Terrestrial Biomes: Types, Diversity, and Human Impact

 Terrestrial ecosystem:

    The terrestrial ecosystem, also known as the lithospheric ecosystem, is a land-based biome where living and non-living component interact on land or soil. 

Component of terrestrial ecosystem:

    There are two main components of the terrestrial ecosystem. 

Biotic factors: 

      It include all living organisms that live on land. Plants are producer there.

Abiotic factors:

    It include all non-living elements present on land. Air, sunlight and soil are a few examples of abiotic factor. Water is limited there for use.

 Types of terrestrial ecosystem:

    Terrestrial ecosystem can be classified into four major biomes, each with distinct climate, vegetation and wildlife. Each containing a unique ecosystem.

• Forest biome
• Grassland biome
• Tundra biome
• Desert biome

Forest biome:

    The forest biome is a vast land-based region where trees are abundant and large. It contain various ecosystem including:

1. Tropical rain forest ecosystem
2. Coniferous alpine and boreal forest ecosystem
3. Temperate deciduous forest ecosystem

Tropical rainforests:

    In tropical rainforests, a high level of rainfall occurs. They receive approximately 70 to 100 inches of rain per year. The temperature is very hot, about 28°C, because sunlight strikes directly. The soil is moist, allowing trees to grow easily without facing   water deficiency. It is a habitat for many species and is nutrient-rich because of the large number of producers. These forests are located in South and North America, Southeast Asia, Pacific islands. Pakistan does not has rainforests.

Human impact:

    Deforestation poses a threat to these forests. Forests are cut for agriculture, timber, and more.

Coniferous alpine and boreal forests:

    Alpine coniferous forests are located at high altitudes(height above sea or ground level), while those at high latitude(angular distance from equator, expressed in degrees) are called boreal forests. Northern coniferous forests are also known as taiga. There is a constant cover of snow in winter and Temperatures can reach up to 10°C.

Biodiversity: 

    Biodiversity is low due to the harsh climate. The growing season is very short, and winters are very long. However, some large animals such as bison, wolf, wolverine, and crossbills are live here. They are located across Europe, Asia and North America. In Pakistan, coniferous forests are found in upper Kaghan, Dir and Chilas, Malam Jaba in Swat valley Coniferous forests are found in Pakistan.

Human impact:

    These forests are major source of lumber. Cutting of trees led to deforestation.

Temperate deciduous forests:

    The average rainfall is almost 750 to 1500mm every year. Sufficient rainfall support the growth of trees. Temperature is moderate, the average range is from 4°C-30°C. Temperature is not constant and change with different season. There leaves are fall during winter. Though leaf fall they excrete all waste product. They covered Japan, North and South America, china, India and Europe. In Pakistan These are present in Neelam valley and Shorgan. Soil is moist and fertile with maximum water absorbing capacity. Biodiversity is large in size. Many species of animal, plant, fungi and bacteria are live here.

Human impact:

    Over hunting of predators such as wolves, lions and black bears causes threaten to these species. Which unstable the forest. Lumber is abundant which use in construction. Need of lumber had reduced many deciduous forests.

Grassland ecosystem:

    Grass land have not woody plants and called Prairies. On the other hand in tropical climate thy have woody plants and are called Savanna. 

Rainfall:

    Approximately 250 to 750mm is annual rainfall. It usually face drought. Sometimes rainfall reach 1500mm in tropical and subtropical grassland. In other words rainfall is in between of forest and desert. 

Temperature:

    Temperature is different in season and type of grassland. Such as in tropical grassland temperature is about 25°C. Temperature is vary in wet grassland. In temperate grassland temperature is about 38°C and in winter season temperature reach about -4°C.

Soil condition and productivity:

    The upper layer of soil is moist in limited region. Rate of evaporation is very high. Its deeper layer is almost dry. The rate of primary production is about 750-1500gm² per year. In sub-humid grassland productivity is about 4000gm² and is consumed by herbivores of small amount about 5-10% of total productivity. 

Layers:

    There are about three layer of grassland ecosystem. Upper layer is made by tall grasses. Mid high grasses form second layer and third deeper layer is made of short grasses with mosses and lichens.

Animal and plant life:

    The dominant species of plants are grass-like plant and grass. Tall trees are lessen here. Many animals and insects are live here. Most dominant species are herbivores. But some predator are also here such as foxes and wolves prey on mammals, lizards and toads prey on insects.

Human impact:

      Due to overgrazing and human impact lands are converted into desert called desertification. The natural grasslands are used for crops and housing society.

Tundra ecosystem:

    A vast treeless region before polar ice-caps is arctic tundra which is around Arctic ocean. It stretches in world across Siberia, Northern Europe and North America. In Pakistan at high altitude it is found in Karakoram and Koh Hindu Kush mounts.

Temperature and rainfall:

    Average rainfall is 6-10 inches sometime in the form of snow. Temperature is very low about-34°C in winter season. In summer temperature is approximately 3-12°C. 

Plant and animal life:

      The species of small flowers and willows with large lichen called reindeer mosses. It is a habitat of mosquito due to standing pools. Lemmings are found there which are eaten by wolf, arctic fox and snowy owls. 

Human impact:

    Due to global warming and ozone depletion ice caps melt and causes rise of sea level. It cause contraction of tundra ecosystem.

Desert ecosystem:

     The desert biome is characterized by arid conditions and contains unique desert ecosystems. Deserts sandy land with warm environment. These are found in every continent often around 20 to 30 north and south latitude. In Pakistan these are found in western Punjab, named Thal in Mianwali and Bukhar. In Sindh desert is called Thar. Desert are also found in southern Punjab.

Rainfall and temperature:

    In day time temperature rise to 38°C and in night-time temperature fall to -3.9°C. Rainfall is sometime zero or 10-20 inches. Soil is drought and dry. 

Plant and animal life:

    Due to its dryness biodiversity is very low here. Some xerophytes such as cacti are found there. They have adaptations to survive. Such as their roots are in depth for absorb more water. They have thick waxy coating and low number of stomata for low concentration of transpiration. Like plants, animals also have adaptations for survival camel stored water in their blood stream. They drink water 58 gallon in three minutes. Mostly animal feed in night when temperature is cool. Some animals are snakes, kangaroo, rat and birds.

Human impact:

    Human activities are reducing extent of many biomes and cause spread of deserts.