Comparison of organic and conventional farms: challenging ecologists to make biodiversity functional

www.frontiersinecology.org © The Ecological Society of America P organic farming enterprises are emerging around the world in response to burgeoning consumer demand and concerns about human and environmental health (Maeder et al. 2002; Kristiansen 2006). Previously restricted to health food stores and farmers’ markets, organic food is now a mainstream commodity. In 2000, US consumers purchased more organic food in supermarkets than in any other venue (Dimitri and Greene 2002). The amount of land under organic management in many European Union countries has risen dramatically in the past decade, and is expected to increase further due to market opportunities and various government mandates and incentives (Stoltz 2005; Ryden 2007). Organic agriculture is now considered a viable option in food security discussions (Badgley et al. 2006; Zanoli et al. 2007). Research support for these alternative farming operations is gaining ground through targeted federal funding and the establishment of certified organic experimental fields by academic institutions (Sooby 2001). Past studies comparing ecological processes on organic versus conventional farms have been limited by a lack of funding and appropriate test sites. However, new studies can take advantage of growth in organic production to strengthen the scientific basis for evaluating and implementing practices designed to foster ecosystem function, improve human health, and produce sustainable yields. To illustrate how ecologists can help to meet research needs at this critical time, we examine the connection between enhanced biodiversity on organic farms and a key ecosystem service – pest control. Ideally, biodiversity that is conserved on organic farms promotes beneficial biological processes that compensate for practices (such as application of synthetic insecticides) that are disallowed under organic certification requirements. Conventional agriculture is managed using a wide range of cultural, biological, and chemical practices and tools (Letourneau and van Bruggen 2006). Organic agriculture, which also encompasses a wide range of practices, is subject to additional national and international regulations. Certification standards differ around the world, but all promote farm management with agronomic, biological, REVIEWS REVIEWS REVIEWS