Terrestrial ecosystems

Terrestrial ecosystems are life-supporting communities found on continents and other large landmasses. The environmental characteristics of these communities vary significantly based on geographical location. As a result, distinct terrestrial ecosystems are typically defined as geographical zones within which environmental conditions remain relatively constant and specific forms of wildlife are able to thrive. Terrestrial ecosystems range from the wet, lush tropical rainforest to the dry, mostly lifeless desert.

General Characteristics

Terrestrial ecosystems differ considerably from their aquatic counterparts. Whereas aquatic ecosystems are primarily or entirely water-based, terrestrial ecosystems generally contain only a limited amount of water. Indeed, the amount of water present in a particular terrestrial ecosystem is often a critical factor in its prevalent environmental conditions. Terrestrial ecosystems are subject to greater temperature fluctuations than aquatic ecosystems, and light and gases are more abundant in these environments.

The availability of water, light, and gases is fundamental to the functional structure of terrestrial ecosystems, which is composed of separate subterranean and atmospheric portions that together provide the fundamental elements necessary to sustain life. The subterranean portion provides access to water and ions, while the atmospheric portion provides access to gases and light energy.

Types of Terrestrial Ecosystems

A wide variety of naturally occurring terrestrial ecosystems exist. Each has unique characteristics in terms of climate, weather, and topography. These characteristics determine the extent to which a given terrestrial ecosystem can sustain life and what types of plants and animals are likely to thrive there.

Tundra

Tundra is an extremely cold ecosystem in which few life forms thrive. Two types of tundra are alpine and arctic. Regions of alpine tundra exist at high elevations in mountainous regions, while regions of arctic tundra exist in non-mountainous regions situated at high latitudes. Tundra regions are generally dry in terms of precipitation, but often retain moisture due to a lack of evaporation. Tundra plant life is usually limited to mosses and shrubs, and the most common forms of animal life include small populations of herbivores such as caribou and carnivores such as wolves.

Coniferous Forests

Coniferous forests are cold-weather ecosystems marked by the dominant presence of cone-bearing trees, including pine, larch, and spruce. Some angiosperm, or flowering, trees can also be found in coniferous forests. These often include birch, aspen, and willow trees.

Temperate Forests

Temperate forests can be categorized as either deciduous forests or temperate rainforests. Deciduous forests exist in regions that experience distinct seasonal shifts between warm summers and cold winters. They are usually home to a large variety of tree species, which include oaks, birches, maples, and walnuts.

Temperate rainforests occur in regions with warm temperatures and relatively mild winters. Typical tree species, some of which can grow to enormous heights, include redwood, cedar, and hemlock. Both deciduous forests and temperate rainforests provide livable habitats for a diverse array of animal species, including rabbits, bears, and mountain lions.

Grasslands and Savannas

Grasslands and savannas occur in consistently warm regions, where different types of grasses are the dominant form of plant life. In North America and Europe, grasslands are typically referred to as prairies or steppes. Rainfall is intermittent and prolonged periods of drought are common. These ecosystems are typically home to animals including deer, gophers, and bison. Grasslands located in more tropical regions, such as those found in Africa, are known as savannas. Here, grasses often are accompanied by shrubs and large, woody plants. Savannas are home to some of the largest animal species on Earth, including elephants, gazelles, lions, and rhinoceroses.

Chaparral

Chaparral is a temperate ecosystem that occurs in regions that experience extreme differences in precipitation levels throughout the year. Such regions may have incredibly rainy winters and excessively dry summers. Plant life in chaparral regions typically includes shrubs and small trees. During the dry season, chaparral regions face a high probability of wildfire, which can spread rapidly and destroy large tracts of land very quickly.

Desert

Deserts are the driest of all terrestrial ecosystems. Precipitation in desert regions rarely exceeds 10 inches per year. The existence of wildlife in the desert is entirely dependent on the availability of water. In areas where some moisture exists or where precipitation is most common, small plants like cacti and a few hardy shrub species may appear. The driest regions feature almost no vegetation of any kind. As a result of this lack of plant life, few animals are able to survive in the desert. The most common desert animal species include lizards and snakes.

Tropical Forests and Rainforests

Where deserts are the driest of the terrestrial ecosystems, tropical forests and rainforests are the wettest. Tropical forests have definitive wet and dry seasons and, as a result, most trees in these regions are deciduous. They also support a diverse array of other plant and animal life forms. Tropical rainforests occur in regions where the climate is warm and wet throughout the year. These conditions create an ideal environment in which life thrives to the maximum degree possible. Many species call the rainforest home, from microscopic organisms to plants and animals of almost every variety. Experts often regard rainforests as the peak of potential terrestrial ecosystem development.

Bibliography

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