Previous Year Question

Tropical Rainforests have the highest Plant Biomass among the given ecosystems. Biomass refers to the total amount of living biological matter present within a specified area, usually measured in terms of Dry Weight or stored carbon. Tropical Rainforests accumulate large quantities of organic matter because of their massive trees, dense vegetation, climbing plants, and multiple layers of plant growth.

High temperatures, abundant rainfall, and year-round availability of solar energy provide favourable conditions for vegetation growth in these forests. Annual rainfall generally reaches 2,000 millimetres or more, while temperatures remain relatively high. These conditions support high rates of Photosynthesis and Primary Productivity. The extended growing period of evergreen trees and their Multi-layered Forest Structure also contribute to greater biomass accumulation.

Tropical Deciduous Forests experience comparatively lower rainfall and a distinct dry season. Many trees shed their leaves during dry periods, affecting vegetation growth and biomass accumulation. Temperate Deciduous Forests generally have lower annual productivity because of colder seasons and a limited growing period. Desert Shrubs have very low biomass because rainfall and water availability are extremely limited, resulting in sparse vegetation. A classical global assessment estimated approximately 202.5 tonnes of carbon per hectare in Tropical Rainforest biomass, compared with 157.5 tonnes in Tropical Seasonal Forests and 135 tonnes in Temperate Deciduous Forests.

The Amazon Basin, Congo Basin, and Southeast Asia are major regions of Tropical Rainforests. In India, such forests occur in parts of the Western Ghats, Northeast India, and the Andaman and Nicobar Islands. These forests store large quantities of carbon and play important roles in the Water Cycle, Climate Regulation, and Biodiversity Conservation. Biomass and Productivity are distinct concepts: Biomass is the quantity of biological matter present at a particular time, whereas Productivity is the rate of new biological matter production over a specified period.