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Banni Grassland invaded by Mad Tree Species – Threat for pastoralists?

Banni Grassland invaded by Mad Tree Species – Threat for pastoralists?

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  • GS 3 || Environment || Biodiversity || Plant Diversity

Why in news?

With over 60 species of grasses, Kutch’s Banni grassland, India’s largest, is home to an array of wildlife and key to its dairy industry.

All about Grassland ecosystem:

Grassland ecosystem:

  • Grasslands are a type of vegetation that can be found in temperate regions. The grasslands of India are a mix of tropical savanna and temperate steppe. Temperate grasslands can be found at high altitudes in the Himalayas.
  • Steppe formations are found in western Rajasthan, India, where the climate is semi-arid, with a dry season lasting 10-11 months and an annual rainfall of less than 20 cm.
  • They take up a lot of space on sandy and saline soil. The soil is always exposed here, sometimes rocky, but mostly sandy, with sand dunes that are either fixed or dynamic.
  • Only during the limited wet season can forage be found. The grass layer is thin and mostly made up of annual grass species.
  • Dry savanna grasslands have grown in Rajasthan’s eastern and central regions. The region receives roughly 500mm of yearly rainfall and has a 6- to 8-month dry season.
  • Rainfall encourages the growth of a small population of trees such as Khetri (Prosopis Cineraria), whose gentle shade encourages grass growth.
  • The main distinction between savannas and steppes is that savanna feed comes mostly from grasses that grow not only during the rainy season but also from a little amount of regrowth throughout the dry season, whereas in the steppes, forage is only available during the short wet season.

Types of Grasslands:

  • Semi-Arid Zone: The type of grassland found here is Sehima-dichanthium. It can be found in Gujarat’s northern region, Rajasthan (save for the Aravalis), western Uttar Pradesh, Delhi, and Punjab.
  • Dry sub-Humid Zone: Except for the Nilgiris, this climatic zone spans the whole peninsula of India. The grassland type found here is Dichanthium cenchrus-lasitrrus, which covers the most area of any grassland type discovered in India.
  • Moist sub-Humid Zone: The Ganga alluvial plains in northern India are covered by this climate zone. The Phragmities-sacchrum-imperata kind of grassland can be found here. The region’s geography is flat, low-lying, and has poorly drained soils.
  • Humid Montane Zone: Themeda – Arundinella grassland is the type of grassland found here. The humid montane and moist sub-humid parts of Jammu and Kashmir, Himachal Pradesh, Punjab, Uttar Pradesh, West Bengal, Assam, and Manipur fall under this climatic zone. Shifting agriculture and sheep grazing have resulted in the formation of these grasslands.

Importance of Grasslands:

  • Grasslands provide unique habitats for a variety of wild animals.
  • Grasslands are essential wildlife habitats as well. They are also important reservoirs of agricultural genes and the lifeblood of pastoral communities.
  • Grasslands have historically provided humans with a variety of food grains, including rice, wheat, and millets.
  • Many agricultural crops may not be able to adapt to the changes as a result of climate change.
  • This gene pool serves as a safeguard for biodiversity, and it can be exploited to generate new crop kinds.

The value of grasslands in terms of economics:

  • India has a sizable cattle population of various kinds. India’s overall livestock population was above 512 million in 2012, according to the 19th Livestock Census.
  • In the rural economy, livestock is extremely important. It is a significant source of food, nourishment, draught power, fuel, and raw materials for the village’s cottage enterprises. They also help farmers who rely on crop farming to supplement their income.
  • Animals require feed to survive and thrive, but there is a scarcity of it in India. Permanent grazing areas account for only about 13 million hectares. Degraded lands account for a large share of these lands.
  • As a result, it is critical to protect and restore grassland ecosystems, not only to feed the livestock population but also to support the region’s biodiversity.
  • The government has established two organizations, the Indian Grasslands and Fodder Research Institute in Jhansi and the Central Arid Zone Research Institute in Jodhpur, to promote research in the development of grassland ecosystems.

Threats of grassland ecosystem:

  • With the diminishing and degradation of grasslands, many species are now on the verge of extinction. For example, arid-region grasslands provide a unique habitat for the blackbuck, which is listed as a Schedule I species under the Wildlife Protection Act.
  • Because of the continual loss and deterioration of dry and semi-arid grasslands, the Great Indian Bustard, one of the heaviest flying birds, has become severely endangered.
  • The Nilgiri tahr, an endangered mountain ungulate native to the Western Ghats, can be found in the high-altitude shola grasslands of the Western Ghats. One of the primary causes of its population reduction is the loss of this habitat.
  • In the mid-1980s, eucalyptus and black wattle monocultures exacerbated the erosion of these undulating grasslands.
  • The degradation of grassland ecosystems in different eco-climatic zones, from the coastal regions to the alpine meadows and steppes, has put Manipur deer or thamin, Asiatic ibex, Kashmir stag or hangul, Kiang or Tibetan wild ass, Himalayan tahr, Swamp deer or barasingha, Great Indian rhinoceros, hog deer, and many other species under threat.
  • Pastoral Communities:
    • Grasslands have been converted to agricultural land or diverted for other uses in large areas.
    • Changes have seeped into traditional pastoral practices as well throughout time.
    • In the Khangchendzonga terrain of Sikkim, pastoral tribes have been substituting small herbivores such as sheep and goats with yak.
  • Grazing’s Effect on Grasslands:
    • Excessive grazing by cattle has caused grassland ecosystems to deteriorate. The mulch cover on the soil decreases, causing the microclimate of the region to dry up, allowing xerophytic plants to invade.
    • The soil surface is highly trodden due to the removal of humus layer. This lowers the soil’s infiltration capacity and speeds up runoff during rainstorms. The region is also at risk of drought as a result of this.
    • These changes disturb the ecosystem’s energy flow and impact primary producers’ stratification and periodicity. The biogeochemical cycles of nitrogen, water, and carbon may be disrupted as a result.
    • Intensive grazing of grasslands exposes the bare soil, allowing burrowing creatures such as mice, jackrabbits, prairie dogs, and gophers to flourish. Large tracts of forage fields may become infertile as a result of these animals’ new home.
  • The Function of Fire:
    • Fire is known to play an essential role in grassland ecosystem management.
    • In wet environments, fire favors grass over trees, yet in dry conditions, fire frequently defends grasslands from alien plants like desert shrubs.
    • After a cycle of burning and regrowth, fodder yields also increase. Cynodon dactylon, for example.

Regulation and protection of grasslands:

  • The Task Force Report on Grasslands and Deserts, submitted to India’s Planning Commission in 2006, aptly illustrates the grasslands’ critical position. “
  • Grasslands are not managed by the forest department, which is primarily concerned with trees; not by the agriculture department, which is concerned with agriculture crops; nor by the veterinary department, which is concerned with livestock but not with the grass on which the livestock is dependent,” it states.
  • The grasslands are the community’s “common” lands, and no one is responsible for them. They are the subcontinent’s most prolific ecosystems, but they belong to everyone, are managed by no one, and have no godfathers.

Conclusion:

Herbs and grasses dominate the vegetation in a grassland ecosystem. These ecosystems are primarily found in areas where there is a lack of water and insufficient and consistent rainfall to support plant and forest growth. The grassland ecosystem is located halfway between desert and forest ecosystems. It is important to take efforts to protect the grassland to maintain the ecosystem.

Mains oriented question:

What are the importance of grassland ecosystem? What are the threats associated to it? Explain in detail. (200 words)