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علوم گیاهی - بیومهای(نواحی)رویشی جهان

بیومهای(نواحی)رویشی جهان

پنجشنبه 8 دی 1390 12:43 ب.ظ

نویسنده : عسکر اله قلی

Biomes of the World web site! 

Although designed primarily for our students in Environmental Biology (Biology 102) and Ecology (Biology 318), we are placing it on the web for the benefit of students and interested  people everywhere.  The photography on this site has been done by Marietta College faculty, staff, students and friends. The photographs may be used for any educational purpose by any non-profit educational institution, but please email for permission.  More about Photo Permissions. More about the project.

Index

Ecology Pages

Marietta College

Biology  Department

 

Biomes of the World - Click on the map  to visit a biome or habitat.

Scroll down for more information on biomes!

Click here for a full-size version of the biome map.

Biomes are major types of ecological communities.  These communities are recognizable on a regional scale, although many other communities may exist there as well.  For instance, here in eastern North America where Marietta College is located, our biome is the temperate deciduous forest.  At La Selva, in Costa Rica, the biome is the tropical rain forest.  

Biomes are formed as a result of the climate present at a site (more on this in a minute).  Perhaps you are familiar with the concept of succession, whereby a series of biological communities replace each other over time in a predictable fashion.  For instance, in southern Ohio, an abandoned farm field will first be covered with a community of weeds and grasses; organisms whose seeds are small and which can colonize the disturbed habitat quickly.  Plants like milkweed, goldenrod, smartweed and joe-pye weed also come early to an abandoned field.  Over time, certain shrubs and small tree species (sassafras, hawthorn, aspen, locust, etc.) will begin to take over from the grasses.  Following these small trees are the larger ones such as oaks, hickories (and, some time ago, chestnuts).  If the site is undisturbed for a very long time - hundreds of years - it may be completely taken over by beech trees.  This sequence will occur over and over again in southern Ohio as long as the climate does not change.  The end result of succession in southern Ohio is always a temperate deciduous forest, where trees lose their leaves in the cold winters.  Down in Costa Rica at La Selva, succession is different, with different plant species making up the communities, and there the end result is atropical rain forest.  In western Costa Rica, the final result of succession is a tropical seasonal forest.  In terms of succession, these final communities that develop at a site are called climax communities, and these climax communities form the basis for the biome classification.




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