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.

Answer: C. FIRE (2), GRAZING HERBIVORES (3), and SEASONAL RAINFALL (4) are the main constraints that keep forest from developing in savanna. The SAVANNA biome is characterised by a continuous grass cover with widely scattered trees (e.g., acacias, baobabs in Africa; dhak/palas, mahua in India). It occupies the latitudinal belt between tropical rainforest and desert. The combination of conditions that prevents savannas from succeeding into closed forest: (2) FIRE: CORRECT. Recurrent grassland fires (natural lightning + indigenous burning) DESTROY YOUNG TREE SAPLINGS but spare deep-rooted grasses, which regenerate quickly from rhizomes. Mature savanna trees have thick fire-resistant bark. Fire is the SINGLE MOST IMPORTANT factor maintaining savanna against forest succession. (3) GRAZING HERBIVORES: CORRECT. Large mammalian herbivores (African elephants, giraffes, gazelles, antelopes, zebras, wildebeest; in India sambhar, chital, blackbuck, nilgai) consume saplings and browse young trees, preventing forest closure. Elephants in particular damage tree saplings. (4) SEASONAL RAINFALL: CORRECT. Savanna rainfall is HIGHLY SEASONAL (typically a 3-6 month wet season and prolonged dry season). The DROUGHT SEASON STRESSES TREE SEEDLINGS while perennial grasses can survive on rhizomes. Total rainfall (500-1500 mm) is too low and irregular to support closed forest canopy. (1) BURROWING ANIMALS AND TERMITES — minor factor; do not prevent forest development at scale. (5) SOIL PROPERTIES — savanna soils vary widely; soil is NOT the primary control. The same soils can carry forest if fire and grazing are excluded. So the textbook answer is FIRE + GRAZING + SEASONAL RAINFALL — option C. Source: NCERT Class 11 Fundamentals of Physical Geography 'Biosphere' / ecology references on disturbance-mediated biomes.