Tropical forest resilience depends on past disturbance frequency

16 07 2014

I’ve recently come across an interesting study that perfectly marries palaeo-ecological data with modern conservation philosophy. It’s not often that such a prehistorical perspective dating at least to the Last Glacial Maximum has been used so effectively to inform future conservation outlooks. I’m particularly interested in this sort of approach considering my own palaeo dabblings of late.

Published in Nature Communications this May, Lydia Cole and colleagues’ paper Recovery and resilience of tropical forests after disturbance is a meta-analysis of 71 studies covering nearly 300 disturbance events in tropical forests over the last 20,000 years or so. Using fossil pollen records as an index of vegetation change, they demonstrated the (somewhat intuitive) main result that the time to recovery following a disturbance generally decreases as the past disturbance frequency increased.

This appears to be a vindication of the idea that a system’s adaptive strategies evolve as a product of the local disturbance regime. More importantly, they found that recovery was faster following ‘large infrequent events’, which are natural perturbations such as cyclones and major fires. While most past disturbances were caused by humans clearing forest, the fact that tropical forest systems were most resilient to ‘natural’ events means that if we can’t stop human disturbances, at least we can attempt to emulate natural processes to maximise the rebound potential. Much like many modern forestry operations try to emulate natural disturbances to limit their damage, we should at least manage our impacts by understanding so-called ‘natural’ regimes as much as possible. Read the rest of this entry »





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.

Read the rest of this entry »





Terrestrial biodiversity’s only chance is avoided deforestation

24 01 2014

farming forestsToday I was shocked, stunned and pleasantly (for a change) surprised. Australia has its first ‘avoided deforestation’ carbon farming project.

It is understandable that this sort of news doesn’t make the Jane & Joe Bloggs of the world stand up and cheer, but it should make conservation biologists jump for bloody joy.

So why exactly am I so excited about the setting aside of a mere 9000 ha (90 km2, or 10 × 9 km) of semi-arid scrub in western New South Wales? It’s simple – nothing can replace the biodiversity or carbon value of primary forest. In other words, forest restoration – while laudable and needed – can never achieve what existing forest already does. We know now from various parts of the world that biodiversity is nearly always much higher in primary forest, and that the carbon structure of the forest (especially below-ground carbon) can take centuries to recover.

Another problem with restoration – and if you’ve ever been involved in any tree planting yourself, you’ll know what I mean – is that it’s incredibly expensive, time-consuming and slow. Wouldn’t it make more financial sense just to save forests instead of trying to rebuild them?

Of course it is, so the logical conclusion from a conservation perspective is to save primary forest first, then worry about restoration next. The problem is, there are few, if any, financial incentives for keeping forests standing in the private sector. The stumbling rise of the carbon economy is a potential resolution to this problem, although neither the Kyoto Protocol nor most national carbon-trading schemes adequately account for the carbon value of existing forests.

Up until today, even Australia didn’t have any examples.

Read the rest of this entry »





Influential conservation papers of 2013

31 12 2013

big-splash1This is a little bit of a bandwagon – the ‘retrospective’ post at the end of the year – but this one is not merely a rehash I’ve stuff I’ve already covered.

I decided that it would be worthwhile to cover some of the ‘big’ conservation papers of 2013 as ranked by F1000 Prime. For copyright reasons, I can’t divulge the entire synopsis of each paper, but I can give you a brief run-down of the papers that caught the eye of fellow F1000 faculty members and me. If you don’t subscribe to F1000, then you’ll have to settle with my briefest of abstracts.

In no particular order then, here are some of the conservation papers that made a splash (positively, negatively or controversially) in 2013:

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Conservation: So easy a child could do it

13 09 2013

child's playI don’t like to talk about my family online. Call me paranoid, but there are a lot of crazy people out there who don’t like what scientists like me are saying (bugger the evidence). Yes, like many climate scientists, I’ve also been threatened. That’s why my personal life remains anonymous except for a select group of people.

But I’ve mentioned my daughter before on this blog, and despite a few people insinuating that I am a bad parent because of what I said, I am happy that I made the point that climate change is a scary concept of which our children must at least be cognisant.

My daughter’s story today is a little less confronting, but equally enlightening. It’s also a little embarrassing as a scientist who has dedicated my entire research career to the discipline of conservation biology.

As a normal six year-old without the ability to refrain from talking – even for a moment – I hear a lot of stories. Many of them are of course fantastical and ridiculous, but those are just part of a healthy, imaginative childhood (I am proud to say though that she is quite clear about the non-existence of fictitious entities like faeries, easter bunnies and gods).

Every once in a while, however, there are snippets of wisdom that ooze out from the cracks in the dross. In the last few months, my daughter has independently and with no prompting from me come up with two pillars of conservation science: (i) protected areas and (ii) biodiversity corridors. Read the rest of this entry »





Cartoon guide to biodiversity loss XVIII

13 02 2013

Here’s the latest 6 biodiversity cartoons for your simultaneous viewing pleasure and pain (see full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here).

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Cartoon guide to biodiversity loss XVII

19 12 2012

I’m winding down here for the year (although there might be a few more posts before the New Year), so here’s the latest batch of 6 biodiversity cartoons (see full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here).

Read the rest of this entry »








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