Describe and explain how the thermal and precipitation regimes characterize the climate of any one distinctive landscape within the tropics.

vegetation to the adverse natural conditions.)Human impact on the natural vegetation described above.Full answerVegetation is directly affected by the climatic conditions. Different vegetation develops under different climatic conditions. Equatorial climate is experienced in the Tropical Rain Forest (TRF). It is characterized by hot and humid condition. This is mainly due to the high angle of the overhead sun and there is no marked seasonality. High and constant insolation is experienced throughout the year. There is strong convection air currents and, together with the convergence of the inter-tropical air, dense cloud formation results. Rainfall is abundant and (more than 2000mm annually) is evenly distributed throughout the year. TRF has a rich flora composition. There is a dense growth of trees of different species. The forest can be divided into five layers, namely, the emergent layer (over 50m in height), the canopy layer (between 25m and 50m in height), the lower layer (less than 25m in height), the shrubs layer and the undergrowth layer. The TRF is an evergreen forest and the plants are mostly hydrophytes. There is a large biomass. The vegetation is luxuriant and plants have to compete for survival.As latitude increases, there are changes in the vegetation properties. In general, the biomass decreases as natural conditions become less favourable.To the north and south of the TRF is the savanna. It is divided into the wet and the dry savanna. The wet savanna is nearer to the TRF. Here, the annual rainfall is lower than that in the TRF (about 750-1400mm). There is a distinct wet and dry season. Annual rainfall is unevenly distributed. The annual range of temperature is larger than that in the TRF.Under these climatic conditions, the savanna has less flora variety and the vegetation is not as dense. There is no distinct stratification in the vegetation cover. The biomass is smaller and is less luxuriant. With increase in latitude, a dry savanna can be found. The climatic condition becomes more adverse to plant growth. The annual rainfall is 250-750mm and there is a marked dry season. Rainfall is unevenly distributed. The mean summer temperature is high and there is a larger range of temperature. The vegetation here becomes more sporadic. As water supply is unreliable and unstable, the main vegetation type is shrubs or woody plant. There is even less flora composition and no distinct stratification can be found. Grass is the dominant vegetation here. The biomass decreases gradually from the TRF towards the dry savanna.At the edge of the savanna, deserts can be found. The climatic conditions do not favour plant growth. There is sporadic and insufficient rainfall (less than 250mm annually) and the range of temperature is large. This is a region of subsiding air and there is little cloud formation. This is why rainfall is scarce.Due to these adverse climatic conditions, vegetation is sparse. Trees can only be found where water is available. The main vegetation type is shrubs and xerophytes. Plants have to be able to withstand the arid condition and the large range of temperature. Desert vegetation develops adaptive features such as waxy stem, roll-up leaves and needle shape leaves in order to reduce water loss through evapotranspiration. Some plants have long deep roots in order to reach to the low water table. The vegetation is sparse as plants need space to compete for water. Vegetation changes along the climatic gradient from the Tropical Rain Forest to the Tropical Desert. However, human activities have played a vital role in altering this natural change.Many economic activities, such as lumbering and agriculture, have reduced the flora composition and the biomass in the TRF. The unique microclimate is changed as trees are cut down. The area becomes drier and allows more air movement in it. In addition, the ecosystem becomes less stable and secondary succession can be found. Trees in the secondary succession have softer wood and are shorter in height. Less species are found in these forests. The ecosystem is fragile on the margin of deserts and in the transitional zone between the TRF and the Tropical Desert. If people who practice farming there use improper methods such as marginal farming with poor irrigation, the soil will become easily exhausted through over-cultivation and overgrazing. As time passes, soil depletion results and productivity decreases. Surface vegetation gives way to barren land. Human activities can disrupt the fragile ecosystem and lead to a process called desertification.Natural vegetation is controlled by physical and climatic conditions. But through human activities, the presence and characteristics of the natural vegetation cover may greatly be altered.