Climate Change

Farmers, ranchers, and forest landowners always face challenges posed by weather, however these challenges are getting more frequent and extreme. Our changing climate is a growing concern and evidence suggests that the accumulation of carbon dioxide and other greenhouse gases in the atmosphere has caused, and will continue to cause, incremental warming and other climate change impacts.

Preparing and Responding to Climate Risks

Increased frequency and intensity of extreme weather events such as droughts and floods can lead to yield reductions or crop and livestock losses. Agroforestry can help landowners prepare for and respond to the risks that come from a changing climate.

Flooding

Once established, trees and shrubs are often more drought and flood tolerant than annual plants. Agroforestry practices can help producers adapt to increased rain intensity by intercepting rainfall, increasing infiltration, and reducing the quantity, speed, and peak flows of runoff. For example, conservation buffers in riparian areas and other parts of the landscape can reduce flood and erosion risks for downstream farms and communities by slowing runoff and stabilizing stream banks. Additionally, riparian forest buffer shade can maintain cold-water fish habitat in areas where stream temperatures may rise.

Flooded willows. — Perennial trees and shrubs can help hold the soil, protect streambanks and reduce in-field sedimentation during flood events. (Photo courtesy of Josh Gamble)

Heat

Predicted higher temperatures may pose a significant challenge for animal production systems. Agroforestry practices can reduce heat stress on livestock by providing shade and moderating the microclimate. Reducing windspeed in the winter by using agroforestry practices, particularly windbreaks, can also lower livestock stress, improve feeding efficiency, and enhance survival during lambing and or calving season.

Cattle grazing under pine trees. — Cattle usually prefer natural shade to artificial shade structures. Evenly distributed shade helps to prevent cattle from congregating. (USDA National Agroforestry Center photo)

Wind Erosion

Current wind erosion and airborne dust problems are likely to increase in the future. During the 1930s Dust Bowl, windbreaks were planted in the Great Plains to control wind erosion and protect crops, and they remain a logical choice for addressing the same issues today. Climate change effects and issues will vary regionally and it is important to consider how these differences will influence application of agroforestry in a specific region.

Black and white photo of two farmers working their crops next to a windbreak. — Thousands of miles of windbreaks were planted after the Dust Bowl era to protect orchards, crops, livestock and farmsteads. (USDA National Agroforestry Center photo)

Greenhouse Gases

Agroforestry can also help mitigate climate change by reducing greenhouse gas emissions. Trees and shrubs on agricultural lands can take carbon dioxide out of the air and "store" it in stems and roots. Agroforestry practices can reduce emissions by increasing soil carbon, decreasing fossil fuel usage by reduced equipment runs in fields, enhancing energy conservation around farm buildings, and improving use of nitrogen fertilizer.

Plant Adaptation

To be an effective adaptation and mitigation option, agroforestry plant materials must themselves be adaptable to climate change effects. Changing climatic conditions will impact plant survival and function, which, in turn, determines agroforestry’s effectiveness as a climate-smart strategy. Assessing suitability of species under future climate regimes will be an important step.