Wildlife and Pollinators

Wildlife

Over 50 percent of land use in the United States is dedicated to agriculture. Farms and ranches are therefore a critical piece in the conservation puzzle, as actions taken on these working landscapes have an impact on wildlife and the health of ecosystems. Agroforestry is one option to create benefits for landowners and wildlife.

Most agroforestry practices can be intentionally designed to provide wildlife habitat. The types of wildlife that can benefit will vary with region, ecotype, and landowner preferences and depend on the landscape context and size of the area and the types, spatial configuration, and age of the plantings. Even when practices are primarily designed for economic purposes, substantial wildlife benefits can still occur.

Agroforestry practices can protect aquatic habitat by providing living cover, which intercepts sediment, nutrients, and other materials in runoff and in shallow subsurface water flow, preventing them from getting into streams, lakes, or wetlands. Riparian forest buffers can also reduce bank erosion and in-stream sedimentation, and help maintain water temperatures for cold water fisheries.

salmon swim in a clear stream lined with trees. — Riparian forest buffers can help maintain water temperatures for cold water fisheries.
(Adobe Stock photo)

Croplands are subject to frequent disturbances that can impact shelter and food sources for wildlife. Agroforestry practices offer more constant habitat in these shifting landscapes, and the woody structure and associated under story increase niche diversity.

Agroforestry systems can help to mitigate the impacts of agricultural pesticides on sensitive wildlife, particularly insects, amphibians, fish, and other aquatic species. Windbreaks, hedgerows, riparian buffers, or alley cropping can help contain drifting pesticides. Tree and shrub layers provide a large surface area over which particles of pesticides may adhere, and also provide wind-speed reduction at the application site, reducing the movement of pesticides off their target.

The conversion of farms and ranches into fragmented and extensively modified urban or suburban patches often has negative impacts on wildlife. Agroforestry can reduce such conversion by diversifying short- and long-term income sources, giving landowners economically-sustainable alternatives. Agroforestry can also decrease the impacts of habitat fragmentation by reducing habitat isolation if plantings are well planned and connected with other habitats.

Pollinators

Over one hundred crop species in North America require a visit from an insect pollinator to be most productive. Whether growing a hedgerow or windbreak, managing a riparian buffer, or farming near forests, agroforestry practices can increase the overall diversity of plants and physical structure in a landscape and, as a result, provide habitat for native pollinators. Agroforestry plantings can also benefit crop pollination.

Many flowering trees and shrubs used in agroforestry can provide critical pollen and nectar for pollinators, particularly early in the season when other flowering plants have yet to bloom. Some trees and shrubs planted for their production value also have pollinator benefits, such as berry-producing shrubs like blueberries and raspberries, ornamental plants like curly willow, and hardwoods like black cherry. Agroforestry plantings can also provide nesting habitat for bees.

Diagram illustrating the benefits of agrforestry practices upon pollinators. — Agroforestry practices can be used to mitigate potential negative impacts of pesticides on pollinators.
(USDA National Agroforestry Center illustration)

Adding agroforestry practices that reduce wind speeds can increase pollination efficiency. Some pollinators, especially honey bees, stop pollinating when it gets too windy. Windbreaks, riparian buffers, hedgerows, and alley cropping are all agroforestry practices that can provide vital pollinator habitat within or adjacent to farm fields requiring insect pollination. Agroforestry practices can reduce pollinator contact with pesticide drift from nearby fields. A systematic review conducted by NAC provides a scientific synthesis on how temperate agroforestry systems can support insect pollinators and their pollination services.