Future Perspectives

This final chapter explores the future challenges for agroecosystem biology. Factors such as population growth and the requirement for increased agricultural production are considered, alongside environmental factors such as climate change. The chapter explores the potential encroachment of new farmland into natural habitats and the limiting factors for agricultural growth (such as land and water availability). The use of new developments to overcome these limiting factors to agricultural growth is discussed. The chapter concludes with consideration of the potential biological impacts of further expansion and change to global agriculture, and of the implications of agricultural management on biological and other environmental factors.

Soils

This chapter gives a basic introduction to soil formation and fundamental soil processes in agroecosystems. The types of soils found in agroecosystems and their importance for agriculture is explored, with a principal focus on soil biodiversity, i.e. soil-dwelling organisms, their variety and function, and the interaction between soil biology, agriculture, and food production. The chapter describes some of the issues associated with soils in agroecosystems. These include interactions between agricultural practices and soil erosion and soil quality issues such as salinization and desertification. The major challenges to maintaining ‘healthy’ soils on productive land are outlined, and approaches and techniques for managing soils described.

Agricultural Environments

This chapter outlines the origin and historical development of global agriculture. Agricultural systems around the world are extremely diverse, but all involve the management of land for the production of food and other commodities. Agroecosystems encompass a wide variety of production systems, both within and between different regions, and different classifications are used to order these. Characteristics and classifications of some major types of contemporary agricultural systems are introduced. The difference between agricultural and natural (or alternatively managed) ecosystems and farmed versus unfarmed habitats on agricultural land is explored, and examples of each are provided. Some of the impacts of agriculture on wider ecosystems are introduced.

Conservation and Sustainable Management of Agroecosystems

This chapter focuses on the role of farm management in biodiversity conservation (and the potential conflicts and synergies between them). It addresses the question of the relationship between productivity and biodiversity, and how this varies between spatial scale and agricultural system. Different methods of farm management for improved biodiversity and resource management on farmland are presented. The focus areas are reintroducing diversity, sustainable pest and nutrient management, and the role of alternative systems such as organic and biodynamic agriculture. Frameworks for regulating the biological impacts of agriculture (e.g. pesticide regulation, ecological engineering, and funding for conservation are also introduced. Other case studies may include organic farming systems, agroforestry systems, and perennial-based cropping systems, as well as the use of integrated pest management techniques.

The Biological Impacts of Globalization of Agriculture

While pre-modern agriculture tended to use local resources, modern (often intensive) agriculture uses resources from a much wider area—even global in some cases. This chapter discusses the role of agriculture as a driver of global environmental change, together with issues and opportunities associated with the globalization of agriculture. The topics explored include the introduction and spread of invasive and pest species; reductions in genetic diversity; changes in the type of commodities demanded locally and globally; and loss of traditional crops. The implications of these changes for wider ecosystems are explored. The potential for some of these global drivers to act synergistically with each other and with other drivers (e.g. climate change) to impact on biological systems is also explored.

Biotic Interactions and Ecosystem Functioning

This chapter introduces different functional groups and their role in agroecosystems and in provision of ecosystem services. Examples include detritivores and other nutrient cyclers, primary producers, pollinators, herbivores, and pest regulators. The importance of plant–fungal interactions (endophytes and mycorrhiza), primary productivity, maintenance of soil fertility through nutrient cycles, biological pest control, and crop pollination are discussed and related to different management systems. The influence of agricultural practices (e.g. pesticide/fertilizer application, introduction of new/genetically modified species) on biotic interactions and ecosystem functioning of agricultural practices are also illustrated, alongside a consideration of the biological issues associated with the replacement of ecological processes with chemicals, machinery, and so on in some modern agricultural systems.

Biodiversity

This chapter discusses biodiversity in farming systems, including a consideration of the ecological importance of non-agricultural habitats within farm systems. The chapter outlines patterns of biodiversity in space and time, as well as at varying levels (genetic, organismal, landscape), before exploring the impact of agriculture on biodiversity at local, regional, and global scales. Farmland is an artificial environment, often characterized by monocultures grown at a density that differs from natural growth patterns. This can generate instability, resistance to environmental change, susceptibility to pests, pollution, and impacts on other ecosystem services such as soil and water. The chapter ends with a discussion of the biological implications of continued agricultural change (e.g. specialization, intensification).

Water (Hydrology)

This chapter outlines the biological impacts of water use and pollution related to agricultural systems. Topics include drainage, irrigation, water harvesting, and the water cycle (e.g. under polytunnels and greenhouses) and how management of water for agriculture links with biology. Water availability as a limiting factor for agriculture is discussed, particularly in relation to arid areas (e.g. salinization, biological impacts of collecting water for storage for agriculture in arid areas). Outputs from agriculture and potential biological impacts are also explored (e.g. nitrates, phosphates, pesticides, bacterial pathogens, sediment in water). Potential management tools for water use and protection in relation to farming are introduced.

Introduction

This chapter describes what agroecosystems are, and considers the importance of studying the biology of agroecosystems. A brief introduction to the extent and general characteristics of agroecosystems is provided, before describing the scope and organization of the rest of the book.