Saturday, 13 August 2016

Viki Sangre

Producer Plants and Vegetation of Semi-arid Region in Indian Ecosystem | Climate Zone, Lands

The ecosystem in a semi-arid region in India has low erratic rainfall. The dominant producer plants are mostly annual plants which manage (therophytes)  to avoid drought by passing the dry period as dormant seeds. This vegetation also persists by means of underground storage organs. Xerophytic shrubs and stem succulents are adapted to tolerate drought.

The proportion of plant life forms in semi-arid ecosystems is nearly 26 percent phanerophytes (woody plants with buds above soil surface) nearly 18 percent hemicryptophytes (herbs with buds at soil levels) 6 percent cryptophytes (herbs with buds below the soil surface) and 41 percent therophytes.

Seeding or planting of fodder grasses, shrubs and trees in semi-arid ecosystems have been tried to re-green it, such as Atriplex, Acacia, Prosopis, Salsola which are well adapted to dry conditions.

Producer Plants in Semi-arid

The shrub legume Cajanus cajan also has been grown for combating water erosion, improving soil structure and water-holding capacity and supply of fodder. Another shrub legume is Stylosanthes, which is grown to build up soil nitrogen, to improve soil organic matter to allow water infiltration and to provide nutritious fodder.

Semi-arid Zones

Stylosanthes hamata is recommended for semi-arid zone in Karnataka, Tamilnadu, and Madhya Pradesh. This is readily eaten by sheep and goat and tolerant to grazing. It also increases earthworm activity and rapid mineralization.

Sometimes a combination of S. hamata and Acacia albida (subabul) have been growing in most semi-arid climate ecosystems, which helps to bring nutrients from subsoil to topsoil and decrease nutrient loss by leaching.

Productivity in semi-arid ecosystem increases with intercropping of the nitrogen-fixing tree (Acacia) with crops like castor, sorghum, pearl millet. Leaves of Acacia albida has high nitrogen content (4 percent), replenishes the soil with nitrogen, which is otherwise nitrogen deficient in semi-arid ecosystems.

Acacia has 2 advantages; it replenishes the soil with a permanent supply of nitrogen and acts as windbreaks, preventing soil erosion. Besides, there are many shrubs and grass having a deep-rooted system.

Consumers

They are mostly grazing animals such as sheep, goat, buffalo. Wild animals are Fox, hare, hedgehog, and wolf. Birds comprise the great Indian Bustard, Quail, Sandgrouse and many others.

Decomposers

Insects fauna in semi-arid ecosystems is rich. Earthworms, ants, termites, locusts, grasshoppers and many other insects prevail.

Human Practices

Human population density is high. Local people have an agro-pastoral occupation. People are engaged in cultivation and agriculture labor. They also practice shifting cultivation with a prolonged fallow period.

State with most semiarid regions in India

Many regions in India where semiarid ecosystems prevail are Madhya Pradesh, Andhra Pradesh, Karnataka, Tamilnadu. There is considerable pressure on semi-arid ecosystems by the human population and associated livestock population. Of late there has been considerable degradation of semi-arid ecosystems measured by loss of productivity, species diversity and soil quality.

Agricultural over-exploitation and overgrazing are the two key causes of degradation of the ecosystem. However, such degradation has the capability to regenerate by an exclusion of human influence, partially or totally.