Department of Environmental Studies, 1156 High Street, University of California, Santa Cruz, Santa Cruz, California, 95064, USA.
Ecol Appl. 2017 Apr;27(3):966-976. doi: 10.1002/eap.1500. Epub 2017 Mar 21.
In agroecosystems, local and landscape features, as well as natural enemy abundance and richness, are significant predictors of predation services that may result in biological control of pests. Despite the increasing importance of urban gardening for provisioning of food to urban populations, most urban gardeners suffer from high pest problems, and have little knowledge about how to manage their plots to increase biological control services. We examined the influence of local, garden scale (i.e., herbaceous and arboreal vegetation abundance and diversity, ground cover) and landscape (i.e., landscape diversity and surrounding land use types) characteristics on predation services provided by naturally occurring predators in 19 urban gardens in the California central coast. We introduced sentinel pests (moth eggs and larvae and pea aphids) onto greenhouse-raised plants taken to gardens and assigned to open or bagged (predator exclosure) treatments. We found high predation rates with between 40% and 90% of prey items removed in open treatments. Predation services varied with local and landscape factors, but significant predictors differed by prey species. Predation of eggs and aphids increased with vegetation complexity in gardens, but larvae predation declined with vegetation complexity. Smaller gardens experienced higher predation services, likely due to increases in predator abundance in smaller gardens. Several ground cover features influenced predation services. In contrast to patterns in rural agricultural landscapes, predation on aphids declined with increases in landscape diversity. In sum, we report the relationships between several local management factors, as well as landscape surroundings, and implications for garden management.
在农业生态系统中，局部和景观特征以及天敌的丰富度和多样性是捕食服务的重要预测指标，这些服务可能导致对害虫的生物控制。尽管城市园艺对为城市人口提供食物的重要性日益增加，但大多数城市园丁都遭受着高虫害问题的困扰，并且对如何管理他们的种植园以增加生物控制服务知之甚少。我们研究了局部特征（即草本和木本植被的丰富度和多样性、地面覆盖物）和景观特征（即景观多样性和周围土地利用类型）对加利福尼亚州中部海岸 19 个城市花园中自然发生的捕食者提供的捕食服务的影响。我们将（蛾卵和幼虫以及豌豆蚜虫）作为哨兵害虫引入温室中饲养的植物中，然后将这些植物带到花园中，并分配到开放或套袋（捕食者隔离）处理中。我们发现，在开放处理中，有 40%至 90%的猎物被清除，捕食率很高。捕食服务随局部和景观因素而变化，但预测指标因猎物物种而异。卵和蚜虫的捕食随着花园中植被复杂性的增加而增加，但幼虫的捕食随着植被复杂性的增加而减少。较小的花园提供了更高的捕食服务，这可能是由于较小的花园中捕食者数量的增加。几种地面覆盖物特征影响了捕食服务。与农村农业景观中的模式相反，蚜虫的捕食随着景观多样性的增加而减少。总之，我们报告了几种局部管理因素以及景观环境与花园管理之间的关系和影响。
