Regulating the Climate with Agroforestry
The agroforestry is known for its benefits in the fight against climate change. Agroforestry systems help adapt agroecosystems to droughts and increasingly frequent heat waves. Numerous interactions between trees and crops have positive impacts on water availability, soil health, and biodiversity.[1]
Impact on water and yields
The presence of trees influences local climatic conditions through various processes that modify the water use by plants :
- Reduction of wind speed and wind erosion : there is less evaporation at the plant and soil level.
- Temperature reduction, up to -4°C [2]: lower temperatures reduce the plants' evapotranspiration rate.
These processes help reduce water losses by plant evapotranspiration and soil evaporation, thus increasing the water use efficiency of plants.
Regarding grasslands in agroforestry, their yield is sometimes lower due to significant shading, but plants with later development also have better nutritional quality for livestock. It is advised to pollard the trees if they develop at the expense of the grassland. The harvested material can be used as fodder, energy wood, or bedding.
Trees help maintain a more constant temperature, so the risk of frost is limited[2].
Impact on soil health
Agroforestry adds organic matter (OM) to the soil through leaves that fall in autumn but also through the root systems of trees which increase the number of microorganisms while secreting exudates composed of sugars that represent an additional OM input.
Impact on biodiversity
Agroforestry systems increase biodiversity by providing new ecological niches within the agroecosystem, and habitats for birds and insects. This increased diversity also allows for recruiting more beneficial animals and reducing damage caused by pests and diseases.
Finally, agroforestry can promote the presence of pollinators by offering them a favorable microclimate and habitat.
Sources
- ↑ Geneviève Gagné, 2021 : Agroforestry, an adaptation measure against climate change https://climatoscope.ca/article/lagroforesterie-une-mesure-dadaptation-contre-les-changements-climatiques/#:~:text=En%20modifiant%20les%20conditions%20climatiques,climatiques%20comme%20le%20stress%20hydrique.
- ↑ 2.0 2.1 Noëlle Dorion : Trees serving climate regulation https://www.jardinsdefrance.org/larbre-au-service-de-la-regulation-climatique/
