Unlike reforestation, which refers to replanting existing forests, environmental scientists define afforestation in short as the practice of planting trees in lands that were not previously under forest cover.1 For instance, it entails the conversion of abandoned lands and former agricultural lands into forests.2
What are the benefits of afforestation?
Firstly, afforestation can improve soil quality. Barren lands with sparse or no vegetation suffer from water and nutrient runoff. Studies have shown, however, that tree plantations can increase water yield and infiltration in soils.3,4 In other words, afforestation can ease water movement into and through the soil profile together with allowing temporary water storage. Consequently, there is more water available for vegetation.
In addition, afforestation has been linked to increased soil organic carbon levels.5 Organic carbon is important for soil’s physical stability and fertility. Therefore, higher organic carbon levels help to prevent land degradation and desertification caused by erosion and the loss of water and nutrients.
Furthermore, planting trees can have a large-scale positive effect on the carbon cycle and the climate. Because forests act as carbon sinks, increased tree cover would help to sequester atmospheric CO2 and slow down global warming.2
Are there any drawbacks to afforestation?
Unfortunately, afforestation can have a few negative effects. The land for planting trees and the tree species need to be carefully selected in order to avoid negative environmental consequences.6
For example, some arid areas in China, which has had the largest areas of afforestation over the last few decades7, have suffered from increased desertification and low survival rates of new trees.8Introducing non-native species can also negatively affect local biodiversity.
To sum up, scientists define afforestation in short as planting trees in areas where there was no forest previously. The United Nations lists afforestation as one of the key strategies for forest development.9 Thus, if carried out responsibly, it can be a valuable asset in the fight against climate change.
- Richards, D. (2003), British Forestry in the 20th Century: policy and achievements, Brill.
- Santos, F. M., Gonçalves, A. L., & Pires, J. C. (2019), Negative emission technologies, In Bioenergy with Carbon Capture and Storage (pp. 1-13). Academic Press.
- Farley, K. A., Jobbágy, E. G., & Jackson, R. B. (2005), Effects of afforestation on water yield: a global synthesis with implications for policy, Global change biology, 11(10), 1565-1576.
- Ilstedt, U., Malmer, A., Verbeeten, E., & Murdiyarso, D. (2007), The effect of afforestation on water infiltration in the tropics: a systematic review and meta-analysis, Forest Ecology and Management, 251(1-2), 45-51.
- Laganiere, J., Angers, D. A., & Pare, D. (2010), Carbon accumulation in agricultural soils after afforestation: a meta‐analysis, Global change biology, 16(1), 439-453.
- Interregional Project for Implementation and Evaluation of Special Public Works Programmes, International Labour Office, 1988.
- Global Forest Resources Assessment 2015, Food and Agriculture Organization of the United Nations (FAO).
- Cao, S. (2008), Why large-scale afforestation efforts in China have failed to solve the desertification problem.
- Six Global Forest Goals agreed at UNFF Special Session, Department of Economic and Social Affairs, Published January 20, 2017.