Nilgiri Ecosystem in Danger | UPSC

• Thousands of trees lay dead and strewn around the western parts of the Nilgiri Plateau in southern India.
• Deep gashes scar ancient mountains, stand contrast to the lush green vegetation that they otherwise support.
• Climate change is causing widespread collapse of ecosystems.

• Global warming caused sea level rise and the melting of polar ice caps and glaciers.

DISASTERS

• EXTREMITY : The steep increase in greenhouse gas concentrations has led to a surge in the frequency of extreme climate events.
• CYCLONES : In the last four years, this region has been affected by eight tropical cyclones.
• RAINFALL : The consecutive extreme rainfall events during the southwest monsoon periods of the last two years.
• ADVERSITY : These bouts of intense storms have been interspersed with periods of severe droughts, heatwaves, deficient and failed monsoons.

• BROKEN RECORDS : It broke the record for the highest rainfall in Tamil Nadu, by nearly twice the amount.
• HIGHEST RAINFALL : Over four days, the region experienced close to 2,500 mm rainfall.
• CONTRARY : Coimbatore, the nearest city in the plains of Tamil Nadu, receives 600 mm of rain annually.

KUNDHA RIVER

• The Kundha watershed bore a deluge that was four times the annual rainfall amount, over just four days.
• The upper watershed of the Kundha river is a complex of several peaks above 2,400 m and broad deep valleys.

LOST SOIL

• Vast tracts of precious soil and shola ecology slipped away on either side of the watercourses.

• Washed away are the dark moss and wild balsam covered rocks that shaped the flow of every stream;
• Lost are the dwarf bamboo and forest kurinji (shrubs of blue flowers), ferns and orchids of the forest floor.
• In place of these are deep cuts of gauged out Earth, revealing the underlying lateritic soil and rocks.

(Left) An Aerides ringens orchid growing on a shola tree; (Right) Shola-grassland mosaic in the hills of the Nilgiri plateau, with the sholas growing in valleys and grasslands covering the slopes. 

SOURCES : DownToEarth

SHOLA-GRASSLAND MOSAIC IN DANGER

SHOLAS

• They are old-growth vegetation.
• These harbour several endemic and rare species of flora and fauna.
• These naturally confined forests are already some of the most endangered forest types.

MONTANE GRASSLANDS

• It is shocking that montane grassland stretches have also experienced large landslides.
• Together, the shola-grassland mosaic is most adept at absorbing high rainfall amounts.

• Over a year they can experience 2,500-5,500 mm of rainfall.

• This is needed to support the ecology upstream.
• The native tussock grasses are highly adapted to hold the soil strongly together on steep slopes.
• However, even this ecology is now giving way under pressure from extreme weather events.
• The shola-grassland mosaic ecology cannot withstand the tremendously high amounts of rainfall (over 2,400 mm) .

Nilgiri Ecosystem in Danger:Record-breaking rainfall and landslides have made deep cuts into the Earth revealing the underlying soil and rocks. 

SOURCES : DownToEarth

• A predominant view was the indiscriminate construction of roads and proliferating concretisation of the hills.
• The actions invariably stem from places that have long lost their plant ecological cover — the global urban-industrial-agricultural complex.

DESTRUCTION BY DAMS AND TUNNELS

• The Kundha watershed region can be broadly divided into two — the higher slopes and the descending valleys.
• Shola-grassland ecology dominates the higher slopes .

• Non-native tree plantations dominating the descending valleys.
• The descending valleys are covered with several dams and hydroelectric structures.

• This includes several kilometres of underground tunnels and a capacity of 585 MW.
• This system is now getting two more dams to generate an additional 500 MW.
• It is disastrous to add more large dams and tunnels.