‘Diversity matters,’ and other secrets of successful landscape restoration

Tea agroforestry. Photo by Sailesh Ranjitkar/ICRAF, via Flikr https://www.flickr.com/photos/icraf/sets/72157648847066916

Tea agroforestry. Photo by Sailesh Ranjitkar/ICRAF, via Flikr https://www.flickr.com/photos/icraf/sets/72157648847066916

“My thinking about restoration has gone through a complete turn-around since starting work on this project,” Rhett Harrison, a tropical forest ecologist with the World Agroforestry Centre (ICRAF)’s East & Central Asia regional office, told the audience at Tree Diversity Day 2014.

Based on his knowledge of two large-scale projects that have ICRAF as a partner, Harrison went on to give some important tips and considerations for successful forest and land restoration.

The two projects—Harapan Rainforest, a 100,000-ha Ecosystem Restoration Concession (ERC) in Sumatra, Indonesia with Burung Indonesia, Birdlife International, Royal Society for the Protection of Birds, and ICRAF as partners; and a Swiss-funded agroforestry-based restoration project in Suan, DPR Korea with the Land and Environmental Protection Ministry and ICRAF as partners—are on-going.

The first overarching point Harrison made is that diversity matters. Research, including that by Tylianakis and others (2008), has shown that as heterogeneity (both spatially and temporally) increases, so does the beneficial role of diversity. Therefore, to restore a landscape—which encompasses different soils, topography, elevation, etc., and which may experience variable weather (such as drought in some years)—encouraging diversity builds in resilience and enhances ecosystem functioning.

In other words, “We can’t restore multiple ecosystem services by putting in a simplified system like a monoculture plantation.”

He added that the plants species used for restoration, particularly trees, should be chosen carefully. There is no point in planting a species or varieties that in the future, because of climate change, will be inappropriate to the landscape, he said.


Harrison recommended the following steps to successful land restoration:

Step 1: Assess and tackle the causes and drivers of degradation

Rhett Harrison on Tree Diversity Day, 10 October 2014 in Pyeongchang, South Korea. Photo by Daisy Ouya/ICRAF

Rhett Harrison on Tree Diversity Day, 10 October 2014 in Pyeongchang, South Korea. Photo by Daisy Ouya/ICRAF

Before attempting to restore a degraded landscape, it is essential to identify the cause or causes of the degradation. These range from (in approximate order of importance) unsustainable agricultural practices; deforestation and (illegal) land clearing; alien invasive species; pollution; mining and infrastructure development. Alongside the causes are the ‘drivers’ of the degradation, such as human population growth as well as economic pressures. Ignoring the drivers and causes is likely to derail any landscape restoration efforts.

With their tendency to chew on young tree seedlings, pull up grass by the roots, and damage soil with their sharp hooves, Harrison singled out goats as a leading driver of land degradation. “Goats are probably the number one organism driving land degradation across the world,” he stated.

“Probably the most important ecosystem service that we get from nature is its incredible capacity for self repair,” he added.

“If you remove the drivers of degradation, in most cases, the land will start to regenerate of its own accord.”

Step 2: Engage stakeholders

Restoration initiatives would be well advised to prioritize stakeholder engagement at all stages. The restoration of the Suan landscape in North Korea, for instance, has recorded outstanding success in large part as a result of full stakeholder engagement.

“Often the land degradation has proceeded through a lack of social capacity to deal with issues as they emerge, although stakeholders may be full aware of the problems. So helping stakeholders identify options, both in terms of alternative land-uses and the institutional arrangements required, can put a landscape on the recovery path without need for more expensive interventions,” said Harrison.

“If you don’t engage the stakeholders, and they don’t see the benefit, they will not be involved.”

Stakeholders participate in land use mapping in Saum, DPR Korea

Stakeholders participate in land use mapping in Saum, DPR Korea. Photo by Jianchu Xu/ICRAF via Flikr

Step 3: Develop a good business model

To be sustainable, a restoration initiative must have a viable business plan that allows it to function in the absence of international donor funding, which can be “constraining and unreliable,” stressed Harrison.

“We need to develop business models—something that can earn income from the land so we are able to pay for the restoration. This assures an economically viable future and allows replication across the world. Critically important is to recognise that restoration practice today is often unrealistically expensive and does not adequately consider the cost-benefit of interventions, such as planting. The business model should seek the greatest dollar efficiency of money spent.

“In fact, if the business model is a good one, the academics and NGOs can go home— communities and businesses will take it up because it is economically sensible to do so,” he continued.

During restoration, it is important that communities in forests and forest margins realise short- and long-term income streams to support their livelihoods. This income typically comes from the sale of forest products and [potentially] ecosystem services. Designed right, these income streams can meet the costs of restoration, which can run up to approximately 3000 USD per hectare in Indonesia, said Harrison.

Forest products include timber, resins, high-value agarwood (gaharu), rubber, honey, and so forth. Harrison, however, stressed that timber is key to forest income generation.

“For tropical rainforests, timber is the basis for income. If you’re not doing timber, you’re not getting the value of the forest.”

In Brazil for instance, a forest restoration initiative is purposely growing both eucalyptus and native trees; the fast-growing eucalyptus is cut down and sold after some years, which generates money to support the project’s continuation.

Another essential part of a sound business model is the land-use management plan. A good zoned forest or landscape plan is information-based, rooted in realism and based on detailed geographical and social surveys, said Harrison.

He emphasized that practitioners should take the time to research and develop such maps, which “are not simply paint-marks on a map,” but a useful resource to guide action.

Step 4: Integrate research

 Small group discussion among researchers and farmers in Melamchi, Nepal. Photo by Sailesh Ranjitkar/ICRAF

Small group discussion among researchers and farmers in Melamchi, Nepal. Photo by Sailesh Ranjitkar/ICRAF

There are many gaps in our knowledge about large-scale restoration. These that can be filled by designing restoration initiatives so they integrate research and learning.

Harrison pointed out key knowledge gaps, including:

  • Cost-benefit analyses of restoration treatments
  • Yield models for timber and non-timber forest products;
  • Trade-offs among ecosystem services;
  • Effects of distribution of ecosystem components (e.g. trees) on ecosystem services; and
  • Policy, governance and socio-economics of forest- and forest-margin-dwelling communities.

Multiple gains

Successful land restoration allows us to regain soil health, biodiversity, water supply quality, soil fertility, erosion control, pollination, pest control, and many other ecosystem services. Food and livelihood security, as well as resilience to climate change also accompanies success in restoration.

Restoration initiatives can also serve as ‘living classrooms,’ allowing us to witness first hand and learn from the amazing workings of the natural world.

Download presentation on Landscape Restoration by Rhett Harrison (World Agroforestry Centre-ICRAF)

Tylianakis et al. (2008) Plos Biology 6: 224-228.


See related stories

Why agroforestry can add so much more to landscape restoration efforts

Breathing life into degraded landscapes with trees: Restoration in Korea, South Africa and Ethiopia

Korea to support global forest restoration

See photos of Tree Diversity Day 2014




Daisy Ouya

Daisy Ouya is a science writer and communications specialist with the World Agroforestry Centre (ICRAF). Over the past 15 years she has been packaging and disseminating scientific knowledge in the fields of entomology, agriculture, health, HIV/AIDS research, and marine science. Daisy is a Board-certified Editor in the Life Sciences (bels.org) and has a Masters’ degree in chemistry from the University of Connecticut, USA. Her BSc is from the University of Nairobi in her native Kenya. She has worked as a journal editor, science writer, publisher, and communications strategist with various organizations. She joined ICRAF in July 2012. Twitter: @daisyouya

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