An Ecophysiographic Stratification Approach
The United States Geological Survey (USGS), Esri, the Group on Earth Observations (GEO), and the Association of American Geographers (AAG) are pleased to present A New Map of Global Ecological Land Units – An Ecophysiographic Stratification Approach. This paper describes the concepts and methods for delineating ecological land units (ELUs) as distinct physical environments and associated land cover. Detailed and accurate maps of ELUs are presented for the Earth and the continents, as well as regional examples.
The ELUs were developed in response to the need for a high resolution, standardized, and data-derived map of global ecosystems for use in analyses of
- climate change impacts,
- assessments of economic and non-economic value of ecosystem goods and services,
- biodiversity conservation planning, and
- natural resource management.
The work was done in a public/private partnership between USGS and Esri, and was commissioned by GEO as part of an intergovernmental protocol called the Global Earth Observation System of Systems (GEOSS). With this special publication, AAG recognizes the work as a contribution to understanding the physical and ecological geography of the Earth.
The United States Geological Survey has published a new global ecosystems map of unprecedented detail.
The map was produced by a team led by Roger Sayre, Ph.D., Senior Scientist for Ecosystems at the USGS Land Change Science Program. It is a mosaic of almost 4,000 unique ecological areas called Ecological Land Units (ELUs) based on four factors that are key in determining the makeup of ecosystems.
- Three of these—bioclimate, landforms, and rock type—are physical phenomena that drive the formation of soils and the distribution of vegetation.
- The fourth, land cover, is the vegetation that is found in a location as a response to the physical factors.
- You can read more about the research in this blog post.
This Story Map Journal has two main features, an ecosystems browser and an ecosystem tour.
In the ecosystem browser, opposite, point and click at any location on the map and the name of that ecosystem appears in a pop-up box. In general, tans are deserts, yellows and light greens are savannas, darker greens are forests, mountainous regions have texture, reddish is warm and bluish is cold. The browser includes pan and zoom functions.