Shifting cultivation (Jhum) in Nagaland has impacted vegetation by leading to:

Forest fragmentation
Increased biodiversity
Soil erosion
Improved forest cover

The correct answer is: a) Forest fragmentation.

Shifting cultivation, also known as jhum cultivation, is a traditional agricultural practice that involves clearing a piece of land for cultivation, then abandoning it and moving on to a new piece of land after a few years. This practice has been used for centuries in many parts of the world, including Nagaland.

While shifting cultivation can be sustainable if it is practiced in a way that allows the land to recover, it can also have a number of negative impacts on the environment. One of the most serious impacts is forest fragmentation. When land is cleared for cultivation, it creates a gap in the forest canopy. This can lead to a number of problems, including:

  • Increased soil erosion: When the forest canopy is removed, the soil is exposed to the elements. This can lead to erosion, which can carry away topsoil and nutrients.
  • Reduced biodiversity: Forests are home to a wide variety of plants and animals. When forests are fragmented, the habitats of these species are reduced, which can lead to a decline in biodiversity.
  • Increased greenhouse gas emissions: Forests play an important role in absorbing carbon dioxide from the atmosphere. When forests are cleared, this carbon dioxide is released back into the atmosphere, contributing to climate change.

In conclusion, shifting cultivation can have a number of negative impacts on the environment, including forest fragmentation. This is a serious problem that needs to be addressed if we want to protect our forests and the biodiversity they support.

Here is a brief explanation of each option:

  • Option a: Forest fragmentation. This is the correct answer. As explained above, shifting cultivation can lead to forest fragmentation, which can have a number of negative impacts on the environment.
  • Option b: Increased biodiversity. This is not the correct answer. Shifting cultivation can actually lead to a decline in biodiversity, as the habitats of many plants and animals are destroyed when forests are cleared.
  • Option c: Soil erosion. This is the correct answer. As explained above, when the forest canopy is removed, the soil is exposed to the elements. This can lead to erosion, which can carry away topsoil and nutrients.
  • Option d: Improved forest cover. This is not the correct answer. Shifting cultivation can actually lead to a decline in forest cover, as forests are cleared for cultivation.