Department of Plant Sciences, University of California, Davis, USA.
Department of Plant Sciences, University of California, Davis, USA; University of California Cooperative Extension, USA.
J Environ Manage. 2018 Apr 1;211:191-197. doi: 10.1016/j.jenvman.2018.01.061. Epub 2018 Feb 4.
The historical management of agroecological systems, such as California's rangelands, have received criticism for a singular focus on agricultural production goals, while society has shifting expectations to the supply of multiple ecosystem services from these working landscapes. The sustainability and the multiple benefits derived from these complex social-ecological systems is increasingly threatened by weed invasion, extreme disturbance, urban development, and the impacts of a rapidly changing and increasingly variable climate. California's grasslands, oak savannas, and oak woodlands are among the most invaded ecosystems in the world. Weed eradication efforts are rarely combined with seeding on these landscapes despite support for the inclusion of the practice in a weed management program. Depending on seed mix choice, cost and long-term uncertainty, especially for native seed, is an impediment to adoption by land managers. We investigated four seeding mixes (forage annual, native perennial, exotic perennial, and exotic-native perennial) to evaluate how these treatments resist reinvasion and support the delivery of simultaneous multiple ecosystem services (invasion resistance, native richness, nitrogen fixing plants, pollinator food sources, plant community diversity, forage quality, and productivity). We found the increase of exotic and native perennial cover will drive resistance to an invading weedy summer flowering forb Centaurea solstitialis but provides a mixed response to resisting invasive annual grasses. The resistance to invasion is coupled with little tradeoff in forage productivity and quality and gains in plant diversity and native cover.
农业生态系统的历史管理，如加利福尼亚的牧场，因其单一关注农业生产目标而受到批评，而社会对这些工作景观提供多种生态系统服务的期望正在发生变化。这些复杂的社会-生态系统的可持续性和多种效益越来越受到杂草入侵、极端干扰、城市发展以及快速变化和日益多变的气候的影响。加利福尼亚的草原、橡树草原和橡树林是世界上受入侵最严重的生态系统之一。尽管支持将该实践纳入杂草管理计划，但在这些景观上进行除草和播种的工作很少结合。根据种子混合物的选择、成本和长期的不确定性，尤其是对于本地种子，这是土地管理者采用的障碍。我们研究了四种播种混合物（饲料一年生、本地多年生、外来多年生和外来-本地多年生），以评估这些处理方法如何抵抗再入侵并支持同时提供多种生态系统服务（抗入侵性、本地丰富度、固氮植物、传粉媒介食物来源、植物群落多样性、饲料质量和生产力）。我们发现，外来和本地多年生植物覆盖度的增加将有助于抵御入侵性夏季开花的杂草豚草 solstitialis，但对抵抗入侵性一年生草本植物的反应则较为复杂。抗入侵性与饲料生产力和质量的小损失以及植物多样性和本地覆盖度的增加相关。
