Description

Disclaimer: Copyright infringement not intended.

Context:

The Nilambur forest in Malapurram district, Kerala, has seen a drastic shift in seasonal patterns over the past decade. This has had a number of impacts, including delayed food production and the disappearance of certain bird species.

About the Western Ghats

General Information	Known as the Sahyadri Hills in northern Maharashtra and Sahya Parvatham in Kerala.
	UNESCO World Heritage Site and one of eight biodiversity hotspots in the world due to high biodiversity and endemism.
Geography	Extends from the Satpura Mountains in the north to Kanyakumari in the south, covering approximately 1,600 km and 140,000 km².
	Runs parallel to India’s west coast, 30 to 50 km inland.
	Foothills include Desh (Maharashtra), Malanadu (Karnataka), and Nilgiri Malai (Tamil Nadu).
Mountain Ranges	Nilgiri Range connects to Shevaroys and Tirumala Range, linking the Western Ghats with the Eastern Ghats.
	Anamudi Peak (Kerala) is the highest peak in the Western Ghats and India outside the Himalayas.
Hill Stations	Includes Matheran, Lonavala Khandala, Mahabaleshwar, Panchgani, Amboli Ghat, Kudremukh, and Kodagu.
Geology	Block mountains formed by land undulation or fault edge of the Deccan Plateau.
	Rocks: Basalt, charnockites, granite gneisses, khondalites, leptynite, crystalline limestones, iron ores, dolerites, and anorthosite.
Rivers	Western flowing: Periyar, Bharathappuzha, Netravati, Sharavathi, Mandovi, etc.
	Fast-moving rivers with steep gradients, are ideal for hydroelectricity.
	Eastern flowing: Godavari, Krishna, Kaveri; tributaries like Tunga, Bhadra, Bhima, Malaprabha, Ghataprabha, Hemavathi, Kabini.
	Slower-moving rivers merge into larger rivers.
Climate and Vegetation	Tropical evergreen forests on western slopes with rosewood, mahogany, cedar, etc.
	Dry and moist deciduous forests on eastern slopes with teak, sal, sandalwood, etc.
	Key barrier influencing monsoon winds; forests home to globally threatened species.
Wildlife	Endemic species: Nilgiri tahr, lion tailed macaque.
	Other fauna: Nilgiri marten, brown civet, Indian mongoose, striped mongoose, leopard cat.
	Globally threatened species: 229 plants, 31 mammals, 15 birds, 43 amphibians, 5 reptiles, and 1 fish.
Protected Areas	Includes 2 Indian Biosphere Reserves, 13 National Parks, several wildlife sanctuaries, and many reserve forests.
	Nilgiri Biosphere Reserve: Largest protected area with evergreen forests (Nagarahole), deciduous forests (Bandipur, Nugu National Park), Wayanad, Mudumalai.
	Silent Valley National Park (Kerala): Last stretches of virgin tropical evergreen forest.

Factors Contributing to Increased Landslides and Environmental Stress

Climate Change and Rainfall Patterns:
- - Increased rainfall events (>300 mm/day) since 2018 in Wayanad and other regions.
  - Rising temperatures, with Wayanad warming by 1.5°C in the past decade.
  - Shifting rainfall patterns leading to drier pre-monsoon and monsoon phases.
Deforestation and Urbanization:
- - Rampant development activities and mining.
  - Loss of green cover exacerbating soil erosion and landslide risks.
Invasive Species:
- - Proliferation of weeds like Senna spectabilis reducing native vegetation and food availability.
Soil Saturation and Weakening Forest Slopes:
- - Intense rainfall saturates soil, leading to slope instability.
  - Increased frequency of landslides in fringe forest areas.

Effects of Climate Change on Environment and Communities

Landslides and Soil Erosion:
- - Frequent landslides from Coorg to Vellarimala destabilizing ecosystems and human settlements.
  - Evidence of soil erosion in streams and rivers like Karimpuzha.
Wildlife and Biodiversity Impacts:
- - Decline in native species and increased forest fires.
  - Disruption of migratory bird patterns; rare species replacing regular ones.
  - Increased human-wildlife interactions due to reduced forest resources.
Impact on Forest Produce:
- - Decline in honey, kokum, wild nutmeg and medicinal plants due to erratic rainfall and rising temperatures.
  - Shifting lifecycle of tuber crops and reduced yields.
Human Livelihood Challenges:
- - Loss of crops to wildlife, particularly elephants, in regions like Ernakulam and Wayanad.
  - Reduced income from forest-based products like honey and fruits.
Forest Fires: Prolonged dry periods increase fire risks altering forest ecosystems.
Human-Wildlife Conflicts: Elephants and tigers moving closer to human settlements for forage and prey.

Key Observations by Experts

Climate Hotspots: Forests in Kerala and Karnataka are classified as climate change hotspots by the Forest Survey of India (FSI), showing temperature increases >1.5°C and rainfall variability >20%.
Rainfall Threshold for Landslides: Landslides are triggered when rainfall exceeds 145-150 mm in 24 hours.
Vegetation Shifts: Replace native flora with invasive species like Eupatorium and Senna spectabilis.

Suggestions for Mitigation and Adaptation

Development of hazard zonation maps to guide sustainable land-use planning.
Strengthening afforestation efforts with native species to stabilize soil and restore ecosystems.
Enhanced monitoring and early-warning systems for landslides.
Sustainable farming practices and diversified income sources for forest-dependent communities.
Controlled management of invasive species to restore ecological balance.

Source:

Down To Earth

PRACTICE QUESTION

Q.Examine how global warming has affected the ecological balance and biodiversity of the Western Ghats. Discuss the major environmental changes observed in this region and their implications for conservation efforts. (250 words)