microclimate

microclimate
microclimatic /muy'kroh kluy mat"ik/, adj.microclimatically, adv.
/muy"kreuh kluy'mit/, n.
the climate of a small area, as of confined spaces such as caves or houses (cryptoclimate), of plant communities, wooded areas, etc. (phytoclimate), or of urban communities, which may be different from that in the general region. Cf. macroclimate.
[1920-25; MICRO- + CLIMATE]

* * *

Climatic condition in a relatively small area, within a few feet above and below the Earth's surface and within canopies of vegetation.

Microclimates are affected by such factors as temperature, humidity, wind and turbulence, dew, frost, heat balance, evaporation, the nature of the soil and vegetation, the local topography, latitude, elevation, and season. Weather and climate are sometimes influenced by microclimatic conditions, especially by variations in surface characteristics.

* * *

      any climatic condition in a relatively small area, within a few metres or less above and below the Earth's surface and within canopies of vegetation. The term usually applies to the surfaces of terrestrial and glaciated environments, but it could also pertain to the surfaces of oceans and other bodies of water.

      The strongest gradients of temperature and humidity occur just above and below the terrestrial surface. Complexities of microclimate are necessary for the existence of a variety of life forms because, although any single species may tolerate only a limited range of climate, strongly contrasting microclimates in close proximity provide a total environment in which many species of flora and fauna can coexist and interact.

      Microclimatic conditions depend on such factors as temperature, humidity, wind and turbulence, dew, frost, heat balance, and evaporation. The effect of soil type on microclimates is considerable. Sandy soils and other coarse, loose, and dry soils, for example, are subject to high maximum and low minimum surface temperatures. The surface reflection characteristics of soils are also important; soils of lighter colour reflect more and respond less to daily heating. Another feature of the microclimate is the ability of the soil to absorb and retain moisture, which depends on the composition of the soil and its use. Vegetation is also integral as it controls the flux of water vapour into the air through transpiration. In addition, vegetation can insulate the soil below and reduce temperature variability. Sites of exposed soil then exhibit the greatest temperature variability.

      Topography can affect the vertical path of air in a locale and, therefore, the relative humidity and air circulation. For example, air ascending a mountain undergoes a decrease in pressure and often releases moisture in the form of rain or snow. As the air proceeds down the leeward side of the mountain, it is compressed and heated, thus promoting drier, hotter conditions there. An undulating landscape can also produce microclimatic variety through the air motions produced by differences in density.

      The microclimates of a region are defined by the moisture, temperature, and winds of the atmosphere near the ground, the vegetation, soil, and the latitude, elevation, and season. Weather is also influenced by microclimatic conditions. Wet ground, for example, promotes evaporation and increases atmospheric humidity. The drying of bare soil, on the other hand, creates a surface crust that inhibits ground moisture from diffusing upward, which promotes the persistence of the dry atmosphere. Microclimates control evaporation and transpiration from surfaces and influence precipitation, and so are important to the hydrologic cycle—i.e., the processes involved in the circulation of the Earth's waters.

      The initial fragmentation of rocks (rock) in the process of rock weathering and the subsequent soil formation are also part of the prevailing microclimate. The fracturing of rocks is accomplished by the frequent freezing of water trapped in their porous parts. The final weathering of rocks into the clay and mineral constituents of soils is a chemical process, where such microclimatic conditions as relative warmth and moisture influence the rate and degree of weathering.

* * *


Universalium. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • microclimate — (n.) 1918, from MICRO (Cf. micro ) + CLIMATE (Cf. climate). Related: Microclimatology …   Etymology dictionary

  • microclimate — ► NOUN ▪ the climate of a very small or restricted area …   English terms dictionary

  • microclimate — [mī′krōklī΄mit] n. [ MICRO + CLIMATE] the climate of a small, distinct area, as a forest, or of a confined space, as a building …   English World dictionary

  • Microclimate — For the viticultural use of the term microclimate, see Regional climates levels in viticulture. Microclimate on rock located in intertidal zone in Sunrise on Sea, South Africa …   Wikipedia

  • microclimate — UK [ˈmaɪkrəʊˌklaɪmət] / US [ˈmaɪkroʊˌklaɪmət] noun [countable] Word forms microclimate : singular microclimate plural microclimates the weather or temperature in a specific small area, especially when this is different from the weather or… …   English dictionary

  • microclimate — noun A small, local region having a unique pattern of weather or weather effects. The microclimate on the south side of a building may differ from the one on the north, so that different plants may thrive …   Wiktionary

  • microclimate — mi|cro|cli|mate [ˈmaıkrəuˌklaımıt US krou ] n the weather patterns in one small area, which are different from the weather patterns in the surrounding area ▪ The valley has its own unique microclimate …   Dictionary of contemporary English

  • microclimate — /ˈmaɪkroʊˌklaɪmət/ (say muykroh.kluymuht) noun the climate affecting a localised region, often created by terrain or conditions which are not prevalent throughout the wider area, ranging from something as small as a garden bed to something as… …  

  • microclimate — patalpos mikroklimatas statusas Aprobuotas sritis žemės ūkio inžinerinė plėtra ir techninė pažanga apibrėžtis Patalpos temperatūros, oro švaros, apšviestumo, triukšmo ir kitų rodiklių visuma. atitikmenys: angl. microclimate vok. Mikroklima, m rus …   Lithuanian dictionary (lietuvių žodynas)

  • microclimate — mikroklimatas statusas T sritis ekologija ir aplinkotyra apibrėžtis Nedidelės teritorijos pažemio klimatas, susidarantis dėl žemės paviršiaus įvairumo (mikrotopografijos, augalijos, vandens telkinių, statinių). atitikmenys: angl. microclimate vok …   Ekologijos terminų aiškinamasis žodynas

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”