The Earth contains an astonishing variety of terrestrial, freshwater, and marine ecosystems, which provide biological resources and services that are essential to our survival. A high resolution, data-derived, global ecosystems map will improve our ability to manage, conserve, and restore ecosystems that are increasingly threatened by fragmentation, alteration, loss, invasive species, fire, climate change, and incompatible resource extraction. We are classifying and mapping global ecosystems in a standardized, robust, and practical manner at scales appropriate for on-the-ground management.

This work has been commissioned by the Group on Earth Observations (GEO), a consortium of over 100 nations that seek to promote earth observation for solving some of society's most difficult problems. GEO is building the Global Earth Observation System of Systems (GEOSS), and one of the GEOSS programs is the Global Ecosystems (GECO) initiative. A GECO task is to develop objective (data-derived) and management-appropriate global ecosystem maps for terrestrial, freshwater, and marine ecosystems. This effort is producing consistent and innovative classification and mapping of global ecosystems at a finer spatial resolution than any existing ecoregionalization of the planet.

Pilot continental-scale efforts in the United States, South America, and Africa developed and refined an approach to mapping standardized global terrestrial ecosystems which models ecosystem occurrences as unique physical environments with biotic and abiotic components. Ecosystems were geospatially delineated as facets of the landscape generated through biophysical stratification by bioclimate, biogeography, lithology, landforms, surface moisture, and land cover. Several standardized geospatial ecosystem models were produced from these efforts, enabling the use of ecosystem occurrences as, for example, a robust spatial unit of analysis for assessing climate change effects on ecosystems.

Subsequent global efforts then focused on an ecological land classification approach where the emphasis is placed on ecologically meaningful characteristics of the land, such as bioclimate, landform type, and lithology. Most recently, as part of a major collaboration between USGS and Esri, a rich, spatially explicit database and map of global ecological land units (ELUs) at a base resolution of 250 meters was developed. These data allow for a fine resolution inventory of land-based ecological features anywhere on Earth, and contribute to increased understanding of terrestrial ecological pattern and terrestrial ecosystem distributions.