USGCRP
Home  Focus Areas
Changing Ecosystems |
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Updated 19 August, 2004 |
Changing Ecosystems A USGCRP Program Element |
| USGCRP
Home Focus Areas
Changing Ecosystems |
| Search |
|
Updated 19 August, 2004 |
Changing Ecosystems A USGCRP Program Element |
|
Changing EcosystemsOverview
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Ecosystems shape societies and nations by providing essential renewable resources and other benefits. They sustain human life by providing the goods and services on which life depends, including food, fiber, shelter, energy, biodiversity, clean air and water, recycling of elements, and cultural, spiritual, and aesthetic returns. Ecosystems also affect the climate system by exchanging large amounts of energy, momentum, and greenhouse gases with the atmosphere. The goal of the Ecosystems research element of the CCSP is to understand and be able to project the potential effects of global change on ecosystems, the goods and services ecosystems provide, and ecosystem links to the climate system. Climate variability and change can alter the structure and functioning of ecosystems. This, in turn, can affect the availability of ecological resources and benefits, can change the magnitude of some feedbacks between ecosystems and the climate system, and can affect economic systems that depend on ecosystems. Research during the last decade focused on the vulnerability of ecosystems to global change and contributed to assessments of the potential effects of global change on ecological systems at multiple scales. We now know that the effects of environmental changes and variability may be manifested in complex, indirect, and conflicting ways. For example, warming may enhance tree growth by extending growing season length (in temperate and cool regions), but pathogens better able to survive the winter because of higher temperature may decrease forest productivity and increase vulnerability of forests to disturbances such as fire. Subtle changes in winds over the ocean can affect currents, which in turn may alter the ranges and population sizes of fish species and increase or decrease fish catches. Whether environmental changes result from human activities or are natural in origin, human societies face substantial challenges in ensuring that ecosystems sustain the goods and services on which we depend for our quality of life and survival itself. Research should be focused on building the scientific foundation needed for an enhanced capability to forecast effects of multiple environmental changes (such as concurrent changes in climate, atmospheric composition, land use, pollution, invasive species, and resource management practices) on ecosystems, and for developing products for decision support in managing ecosystems. Near-term priorities will be placed on economically important ecosystems and special studies relevant to regions where abrupt environmental changes or threshold responses by ecosystems may occur. Investigations will emphasize changes in ecosystem structure and functioning and changes in the frequency and intensity of disturbance processes anticipated to have significant consequences for society during the next 50 years, including altered productivity, changes in biodiversity and species invasions (including pests and pathogens), and changes in carbon, nitrogen, and water cycles. Ensuring the desired provision of ecosystem goods and services will require understanding of interactions among basic ecosystem processes and developing approaches to reduce the vulnerabilities to, or take advantage of opportunities that arise because of, global and climatic changes. Scientific research can contribute to this societal goal by addressing three questions that focus on linkages and feedbacks between ecosystems and drivers of global change, important consequences of global change for ecological systems, and societal options for sustaining and enhancing ecosystem goods and services as environmental conditions change. This research will produce critical knowledge and provide a forecasting capability that will continuously improve decisionmaking for resource management and policy development.
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CCSP-supported
research on ecosystems focuses on: (1) how natural and human-induced
environmental changes interact to affect the structure and functioning
of ecosystems (and the goods and services they provide) at a range
of spatial and temporal scales, including those ecosystem processes
that in turn influence regional and global environmental changes; and
(2) what options society may have to ensure that desirable ecosystem
goods and services will be sustained, or enhanced, in the context of
still uncertain regional and global environmental changes. Among the
specific focus areas are the cycling of nutrients such as nitrogen
and how these nutrients interact with the carbon cycle; key processes
that link ecosystems with climate; and options for managing agricultural
lands, forests, and other ecosystems to sustain goods and services
essential to societies.
