Forest ecosystem

FOREST ECOSYSTEM A forest is more than just the trees. A single forest is a complete, functioning ecosystem that supports innumerable plant and animal species as well as earth, water, and air subsystems. The subsystems provide the essence of life of the forest and are in themselves a byproduct of forest systems, all of which are reciprocal and inter dependent. A forest ecosystem is a complex of living and non-living elements which interrelate. An ecosystem can be small (like your backyard) or large (like the planet earth). It depends on the range of individual species or group of species being discussed (e.g.: a salmon stock or a forest type), geology (e.g.: a mountain range or watershed), and other issues. Different organisms exist within the forest layers. These organisms interact with each other and their surrounds. Echo organism has a role or niche in sustaining the ecosystem. Some provide food for other organisms, other provide shelter or control populations trough predation.

NEEDLE LEAF

Needle leaf trees fall into two categories based on how they are attached to the twig coming off the branch of the tree. On coastal redwoods and true firs, the needles will be connected directly to the twig, growing off it like leaves off the branch of a common plant. On trees like spruce trees, the individual needles will be connected to the tree via a peg-like stalk, which is also known as a needle peg. Sometimes needles on conifers are bundled together, grouped in bundles that are attached directly to the twig. Often there are two, three or five needles per bundle. A given tree usually has the same number of needles per bundle. Bundles are most common in pine trees. The Austrian pine can be identified by having two needles per bundle. The ponderosa pine can be identified by having three needles per bundle. The western white pine can be identified by having five needles per bundle.

BROAD LEAF

BROAD LEAF tree is any tree that has wide leaves, rather than slim, needle-like leaves as found in conifers. Most broad-leaved trees are deciduous, such as birch, elm, oak, and maple, but some such as arbutus and live oak are evergreen; the latter type are most common in subtropical or tropical climates.

RAINFOREST

Rainforests are forests characterized by high rainfall, with annual rainfall between 250 and 450 centimeters (98 and 177 in). There are two types of rainforest: tropical rainforest and temperate rainforest. The monsoon trough, alternatively known as the inter tropical convergence zone, plays a significant role in creating the climatic conditions necessary for the Earth's tropical rainforests. Around 40% to 75% of all biotic species are indigenous to the rainforests. It has been estimated that there may be many millions of species of plants, insects and microorganisms still undiscovered in tropical rainforests. Tropical rainforests have been called the "jewels of the Earth" and the "world's largest pharmacy", because over one quarter of natural medicines have been discovered there. Rainforests are also responsible for 28% of the world's oxygen turnover, sometimes misnamed oxygen production, processing it through photosynthesis from carbon dioxide and consuming it through respiration.

GRASSLAND ECOSYSTEM

Grasslands are areas where the vegetation is dominated by grasses however sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica. Grasslands are found in most ecoregions of the Earth. For example there are five terrestrial ecoregion classifications (subdivisions) of the temperate grasslands, savannas, and shrub lands biome which is one of eight terrestrial eco zones of the Earth's surface. Grasslands often occur in areas with annual precipitation between 600 mm (24 in) and 1,500 mm (59 in) and average mean annual temperatures ranges from −5 and 20 °C (Woodward et al. 2004). However, some grasslands occur in colder (-20°C) and hotter (30°C) climatic conditions. Grassland can exist in habitats that are frequently disturbed by grazing or fire, such as disturbance prevents the encroachment of woody species. Species richness is particularly high in grasslands of low soil fertility such as serpentine barrens and calcareous grasslands. Infertility may also prevent woody encroachment as low nutrient levels in the soil may inhibit the growth of forest and shrub species. Most plants from growing. Temperate grasslands occur in temperate climates typified by distinct seasonality (warm summers and cold winters). PRAIRIES

Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrub lands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type. Temperate grassland regions include the Pampas of Argentina, Brazil and Uruguay as well as the steppes of Eurasia. Lands typically referred to as "prairie" tend to be in North America. The term encompasses the area referred to as the Interior Lowlands of the United States, Canada and Mexico, which includes all of the Great Plains as well as the wetter, somewhat hillier land to the east. In the U.S., the area is constituted by most or all of the states of North Dakota, South Dakota, Nebraska, Kansas, and Oklahoma, and sizable parts of the states of Montana, Wyoming, Colorado, New Mexico, Texas, Missouri, Iowa, Illinois, Indiana, Wisconsin, and western and southern Minnesota. The Central Valley of California is also a prairie. The Canadian Prairies occupy vast areas of Manitoba, Saskatchewan, and Alberta.

PAMPAS

PAMPAS is a wide, flat, grassy plain of temperate South America, c.300, 000 sq mi (777,000 sq km), particularly in Argentina and extending into Uruguay. Although the region gradually rises to the west, it appears mostly level. Precipitation decreases from east to west. Trees are found only along watercourses. Covered by grasses whose height varies with the amount of rainfall received, the soil of the pampas is very fertile and supports a thriving pastoral and farming economy. The Pampa, c.250, 000 sq mi (647,500 sq. km), of central and N Argentina embraces parts of the provinces of Buenos Aires, Santa Fe, Córdoba, and La Pampa. Cattle is first introduced to the region by the Portuguese in the 1550s. Throughout the colonial period under Spain, only a small part of the Pampa was used; economic activity was practically restricted to primitive stock raising for the exportation of hides, tallow, and jerked beef. Herds of cattle roamed freely over the Pampa, and the gaucho.

