Which agroforest for which farm under changing climates?
Agroforestry systems, as demonstrated in studies around the world, can help smallholders adapt to climate risks and at the same time mitigate climate change. However, to identify the best system there is a need to look closely at the benefits and trade-offs, say Rodel Lasco, Rafaela Jane Delfino and Marya Laya Espaldon
By Amy C. Cruz
Climate change is often thought to mean rising temperatures, drought and stronger typhoons. However, it is not limited to only extreme events. The impacts of climate change also reach the agricultural sector, affecting, to name but a few, the yields, incomes and security of supply of nutritious food of the many millions of smallholding farmers.
A joint study by Rodel Lasco and Marya Laya Espaldon of the World Agroforestry Centre and Rafaela Jane Delfino of the Oscar M. Lopez Center for Climate Change Adaptation and Disaster Risk Management Foundation Inc examined how different agroforestry systems around the world improved the resilience of smallholders in the face of climate change. They also looked at the potential of these systems to mitigate climate change and the trade-offs involved in adopting them.
In their newly published study, Agroforestry systems: helping smallholders adapt to climate risks while mitigating climate change, they state that agroforestry is ’agricultural systems that use trees and shrubs in land management, crop and/or animal production practised by an estimated 30% of the global rural population’ or, more simply, the incorporation of trees on farms.
Trees on farms have a variety of benefits. On sloping land, such as in Claveria, Misamis Oriental, Philippines, trees can help control erosion. Photo: World Agroforestry Centre/Bindu Johnson
These systems provide a host of benefits that help farmers adapt their farms to a changing climate, such as water conservation, improved micro-climatic conditions, enhanced soil productivity, nutrient cycling and conservation, and control of pests and diseases.
Studies also show how agroforestry systems can be used in mitigation schemes because they store carbon in biomass and the soil. However, Dr Lasco and team recommended that more studies be done on more accurate methods of accounting for the stored carbon.
Not only can agroforestry contribute by mitigating and improving resilience to climate change but also by providing alternative and additional sources of income and sustaining production. For example, fertilizer-tree species that enhance the soil’s physical properties can increase maize yields. Trees are also easier, safer and more stable sources of fuel wood.
However, adopting agroforestry has its trade-offs, as shown in other studies. For example, while agroforests stabilize ecosystems this could also provide easier access for pathogens or destroy other useful plants. Also, the productivity of agroforestry systems cannot surpass that of monoculture farms. And on a larger scale, an agroforestry system stores a smaller amount of carbon compared to a primary forest.
In order for more people to adopt and promote agroforestry practices, farmers need to know whether the advantages outweigh the disadvantages. Even after more than 40 years of research by the World Agroforestry Centre and other organizations, there is still a need for more research to more accurately measure and identify the benefits and trade-offs given the huge number of variations in biophysical and socio-economic conditions around the world. This would mean that more people could benefit from more specific research that identifies which systems and practices fit particular situations.
Edited by Robert Finlayson
Read the article
Lasco RD, Delfino RJP, Espaldon MLO. 2014. Agroforestry systems: helping smallholders adapt to climate risks while mitigating climate change. Wiley Interdisciplinary Reviews: Climate Change. doi: 10.1002/wcc.301
This work is linked to the CGIAR Research Program on Forests, Trees and Agroforestry