Is management of an invasive grass Agropyron cristatum contingent on environmental variation

摘要: Summary 1 The control of invasive species is a challenge heightened by the dependency management outcomes on environmental variation. This especially true for plants invading semi-arid habitats, where growing season precipitation varies greatly among years. 2 Agropyron cristatum an grass widely introduced in Great Plains North America. We studied its demographic responses to using field experiments and matrix population models. Plants were clipped simulate grazing, treated with herbicide or left unmanaged, at three levels water availability, 2 years. 3 Growth rates (λ) high unmanaged populations. Clipped populations mainly stable, whereas λ herbicide-treated varied availability between years. Low was result low seed production, these most sensitive availability. 4 Clipped produced no seeds second year, indicating cumulative negative effect defoliation. In general, germination juvenile survival all increased supply, suggesting that invasion may increase under wet conditions. 5 Population projections revealed steady size populations, more stable. Herbicide-treated decreased. Life-cycle stages associated recruitment contributed rapid growth whilst persistence managed relied established tussocks. 6 Synthesis applications. These results demonstrate strong effects A. spite significant availability. Management can therefore have large native grasslands regardless among-year variability precipitation.