The following factors are responsible for the huge diversity in flora and fauna kingdom in our country: (i) Land:. Land affects the natural vegetation directly and indirectly. The nature of land influences the type of vegetation. The fertile level is generally devoted to agriculture. The undulating and rough terrains are areas where grassland and woodland develop and give shelter to a variety of wildlife, (ii) Soil: Different types of soil provide basis for different types of vegetation. The sandy soils of the desert support cactus and thorny bushes while wet marshy, deltaic soils support mangroves and deltaic vegetation. The hill slopes with some depth of soil have conical trees.. (iii) Temperature: Temperature along with humidity in the air, precipitation and soil determine the character and extent of vegetation. On the slopes of the Himalayas and the hills of the peninsula above the height of 915 metres, the fall in temperature affects the types of vegetation and its growth and changes it from tropical to subtropical temperature and alpine vegetation. (iv) Sunlight: The variation in duration of sunlight at different places also affect the growth of trees. Due to longer duration in sunlight, trees grow faster in summers.. (v) Precipitation: In India almost the entire rainfall is brought in by the advancing southwest monsoon (from June to September) and retreating north-east monsoons. Areas of heavy rainfall have more dense vegetation as compared to other areas of less rainfall.