Loss of biodiversity in a region may lead to all of the following EXCEPT:

Increase in plant productivity

The answer is (d) Increase in plant productivity.

Loss of biodiversity in a region can lead to a decline in plant production, lowered resistance to environmental perturbations, and increased variability in ecosystem processes. However, it is unlikely to lead to an increase in plant productivity.

In fact, the opposite is more likely to be true. When a region loses biodiversity, it loses the variety of species that play different roles in the ecosystem. This can lead to a decline in the overall health of the ecosystem and a decrease in the ability of the ecosystem to support plant growth.

For example, if a region loses its pollinators, it will likely see a decline in plant production. This is because pollinators are responsible for transferring pollen from one plant to another, which is essential for plant reproduction. Without pollinators, plants will have difficulty reproducing and their numbers will decline.

Similarly, if a region loses its decomposers, it will likely see an increase in plant litter. This is because decomposers are responsible for breaking down dead plant matter and returning nutrients to the soil. Without decomposers, the soil will become depleted of nutrients and plant growth will be hindered.

In conclusion, loss of biodiversity in a region is likely to lead to a decline in plant production, lowered resistance to environmental perturbations, and increased variability in ecosystem processes. It is unlikely to lead to an increase in plant productivity.