Principles and practices for managing rangeland invasive plants

Invasive plants reduce the capacity of ecosystems to provide goods and serv ices required by society, alter ecological processes, and can displace desi rable species. They can reduce wildlife habitat quality, riparian area inte grity, rangeland economic value, and enterprise net returns. The invasion p rocess is regulated by characteristics of the invading plant and the commun ity being invaded. The presence and spread of invasive plants is often symp tomatic of underlying management problems that must be corrected before acc eptable, long-term rangeland improvement can be achieved. Disturbance appea rs to be important early in the invasion process because it creates vacant niches that alien plants can occupy. Control of invasive plants may only op en niches for establishment of other undesirable plants unless desirable pl ants are present to fill the vacated niches. In many instances, rangelands have deteriorated to the point that desirable species are either not presen t, or in such low abundance that plant community recovery is slow or will n ot occur without revegetation after invasive plants are controlled. Integra ted weed management employs the planned, sequential use of multiple tactics (e.g. chemical, biological, cultural, and mechanical control measures) to improve ecosystem function (energy flow and nutrient cycling) and maintain invasive plant damage below economic levels, and emphasizes managing rangel and ecosystem functions to meet objectives rather than emphasizing a partic ular weed or control method. Sustainable, integrated invasive plant managem ent strategies require assessing plant impacts, understanding and managing the processes influencing invasion, knowledge of invasive plant biology and ecology. and are based on ecological principles. Invasive plant management programs must be compatible with and integrated into overall rangeland res ource management objectives and plans. Because of the complexity of managin g invasive plants, it is imperative that relevant ecological and economic i nformation be synthesized into user-friendly decision support systems.