Monday 30 July 2012

Biomes

Biomes
A major ecological community of organisms adapted to a particular climatic or environmental condition on a large geographic area in which they occur.  
Biomes may be classified into:

  1. Terrestrial biomes or land biomes - e.g. tundra, taiga, grasslands, savannas, deserts, tropical forests, etc. 
  2. Freshwater biomes - e.g. large lakes, polar freshwaters, tropical coastal rivers, river deltas, etc. 
  3. Marine biomes - e.g. continental shelf, tropical coral, kelp forest, benthic zone, pelagic zone, etc. 
 Word origin: bi: variant of bio-, esp. before a vowel + -ome: New Latin -ōma, -ōmat.

PT
Tundra Biome 
Located at latitudes 55° to 70° North, the tundra is a vast and treeless land which covers about 20% of the Earth's surface, circumnavigating the North pole. It is usually very cold, and the land is pretty stark. Almost all tundras are located in the Northern Hemisphere. Small tundra-likeareas do exist in Antarctica in the Southern Hemisphere, but because it is much colder than the Arctic, the ground is always covered with snow and ice. Conditions are not right for a true tundra to form. Average annual temperatures are -70°F (-56°C).

Ecology

Factors
oxygen salinity light
pH
-may be influenced by photosynthetic activity of aquatic plants

The more acidic a substance, the sourer it is. 
The higher the acidic, the lower the pH
7pH is neutral. 

acids --> pH1-6.9

alkali pH --> 7.1-14

Water
(neutral) --> pH7.0

Biotic Factors

Symbiosis
1.Mutualism +/+ positive! (Hermit crab)
2. Commensalism (one benefits;the other unaffected) +/0
3. Parasitism (parasite benefits and host harmed) +/- dog and fleas. worms in human body

1. competition -/- (Interspecific- a form of symbiosis) (Intraspecific-same species)
2. Predation (one feeds on the other) +/-

Producer-Primary consumer->secondary consumer->tertiary consumer-> quaternary consumer