Ecological Consequences of Using Prescribed Fire and Herbivory to Manage Juniperus Encroachment

Encroachment of Juniperus species into what had previously been grasslands or savannas coincides with the development of the livestock industry (Archer 1994). Before European settlement and their introduction of stock-farming practices, these vegetation communities were maintained by periodic fires (Frost 1998) and the grazing/browsing habits of native wildlife (Smeins et al. 1997). These early ranchers did not have experience in semiarid regions, and consequently they did not anticipate how their introduction and management of domesticated livestock and suppression of fire would alter the rangeland structure from mostly a grassland to a woodland dominated by oak, mesquite, and juniper (Taylor and Smeins 1994; Wills 2005). The increase in these woody plants, particularly juniper, has resulted in major environmental tradeoffs that have significant implications for ranch enterprises and for the land use patterns supported by rangelands and surrounding regions, particularly in the Edwards Plateau of central Texas (Thurow et al. 1997). Many research studies report that dense stands of mature juniper cannot be managed effectively with fire alone (Ansley and Rasmussen 2005). Because the cost of traditional brush management practices (i.e., herbicides and mechanical treatments) often exceeds the economic returns that result from implementing these practices, viable options to solving the juniper problem are limited, especially once larger juniper trees are established. However, landscapes dominated by juniper, even mature juniper, can be returned to a grassland community with the use of prescribed fire and herbivory, especially by goats. The objective of this chapter is to discuss the ecological consequences of reclaiming juniper rangelands with sustainable, cost-effective management practices.