Nothing like a good forest

31 07 2019

Our history and culture are intimately tied to the planet’s forests and the services they provide to all living beings. In modern times, forests also help combat the impacts of anthropogenic climate change, not only by acting as powerful sinks of the carbon excess resulting from our greenhouse-gas emissions, but also as thermal shields we and many other species can benefit from.

55_ForestBufferingPhotoPortadaQuercusCoverProposed2

Understory of the laurel forest in Garajonay National Park (La Gomera, Canary Islands) – also part of the World Network of Biosphere Reserves since 2012. The fog, combined with the cloud belt blowing from the Atlantic Ocean against the mountains (Garajonay is the highest peak at 1500 m), creates a mesic microclimate crucial for plant endemism. Forest canopies reinforce humidity and buffer temperature variation for many species. Photo: Paco Rodríguez.

If we were to choose a house to live, most would likely opt for one with water and electricity supply, noiseless nights, nearby leisure and shopping, and easy communication by public transport. Lacking only one of those aspects could be off-putting.

In truth, those who have the privilege of living in a stable household value it by the full set of available commodities. Similarly, the value of an ecosystem rests on its entire repertoire of ecological functions (1). And this is particularly so for forest ecosystems.

The ecological value of a forest relies on the collection of its native characteristics (2): how many autochthonous and mature trees it can host, how much photosynthesis it fuels, how many pollinisers it feeds, how much soil and water it creates and retains, and many more (3). Read the rest of this entry »





Save a jaguar by eating less meat

8 10 2018
Kaayana

My encounter with Kaayana in Kaa-Iya National Park in the Bolivian Chaco. Her cub was around but cannot be seen in the photo

I was trapped. Or so I thought.

The jaguar came towards me on the dirt road, calmly but attentively in the dusky light, her nearly full grown cub behind her. Nervous and with only a torch as defence, I held the light high above my head as she approached, trying to look taller. But she was merely curious; and, after 20 minutes, they left. I walked home in the thickening darkness, amazed at having come so close to South America’s top predator. We later named this mother jaguar ‘Kaayana’, because she lives inside Kaa-Iya National Park in the Bolivian Chaco. My fascination with jaguars has only grown since then, but the chances of encountering this incredible animal in the wild have shrunk even since that night.

A few years after that encounter, I’m back to study jaguars in the same forest, only now at the scale of the whole South American Gran Chaco. Jaguars are the third largest cats in the world and the top predators across Latin America. This means that they are essential for keeping ecosystems healthy. However, they are disappearing rapidly in parts of their range.

Understanding how and where the jaguar’s main threats — habitat destruction and hunting — affect them is fundamental to set appropriate strategies to save them. These threats are not only damaging on their own, but they sometimes act simultaneously in an area, potentially having impacts that are larger than their simple sum. For instance, a new road doesn’t only promote deforestation, it also increases hunters’ ability to get into previously inaccessible forests. Similarly, when the forest is cut for cattle ranching, ranchers often kill jaguars for fears of stock loss.

Kaayana & kittens

Kaayana was seen years later by Daniel Alarcón, who took much better photos of her and her new cubs

However, the interactions between these threats are still not fully understood. In our new study, just published in the journal Diversity and Distributions, we developed a new framework to quantify how and where habitat destruction and hunting risk acted together over three decades, at the expense of highly suitable jaguar habitat in the Gran Chaco. We also analyzed how well the different Chaco countries — Bolivia, Paraguay and Argentina — and their protected areas maintained key jaguar habitat. Read the rest of this entry »





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 »





Covet thy neighbour’s paddock

2 03 2010

Apologies to Matt Lucas

An interesting, frightening and and at the same time, potentially hopeful, paper has just appeared in the latest issue of Proceedings of the Royal Society B.

Co-authored by a previously highlighted Conservation Scholar Georgina Mace, the paper by Boakes and colleagues entitled Extreme contagion in global habitat clearance is probably one of the strongest bits of evidence to save intact habitat complexes.

Yes, yes – save things so you don’t destroy biodiversity. What’s new about that? Well, Boakes and colleagues’ paper shows at a global scale that over the last 300+ years, the chance of a patch of forest or grassland being converted to agriculture depends strongly on whether its neighbouring patch has already been cleared. In other words, once you start to hack away at natural habitats, people have a tendency to assume that it’s perfectly acceptable to do the same on their own patch.

The authors reprojected the History Database of the Global Environment to ~ a 50 x 50 grid and examined habitat conversion from 1700 to the present (in 50-year increments). Using some rather simple contagion statistics, they came up with the startling result that conversion probability is strongly dependent on whether an adjacent cell has already been converted.

What I found particularly frightening was the result that:

“A quarter of the world’s forest and half its grassland has been converted to agriculture since 1700.”

and from a personal perspective, the highest grassland conversion rates have happened in Australasia (the highest forest conversion rates have been in the Indo-Malay and Nearctic realms).

What are the implications for conservation? In my opinion, this relatively simple analysis and result confirms even more strongly that saving intact, large tracts of forest and grassland is essential for long-term biodiversity conservation. Cutting up the forest into smaller bits not only compromises biodiversity via fragmentation, it ends up speeding the entire process of full-scale ecosystem degradation.

‘Get ’em protected while they’re still unaffected’.

CJA Bradshaw

ResearchBlogging.orgBoakes, E., Mace, G., McGowan, P., & Fuller, R. (2009). Extreme contagion in global habitat clearance Proceedings of the Royal Society B: Biological Sciences, 277 (1684), 1081-1085 DOI: 10.1098/rspb.2009.1771

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