Considerations for successful forest restoration in a changing climate
Even with a stable climate, forest restoration is a tricky and costly affair; the right species have to be carefully chosen, seeds or seedlings have to be procured, and these have to be planted and nurtured over long periods. If there are people in the targeted landscapes, their buy-in and cooperation is essential.
Add climate change, and this already knowledge-intensive and long-term undertaking acquires a new complexity and uncertainty.
Yet the opportunity is immense. According to a recent forestry conference, “humankind is experiencing historical momentum that favors forest restoration at the global, regional, and national levels.” And globally, some 2 billion hectares of land area is available for restoration, half of this croplands and settled areas.
Uncertain future climate, social conditions
The 2nd IUFRO Forests Congress, 14-16 October 2014, in Lafayette, Indiana, USA, brought together 114 participants from 16 countries to discuss what success in reforestation looks like in the 21st century, and discussed important considerations for restoration practitioners working in a changing climate.
“It is uncertain what the ecological and societal conditions of forest ecosystems to be restored will look like 50 or 100 years from now,” say Douglass Jacobs and co-authors, in the introductory chapter to the Special Issue of the journal New Forests.
Consisting of 21 papers from this Congress, the Special edition, published on 5 October 2015, highlights priority considerations for forest restoration in the 21st century as put forward at the conference. Summing up the chapters in the special edition, the introductory chapter distills some prime considerations for restoring forests in the 21st century. They include the following:
- Revisit the definition and utility of a ‘reference ecosystem’, distinguishing restoration and ecological rehabilitation. Practitioners have traditionally based their decisions for which species to use for land restoration on “reference vegetation” (the original vegetation before a forest was degraded). But with climates becoming hotter, more water-stressed and more extreme, the trees used for restoration must be able to withstand these new conditions, and may be different from those of the “reference vegetation.” As such, rather than trying to match reference species every time, select species to use according to ‘plant functional groups,’ which are classified according to ecological niche adaptations.
- Practice adaptive management, which involves iteratively defining and refining objectives and practices. Adaptive management has to happen within a flexible framework in a rapidly changing world.
- Restore, rehabilitate, and in some cases design resistant and resilient forest ecosystems that can adapt to emerging conditions caused by climate change.
- Prioritize restoration efforts according to cost-benefit analyses that include ecological risks.
- Pick out a suite of species for restoration that provide more stress resistance and competitive combinations in the longer term. While native species should be prioritized whenever possible, non-native species may serve an important role in restoration.
- Design nursery propagation and seedling quality assessments so they promote seedling survival through greater stress resistance.
- In degraded sites, use low-impact mechanical site preparation to restore structural elements and sources of microsite diversity.
- Identify better-adapted species and optimize provenance selection (where the seeds/seedlings used in the restoration will come from): This is one way to circumvent the rapid responses in genetics that species would need in order to adapt to new climates.
- Consider multiple objectives and approaches to minimize trade-offs in achieving the many benefits in terms of ecosystem goods and services that society gains from protected and restored forests.
- Use effective technology transfer and a community-based approach to forest restoration. This will help the new concepts and technologies to be adopted by forest managers, and accepted by society.
The authors, furthermore, emphasize the importance of learning from past experiences with restoration.
According to chapter co-author John Weber, Senior Associate with the World Agroforestry Centre (ICRAF), examples such as the massive landscape restoration achieved in the Sahel through farmer-managed natural regeneration, are instructive.
The authors called on the development and use of tools to evaluate and monitor restoration progress objectively. The ICRAF co-developed VegetationMap4Africa and the Land Degradation Surveillance Framework (LDSF) are just two examples of such tools. The former allows users in 8 African countries to determine an area’s natural vegetation and its useful species, while the latter applies GIS techniques combined with soil analyses to create digital maps that show trends over time and space. Other tools are: the TESSA toolkit, which allows users to properly evaluate and decide on the best interventions for forest restoration, and the BIP indicator toolkit, which guides practitioners in the design of good indicators for measuring the state of biodiversity and ecosystem health at various points of forest restoration programs.
Besides major global declarations supporting forests restoration—notably the 2011 Bonn Challenge to restore 150 million hectares of degraded and deforested land worldwide by 2020; the 2014 Forest Declaration to restore 350 million hectares of forests by 2030; and the Lima 20 x 20 Initiative to restore 20 million ha of forests by 2020 in some Latin American and Caribbean countries, many countries around the world have made reforestation commitments. Development partners, too, including Germany, Norway, the United Kingdom and the Global Environment Facility (GEF) are putting their weight behind landscape restoration.
Forest and landscape restoration aims to bring back ecological, social, and economic benefits of forests and trees within a broader pattern of land-uses.
It is widely seen as a sustainable option to reduce poverty, improve food security, mitigate and adapt to climate change, and conserve biodiversity around the world—all directly linked to achieving the Global Sustainable Development Goals .
Convened by IUFRO together with partners including World Agroforestry Centre (ICRAF), the IUFRO conference in Lafayette was organized and supported by IUFRO, Purdue University, the USDA Forest Service, and the Hardwood Tree Improvement and Regeneration Center.
Read Introductory Chapter:
Restoring forests: What constitutes success in the twenty-first century? By Douglass F. Jacobs, Juan A. Oliet, James Aronson, Andreas Bolte, James M. Bullock, Pablo J. Donoso, Simon M. Landhäusser, Palle Madsen, Shaolin Peng, José M. Rey-Benayas, John C. Weber. New Forests, 2015, Page 1.
Atlas of Forest Landscape Restoration Opportunities an online interactive map from WRI, the University of Maryland, and IUCN