The vegetation of savannah consists of grassland with scattered small trees, but extensive areas have no trees. The forest development in such areas is generally kept in check by one or more or a combination of some conditions. Which of the following are such conditions.
1. Burrowing animals and termites
2. Fire
3. Grazing herbivores
4. Seasonal rainfall
5. Soil properties
Select the correct answer using the code given below:

The correct answer is 2, 3 and 4 only.

Savannah ecosystems are characterized by a continuous grass layer interspersed with trees and shrubs. The open structure of savannahs and the restriction of forest development in these regions are primarily driven by a combination of ecological and climatic factors:

1. Fire (Condition 2): Bushfires are very common in savannah regions, especially during the dry season. Fire destroys tree seedlings and keeps the growth of woody vegetation in check, encouraging the growth of fire-adapted grasses.

2. Grazing Herbivores (Condition 3): Savannahs support large populations of grazing and browsing mammals (such as zebras, wildebeests, and elephants). Heavy grazing and browsing prevent young tree seedlings from establishing into dense forest cover.

3. Seasonal Rainfall (Condition 4): Savannahs experience alternating distinct wet and dry seasons. The prolonged dry season creates moisture stress that limits the survival and canopy expansion of dense forest trees, giving deep-rooted grasses a competitive advantage.

While burrowing animals and soil properties influence local vegetation dynamics, fire, grazing herbivores, and seasonal rainfall are the primary drivers that globally maintain savannahs and prevent forest development.

Therefore, the conditions responsible are 2, 3 and 4 only.