The ecosystems formed by the interaction of biotic and abiotic components on the land are termed as terrestrial ecosystem.
Primarily, four types of ecosystems are found on land namely, Grassland, Taiga, Temperate Deciduous Forest and Tundra. Humans, animals, plants and micro-organisms that thrive on land are the biotic components while air, water, soil, etc. form the abiotic components of land ecosystem. Various gases that are present in the air have major influence on terrestrial ecosystem. Carbon Dioxide, Nitrogen and Oxygen respectively serve as substrates for photosynthesis, nitrogen fixation and aerobic respiration.
Species part of the ecosystem
This land ecosystem constitutes less than 1/3 of the surface of Earth and is among the youngest developed ecosystems on Earth according to history. Terrestrial plants are divided into 3 classes. Flowering plants are termed Magnoliophyta, conifers are termed Pinophyta while mosses and liverworts are termed Bryophyta. Magnoliophyta has 275,000 species, Pinophyta has 500 species and Bryophyta has 24,000 species according to approximations based on researches. Animals are classified into 3 categories too. Birds are termed Aves, insects are termed Insecta and mammals are termed Mammalia. There are 4,100 species of Mammalia, 8,500 species of Aves and 900,000 species of Insecta according to approximations based on researches.
Although terrestrial ecosystem is quite smaller than aquatic ecosystem and has lesser biodiversity, it is still quite complex and heterogeneous. The peculiarity of terrestrial organisms is the ability to transport water throughout the body without submerging the entire body into it. It is quite the opposite of aquatic animals, which are able to extract oxygen from liquid water while remaining completely submerged in it. Besides, terrestrial organisms have evolved to thrive in the atmosphere, which is not as buoyant as water is, and their bodies respond according to the weather and climate of the region where they thrive.
The elements of terrestrial ecosystem
Plants are the primary source of food in these land ecosystems. Only plants can utilize the energy of sun, which is the ultimate source of energy, and transform it into organic components that are substances with Carbon-bonds. Plants are called the producers in this ecosystem while herbivores, carnivores and omnivores are called consumers. Thus, plants lie at the bottom of food-pyramid in this ecosystem. Plants are served by micro-organisms, called Decomposers, which decompose every dead organic body on the land and supply nutrients to plants through soil. Micro-organisms are also involved with Nitrogen fixation, which is necessary for plants.
Types of terrestrial ecosystems
Of the 4 types of these ecosystems, temperate and tropical forests are the most productive with a contribution of 45% of the net land-productivity. The tundras are the least productive of all terrestrial ecosystems as they occupy least area as well as have extreme climatic conditions. However, human actions have disturbed the complexity of every kind of ecosystem on Earth.