bang for your planting buck.

The problem is that it’s not even close to being a theory in ecology, let alone a law. In fact, the hypothesis has very mixed empirical support, and the majority of it is in manipulated and simplified grasslands, with no net effect, or even negative relationships, reported for natural forest stands. Not a good sell really if you’re trying to convince a policy maker that more species are better to maximise productivity, and hence, carbon uptake.

Enter Yu Zhang and colleagues and their recently published (online) paper: Forest productivity increases with evenness, species richness and trait variation: a global meta-analysis. Now, I’m a big fan of meta-analyses to answer big questions; there’s nothing like a lot of disparate studies collated to provide insight into broad-scale pattern (e.g., see our recent meta-analysis on the value of primary forests for tropical biodiversity published in Nature last year).

And that’s exactly what they did – Zhang and colleagues collated diversity-productivity data from 54 forest studies to determine the overall ‘average’ direction of the diversity-productivity relationship. Using boosted-regression trees (and slick way to deal with complex multi-variate data), their overall conclusion was that ‘polycultures’ (i.e., many species) were more productive than ‘monocultures’ (single-species stands). So much for the DPR debate in forest ecosystems.

More interestingly perhaps was that the biodiversity metric used dictated the strength of effect found. Even though there was a positive richness relationship (more species = higher productivity), it plateaued after a certain threshold number of species. However, when using ‘evenness’ as the measure of ‘diversity’ (i.e., a metric which includes relative abundance of each species in system), stands that were more even (i.e., not dominated by a few common species) were more productive, and this metric explained a much higher component of the variance in productivity than richness alone. This means that a simple list of species doesn’t really indicate the full potential of the stand because of things like functional redundancy. Finally, they found no evidence for a deviation of the relationship among biomes, suggesting that the effect is global and real.

Now there are a lot of fine details in the analysis that complicate matters, but I think the take-home message is clear. This is a hugely important finding and one that all conservation ecologists should be able to cite when justifying the essential role of diversity in ecosystem function.

CJA Bradshaw

I suppose the delve from historical/modern ecology into prehistory was inevitable given (a) my long-term association with brain-the-size-of-a-planet Barry Brook (who, incidentally, has reinvented his research career many times) and (b) there is no logic to contend that palaeo extinction patterns differ in any meaningful way from modern biodiversity extinctions (except, of course, that the latter are caused mainly by human endeavour).

So while the last, fleeting days of my holiday break accelerate worringly toward office-incarceration next week, I take this moment to present a brand-new paper of ours that has just come out online in (wait for it) Quaternary Science Reviews entitled Robust estimates of extinction time in the geological record.

Let me explain my reasons for this strange departure.

It all started after a few drinks (doesn’t it always) with Alan Cooper, Chris Turney and Barry Brook when we were discussing the uncertainties associated with the timing of megafauna extinctions – you might be aware that traditionally there have been two schools of thought on late-Pleistocene extinction pulses: (1) those who think there were mainly caused by massive climate shifts not to dissimilar to what we are experiencing now and (2) those who believe that the arrival of humans into naïve regions lead to a ‘blitzkrieg‘ of hunting and overkill. Rarely do adherents of each stance agree (and sometimes, the ‘debate’ can get ugly given the political incorrectness of inferring that prehistoric peoples were as destructive as we are today – cf. the concept of the ‘noble savage‘).

As most readers of CB might appreciate, I generally do not subscribe to the ‘one equation fits all’ hypothesis when it comes to extinctions. Close inspection of the historical record general supports the conclusion that most extinctions arise from a perverse synergy of drivers which increase kill rates beyond the mere sum of their individual effects. Thus, why human overkill and a series of large climate shifts could not have ‘worked’ in unison to drive the major extinction events recorded in the fossil record over the last 100,000 years or so has no real theoretical justification; it seems that many engaged in the debate adhere exclusively to one view or the other. To us, this is clearly a gross over-simplification.

But as I am want to do, I digress (there will be much more of this in the next few months as Alan, Chris, Barry and I finalise a few analyses on this subject for the Holarctic, late-Pleistocene megafauna extinctions). The issue about which I am writing today (and the subject of the paper in question) is the precursor to all this debate, for how can you possibly determine the contribution of possible drivers if you don’t really know when species x went extinct?

You can see where I’m going with this if you know a little about fossils. As you can appreciate, most dead things don’t fossilise, and even if they do, the rate and extent at which fossilisation occurs can be extremely variable. Plus, there’s the added complication of finding the bloody things (we haven’t yet dug up the entire surface of the planet). So the probability of an animal dying in the right place, having the right conditions for fossilisation, persisting through time in some state of preservation and being found by one of those strange people who like digging for the fossilised remains of long-dead creatures (that bizarre breed of human known as a ‘palaeontologist’) is mind-numbingly small.

