Loss of biodiversity in a region may lead to all of the following EXCEPT:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Increase in plant productivity
Biodiversity keeps an ecosystem productive and steady. When a region loses many of its species, the book lists three general effects: plant production falls, the ecosystem copes less well with disturbances such as drought, and some ecosystem processes become more variable.
Option (1) Decline in plant production — An effect of biodiversity loss. With fewer plant species, the total plant production of the region declines.
Option (2) Lowered resistance to environmental perturbations — An effect of biodiversity loss. A species-poor ecosystem has lowered resistance to environmental perturbations such as drought.
Option (3) Increased variability in ecosystem processes — An effect of biodiversity loss. Processes such as plant productivity, water use and pest and disease cycles show more variability.
Option (4) Increase in plant productivity — Not an effect of biodiversity loss. Loss of species makes plant production fall and plant productivity more variable. It does not raise plant productivity.
NCERT Extract:
Loss of Biodiversity – “… Ecologists warn that if the present trends continue, nearly half of all the species on earth might be wiped out within the next 100 years. In general, loss of biodiversity in a region may lead to (a) decline in plant production, (b) lowered resistance to environmental perturbations such as drought and (c) increased variability in certain ecosystem processes such as plant productivity, water use, and pest and disease cycles.”