Restoration, otherwise known as the process of re-inserting nature’s pumping heart into the cadaver of degraded lands, is gaining huge global traction under the auspices of the ambitious Bonn Challenge. And, as always seems to be the case when something gathers momentum in science or policy-making arenas, some pretty nice and colourful maps have followed.
These maps have variously shown us places where restoration makes the most sense, though they have done so in different ways, with different assumptions and priorities (and to different degrees of uproar).
Griscom et al (1). took one of the first decent stabs at it, mapping the global potential for reforestation. They based their work on an earlier attempt by the World Resources Institute and envisioned a planet where we eat less meat, opening up pastures around the globe to reforestation.
Bastin et al followed next (2), in what must have been one of the most read (and controversial) pieces of environmental science of the past few years. They tried to calculate planet Earth’s total tree carrying potential, a measure of just how many trees our blue and green marble might be able to support, if we could but remove the pressures we put upon it. To do this, they used a sophisticated satellite image approach, extrapolating out tree cover potential across the globe based on thousands of high-resolution photographs of Earth’s protected areas.
The take-home message, plastered across the newspapers at the time, was that Earth could support a whopping 0.9 billion hectares more continuous forest (though, not all of these places are suited, available, or necessarily even good spots to tree-ify).
Next up came a map confined to the lowland tropics. Bracalion et al (3) took a bit of a different and very cool approach. They didn’t just look at where restoration was physically possible, but also where it might deliver the greatest number of benefits for people and wildlife.
They produced a multi-layered map that mixed together potential constraints on restoration, say, how expensive it might be, or how vulnerable to the future risk of backsliding into deforestation, and then blended that together with a cocktail of delightful potential positives. Positives such as the likelihood that restoration could help support wildlife, reduce the risk of injurious climate change and deliver watery wins for places beset by H20 security problems.
A particularly wicked output of the Brancallion et al. effort was the identification of so-called “restoration hotspots”. These are essentially big fat smiley faces on their pan-tropical map that pinpoint where cheap and lasting rainforest restoration could also be particularly cheerful, and most able to hand out a mixed cheese-board of delights.
These places are dotted around the tropics, from the Atlantic Forests of Brazil’s eastern coast, to the Guinean forests of West Africa and the Sundaland lowlands, and are chockerblock with opportunity and endemism.
Next to take a go were Strassburg et al. (4). Again, they zoomed out globally, and, leaping on from previous work, once more mapped places where restoration might increase thumbs up whilst reducing thumbs down.
You don’t need to be a scientist to get excited when a paper develops the first “multi-criteria optimization approach that identifies priority areas for restoration across biomes and estimates their benefits and costs“.
Key Strassburg et al. findings were that restoring just 15% of converted lands could avoid 60% of wild species extinctions whilst gulping up nearly a third of the carbon dioxide spewed into the atmosphere since the industrial revolution.
These areas aren’t just forests, which tend to grab the limelight and suck up the glory in the restoration world. They’re grasslands, arid areas and wetlands too, widening the umbrella of ecosystems in need of a helping hand.
Three last MAPstoration efforts I’ve stumbled across are particularly interesting.
The first hearkens from South-east Asia.
In a bit of a stocktaking of the potential for restoration across the region, Yiwen et al. (5) provide some much needed context and nuance. In step-wise fashion, Yiwen et al. warn of a number of additional variables we might wish to consider before hollering about just how darn restorable an area is.
These include not only biophysical and financial constraints, but also potential blockades and considerations that become important when you start on the nitty-gritty of actually restoring areas on-the-ground. These are factors like whether smallholder farmers are already making use of the land for other purposes, as well as stuff like the distance to seed sources and potential monitoring efforts.
All told, a consideration of the potential roadblocks, constraints and banana skins to reforestation means that only a small fraction (0.3-18%) of the area technically suitable to restoration might in fact be open to larger reforestation efforts.
On a related note, Erbaugh et al. (6) pull the importance of local communities to the fore, both as essential agents and as beneficiaries of properly done restoration. Erbaugh et al. show that 294.5 million people live in areas previously classified as restorable, some 12% of the total population of low-income countries.
Such high numbers underscore the importance that people and nature are connected and that the needs and goals of communities help to shape the directions of forest restoration. They also bring to light the sheer potential for the restoration of nature to deliver wellbeing and improve livilihoods, if done properly.
And last but not least to the dry forests of northwestern Peru and Southern Equador. In what is one of my favourite pieces of science of the past few years, Fremout et al. (7) use a trait-based approach to map where 50 of the region’s most common tree species might be most threatened, as a guide for urgent conservation and restoration actions.
Using species-specific tree traits like how thick a species’ bark is (a measure of vulnerability to fire) and how unpalatable its leaves are (a proxy of vulnerability to grazing herbivores) this study creates species level maps for where conservation and restoration efforts are most needed across the region’s vanishing dry forests.
Meaningful mapping
So what do these MAPstoration efforts tell us about the potential for restoration during our age of The Great Appropriation? A few of the take home messages are:
- The opportunity for restoration to deliver benefits is vast and dotted around a bit everywhere, which is good news given how so many countries have made commitments to the Bonn Challenge. That said, there are emerging hotspots that mean there are smarter places to get started.
- There can be really important differences in the benefits and feasibility of restoration. Restoring a chunk of land over here can have notable differences than doing so over there; some places truly are easier and more urgent to restore than others.
- There can be trade-offs between how feasible restoration is, and how many benefits it can provide. This makes sense, because you can probably assume that although restoring more heavily degraded areas may well bring with it more benefits, these areas will be tougher and more expensive to restore, exactly because they are so degraded. There can be trade-offs between different benefits too (though there’s also tonnes of room for happy synergies)
- We have to consider constraints and realities on the ground so that we can target interventions in ways that have the highest chance of succeeding. We also have to consider what the goals of restoration are and who they will benefit.
- It’s not just all about forests—there are globally important restoration opportunities in degraded wetlands, scrublands, and arid areas too, to name but a few.
- And finally, the time to act is NOW. The opportunity is there for science-based restoration efforts to put a decent dent in both climate change and species extinction, with substantial other human benefits to boot. But it will get harder to restore in a changing future, and indeed the restoration efforts of today need to be able to cope with the challenges and climates of tomorrow.
And lastly, lest we should forget… As I’ve written before, restoration is awesome but only as a slice of the solution. We cannot allow it to become a distraction to what should ultimately be our primary goal as conservationists: stopping the ongoing degradation and destruction of intact ecosystems, and limiting further climate change.
But the maps are there and they are one piece in the puzzle for helping us navigate towards a better future for people and the planet.
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