A view from space gives emphasis to areal dimensions of vegetation and agriculture at the thin interface between atmosphere and solid earth. It is only by spreading plants across the landscape that they can efficiently intercept fluxes of limiting resources such as CO2, water, and sunlight. Farmers make strategic and tactical decisions about planting and management to optimize rates of crop growth and accumulation of yield. In farming, land is divided into individual fields as the units of management and production. In ecological terms, plants that occupy those fields constitute a community of cohabiting organisms. A community, considered together with the chemical and physical features of the environment, forms a further fundamental grouping, the ecosystem.

Farmers' efforts in crop and pasture management aim at beneficial control over the structure of crop communities and physical and chemical aspects of their environment. These issues are introduced in Chapter 1, which also presents five major themes that recur throughout the book. Chapter 2 presents concepts of trophic chains seminal to understanding the role of animals in agriculture and the nutritional requirements of humans. Establishment and productivity of plant communities dominated by agricultural species is presented in Chapter 3, and their genetic resources in Chapter 4. This part terminates, in Chapter 5, with a discussion of plant phenological development as the primary basis for adaptability to environment and determination of reproductive yield.