Reforestation is more than carbon
A team of researchers are advocating ‘climate-smart reforestation’: reforestation for climate-change mitigation and adaptation that takes into account the impacts of climate change on the reforestation itself.
Researchers from different universities and institutions discuss in a recently published paper how tropical reforestation could contribute to both the mitigation of, and adaptation to, climate change. The team, which includes Dr Rodel Lasco, country coordinator of the World Agroforestry Centre Philippines, propose that strategies aiming for both climate-change mitigation and adaptation could result in synergies. This study was supported by the National Science Foundation and the CGIAR Research Program on Forests, Trees, and Agroforestry.
Reforestation in the tropical regions has large potential for carbon storage and significant biophysical effects, making it a key activity in climate-change mitigation efforts. For one, reforestation could result in either warming or cooling a local climate, depending on choice of trees and the location. Large-scale reforestation could also affect rainfall patterns, leading to increased rainfall in arid areas. Sustainable production and use of forest products from reforestation could also help mitigate climate change. Forests can provide alternative sources of energy or materials that emit less greenhouse gases.
However, tropical reforestation could not only contribute to mitigation efforts but also to adaptation. According to the authors, reforestation can help communities and ecosystems adapt to climate change by reducing their vulnerability to current and future climate hazards. Forests give communities more diverse sources of livelihoods. In addition, forest products could be used to cope during, and recover after, extreme events. Trees also improve a microclimate, making it more conducive for growing crops.
Reforestation also reduces the impacts of water-related stresses. Trees increase water flow of rivers and can also reduce the impact of droughts, floods and heat waves. Coastal ecosystems that are reforested with mangroves would be better protected from waves and storms. Reforested sloping lands are more stable and therefore are less prone to landslides. Biodiversity also benefits as reforestation provides plants and animals with habitats.
The authors warn, though, that the mitigation and adaptation potential of reforestation would vary according to the type done as well as the diversity of the area and the age of the forest.
According to the authors, reforestation may be called ‘climate-smart’ when it is done ‘for climate-change mitigation and adaptation while ensuring that the direct and indirect impacts of climate change… are anticipated and minimized’. Climate change and climate-related policies and market changes have direct and indirect impacts on reforestation that should be considered in reforestation activities. Climate change influences the survival and growth rates of trees planted. It is also linked to the spread of pests, invasive species and diseases. The suitability of a tree species to an area could be affected as well because of a shifting climate. Climate change may push humans to move to more suitable areas thus affecting the availability of areas for reforestation.
Climate-related policies provide incentives for reforestation and influencing management decisions thus directly affecting reforestation. In addition, changes in energy policies and biofuel demand would affect land use and might even provide incentives for planting tree species that are alternative energy sources.
Existing policies and programs take reforestation for either its mitigation or adaptation capacities, however, possible trade-offs and synergies could be missed in doing so. Reforestation strategies should consider taking a multi-objective focus and explore how the activities could interact to produce synergies. Also, reforestation is almost always just one strategy for climate-change mitigation and adaptation. Activities from other sectors should complement reforestation efforts to maximise the benefits.
Further studies need to be done on several topics, like the criteria for choosing tree species for reforestation with the most benefits, the choice of exotic versus native species (when considering biodiversity issues, reforestation success and suitability to certain conditions), the response of reforested areas to climate change and the ecosystem services derived from tropical reforestation.
Read the article
Locatelli B, Catterall CP, Imbach P, Kumar C, Lasco R, Marín-Spiotta E, Mercer B, Powers JS, Schwartz N, Uriarte M. 2015. Tropical reforestation and climate change: beyond carbon. Restoration Ecology. doi: 10.1111/rec.12209
This work is linked to the CGIAR Research Program on Forests, Trees and Agroforestry