Healthy and Diverse Ecosystems
The ecosystem is a natural unit in the environment consisting of plants, animals and microbes functioning together within the physical environment. It represents the highest level in a hierarchical organization of biological systems which ranges from the cell to organism to population to ecosystem.
A healthy ecosystem shows a pattern of organization in the functional relationships between its components. These functional relationships and their products are sometimes referred to as ecosystem services. Some are primarily internal to the ecosystem, such as nutrient cycling, controlling water flow, or avoiding erosion. These services are often referred to as regulating or supporting services as they regulate material movement or support other ecosystem functions. Others may produce a product which is harvested for human use, such as wood and agricultural products. They are referred to as provisioning services. There are also non-material cultural and spiritual benefits that people derive from ecosystems, which are called enriching services
The regulating and supporting services reduce the impact of the physical environment on humans. For example, adequate vegetation cover and beaver dams reduce peak runoff and downstream flooding in extreme rain events. These services also support the production of provisioning and enriching services and are the foundation of sustainability. Ecosystem services, whether directly used by humans or not, are important to human well-being.
Biodiversity is believed to enhance the ability of ecosystems to withstand stresses such as drought. It also contributes to the supporting and regulating services of the ecosystem. In addition, it is likely not possible to preserve an endangered species without maintaining the ecosystem in which it resides.
Agricultural ecosystems are a type of working landscape in which elements of the natural ecosystem have, to varying degrees, been modified to enhance the capture of provisioning services. For example, grazing on native rangeland may have minimal effect on species composition and productivity of the ecosystem while cropland has had most non-crop species removed.
Sustainable management of agri-ecosystems maintains the regulating and supporting services for the ecosystem. Some are maintained within the fields, e.g. reduced tillage to control erosion. Others are provided in the uncropped portions of the landscape, including hedgerows, field boundaries, riparian areas, and wetlands. Services related to water flow regulation, water filtering, habitat for pollinators and other beneficial organisms, for example, are often a result of appropriate management of lands not directly used for production.
The goal of sustainable use of ecosystem services is to maintain healthy, diverse ecosystems which deliver clean air and water and are able to recover and adapt to environmental stresses. Many Agriculture Policy Framework Programs are helping to maintain and improve the health of agri-ecosystems.
Further information on the benefits and threats to healthy ecosystems: