U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2007–3107

December 2007

FACING TOMORROW’S CHALLENGES: USGS SCIENCE IN THE DECADE 2007–2017

Understanding Ecosystems and Predicting Ecosystem Change

Printed on recycled paper

In 2007, the U.S. Geological Survey (USGS) developed a science strategy outlining 

the major natural science issues facing the Nation in the next decade. The science 

strategy consists of six science directions of critical importance, focusing on areas 

where natural science can make a substantial contribution to the well-being of the 

Nation and the world. This fact sheet focuses on understanding ecosystems and predicting ecosystem change, and how USGS research can strengthen the Nation with 

information needed to meet the challenges of the 21st century.

Importance of Ecosystems

Ecosystems constitute the Earth’s 

biosphere and support human existence. 

Knowledge of ecosystems is critical to 

the well-being of the Nation because 

ecosystems supply the natural resources 

and other goods and services that humans 

require. Resilient, functioning ecosystems 

build soil, enhance pollination of crops, 

purify water, supply raw materials, regulate the atmosphere, cycle nutrients, and 

detoxify waste. These and other ecosystem processes collectively form the basis 

for all life on Earth.

For terrestrial, freshwater, and 

coastal/marine ecosystems to continue 

supplying these benefits, human interactions with ecosystems need to be 

well managed, especially in the face of 

increasing global pressures. A proactive approach to managing ecosystems 

will require an advanced understanding, 

gained through research, of ecosystem structure, function, condition, and 

distribution. The ability to project future 

ecosystem states in response to societal 

pressures is vital to ensuring that ecosystems continue as the essential life-support 

systems for the Earth.

Land change affects ecosystems 

in critical ways. It alters their structure 

and function; can limit the availability 

of goods and services that are essential 

for ecosystem health and societal wellbeing; directly impacts habitat quality 

and biodiversity; creates pathways for the 

spread of invasive species; and affects 

atmospheric chemistry, weather and 

climate, water quality and quantity, and 

other environmental systems. Because the 

resilience of ecosystems varies geographically, understanding change in a geographical and ecosystems framework is 

essential for managing its consequences.

Why Action is Needed Now

Large-scale, rapid change is now 

taking place in all natural systems 

throughout the world. Growing human 

populations and substantial alterations to 

landscapes, oceans, and the atmosphere 

have caused widespread changes in the 

global distribution and abundance of 

organisms. Changes in biodiversity alter 

ecosystem processes, productivity, and 

structure, and often reduce the resilience 

of ecosystems to future environmental 

change.

The state and fate of ecosystems 

and the materials they supply to human 

societies, previously of interest mainly 

to earth scientists and environmentalists, 

are rapidly emerging as a global concern 

of citizens, governments, and industry. 

There is a growing realization that it is 

impossible to separate economic development from the environment and that 

environmental degradation can undermine economic development.

Effective management of ecosystems and natural resources depends on a 

thorough knowledge of the types and distributions of ecosystems and their attributes, in concert with a comprehensive 

understanding of ecosystem processes 

and function. However, understanding of 

ecosystem condition, change, and causes 

of change is currently hampered by 

incomplete knowledge of the connections 

between and among species, including humans, and the environment. The 

United States currently lacks scientifically sound indicators of ecosystem condition, comprehensive maps of ecosystem 

distributions, and a rigorous ecosystem 

monitoring program. These deficiencies 

★ Ecosystems ★ Climate ★ Energy and Minerals ★ Natural Hazards ★ Environment and Human Health ★ Water ★

Ground water

Soils

Macroclimate

Topoclimate

Landform

Surface water

Ecosystem

Biota

Bedrock

What is an Ecosystem?

An ecosystem is an integrated system of organisms interacting with their physical environment. Energy and materials cycle through these 

organisms and their environment, including soil, 

sediment, water, and the atmosphere. Ecosystems 

serve as a framework for understanding the diversity of the Earth’s physical and biological processes. Because organisms interact with the physical environment at all scales—from microscopic 

to global—ecosystem boundaries are by definition 

a human construct. Nevertheless, defining discrete 

ecosystem units can be useful for management or 

conservation purposes.

