Maximizing arthropod-mediated ecosystem services in agricultural landscapes: the role of native plants

www.frontiersinecology.org © The Ecological Society of America C of beneficial arthropods in agricultural landscapes is increasingly justified based on the value of the services they provide to society. The annual value of natural enemies and native pollinators to agriculture has recently been estimated at nearly $8 billion in the US alone (Losey and Vaughn 2006). These arthropod-mediated ecosystem services (AMES) include biological control of insect pests, worth $4.5 billion, and pollination of crops, worth $3.1 billion, each year. Despite the impressive economic value of these services, there is widespread concern over both the current and future status of beneficial arthropods. Farm intensification, urbanization, habitat fragmentation, climate change, diseases, and pesticides all threaten the services provided to agriculture by these arthropods (Allen-Wardell et al. 1998; Kremen et al. 2002; NRC 2007). Recognition of this situation has stimulated investigations around the globe, addressing how best to conserve and enhance arthropod diversity in intensively managed farmland (Landis et al. 2000; Gurr et al. 2004; Samways 2007; Whittingham 2007). If conservation programs aimed at enhancing agricultural sustainability are to deliver the increases in AMES they are designed to provide, there is an urgent need to determine how best to manipulate agricultural landscapes to support beneficial arthropods. Coordinating such efforts so that multiple services are enhanced is expected to improve the likelihood of adoption by farmers (Gurr et al. 2003; Olson and Wäckers 2007), and quantifying additional benefits for native biodiversity and cultural services may further increase society’s willingness to support such programs (Fiedler et al. 2008). Based on our recent findings (Fiedler and Landis 2007 a, b; Tuell et al. in press), we present a brief synthesis of the role that native flowering plants can play in sustaining pollinators, predators, and parasitoids in agricultural landscapes. We also discuss key areas of research needed to facilitate the use of native plants in conservation programs, with the goal of providing economic benefits to farmers through AMES.