CK12 Life Science

(Marvins-Underground-K-12) #1

  • The biosphere is considered to be a global ecological system. Given all you now know
    about ecology, what do you think the biosphere consists of?


23.5 Lesson 23.5: Biomes and the Biosphere


Lesson Objectives



  • Explain what biomes are.

  • Describe terrestrial biomes.

  • Describe aquatic biomes.

  • Describe the features of the biosphere and list specific systems.


Check Your Understanding



  • What is an Ecosystem?

  • How can Ecosystems be discussed with respect to Humans?


Introduction


The concept of biomes and the largest biome of all, the biosphere, is the highest level of
organization in ecology, building on everything you have already studied at the population,
community, and ecosystem levels. There is a wide variety of biomes, classified into two major
groups, terrestrial and aquatic biomes. Because the biosphere integrates all living beings,
and can be considered itself a kind of living organism, human activities on one part of Earth
can have a major effect on another. In order to better understand all the interactions on
Earth, scientists have created various small-scale models.


What are Biomes?


Abiomeis a climatically and geographically defined area of ecologically similar commu-
nities of plants and animals, often referred to as ecosystems. Biomes are often identified
with particular patterns of ecological succession and climax vegetation (See theEcosystem
Dynamicschapter).


Biome type may also be based on differences of the physical environment (for example,
mountain ranges or oceans). Their variation is generally related to the distribution of species
according to their ability to tolerate temperature and/or dryness. For example, one may find
photosynthetic algae only in the part of the ocean where light penetrates, while conifers are
mostly found in mountains.

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