Landforms both provide subtrate for and exert influence upon biomes.
Biomes refer to distinct regions of interconnected ecological systems, encompassing both organisms and the forces of climate and geology that influence them. Among the components of these complicated communities are landforms, the topographic features that provide a physical foundation for their development and, on broad scales of geologic time, prove themselves active participants.
Influence on Microclimate
When appraising a site in a particular biome, ecologists often consider the influence landforms have on microclimates. These are pockets of distinct climatic conditions -- temperature, humidity, prevailing wind and the like -- created by topographic features. For example, a ridge trending roughly west to east often supports different vegetation communities on either side because its south-facing slope receives more solar radiation than the north-facing. Thus there may be a relatively dry open woodland on the south slope, contrasted with a lusher, denser forest over the divide. The cool air tumbling from a cave mouth in a tract of hills might support a small, isolated patch of moisture-dependent plants.
Origin Questions
Another common line of inquiry is determining the "biography" of a given landform: its geologic history. This takes into account not just its original origin but the forces of erosion, weathering and deposition that may have acted upon it since. The same general kind of landform may owe its existence to any number of processes: a cliff-edged butte, for example, may have been uplifted by faulting or exposed as a resistant layer by the erosion of rock once surrounding it.
Wildlife Movements
In their seasonal migrations from summer to winter range, elk seek out efficient travel routes.
One of the many geographies at play in a particular biome is the long-scale movements of wildlife within and through its bounds. Some, like birds migrating through from far-off wintering grounds to far-off breeding territories, may simply pass through an ecosystem. Others, like ungulates yielding higher-elevation summer range for more sheltered lowlands for the winter, may do their ranging entirely within a single region. Landforms influence such travels: migrating birds may track along an escarpment, taking advantage of the winds it funnels, while a herd of elk might use a river valley or ridgetop to efficiently cross rugged country.
Soil Profile
Landforms play a role in soil development, which, acting interdependently with climate and vegetation zone, helps define biomes. The floodplain of a mature river, formed by its occasional inundations, develops deep, rich soils from the deposited sediments. A volcano heavily impacts its surroundings by occasionally spewing ash over a broad area, elevating soil fertility.
Tags: particular biome, topographic features
