Ecosystems, Energy Flow, and Biodiversity Conservation

Ecosystem

Interacting communities of organisms and their environment.

Biotic components

Living elements of an ecosystem.

Abiotic components

Non-living elements of an ecosystem.

Trophic levels

Producers (autotrophs), primary consumers, secondary consumers, tertiary consumers, and decomposers.

Gross Primary Production (GPP)

Total energy produced by autotrophs.

Net Primary Production (NPP)

Energy remaining after respiration, used for growth and reproduction.

Energy transfer efficiency

Approximately 10% of energy is transferred between trophic levels; the rest is lost as heat.

Ecological pyramids

Types include energy, biomass, and numbers.

Carbon cycle

Involves photosynthesis, respiration, fossil fuel combustion, and climate change.

Nitrogen cycle

Includes nitrogen fixation, nitrification, denitrification, and the role of bacteria.

Water cycle

Consists of evaporation, condensation, precipitation, and human impacts.

Carrying capacity (K)

Maximum sustainable population size.

Exponential growth

Characterized by a 'J-curve,' indicating unlimited resources.

Logistic growth

Characterized by an 'S-curve,' indicating limited resources and stabilizing at carrying capacity.

Density-dependent factors

Factors that affect population size based on population density, such as resource availability and predation.

Density-independent factors

Factors that affect population size regardless of population density, such as climate events and natural disasters.

Demographic transition model

Describes stages of birth and death rate changes with development.

Age structure diagrams

Visual representations of population age distributions, indicating expanding, stable, and declining populations.

Point source pollution

Pollution from a single identifiable source, such as factory discharge.

Nonpoint source pollution

Pollution from diffuse sources, such as agricultural runoff.

Eutrophication

Process where excess nutrients lead to algal blooms, oxygen depletion, and harm to aquatic life.

Bioaccumulation

The accumulation of toxins in an organism from its environment.

Biomagnification

The increase in toxin concentration at each trophic level.

Soil degradation

Caused by erosion, overgrazing, and deforestation.

Desertification

Land degradation in arid areas, such as Sub-Saharan Africa.

In-situ conservation

Protection of species in their natural habitat, such as national parks.

Ex-situ conservation

Protection of species in controlled settings, such as zoos and botanical gardens.

Endangered Species Act

Legislation that protects threatened and endangered species in the U.S.

CITES

Convention on International Trade in Endangered Species.

Sustainable agriculture

Farming practices that avoid degradation and conserve resources.

Restoration ecology

Efforts to repair and restore ecosystems, such as reforestation.