Application of Ecologically Based Weed Management in Pastures

Grasslands cover up to about 40% of the world's total land area (Suttie et al. 2005" Gibson 2009). These complex plant communities are generally comprised of a range of species including grasses, legumes, shrubs, and/or other forbs (Figure 17.1) (Allen et al. 2011), and are used primarily for grazing livestock such as cattle, sheep, and goats (Sanderson et al. 2004). The nomenclature associated with grasslands varies around the world and is largely influenced by the level of management needed to achieve some level of productive potential (Gibson 2009). For example, rangelands are generally comprised of indigenous vegetation that is sparingly grazed with little other management. In contrast, intensively managed pastures are likely to include improved species and agrochemical inputs, and are specifically devoted to the production of forage for harvest by either grazing or cutting. Furthermore, grazing is generally carefully managed to maintain satisfactory levels of plant persistence and animal productivity (Sindel 2006" Allen et al. 2011). For the purposes of this chapter, all plant communities that are grazed and have some level of management will be referred to as pastures.