Thus, trying to figure out the ‘last’ time extinct species x walked the planet isn’t as straight-forward as it might initially seem simply by dating the most recent fossil in a series of fossils. Who’s to say the ‘most recent’ is indeed that? Then, off course, there’s the added uncertainty in the dating method itself; radiocarbon methods used to date fossils from several thousand to about 60,000+ years ago have a certain margin of error that increases the farther back in time you go.

You might be beginning to get the picture – fossil records generally are pretty crap for inferring extinction times.

Now, several clever people have attempted to incorporate all this uncertainty together in fairly sophisticated statistical models to estimate the time that a species actually went extinct. One of the most famous was the application by Solow and Roberts of the Weibull distribution to a series of known dodo sightings prior to their demise (although in this case, Solow and Roberts assumed that there was no uncertainty in the dates); Solow and colleagues went on to modify the approach to incorporate radiocarbon dating uncertainty. And there are others.

However, all approaches developed to date make certain assumptions about the underlying distribution of the probability of fossilisation and discovery, and few make any attempt to correct for sampling artefacts in the time series themselves (i.e., how many fossil records are there?). Enter us.

Our paper describes a new method built on one constructed by McInerney and colleagues that incorporates most of the uncertainty, as well as making no assumptions about the underlying distribution. We call it the ‘GRIWM’ method (‘Gaussian-resampled inverse-weighted McInerney’ – I know, a clumsy mouthful, but the acronym helps) because it resamples the dates within their radiocarbon confidence bounds, and it weights the most recent fossils more heavily than older ones to account for sample-size differences among series. The McInerney method itself is based on the sighting interval (time between fossil discoveries) to predict the probability of another one being found.

While the maths might be a little impenetrable for some, it’s really a rather straight-forward approach that I hope will get a lot of use. The links to the modern biodiversity crisis are manifold – if we can decipher the set of conditions leading to some of the biggest extinction events in the history of the Earth, we should be better placed to prevent some of the worst ravages in the future

CJA Bradshaw

Paul has recently blogged about the ‘species’ concept as it relates to DNA barcoding, which I highly recommend. It also prompted me to write this post because now the video of the discussion is available online (see below).

Now, the panel was a bit of a funny set-up in a way – I was really one of the only ‘conservation biologists’ represented (Patrick O’Connor and Andy Lowe perhaps excepted), with the rest mainly made up of molecular people (Pete Hollingsworth, Bob Hanner, Karen James) – and I was told prior to the ‘debate’ that I was meant to be the contrarian (i.e., that there is no role for DNA barcoding in conservation).

Fundamentally, I don’t actually embrace the contrarian view on this one given that I see no reason why DNA barcoding can’t enhance or refine our conservation knowledge and skills. But the ‘debate’ did raise some important issues about technological advancements in the application of conservation science to real conservation.

I suppose that prior to getting stuck into the polemic I should define DNA barcoding for the uninitiated; it’s a basic technique that analyses short sequences of DNA with the sole purposes of identifying from which species they come. Imagine walking through the bush with a barcode scanner and pointing at random species you see and getting an instant identification read-out without actually knowing the species beforehand. You can see why it’s called ‘barcoding’ because it is like running products through the check-out to get instant price details.

Some of the advantages for conservation should be immediately obvious – ‘forensics’ of the wildlife or illegal timber trade can be enhanced by letting authorities know the origin and pathway of illegally imported or marketed animal or plant products. This can give bodies like customs and quarantine departments a big legal stick to smash poaching rings, et cetera. Another is determining the presence of a rare species that is difficult or impossible to survey – for example, identifying DNA fragments of rare fish in samples of river water. Once identified using DNA barcoding, a legal argument to preserve that habitat on the basis of threatened wildlife legislation can be made without the expense and uncertainty of traditional wildlife surveys.

I suppose the main point of contention about DNA barcoding is that it merely refines our capacity to survey species we probably already know are in trouble. I submitted during the discussion that we could probably kill every single conservation biologist in the world and not really handicap ‘conservation implementation’ in any major way because we have the main aspects of the science sorted (fragmentation is bad; more habitat area = more species; climate change is bad; invasive species are bad; too few individuals is bad; small populations tend to go extinct; drivers of extinction synergise to make things worse – see full list on Conservation Classics). The principal conservation science discoveries have been made; now we need to manage the resource consumption of 7 billion humans more than anything else. You can also read more about conservation science ‘mucking around the edges‘ in a previous post here on CB.

