Agriculture As User and Provider of Ecosystem Services.

Agriculture is the world’s largest managed ecosystem.  It provides food, fiber, and biofuel to consumers, while sustaining livelihoods of farmers.  It also offers a host of other natural benefits, known as ecosystem services.  Apart from the services that meet human needs for food, fiber, and biofuel, these other services include maintaining balance in water, climate and predator-prey systems, as well as offering recreational and inspirational experiences.  If agriculture generates many ecosystem services, it also relies upon many supporting ecosystem services as inputs to enable agricultural productivity.  These include the maintenance of soil nutrient cycling and natural enemies of agricultural pests, as well as the regulation of water quality and quantity.  Natural ecosystems can generate disservices, such as pests and diseases that afflict agriculture, just as disservices from agricultural management can disturb balances in water, climate, and biotic systems.  Sustainable management of agricultural ecosystems calls for understanding both 1) the ecosystem services and disservices to and from agriculture, and 2) how farmers perceive those services and make choices.  Better knowledge of how agricultural ecosystems function will help sustainability and long-term productivity, as will the design of policies and technologies to align incentives for individual farmers with those of society at large.