STEPPE

STEPPE is an ecoregion, in the montane grasslands and shrublands and temperate grasslands, savannas, and shrublands biomes, characterized by grassland plains without trees apart from those near rivers and lakes. The prairie (especially the short grass and mixed prairie) is an example of a steppe, though it is not usually called such. It may be semi-desert, or covered with grass or shrubs or both, depending on the season and latitude. The term is also used to denote the climate encountered in regions too dry to support a forest, but not dry enough to be a desert. The soil is typically of chernozem type. Steppes are usually characterized by a semi-arid and continental climate. Extremes can be recorded in the summer of up to 40 °C (104 °F) and in winter, –40 °C (–40 °F). Besides this huge difference between summer and winter, the differences between day and night are also very great. In the highlands of Mongolia, 30 °C (86 °F) can be reached during the day with sub-zero °C (sub 32 °F) readings at night. The mid-latitude steppes can be summarized by hot summers and cold winters, averaging 250–500 mm (10-20 inches) of precipitation per year.

SAVANNA

A savanna, or savannah, is a grassland ecosystem characterized by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses. Some classification systems also recognize a grassland savanna from which trees are absent. This article deals only with savanna under the common definition of a grassy woodland with a significant woody plant component.
It is often believed that savannas feature widely spaced, scattered trees. However, in many savannas, tree densities are higher and trees are more regularly spaced than in forest. Savannas are also characterized by seasonal water availability, with the majority of rainfall confined to one season. Savannas are associated with several types of biomes. Savannas are frequently in a transitional zone between forest and desert or grassland. Savanna covers approximately 20% of the Earth's land area.

SERENGETI PLAIN

The Serengeti Plain, located in north-central Tanzania, (Africa) is world renowned as an ideal location for wildlife and nature photography. Much of the beauty is attributed to its sweeping vistas and dramatic natural features that extend over 60,000 square kilometers. The Serengeti has more than 2 million herbivores and thousands of predators. Blue Wildebeests, gazelles, zebras and buffalos are the animals most commonly found in the region.
A significant portion of the Serengeti Plain is protected and preserved from the ravages of modern society in the Serengeti National Park. This park, which extends for roughly 12,950 square kilometers, contains a diverse selection of habitats and wildlife. For the sake of comparison, the Serengeti National Park is approximately the size of Northern Ireland. It offers some of the most spectacular and undisturbed natural habitats found anywhere on the globe. The Serengeti National Park is bordered by Lake Victoria in the west, Lake Eyasi in the south, and the Great Rift Valley to the east.

ARCTIC ECOSYSTEM

The Arctic Ecosystem through the solar winds generated by the outpourings of the sun gusting to 200 km per minute, through the -200° C ozone depleted stratosphere, through the boundary layer at 3 km between the upper and lower atmosphere, there you see the Arctic lying in winter darkness dominated by the 15 million square miles of polar sea ice. In summer this is reduced to about 8 million square kilometres. The sea ice extends south to three exits of the Arctic Ocean - the narrow exit west of Greenland into the North Atlantic; through the 500 km wide strait between Greenland and Svalbard; and through the 70 kilometre Bering Strait between Chukotka and Alaska into the Bering Sea and onwards to the Pacific Ocean. The land surrounding the Arctic Ocean is covered by many glaciers but is dominated by the Greenland Ice Cap covering 1.7 million square kilometres and with a maximum thickness of 3200 km - a massive volume of 2.8 million cubic kilometres. Glacial fingers extend down the mountain ridges in Norway, the Urals, Kolyma, Alaska, the Yukon and Baffin Island reaching well below the Arctic Circle.

POLAR ICE CAP

A polar ice cap is a high latitude region of a planet or natural satellite that is covered in ice. There are no requirements with respect to size or composition for a body of ice to be termed a polar ice cap, nor any geological requirement for it to be over land; only that it must be a body of solid phase matter in the polar region. This causes the term "polar ice cap" to be something of a misnomer, as the term ice cap itself is applied with greater scrutiny as such bodies must be found over land, and possess a surface area of less than 50,000 km²: larger bodies are referred to as ice sheets.
The composition of the ice will vary. For example Earth's polar ice caps are mainly water ice, while Mars's polar ice caps are a mixture of solid phase carbon dioxide and water ice.
Polar ice caps form because high latitude regions receive less energy in the form of solar radiation from the sun than equatorial regions, resulting in lower surface temperatures.
The Earth's polar ice caps have changed dramatically over the last 12,000 years. Seasonal variations of the ice caps takes place due to varied solar energy absorption as the planet or moon revolves around the sun. Additionally, in geologic time scales, the ice caps may grow or shrink due to climate variation. TUNDRA

In physical geography, a tundra is a biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russian from the Kildin Sami word tūndâr "uplands", "treeless mountain tract". There are three types of tundra: arctic tundra, alpine tundra, and Antarctic tundra. In a tundra, the vegetation is composed of dwarf shrubs, sedges and grasses, mosses, and lichens. Scattered trees grow in some tundras. The eco tone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline. Arctic tundra occurs in the far Northern Hemisphere, north of the taiga belt. The word "tundra" usually refers only to the areas where the subsoil is permafrost, or permanently frozen soil. (It may also refer to the treeless plain in general, so that northern Sápmi would be included.) Permafrost tundra includes vast areas of northern Russia and Canada. The polar tundra is home to several peoples who are mostly nomadic reindeer herders, such as the Nganasan and Nenets in the permafrost area.

DESSERT ECOSYSTEM