Relationships between the living organisms (Biotic factors) and the non-living physical

An ecosystem is an environment that is self-sustaining and contains a complex set of relationships between the living organisms (Biotic factors) and the non-living physical environment referred to as Abiotic factors. These include sunlight, air, water, and soil. Ecosystems that share similar characteristics are grouped together from as biomes. A biome is therefore a large area that has specific climatic conditions and specific species of both animals and plants. Biomes are mainly described by the vegetation they support. This is because the plant life in that region will determine what kind of animal species will be found there. The worlds major biomes include tropical rainforests, coniferous forests, temperate deciduous forests, grasslands, deserts, freshwater and saltwater ecosystems, and the tundra.

The Tundra
The word tundra is derived from the Finnish word Tunturi, which means a treeless plain. This region is marked by extremely low temperatures making it the coldest of all the biomes. Its land surface is covered by frost. The tundra is also characterized by a climate that is extremely cold for most of the year, little biotic life, and simple vegetation structures that have short growing seasons. The tundra is also further classified into two types (Johnson 93).

Arctic tundra
This region is located in the northern hemisphere of the equator. It surrounds the North Pole and spreads south where it links the coniferous forests of the Taiga belt. The Arctic is a cold region with winter temperatures of 35o c and summer temperatures of 3 to 15o c. Since the growing seasons are often short, they range from 40 to 60 days in a year. The tundra is sometimes referred to as a cold desert because it , ranging from 12 25 cm. During the summer, the frozen ground that is known as Permafrost melts to give little water that supports vegetation growth. The major plants found in the tundra are cold-resistant and , reindeer mosses, a limited species of flowers, liverworts, and lichens. The short vegetation is adapted to the high-speed winds of the tundra that blow with speeds ranging from 50 to 100 km/h. The biodiversity of the region is very low due to the low temperatures; however, it supports approximately 45 species of animals like the reindeer, musk ox, arctic fox, polar bears, snow owls and lemmings, the harlequin duck.

Alpine tundra
The alpine tundra has a high altitude and is also treeless. The major difference between the alpine and the arctic tundra is that the alpine grounds are not covered by the permafrost. The alpine tundra also has a better drainage system occasioned by its high altitude.

As it is cold in the tundra biome, most of the animals found here have thick fur or feathers to protect them from the cold. They have also adapted mechanisms to enable survival in these regions. Most of these animals hibernate or migrate during the cold seasons and show up when the conditions are more favorable.

Energy flow and food chain
Sunlight is powering energy in this biome, but since the arctic tundra experiences, longer periods of nights and winter for most of the year; the suns energy is only beneficial during the short summer season. The plants use the sunlight to grow within a short period. The plains are mainly covered with red-leafed vegetation at this time of the year. As the plants grow, they provide food for the herbivorous species of animals like the arctic hares, musk ox, and reindeer. These herbivorous animals in turn provide a source of food for carnivorous animals like the polar bears, the arctic fox, and the snowy owls. When winter comes, the plants die off and act as nutrients for the soil. This process is cyclical year after year (Latham 154).

Environmental impacts on organisms
The harsh conditions in the tundra contribute to the low and sparse population in the region; however, the region has rich resources of minerals, gas, and oil. The presence of these resources has promoted ventures into this region, creating a population increase. The extraction of oil and gas has caused drastic changes to the environment, due to the construction of roads, pipelines, and factories. The , have changed the composition of the air and are also eating away the ozone layer; promoting global warming (Forman 23. This is the major threat to the tundra, as global warming will cause the tundra to melt and erode away. The net effect of this phenomenon will cause the permafrost to disappear and the organic material in the soil will start to decompose and release carbon dioxide which will contaminate some plants like lichens. Oil spills contaminate the soil, killing plant life and essentially destroying food for the animals that depend on the plants. This ultimately destabilizes the ecosystems within the tundra.