The graphic portrayal of spatial distributions of vegetation, ecosystems, or their characteristics. Vegetation is one of the most conspicuous and characteristic features of the landscape and has long been a convenient way to distinguish different regions; maps of ecosystems and biomes have been mainly vegetation maps. As pressure on the Earth's natural resources grows and as natural ecosystems are increasingly disturbed, degraded, and in some cases replaced completely, the mapping of vegetation and ecosystems, at all scales and by various methods, has become more important. Biome Ecosystem Three approaches have arisen for mapping general vegetation patterns, (1) based on vegetation structure or gross physiognomy, (2) based on correlated environmental patterns, and (3) based on important floristic taxa. The environmental approach provides the least information about the actual vegetation but succeeds in covering regions where the vegetation is poorly understood. Most modern classification systems use a combination of physiognomic and floristic characters. Plant geography Mapping has expanded to involve other aspects of vegetation and ecosystems as well as new methodologies for map production. Functional processes such as primary production, decomposition rates, and climatic correlates (such as evapotranspiration) have been estimated for enough sites so that world maps can be generated. Structural aspects of ecosystems, such as total standing biomass or potential litter accumulations, are also being estimated and mapped. Quantitative maps of these processes or accumulations can be analyzed geographically to provide first estimates of important aspects of world biogeochemical budgets and resource potentials. Computer-produced maps, using Geographic Information Systems (GIS), often coupled directly with predictive models, remote-sensing capabilities, and other techniques, have also revolutionized vegetation and ecosystem mapping. This gives scientists a powerful tool for modeling and predicting the outcome from global climate change, in that feedback from the world's vegetation can be accounted for. Before computer technology exploded in the early 1980s, the spatial scale and related resolution or grain of vegetation and ecosystem mapping was limited by the static nature of hard-copy maps. The advent of GIS technology enabled the analysis of digital maps at any spatial scale, and the only limitation was the resolution at which the data were originally mapped. In addition, GIS software is used for sophisticated spatial analyses on maps, and this was virtually impossible before. Climate modeling Geographic information systems |
