Perspectives on Terrestrial Biomes: The International Vegetation Classification

Despite the widespread use of the term biome, systematic, multi-scaled biome classifications are hard to come by. This may be in part because biomes represent large-scale ecosystems, and the complexity of ecological and biotic factors makes it hard to classify them at these large scales. In addition, humans play a large role in shaping biomes, such that both natural and anthropogenic biomes need to be treated. Here we introduce the International Vegetation Classification (IVC), based on the EcoVeg approach, as a useful, multi-scaled and comprehensive terrestrial classification that can inform biome concepts. We rely on vegetation as a primary criterion (typical of many approaches to biome concepts) while noting that ecoregional and functional approaches add additional valuable perspectives. The IVC uses an 8-level hierarchy for both natural and cultural vegetation. For natural vegetation, the IVC includes three upper (formation) levels, three mid (physiognomic-biogeographic-floristic) levels and two lower (floristic) levels. The IVC is most advanced in North and South America, but we describe a number of other major vegetation classifications with similar approaches that allow for a collaborative approach to describing ecosystems across the globe at all scales. The IVC provides a consistent thematic framework to support broad-scale vegetation mapping, inventory and assessment, including applications to both the IUCN Red List of Ecosystems and NatureServe Conservation Status Assessment protocols. The classification approach meets the need for a dynamic, 8-level catalogue of types for all existing vegetation, including large-scale ecosystems or biomes. The open, peer-review model allows for ongoing improvement by ecologists, while always providing comprehensive versions for users.