Forest

The forest biome
Forest Biomes represent the largest and most ecologically complex systems. They contain a wide assortment of trees, plants, mammals, reptiles, amphibians, invertebrates, insects and micro-organisms which vary depending on the zone's climates. There are three major types of forests, classed according to latitude:

Tropical forests are characterized by the greatest diversity of species. They occur near the equator, within the area bounded by latitudes 23.5 degrees N and 23.5 degrees S. One of the major characteristics of tropical forests is their distinct seasonality: winter is absent, and only two seasons are present (rainy and dry). Soil is nutrient-poor and acidic. Decomposition is rapid and soils are subject to heavy leaching. Further subdivisions of this group are determined by seasonal distribution of rainfall:

• evergreen rainforest: no dry season.
• seasonal rainforest: short dry period in a very wet tropical region
• semievergreen forest: longer dry season
• moist/dry deciduous forest (monsoon): the length of the dry season increases further as rainfall decreases

Temperate forestoccur in eastern North America, northeastern Asia, and western and central Europe. Well-defined seasons with a distinct winter. Soil is fertile, enriched with decaying litter.

Further subdivisions of this group are determined by seasonal distribution of rainfall:

• moist conifer and evergreen broad-leaved forests: wet winters and dry summers
• dry conifer forests: dominate higher elevation zones; low precipitation.
• mediterranean forests: precipitation is concentrated in winter
• temperate coniferous: mild winters, high annual precipitation
• temperate broad-leaved rainforests: mild, frost-free winters, high precipitation evenly distributed throughout the year.
  

Boreal forest (taiga)
Seasons are divided into short, moist, and moderately warm summers and long, cold, and dry winters. Temperatures are very low. Soil is thin, nutrient-poor, and acidic.