"El Niño Set to Stress Kerala's Forests and Wildlife"
El Niño
periodic warming of central-eastern Pacific waters that weakens monsoon-carrying winds
Walker Circulation
atmospheric loop that normally pulls monsoon moisture toward India
El Niño is the periodic warming of the central and eastern Pacific Ocean. It weakens trade winds and disrupts the Walker Circulation (the atmospheric loop that normally pulls monsoon moisture toward India). Strong El Niño years have historically coincided with major Indian droughts, including 1972, 2002 and 2009. The Indian Ocean Dipole (IOD) is the sea-temperature difference between the western and eastern Indian Ocean. It can offset or worsen El Niño's effect. This is why monsoon outcomes in El Niño years are not always uniformly poor.
Irrigation covers only about a third of India's cultivated area. Most agriculture and much of forest ecology remain directly dependent on rainfall. This dependence extends beyond crops to forest streams, waterholes and soil moisture. These sustain wildlife through the dry months. When a rainfall deficit occurs, the resulting stress on the ground is not uniform. Local soil moisture, groundwater recharge, vegetation cover and elevation decide how badly an ecosystem is hit, not the rainfall shortfall alone. This is why two forest patches facing a similar monsoon deficit can show very different levels of ecological strain.
Keralam's current southwest monsoon closed with a 28% rainfall deficit. A strengthening El Niño threatens to prolong dry conditions into the post-monsoon period. This sets the stage for compounded stress on forest ecosystems that are already adjusting to a weak monsoon year.
Wet-bulb temperature is the lowest temperature to which air can be cooled by evaporative cooling (perspiration). When it exceeds 35°C, the human body cannot shed heat through sweating. Core temperature rises uncontrollably. This threshold affects not just humans but all animals that rely on evaporative cooling. Survival becomes physiologically impossible beyond that point.
A severe El Niño does not by itself cause ecological collapse. It works as a stress multiplier that can push an already-weakened ecosystem past a recovery threshold. A forest with declining groundwater or a stream already reduced by encroachment is far more vulnerable to the same degree of heat or dryness than a healthier system nearby. This is why identifying ecosystems close to such a threshold matters more than treating all forests as equally at risk.
Central to this stress is forest phenology. This is the seasonal timing of flowering, fruiting, leaf-shedding and growth, closely tied to rainfall and temperature. When rainfall is delayed or reduced, soil moisture drops. Plants face water stress. …
The World Bank warned that India could become one of the first places where wet-bulb temperatures routinely exceed 35°C. Which of the following statements best reflect(s) the implication of the above-said report?
I.Peninsular India will most likely suffer from flooding, tropical cyclones and droughts.
II.The survival of animals including humans will be affected as shedding of their body heat through perspiration becomes difficult.
Select the correct answer using the code given below.
Consider the following statements regarding El Niño:
1.El Niño is associated with a weakening of the trade winds over the tropical Pacific Ocean.
2.The Indian Ocean Dipole can offset or intensify the effect of El Niño on the Indian monsoon.
3.All recorded El Niño years in India have resulted in severe droughts without exception.
Which of the statements given above is/are correct?
A high 'wet-bulb temperature' primarily poses a survival risk to humans and animals because it:
With reference to the ecological effects of a severe El Niño-driven drought on forests, consider the following statements:
1.Prolonged drought can shift forest species composition towards drought-tolerant species over time.
2.A forest's canopy appearance always accurately reflects its underlying physiological health.
3.Species vary in their tolerance to water stress, with some more drought-resistant than others.
Which of the statements given above is/are correct?
'Forest phenology' most accurately refers to which of the following?
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