Influential conservation papers of 2015

25 12 2015

most popularAs I did last year and the year before, here’s another arbitrary, retrospective list of the top 20 influential conservation papers of 2015 as assessed via F1000 Prime.

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National commitment to conservation brings biodiversity benefits

16 06 2015

united-nations-dayWhat makes some conservation endeavours successful where so many fail to protect biodiversity? Or, how long is a piece of string?

Yes, it’s a difficult question because it’s not just about the biology – such as resilience and area relationships – in fact, it’s probably more about the socio-economic setting that will ultimately dictate how the biodiversity in any particular area fares in response to disturbance.

In the case of protected areas (that I’ll just refer to as ‘reserves’ for the remainder of this post), there’s been a lot of work done about the things that make them ‘work’ (or not) in terms of biodiversity preservation. Yes, we can measure investment, how much the community supports and is involved with the reserve, how much emphasis is put on enforcement, the types of management done within (and outside) of the reserves, et ceteraet cetera. All of these things can (and have to some extent) been correlated with indices of the fate of the biodiversity within reserves, such as rates and patterns of deforestation, the amount of illegal hunting, and the survival probability of particular taxa.

But the problem with these indices is that there are just indices – they probably do not encapsulate the overall ‘health’ of the biodiversity within a reserve (be that trends in the overall abundance of organisms, the resilience of the community as a whole to future disturbances, or the combined phylogenetic diversity of the ecosystem). This is because there are few long-term monitoring programmes of sufficient taxonomic and temporal breadth to summarise these components of complex ecosystems (i.e., ecology is complex). It’s no real surprise, and even though we should put a lot more emphasis on targeted, efficient, long-term biodiversity monitoring inside and outside of all major biodiversity reserves, the cold, hard truth of it is that we’ll never manage to get the required systems in place. Humanity just doesn’t value it enough. Read the rest of this entry »

Missing the forest despite its trees

21 04 2015

An exchange on over the intactness of boreal forests has just erupted. Bill Laurance asked me to weigh in as an independent appraiser of the debate, so I copy my thoughts below. You can read the original exchange between Jeff Wells and Nick Haddad (& colleagues) here.

Despite its immense size, there is little doubt that the ugly second cousin of forest conservation is the boreal region covering much of Alaska, Canada, Fennoscandia and Russia. Indeed, extending some 1.4 billion hectares, of which well over 60% is found in Russia alone (1, 2), the entirety of the boreal forest is more than double the area of the Amazon forest. Yet despite this massive expanse, the impressive biota it shelters (2), and its important contribution to the global carbon (1), nitrogen (3) and oxygen (4) cycles, the boreal is an oft-overlooked region in terms of global conservation priorities and possibilities (5).

The exchange between Haddad & Sexton and Wells regarding the former researchers’ recent paper (6) highlights this problem, of which even many expert ecologists are often only vaguely aware. Wells takes particular issue with Haddad and colleagues’ assertion that the boreal forest is highly fragmented, claiming to the contrary that the (North America) boreal forest is “… truly intact … ”. While Haddad et al. respond that they did not differentiate between ‘natural’ and human-caused fragmentation, my view is that the exchange misses some important concerns about the state of the boreal forest.

Wells correctly points out that the boreal zone in North America is “massive”, but can his other claim – that it is “truly intact” – stand up to scrutiny? Citing one of my own papers from 2009 (2) to demonstrate (correctly) that the boreal forest of North America holds a stunning array of species, Wells neglects to highlight that in that same paper we also identified the extensive, artificial fragmentation that has occurred there and in other parts of the boreal zone over the last few decades. For example, we showed clearly that only 44% of the entire biome is considered to be ‘intact’, defining the term precisely as “areas ≥ 500 km2, internally undivided by infrastructure (e.g., roads) and with linear dimensions ≥ 10 km”. Satellite imagery has also confirmed that between 2000 and 2005, the boreal biome experienced the largest area of gross forest cover loss compared to any other (7). Despite recent evidence that so-called edge effects (characteristics of a disturbed matrix that penetrate some distance into habitat fragments) are probably of a smaller spatial magnitude in boreal compared to other biomes (8), it is disingenuous to claim that North America’s boreal forests are “truly intact”. Read the rest of this entry »

Earth’s second lung has emphysema

19 02 2015


Many consider forests as the ‘lungs’ of the planet – the idea that trees and other plants take up carbon and produce oxygen (the carbon and oxygen cycles). If we are to be fair though, the oceans store about 93% of the Earth’s carbon pool (excluding the lithosphere and fossil fuels) and oceanic phytoplankton produces between 50 and 80% of the oxygen in the atmosphere. For comparison, the terrestrial biosphere – including forests – stores only about 5% of the Earth’s carbon, and produces most of the remainder of atmospheric oxygen.