Another potentially questionable application of barcoding to conservation is that it merely tells us if something is there, not how many or in what state. With a simple binary output, we lack some essential information regarding the value of an area based on mere presence/absence. Certainly we do now do area prioritisation based largely on presence/absence data, but how many more cryptic species identifications do we need to prioritise habitats for preservation?

Those somewhat philosophical beefs aside, I’m still very much in support of the concept of quantifying species better than the somewhat subjective and categorical binomial genus-species system we currently use. I’m also excited by the prospect of using DNA barcoding to quantify ecosystem health better by measuring soil and water microbia composition, and perhaps even starting to get a handle on soil fungus diversity. If we can even improve DNA barcoding to become ‘q-barcoding’ that quantifies relative abundance in addition to identification, we’ll really have a massively important tool for measuring ecosystem and species health.

I’ll be interested in CB readers’ opinions on the subject.

CJA Bradshaw

Filed under: anthropocene, conservation, DNA, ecosystem function, genetics, mycorrhiza ]]> http://conservationbytes.com/2012/01/05/does-conservation-biology-need-dna-barcoding/feed/ 1 -34.917731 138.603034 -34.917731 138.603034 CJAB dna http://conservationbytes.com/2011/12/30/cartoon-guide-to-biodiversity-loss-xiv/ http://conservationbytes.com/2011/12/30/cartoon-guide-to-biodiversity-loss-xiv/#comments Fri, 30 Dec 2011 02:16:00 +0000 CJAB http://conservationbytes.com/?p=6570 ]]> The last post of 2011, I thought I’d focus on the lighter side (that is to say, my brain is muddled by the lovely break from academia, so I don’t really feel like investing too much cerebral energy). Here, therefore, are the latest six cartoons… (see full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here). May fewer species go extinct in 2012 than 2011…

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© 2008-2011 ~Hiuki http://fav.me/d1j3ns9

I apologise to CB readers for the unusually low frequency of posts this month. With the International Congress for Conservation Biology taking up a lot of my time earlier this month, and the standard palaver of xmas preparations (i.e., getting shit done before the end of the year), I’m afraid the blog has taken a back seat. Now officially ‘on leave’ (whatever that means for an academic), I have found a brief window during which I can put a few thoughts together.

For this post I must take you back to October 2011 when, if you were in Australia, you might have heard about the so-called ‘debacle‘ of the Macquarie Island rabbit/rate/mouse-eradication programme in which it was identified that a few thousand seabirds had become the collateral damage.

To recap, an intense poisoning programme was initiated on subantarctic Macquarie Island to eradicate these pests after years of massive environmental degradation had finally forced the government’s (of Tasmania and the Commonwealth) hand to do something. What caught my eye in all this was the sheer stupidity and politicking associated with the programme, in which hyper-conservative Eric Abetz (Liberal Senator for Tasmania) managed to turn this amazing success into a Labor-bashing political sledge-hammer.

Abetz is no stranger to anti-environmentalism and fights vehemently for Tasmania’s forest-raping industry; he considers political parties such as the Greens, environmental groups such as The Wilderness Society and pro-democracy groups such as Get Up! his mortal enemies. He’s even had a go at esteemed author Richard Flanagan for supporting the anti-deforestation movement in Tasmania!

His latest regurgitation of spectacularly uninformed and politically motivated, anti-environmental vomit couldn’t have missed the point more on the Macquarie Island feral eradication programme. Most would agree that despite our general failing of biodiversity conservation, conservation biologists have had a fair share of major wins with island pest eradications; indeed, at times it seems the only thing we can get right is killing the baddies we were originally responsible for introducing.

Now, I’m no fan of the Tasmanian legislators and government drones who for years delayed or severely under-appreciated science to inform sound environmental policy when it came to Macquarie Island (indeed, I would go so far as to say that the established environmental autocracy in the Tasmanian government is one of the principal enemies of conservation because of their entrenched anti-science stance), but for once, they finally got around to doing something good with this ~ million-dollar programme.

And I have some history there too – I was stationed on Macquarie Island over 4 years from 1999-2004 during my postdoctoral fellowship, during which time I worked on many aspects of elephant seal population and behavioural ecology (see associated publications here). In my last year there, I was shocked upon my return to the island after an 18-month stint back in mainland Australia about just how much damage the rabbits had done after the last cat had been shot a few years before. I was so moved that I wrote a popular article on the matter to bring it to the public’s attention – you can read that article (published in Australasian Science) here for more background information.

