AS Environmental Management: Key Ecosystem Concepts

Front

Define **Sustainability** in the context of environmental management.

Back

Sustainability is meeting the needs of the present without compromising the ability of future generations to meet their own needs. It relies on maintaining natural capital and living within the carrying capacity of the Earth's ecosystems.

Front

Distinguish between a **Population** and a **Community**.

Back

A population consists of organisms of the *same species* living in the same area at the same time (e.g., a herd of elephants). A community consists of *all the different populations* of species living and interacting in a specific area (e.g., the elephants, giraffes, and trees in a savanna).

Front

What is an **Ecosystem**?

Back

An ecosystem is a distinct, self-supporting system of organisms interacting with each other and with their physical (abiotic) environment. It includes the transfer of energy and the cycling of nutrients.

Front

Define **Niche**.

Back

A niche is the specific role and position of a species within its environment. It includes what it eats, where it lives, how it reproduces, and how it interacts with biotic and abiotic factors. No two species can occupy the exact same niche indefinitely (Gause's Law).

Front

Explain the **10% Law** regarding energy transfer between trophic levels.

Back

Only about 10% of the energy available at one trophic level is transferred to the next. The remaining 90% is lost as heat (through respiration) or remains in uneaten/undigested matter. This limits the number of trophic levels in a food chain.