Global pledges to restore forests face challenges, and need increased support

Matthew Fagan is an assistant professor in Geography and Environmental Systems at University of Maryland Baltimore County. Here he describes the challenges confronting countries as they attempt large-scale forest restoration, and why many countries will need help to fulfill their goals. For more information, read his new, open-access paper in Conservation Letters.

Degraded and deforested landscapes are widespread, and tropical forests are being lost at a rate of 15.8 million hectares a year. But there is good news—temperate forest area is increasing, and more and more countries are voluntarily pledging to restore vast tracts of degraded land. Restoring forests benefits biodiversity and society, and can combat global warming as well, as growing trees lock away carbon dioxide.

International interest in restoring trees to landscapes emerged out of policy discussions last decade, and resulted in the 2011 Bonn Challenge and the creation of voluntary national restoration targets by many countries. The Bonn Challenge seeks to bring 150 million hectares into restoration by 2020, and 350 million hectarees by 2030 (that’s roughly 700 million American football fields, 350 million rugby fields, 500 million FIFA football fields, or an area a bit larger than India).

Current Bonn Challenge pledges total some 172 million hectares. That’s a massive international commitment, and when you add in internal commitments by countries, the potential restoration area swells to 318 million hectares.

All that area voluntarily committed to restoration got my co-authors and I excited, but also skeptical—were countries really going to follow through on their commitments?


A rain forest blow-down in northeastern Costa Rica, with a storm-downed tree cut to clear a path. Silviculture restoration promotes the recovery of disturbed forests like this one. Photo credit: Matthew Fagan.

To try to answer that question at this early stage, myself, Leighton Reid (Virginia Tech), Maggie Holland (UMBC), Justin Drew (UMBC), and Rakan Zahawi (University of Hawaiʻi at Mānoa) asked three related questions in a recent paper in Conservation Letters.

  1. Is the amount of land a country pledged to restore related to their past record of restoring forested landscapes and implementing sustainable development?
  2. For the small group of countries that have publicly reported their progress on commitments, is the amount of restoration they completed predictable by their development level or other risk factors, like deforestation?
  3. Which countries will likely face the greatest challenges to meet their commitments and maintain restored land into the future?

We then set to gathering published information on country commitments and progress, and recent national rates of forest loss, agricultural expansion, and forest recovery.


Recent natural regeneration in northeastern Costa Rica of varying ages. Photo credit: Matthew Fagan.

All of these programs seek to reforest landscapes in ways that benefit both nature and people, including options like natural regeneration (letting natural forests recover and expand), silviculture (interventions to restore standing forests, like preventing forest fires and promoting recovery from selective logging), tree plantations (often tree monocultures to produce timber and pulp on degraded lands), and agroforestry (planting trees on and around farmland to shade crops or protect streams and fields). These options are not all equal in their benefits for biodiversity, carbon, and society, but a diverse menu of options allows countries to consider committing to at least some form of restoration over large areas.


A tree plantation in northeastern Costa Rica funded by the national payments for environmental services program. It is a monoculture of a single native species, Vochysia guatemalensis, grown for timber. Photo credit: Matthew Fagan.

In a nutshell, what we found was both discouraging and encouraging.

First, after adjusting for the size of a country and how much restoration they had done previously, we found that less-developed countries committed more land for restoration. This might be for positive reasons; for example, they may be taking proactive action against the greater risk they face from climate change. Or it might be because they underestimated how challenging it would be to achieve a large pledge.


Silvopastoral restoration, a type of agroforestry, in northeastern Costa Rica. The understory is a cattle pasture, while the overstory is plantation of a native tree species, Dipteryx panamensis. Photo credit: Matthew Fagan.

Second, for twelve early-reporting countries, restoration progress was predictable based on a risk index. Countries with higher risk (risk factors included deforestation rates and progress on sustainable development goals, among others) had less restoration progress.

