Presentation on theme: "Terrestrial Biomes. Tundra Tundra is a treeless biome occurring in areas with cold climates and a short growing season. Alpine tundra occurs at high altitudes."— Presentation transcript:
Tundra Tundra is a treeless biome occurring in areas with cold climates and a short growing season. Alpine tundra occurs at high altitudes on mountains, while arctic tundra occurs at high latitudes. Most tundras receive very small inputs of water as precipitation, but nevertheless their soil may be moist or wet because there is little evaporation in such cold climates, and deep drainage may be prevented by frozen soil. Tundra mountains waterprecipitationsoil evaporation Tundra mountains waterprecipitationsoil evaporation
The coldest, most northern, high-arctic tundras are very unproductive and dominated by long-lived but short- statured plants, typically less than 1.97-3.94 in (5-10 cm) tall. Low-arctic tundras are dominated by shrubs as tall as 3.28 ft (1 m), while wet sites develop relatively productive meadows of sedge, cotton-grass, and grass. In North America, arctic tundras can support small densities of mammalian herbivores such as caribou and muskox (although during migration these animals can occur in locally large densities), and even smaller numbers of their predators, such as wolves. caribou migrationcaribou migration
Boreal coniferous forest or Taiga The boreal coniferous forest, or taiga, is an extensive northern biome occurring in moist climates with cold winters. The boreal forest is dominated by coniferous trees, especially species of fir, larch, pine, and spruce. Some broad-leaved, angiosperm trees are also important in the boreal forest, especially species of aspen, birch, poplar, and willow. Usually, particular stands of boreal forest are dominated by only one or several species of trees. angiosperm
Most regions of boreal forest are subject to periodic events of catastrophic disturbance, most commonly caused by wildfire and sometimes by insects, such as spruce budworm, that kill trees through intensive defoliation. Montane forests, also dominated by conifers and similar in structure to the boreal forest, can occur at sub-alpine altitudes on mountains in southerly latitudes. wildfireinsectsforestswildfireinsectsforests
Temperate deciduous forest Forests dominated by species-rich mixtures of broad-leaved trees occur in relatively moist, temperate climates. Because these forests occur in places where the winters can be cold, the foliage of most species is seasonally deciduous, meaning that all leaves are shed each autumn and re-grown in the springtime. Common trees of this forest biome in North America are species of ash, basswood, birch, cherry, chestnut, dogwood, elm, hickory, magnolia, maple, oak, tulip-tree, and walnut, among others. These various tree species segregate into intergrading communities on the basis of site variations of soil moisture, fertility, and air temperature. basswoodchestnutelmmagnoliatreetemperaturebasswoodchestnutelmmagnoliatreetemperature
Temperate rainforest Temperate rainforests develop under climatic regimes characterized by mild winters and an abundance of precipitation. Because these systems are too moist to support regular, catastrophic wildfires, they often develop into old-growth forests, dominated by coniferous trees of mixed age and species composition. Individual trees can be extremely large, and in extreme cases can be more than 1,000 years old. Common trees of this biome are species of Douglas fir, hemlock, cedar, redwood, spruce, and yellow cypress. In North America, temperate rainforests are best developed on the humid west coast. old-growth forestsIndividualold-growth forestsIndividual
Temperate grassland These grasslands occur under temperate climatic regimes that are intermediate to those that support forest and desert. In the temperate zones, grasslands typically occur where rainfall is 9.9-24 in (25-60 cm) per year. Grasslands in North America are called prairie and this biome occupies vast regions in the interior. grasslandsdesert prairiegrasslandsdesert prairie
Tropical grassland and savanna Tropical grasslands can occur in regions with as much as 47.2 in (120 cm) of rainfall per year, but under highly seasonal conditions with a pronounced dry season. Savannas are dominated by grasses and other herbaceous plants, but they also have scattered shrub and tree-sized woody plants, which form a very open canopy. Tropical grasslands and savannas can support a great seasonal abundance of large, migratory mammals, as well as substantial populations of resident animals. This is especially true of savannas in Africa, where this biome supports a very diverse assemblage of large mammals, including gazelles and other antelopes, rhinos, elephant, hippopotamus, and buffalo, and some of their predators, such as lion, cheetah, wild dog, and hyena. mammalsAfricagazelles elephant hyenamammalsAfricagazelles elephant hyena
Chaparral Chaparral is a temperate biome that develops in environments with seasonally extreme moisture gradients, characterized by a so-called Mediterranean climate with winter rains and summer drought. The chaparral biome is typically composed of dwarf forest and shrubs, and interspersed herbaceous vegetation. Chaparral is highly prone to events of catastrophic wildfire. In North America, chaparral is best developed in parts of the southwest, especially coastal southern California.
Desert Desert is a temperate or tropical biome, commonly occurring in the center of continents, and in the rain shadows of mountains. The distribution of this biome is determined by the availability of water, generally occurring where Not surprisingly, the productivity of desert ecosystems is strongly influenced by the availability of water. The driest deserts support almost no plant productivity, while less-dry situations may support communities of herbaceous, succulent, and annual plants, and somewhat moister places will allow a shrub- dominated ecosystem to develop. plant
Semi-evergreen tropical forest This type of tropical forest develops when there is a seasonality of water availability due to the occurrence of pronounced wet and drier seasons during the year. Because of this seasonality, most of the trees and shrubs of this biome are seasonally deciduous, meaning that they shed their foliage in anticipation of the drier season. This biome supports a great richness of plant and animal species, though somewhat less than in tropical rainforests. seasonsanimalseasonsanimal
Evergreen tropical rainforest This biome occurs under tropical climates with abundant precipitation and no seasonal drought. Because wildfire and other types of catastrophic disturbance are uncommon in this sort of climate regime, tropical rainforests usually develop into old- growth forests. As such, they contain a diverse size range of trees, a great richness of species of trees and other plants, as well as an extraordinary diversity of animals and microorganisms.