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.

Savannahs are characterized by grasslands with scattered trees, and forest development is often kept in check by several factors:

2. Fire: Frequent natural or human-induced fires are a major factor. Grasses are more resistant to fire and recover quickly, while tree seedlings and saplings are often killed, preventing the establishment of dense forests.
3. Grazing herbivores: Large populations of grazing animals (like zebras, wildebeest, elephants) consume tree seedlings and saplings, suppressing tree growth and favoring the dominance of grasses.
4. Seasonal rainfall: Savannahs experience distinct wet and dry seasons. The prolonged dry season creates conditions (e.g., water scarcity) that are unfavorable for the growth of a dense, closed-canopy forest, but sufficient for drought-adapted grasses and scattered trees. This rainfall pattern is a fundamental limiting factor for forest development.
5. Burrowing animals and termites: While these animals affect soil structure and nutrient cycling, they are generally not considered primary factors that check extensive forest development on a landscape scale in savannas.
6. Soil properties: While specific soil properties can influence vegetation, they are not a universal or primary checking factor across all savannas compared to the direct impact of fire, grazing, and rainfall patterns. Therefore, fire, grazing herbivores, and seasonal rainfall are the most significant conditions that prevent the extensive development of forests in savanna regions.