Effects Of Agroecosystems On Wildlife

Positive Effects of Agriculture on Wildlife

Several aspects of agroecosystems can positively affect wildlife populations. One aspect of the fragmentation of an agroecosystems/forest mosaic is the creation of edge habitat. This results in the edge effect, or the tendency for the variety and density of some species of plants and animals to increase at the border between different plant communities (Forman, 1997). Edges, or ecotones, contain species from both habitats as well as a subset of species considered to be edge specialists (Yahner, 1988). Some of these species are important game species (e.g., white-tailed deer in North America), which has resulted in a management practice among game biologists of creating edge habitat (Yoakum and Dasmann, 1971). The cost of edge creation is a reduction in the amount of forested habitat available and a decline in the abundance and richness of forest species if fragmentation becomes too severe. There are, however, some species that exist and even thrive in altered or fragmented habitats, especially those that have small area requirements or that are mobile and can easily move among habitat patches (Merriam, 1991; Noss and Cooperrider, 1994).

Grain agriculture often leaves residual seeds on the ground after harvest that serve as a valuable resource for many species of wildlife. Rice plantations provide rice grains as food as well as surrogate wetlands for many species of waterfowl (see below for a detailed case study). In the U.S., concern over the environmental impact of agriculture has also led to the passage of legislation geared toward the enhancement of wildlife habitat. Although not specifically tied to agriculture, the Endangered Species Act of 1973 has led to changes in agricultural practices when species of concern were potentially impacted. For example, concerns over the impact of irrigation on salmon fisheries led to the restriction of access to federally supplied irrigation water in California (Day, 1996). The Farm Act of 1996 created several valuable programs for the protection of wildlife (Table 1) and has included the conservation

Table 1 Programs and Provisions of the 1996 Federal Agriculture Improvement Act (Farm Act)

1. Environmental Quality Incentives Program

2. Wetlands Reserve Program and Conservation Reserve Program

3. Farmland Protection Program

4. Swampbuster and Wetland Provisions

5. Wildlife Habitat Incentives Program

6. Flood Risk Reduction Program

7. Emergency Watershed Protection Program

8. Conservation of Private Grazing Land

9. National Natural Resources Conservation Foundation

10. Conservation Farm Option

11. State Technical Committees

Source: U.S. Department of Agriculture, America's Private Land: A

Geographiyof Hope, U.S. Department of Agriculture, Washington, D.C.,

Was this article helpful?

0 0

Post a comment