Third, countries made massive individual commitments that will be hard to achieve without wholesale transformation of their food systems. One third of countries committed >10% of their land area (with a maximum of 81%, in Rwanda). A quarter either committed more area than they had in agriculture, or committed more area than they had in forest. And one quarter of countries had more forest loss and agricultural conversion in 2000–2015 than their restoration commitment for 2015–2030.


Coffee plantation under tree cover, a type of agroforestry, in central Costa Rica. The understory is a monoculture of coffee shrubs, while the overstory is scattered planted trees. The partial cover helps the shade-loving coffee plants stay healthy, but many coffee farmers are moving away from this traditional farming approach. Photo credit: Matthew Fagan.

As noted in our paper, “If voluntary commitments like the Bonn Challenge fail to precipitate meaningful restoration across large areas, the UN’s vision of a sustainable future will become less attainable.” But what this study found is not countries that have failed on their restoration pledges. We are still in the first days of the UN Decade of Ecosystem Restoration. What we have identified is countries that will need help to restore their lands.

We believe it is time for the international community to step up and aid all countries in achieving their restoration goals. To quote Thoreau, “If you have built castles in the air, your work need not be lost; that is where they should be. Now put the foundations under them.”


A regrowing forest in central Costa Rica, showing the promise of restoration. Photo credit: Matthew Fagan.

To plant or not to plant?*

What we think we know about how to restore tropical forests is getting a second look. A new paper produced by scientists in Missouri Botanical Garden’s Center for Conservation and Sustainable Development (CCSD), the University of Hawaii’s Lyon Arboretum, and the University of Maryland Baltimore County points out an important bias in recent studies.

How should we restore forests in places where they have been lost? This is one of the main questions that we study in the CCSD, so we were surprised last year when a big synthesis paper that compiled data from many earlier studies said that, when it comes to restoration, doing nothing was the same as doing something.

That’s only a slight exaggeration. The paper, by Renato Crouzeilles and several other scientists, said that letting a forest regrow on its own (that is, natural regeneration) was usually more successful than planting trees (that is, active restoration). Their conclusion was based on comparing many studies done throughout the world’s tropical forest regions.

Unequal comparison

The problem with this paper (and several like it) was that the set of studies looking at natural regeneration were not really the same as the set of studies looking at tree planting. The natural regeneration studies focused on forests that already existed, while the tree planting studies focused on a wider range of sites, many of which started with no forest. In other words, the natural regeneration studies had already been filtered to exclude places with a weak ability to grow forests.

To understand the problem, it is helpful to look back at the history of tropical forest restoration research. For many years, scientists who wanted to know about how forests recover after a disturbance (like a hurricane or logging) would go out and find several forests that had been recovering for different amounts of time. If you take forests that are 5, 10, and 20 years old, you can try to compare them to each other in order to see how a forest might change over 20 years. In contrast, tree planting studies usually start with a piece of land that has no trees on it. Scientists who want to know how trees grow on this land will plant some and then observe their survival and growth over time.  These trees may or may not create a forest there, as the land can vary in quality.

So where does that bring us with respect to this study? If you compare a forest that already exists with another potential forest where planted trees may or may not survive and grow well, it’s a safe bet that the pre-existing forest will have taller trees. It has a head start over the planted forests, and we argue in our paper that the comparison is not a fair one.

This means that letting forest regrow on its own is not always a better option than planting trees. In fact, there are many places – like overgrazed pastures, mine sites, and other heavily degraded lands – where forests have been cleared and most likely will not be able to grow back on their own.


Comparison of natural regeneration (foreground) and active tree planting (background) to restore a cattle pasture in southern Costa Rica. Tree seedlings planted on the hillside are just visible in the 2005 image. The yellow circle indicates a person for scale. After nine years, active tree planting had produced a forest, whereas natural regeneration was stalled. Overgrown pasture grasses covered the ground. Natural regeneration is highly variable, so this example is not representative of all situations. Photos courtesy of Karen Holl.

 Same team!

While we were not convinced by studies that said that natural regeneration is better than tree planting, we also don’t want to take any options off the table. Natural regeneration and tree planting are not mutually exclusive – in fact, they are highly complementary. Our practical advice is that if you want to get forest back, the best option is to see if natural regeneration can do the trick before you invest in tree planting. Or better yet, set up a paired experiment comparing the two strategies at the same site.