So there’s no denying that the biggest player in these cycles is the ocean, but that’s not the topic of today’s post. Instead, I’m going to focus on the terrestrial biosphere, and in particular, the carbon storage and flux of forests.

Now it’s pretty well established that tropical forests are major players in the terrestrial carbon cycle, with the most accepted estimates of about 55% the terrestrial carbon stock stored therein. The extensive boreal forest, covering most of the northern half of North America, most of Scandinavia and a huge chunk of Russia, comes in globally at about 33%, and temperate forests store most of the remainder.

That is, until now. Read the rest of this entry »

It’s all about the variation, stupid

12 01 2015

val-1-3It is one of my long-suffering ecological quests to demonstrate to the buffoons in government and industry that you can’t simply offset deforestation by planting another forest elsewhere. While it sounds attractive, like carbon offsetting or even water neutrality, you can’t recreate a perfectly functioning, resilient native forest no matter how hard you try.

I’m not for a moment suggesting that we shouldn’t reforest much of what we’ve already cut down over the last few centuries; reforestation is an essential element of any semblance of meaningful terrestrial ecological restoration. Indeed, without a major commitment to reforestation worldwide, the extinction crisis will continue to spiral out of control.

What I am concerned about, however, is that administrators continue to push for so-called ‘biodiversity offsets’ – clearing a forest patch here for some such development, while reforesting or even afforesting another degraded patch there. However, I’ve blogged before about studies, including some of my own, showing that one simply cannot replace primary forests in terms of biodiversity and long-term carbon storage. Now we can add resilience to that list.

While I came across this paper a while ago, I’ve only found the time to blog about it now. Published in PLoS One in early December, the paper Does forest continuity enhance the resilience of trees to environmental change?1 by von Oheimb and colleagues shows clearly that German oak forests that had been untouched for over 100 years were more resilient to climate variation than forests planted since that time. I’ll let that little fact sink in for a moment … Read the rest of this entry »

Influential conservation papers of 2014

22 12 2014

splash2Another year, another arbitrary retrospective list – but I’m still going to do it. Based on the popularity of last year’s retrospective list of influential conservation papers as assessed through F1000 Prime, here are 20 conservation papers published in 2014 that impressed the Faculty members.

Once again for copyright reasons, I can’t give the whole text but I’ve given the links to the F1000 assessments (if you’re a subscriber) and of course, to the papers themselves. I did not order these based on any particular criterion.

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Biodiversity Hotspots have nearly burnt out

10 07 2014

dying embersI recently came across a really important paper that might have flown under the radar for many people. For this reason, I’m highlighting it here and will soon write up a F1000 Recommendation. This is news that needs to be heard, understood and appreciated by conservation scientists and environmental policy makers everywhere.

Sean Sloan and colleagues (including conservation guru, Bill Laurance) have just published a paper entitled Remaining natural vegetation in the global biodiversity hotspots in Biological Conservation, and it we are presented with some rather depressing and utterly sobering data.

Unless you’ve been living under a rock for the past 20 years, you’ll have at least heard of the global Biodiversity Hotspots (you can even download GIS layers for them here). From an initial 10, to 25, they increased penultimately to 34; most recently with the addition of the Forests of East Australia, we now have 35 Biodiversity Hotspots across the globe. The idea behind these is to focus conservation attention, investment and intervention in the areas with the most unique species assemblages that are simultaneously experiencing the most human-caused disturbances.

Indeed, today’s 35 Biodiversity Hotspots include 77 % of all mammal, bird, reptile and amphibian species (holy shit!). They also harbour about half of all plant species, and 42 % of endemic (not found anywhere else) terrestrial vertebrates. They also have the dubious honour of hosting 75 % of all endangered terrestrial vertebrates (holy, holy shit!). Interestingly, it’s not just amazing biological diversity that typifies the Hotspots – human cultural diversity is also high within them, with about half of the world’s indigenous languages found therein.

Of course, to qualify as a Biodiversity Hotspot, an area needs to be under threat – and under threat they area. There are now over 2 billion people living within Biodiversity Hotspots, so it comes as no surprise that about 85 % of their area is modified by humans in some way.

A key component of the original delimitation of the Hotspots was the amount of ‘natural intact vegetation’ (mainly undisturbed by humans) within an area. While revolutionary 30 years ago, these estimates were based to a large extent on expert opinions, undocumented assessments and poor satellite data. Other independent estimates have been applied to the Hotspots to estimate their natural intact vegetation, but these have rarely been made specifically for Hotspots, and they have tended to discount non-forest or open-forest vegetation formations (e.g., savannas & shrublands).

So with horribly out-of-date vegetation assessments fraught with error and uncertainty, Sloan and colleagues set out to estimate what’s really going on vegetation-wise in the world’s 35 Biodiversity Hotspots. What they found is frightening, to say the least.

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