The Nature of Ecosystems

The Concepts behind Ecosystems

Ecosystem refers to the biological community of interacting organisms and their physical environment.
It consists of the biotic components (living organisms) and the abiotic components (non-living aspects such as water, sunlight, and soil).
Producers, such as plants, are organisms that can produce their own food and energy usually through photosynthesis.
Consumers are organisms that get their energy by consuming other organisms, cannot manufacture their own food.
Decomposers break down dead organisms, returning essential nutrients to the environment.

Structure of Ecosystems

Each ecosystem has a trophic level, which refers to the various stages of feeding levels in a food chain, consisting of producers (primary), consumers (secondary and tertiary), and decomposers.
All ecosystems consist of a food chain, where energy and nutrients are transferred from one organism to another.
A food web, a more realistic and complex version of a food chain, represents multiple interconnected food chains within an ecosystem.

Ecosystem Dynamics

Succession is the process by which a biological community evolves over time, usually from a barren or damaged state to a stable, mature state.
This occurs in stages: primary succession (starts with bare or lifeless a substrate), secondary succession (areas where existing communities have been cleared), and climatic climax (maximum potential vegetation and stability).

Ecosystem Productivity

The measure of the rate at which new organic matter is generated through photosynthesis, known as primary productivity.
Energy transfer through trophic levels is never 100% efficient, typically about 10% efficiency from one level to the next.
Productivity within the ecosystem is limited by the available sunlight, temperature, nutrient availability, and other physical and chemical conditions.

Features of Aquatic and Terrestrial Ecosystems

Aquatic ecosystems (such as freshwater, estuarine, and marine environments) and terrestrial ecosystems (such as forests, grasslands, and deserts) have unique physical, chemical, and biological characteristics.
Aquatic ecosystems may have more stable conditions but lower sunlight penetration compared to terrestrial systems.
Aquatic systems are classified by salinity, depth, and whether the water is flowing or standing.

Biodiversity within Ecosystems

Biodiversity refers to the variety of animal, plant, and microbial life within an ecosystem.
High biodiversity usually indicates a healthy ecosystem. It creates resilience against changes in the environment.
Biodiversity can be measured at the level of genes, species, and ecosystems or habitats.