*Thanks to Erle Ellis for coming up with the title for this blog post. For more information, please see our open-access paper and press releases at EurekAlert, UMBC News, and Science Daily.


Restoring Peruvian Forests for Bees

A box of little angels (angelitos). Freddy sells their honey, as well as the nutritious, yellow pollen that accumulates near the opening.

A box of little angels (angelitos). Freddy sells their honey, as well as the nutritious, yellow pollen that accumulates near the opening.

There are bee hives all over Freddy’s farm in Oxapampa, Peru. An old tree stump houses a colony of curco negro, a stingless bee native to the eastern Andes. Another species, commonly called niño de monte real, has nearly been extirpated from the area. These bees are Freddy’s livelihood, and the basis for a collaborative reforestation project with one of the world’s most diverse national parks.

Freddy is one of a handful of farmers cultivating land within the buffer zone of Yanachaga-Chemillén National Park. His family has been here since 1978 and has seen the area transform from forests full of Wattled Guans and Andean bears to eroded cow pastures and pesticide-laced rows of passion fruit.

Now some of these degraded areas are being replanted with native trees. Peru’s national park service is using sticks and carrots to create a buffer around Yanachaga-Chemillén. Law mandates that farmers working in special use areas must only do agriculture that is nature-friendly – things with trees, like shade coffee. But the park service also offers funding to farming associations to help them make the transition. In Freddy’s case, the park service provided tree seedlings, fertilizer, and transport of these to his farm, at the end of a very rough road.

Tree seedlings and an edible fruit, Solanum quitoensis, are sprouting up in this native tree plantation.

Tree seedlings and an edible fruit, Solanum quitoensis, are sprouting up in this native tree plantation.

Honey from the flowers of native trees. I tried some, and it was delicious.

Honey from the flowers of native trees. I tried some, and it was delicious.

Freddy and the national park managers see this arrangement as mutually beneficial. As we walked through his seven-year old plantation, Freddy pointed out native trees, like cedro (Cedrela sp.), and told me about the flowers they produce for his bees. At different times of the year, Freddy’s bees collect nectar and pollen from different trees. The artisanal honey he sells is well-known in Lima. These plantations also help protect the core of Yanachaga-Chemillén National Park by reducing outside influences, like domestic animals that wander into the forest.

It’s not all gravy though. Programs like the one in Alto Navarro have not been as successful everywhere. Of seven farming associations that are currently receiving funds from Yanachaga-Chemillén, three are stalled with infighting. In one case, thousands of native tree seedlings were transported to a community six hours’ drive from Oxapampa; a year later most of the seedlings still sat unplanted by the side of the road.

Within individual projects there are also compromises. One project area in Alto Navarro was planted in exotic pines – trees that are little more than wood factories. But these pines can be harvested and sold after just ten years, and in the meantime cows can graze in the understory. This short tree rotation makes it more economically attractive to plant other areas with native trees, which will not be available to harvest for much longer.

Cow grazing lush grass in an exotic pine plantation at Alto Navarro.

Cow grazing lush grass in an exotic pine plantation at Alto Navarro.

Is this ecological restoration? In one sense, no. When Freddy plants native trees, he plans to use them to make honey, and then to cut them down and sell them for timber. The area will not turn into a mature forest. But these same trees are likely reducing edge effects, like elevated wind and light, in the adjacent national park forest. Trees planted just outside the old-growth forest could increase habitat area for plants and animals that live in the forest interior. At a broader scale, the collaborations between the national park and local farming associations are also likely restoring natural capital, stocks of natural assets like soil, water, and biodiversity.

Freddy and me in a cow pasture at the edge of Yanachaga-Chemillén National Park. Freddy plans to plant native trees here in May 2015.

Freddy and me in a cow pasture at the edge of Yanachaga-Chemillén National Park. Freddy plans to plant native trees here in May 2015.