For the ultra-right wing Senator Abetz to turn this success into his own political poisoned arrow is, to be perfectly honest, an environmental crime in its own right. Using the weak argument that some protected species have suffered as a consequence is the classic tool of the so-called ‘environmentalists’ who would rather focus on a single species (or even individual) while the rest of biodiversity melts into extinction (see related post here). We just don’t have time for this nonsense, and this is why we have to consider uncomfortable choices such as triage and controversial energy-generation technology.

I’m not for a moment insinuating that Senator Abetz truly feels for the poor seabirds who had the misfortune of swallowing a bit of poisoned bait in the quest to return their island to its former pristine biodiversity greatness; rather, I think he used the weak and uninformed argument for his own political gains (a double travesty). We have to move past this double-dipped bullshit if we want to make some real gains for biodiversity in Australia.

CJA Bradshaw

© WWF

Apologies for the slow-down in postings this past week – as many of you know, I was attending the International Congress for Conservation Biology in Auckland. I’ll blog about the conference later (and the stoush that didn’t really occur), but suffice it to say it was very much worthwhile.

This post doesn’t have a lot to do per se with the conference, but it was stimulated by a talk I attended by Conservation Scholar Stuart Pimm. Now, Stuart is known mainly as a tropical conservation biologist, but as it turns out, he also is a champion of temperate forests – he even sits on the science panel of the International Boreal Conservation Campaign.

I too have dabbled in boreal issues over my career, and most recently with a review published in Trends in Ecology and Evolution on the knife-edge plight of boreal biodiversity and carbon stores. That paper was in fact the result of a brain-storming session Navjot Sodhi and I had one day during my visit to Singapore sometime in 2007. We thought, “It doesn’t really seem that people are focussing their conservation attention on the boreal forest; how bad is it really?”.

Well, it turns out that the boreal forest is still a vast expanse and that there aren’t too many species in imminent danger of extinction; however, that’s where the good news ends. The forest itself is becoming more and more fragmented from industrial development (namely, forestry, mining, petroleum surveying and road-building) and the fire regime has changed irrevocably from a combination of climate change and intensified human presence. You can read all these salient features here.

So, back to my original thread – Stuart gave a great talk on the patterns of deforestation worldwide, with particular emphasis on how satellite imagery hides much of the fine-scale damage that we humans do to the world’s great forests. It was when he said (paraphrased) that “50,000 km² of boreal forest is lost each year, but even that statistic hides a major checkerboard effect” that my interest was peaked.

So I finally come to the point of this post. In the special issue of essays devoted to the memory of Navjot Sodhi to be published in Biological Conservation in early 2012 (see also the previous post on another paper of ours that will appear in that issue), Ian Warkentin and I (Ian co-authored the first paper in TREE mentioned above) have written a ‘boreal’ tribute to Navjot that has just come out online early.

The paper is entitled A tropical perspective on conserving the boreal ‘lung of the planet’ and in it we describe the little-known fact that despite being one of the world’s top tropical ecologists, like Stuart Pimm, Navjot had his roots in the boreal realm and was keen to apply his expertise to saving its species. So much did he believe this was necessary that prior to his untimely death, Navjot had accepted a posting at the University of Toronto where he was to set a portion of his research focus on developing a hard-hitting boreal conservation programme. Unfortunately, he never made it.

In the essay we describe Navjot’s boreal past and future intentions, and we also highlight another research project currently under way that has impressed me in its scope and breadth. The project is called Ecosystem Management Emulating Natural Disturbance (EMEND) and I believe it is EXACTLY the sort of long-term experiment that needs to be done across the boreal biome to examine how fire, timber harvesting and other human activities interact to change biodiversity and ecosystem resilience. Bit of a coincidental story there – the only reason I knew about EMEND at all prior to writing the essay was that I had the good fortune of meeting John Spence in Guangzhou, China earlier this year for the International Symposium for Biodiversity and Theoretical Ecology organised by Fangliang He. John gave a wonderful talk describing EMEND, so I just had to include a blurb about it in our essay.

And good things come to those who dabble. Very soon after the Guangzhou symposium, I was contacted by Jon Moen and Lucy Rist of Umeå University in Sweden about joining their special symposium entitled ‘Boreal Forests in a Sustainable World’ to be held during the EcoSummit 2012 conference in Columbus, USA in September 2012. I’m not entirely sure what analysis I’ll be presenting with Ian, but it probably will be along the lines of measuring the fragmentation component more precisely (perhaps in collaboration with Stuart Pimm if he’s keen). Jon and Lucy have also organised a pre-EcoSummit meeting in Sweden in April that I hope to attend. Should be interesting.

Enough waffle for a Monday morning. If you’d like a PDF copy of the boreal ‘lung’ essay, just e-mail me.

CJA Bradshaw