The vertical structure of an ecosystem, showing 

the spatial integration of its biological and physical 

components. (Reproduced with permission from 

Bailey, R.G., 1996, Ecosystem geography: New 

York, Springer-Verlag.)
USGS Science Can Meet the Challenge A Vision For the Future

The USGS is the Nation’s premier 

source of information in support 

of science-based decisionmaking 

for ecosystem management. USGS 

scientists collaborate with others 

to document the nature and causes 

of ecological change across the 

Nation and to provide information 

on the consequences of change to 

human health and safety, ecosystem function and resilience, and 

the resources upon which human 

societies are built.

For Additional Information

U.S. Geological Survey, 2007, Facing 

Tomorrow’s Challenges—U.S. Geological Survey Science in the Decade 

2007–2017: Available online at http://

pubs.er.usgs.gov/usgspubs/cir/cir1309

Also, visit the USGS home page at

http://www.usgs.gov/

The USGS is ready to take action by: 

•	 Conducting basic, place-based research into ecosystem structure, function, and 

processes.

•	 Coordinating, developing, and regularly updating scientifically rigorous, standardized, geospatial classification models and maps of national ecosystems at 

scales appropriate to land-manager needs.

•	 Identifying ecosystems vulnerable to ongoing changes of climate, contamination, and land use, and quantifying the consequences of ecosystem and land-use 

change to water quality and quantity, health, hazard risk, biodiversity, and other 

ecosystem services to human society.

•	 Developing a multipartner, robust assessment of the status and trends of the 

Nation’s ecosystems.

•	 Expanding and modernizing USGS observation networks by using new and 

emerging technologies for long-term observations of the physical and biological 

resources that are impacted by land-use/land-cover change, climate, contaminants, and other drivers of ecosystem structure and function.

•	 Developing credible forecasts of responses to ecosystem stressors, including land 

use, climate change, contaminants, invasive species, and other threats.

•	 Working with other Federal agencies to evaluate and test restoration or mitigation 

methods and technologies for increasing ecosystem resilience to disturbances.

Land use has dramatically altered the distribution and composition of forest lands in the 

Eastern United States, changing the structure and function of these ecosystems. The 

extensive loss of bottomland hardwood forests, for example, has affected water quality, 

increased the risk of floods, and altered the distribution and abundance of animals that 

depend on these forests, such as the ivory-billed woodpecker.

hamper the Nation’s ability to understand, forecast, and mitigate ecosystem 

change, assess ecosystem vulnerability 

to human activities, and avoid damage to 

regional and global ecosystems.

How the USGS Can Help

Ecosystem studies require the full 

power of an integrated systems approach 

and thus are a perfect fit with USGS 

capabilities and strengths. As the only 

Federal agency that combines scientific 

expertise in biology, hydrology, geology, 

and geography, the USGS is uniquely 

positioned to advance understanding of 

terrestrial, freshwater, and marine ecosystems and to predict ecosystem change.

During the next decade, the USGS 

will emphasize the fundamental research, 

mapping, and monitoring necessary to 

assess the Nation’s ecosystem function, 

as well as begin to document and forecast 

change. Working with partners, the USGS 

will develop new products, including 

standardized national maps of ecosystems 

in the United States and regularly updated 

status and trends assessments, that will 

help communities and land and resource 

managers make informed decisions about 

sustainable resource use. In addition to 

forming an excellent science foundation for managing ecosystems across the 

Nation, the information, understanding, 

and tools and systems approach provided 

by this strategic direction will serve as 

a critical underpinning for other USGS 

strategic focus areas, including climate 

variability and change, energy and minerals, natural hazards, the role of environment and wildlife in human health, and 

water.