Exotic grasses and wildlife in northern Mexico

Abstract

Seeding exotic grasses remains a common practice to increase forage production for cattle in northern Mexico. Even while interest in wildlife conservation and management has been increasing since the late 1990s because of the economic value of wildlife for sport hunting, cattle production still represents an important part of the ranch income. Our objective was to review the available information on exotic grasses and its effect on native rangelands and wildlife. To obtain the information included in this article, we reviewed the published information and personal information and observations. Ranchers need to balance and make commitments to optimize cattle and wildlife economic output. In general, the negative perception of biologists, ranchers, and the general public toward exotic grasses is less pronounced than in the United States even when the ecological benefits of maintaining healthy native rangelands is well‐understood. Differences in primary productivity and domestic animal production between exotic and native grasses are well‐documented; however, information on impacts of exotic grasses on wildlife is extremely limited. The preservation of native rangelands is important; however, exotic grasses will continue to be seeded in northern Mexico as long as cattle production remains an important economic activity. Exotic grasses in many cases will be impossible to eradicate; therefore, management will be necessary to ensure optimization of habitat for livestock and wildlife species. In this context many research questions need to be answered to optimize domestic livestock production and maintain healthy wildlife populations. Governments, non‐governmental organizations, and other entities interested in conservation should combine efforts and develop incentive programs for ranchers to preserve native rangelands in Mexico and to avoid seeding exotic grasses. © 2013 The Wildlife Society.

Invasive grasses in South Texas rangelands: historical perspectives and future directions

“…Pennisetum ciliare can also reproduce vegetatitvely via rhizomes and stolon production (Marshall et al 2012). Seed is spread via attachment to animal fur, vehicles, runoff, and wind (Ortega-S et al 2013). Some studies suggest P. ciliare may have allelopathic qualities (Franks 2002;Fulbright and Fulbright 1990).…”

“…Similarly, Sonoran Desert stocking rates increased from 27 to 40 ha AUY −1 (animal unit year) on native range to 9 to 15 ha per AUY −1 on P. ciliare pasture (Martin-R et al 1995). However, high stocking rates may weaken stands of P. ciliare and decrease its spread (Ortega-S et al 2013).…”

“…Pennisetum ciliare has been studied as a forage component of O. virginianus and mule deer (Odocoileus hemionus Rafinesque) diets. Both deer species were shown to use the grass, mostly fresh green growth, as forage in Sonora (Ortega-S et al 2013). Additionally, O. hemionus used P. ciliare sites in a manner similar to native range as long as water and thermal cover were provided (Ortega-S et al 2013).…”

“…Both deer species were shown to use the grass, mostly fresh green growth, as forage in Sonora (Ortega-S et al 2013). Additionally, O. hemionus used P. ciliare sites in a manner similar to native range as long as water and thermal cover were provided (Ortega-S et al 2013). Levels of crude protein were below winter requirements of O. virginianus in South Texas, but the grass contributed significantly to winter diets (Everitt and Gonzalez 1979).…”

“…Lagomorphs in Sonora showed between 70% and 80% use of P. ciliare in areas where native grasses were available (Ortega-S et al 2013).…”