JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech III ENVIRONMENTAL MANAGEMENT IN MINES Previous Question Paper (March - 2021 - R18)

An ecosystem is a functional unit of nature where living organisms interact with their physical environment. Ecosystems are broadly classified into two main categories:

1. Terrestrial Ecosystems: These are land-based ecosystems. Examples include forests (tropical, temperate, and boreal), grasslands (savannas and prairies), deserts (characterized by low precipitation), and tundra (cold, treeless regions).
2. Aquatic Ecosystems: These are water-based ecosystems. They are further divided into:
   • Freshwater Ecosystems: Includes lotic (flowing water like rivers and streams) and lentic (standing water like lakes and ponds) systems.
   • Marine Ecosystems: The largest ecosystems, including oceans, coral reefs, and estuaries, characterized by high salinity and distinct depth zones.

Ecological concepts describe the fundamental processes and structural relationships within an ecosystem:

• Energy Flow: Energy enters the ecosystem via solar radiation and flows through trophic levels (producers, consumers, and decomposers). This process follows the laws of thermodynamics, where energy decreases as it moves up the food chain.
• Nutrient Cycling: Unlike energy, nutrients (such as carbon, nitrogen, and phosphorus) are recycled through biogeochemical cycles, moving between biotic and abiotic components of the environment.
• Food Chains and Food Webs: A food chain represents a linear sequence of energy transfer, while a food web is a complex, interconnected network of multiple food chains, reflecting the reality of diverse feeding relationships.
• Ecological Niche: This defines the functional role of a species within its habitat, including its resource requirements, interactions, and survival strategies.
• Ecological Succession: The gradual and predictable process of change in the species structure of an ecological community over time, moving from pioneer species to a stable climax community.