Importance of Land Cover
Land cover is an important variable in understanding the ecology of a given area. By carefully studying the plants and other living things in an area, scientists can gain much useful information about environmental factors such as soil, climate, and general environmental health. All these factors are inter-related.
One of the first steps to studying a particular ecosystem is to classify the type of ground cover. GLOBE uses a classification system called MUC pronounced”muck”), short for Modified Unesco Classification System. Using MUC scientists and students can classify any the ground cover in their particular study site.
The MUC classification uses four levels. Any ecosystem can be classified and assigned a classification number. Some kinds of plant communities will take all four levels to be adequately defined, some take as few as two levels.
Knowing MUC classifications for specific ecosystems, scientists can then relate those community types to other variables, such as latitude, altitude, climate, soil type, and human intervention. MUC classification can be seen as a first step in completing more detailed research and studies of an ecosystem. Additionally, actual on the ground research can be correlated to remote sensing data, such as aerial photos, and satellite photos from LandSat satellites. Remote sensing specialists are eager for your data to enable them to complete a global inventory of ecosystems and for the purposes of monitoring change in the Earth’s ecosystems.
Factors influencing ground cover
Ground cover, usually but not always plants, is influenced by two things, climate and human activity.
Climate is a long term measure of temperature and precipitation. Climate is affected by latitude and elevation. Temperature, as we all know, is affected by latitude. Warmer climates tend to be located at lower latitudes – closer to the equator, while colder climates tend to be located at higher latitudes – farther from the equator. Climatologists divide the Earth into three general Global Climate Zones. The Tropical Zone is the region between the Equator and the Tropics of Cancer and Capricorn, generally from 23.5° north latitude to 23.5° south latitude. Next are the Temperate Zones. Temperate Zones extend from the tropics to the Arctic and Antarctic Circles, from 23.5° north to 76.5° north and from 23.5° to 76.5° south latitude. Finally, the Polar Climate Zones extend from the Arctic Circle to the North Pole and from the Antarctic Circle to the South Pole.
The tropical Zone and Temperate Zones are further divided depending on local temperature and precipitation conditions. You should read section “Key Factors That Affect Vegetation” in your MUC guide and perhaps other references for further information on Climate Zones.
Elevation changes also impact the environment. Average annual temperature decreases by about 1°C for each 150 m increase in elevation. Thus, climbing a mountain is much like traveling north or south from the Equator. We use lowland, submontane, montane, subalpine and alpine to describe elevation differences and the associated plant communities. Your MUC guide provides definitions of the elevation categories. The actual classification depends on a combination of both latitude and elevation. Local references may be necessary in order to properly classify your land cover site.
Precipitation is affected by latitude, elevation, and topography, among other factors. Within any given climate zone one might find dry, medium and wet climates.
Finally, ocean currents and large bodies of water, such as lakes, can have significant impacts on climate.
Besides climate, human activity has a large impact on the land cover. We change the natural plant communities through agriculture and other developments to make the land more useful for meeting human needs. The signs of human influence are usually, but not always, fairly easy to spot. Your MUC guide provides guidance in determining if a site is developed or natural. Sometimes you might encounter lands that are difficult to classify. You would need to use your judgment to decide the extent of manipulation of the land cover
All these factors must be considered as you determine the classification of your Land Cover Site. Thinking about them will help you to explain the existence of your cover type and the interactions between the various biotic (living) and abiotic (nonliving) factors.