Key Concepts in Ecology and Ecosystem Dynamics

Ecology

The study of interactions of organisms with each other and their physical surroundings

Ecosystem

Physical area with biotic and abiotic factors.

Biosphere

Earth's part where life exists.

Communities

Collective terms for all species living in one ecosystem

Niche

Organism's role in its ecosystem.

Climate

Average year-to-year atmospheric conditions.

Weather

Day-to-day atmospheric conditions.

Producers

Organisms that capture energy from sunlight.

Primary Consumers

Organisms that feed on producers.

Secondary Consumers

Organisms that feed on primary consumers.

Tertiary Consumers

Organisms that feed on secondary consumers.

Decomposers

Organisms that break down dead matter.

Food Chain

Linear sequence of energy transfer.

Food Web

Interconnected food chains in an ecosystem.

Pyramid of Biomass

Illustrates biomass at different trophic levels.

Rule of Energy Flow

Only 10% of energy is transferred upward.

Herbivores

Animals that eat plants.

Carnivores

Animals that eat other animals.

Omnivores

Animals that eat both plants and animals.

Detritivores

Organisms that consume dead organic matter.

Keystone Species

Species that significantly impacts ecosystem structure.

Greenhouse Effect

Gases trap heat in Earth's atmosphere.

Heat Transport

Movement of heat influences climate and weather.

Energy Flow

Energy moves through ecosystems but is not recycled.

Trophic Level

Position in a food chain or web.

Energy Transfer

Energy movement between trophic levels.

Biomagnification

Increase of toxin concentration in food chains.

Primary Succession

Community development in lifeless areas.

Secondary Succession

Community replacement after disturbance.

Pioneer Species

First organisms to colonize barren environments.

Climax Community

Stable, mature ecological community.

Nutrient Limitation

Insufficient nutrients restrict ecosystem productivity.

Limiting Nutrients

Nutrients that limit primary productivity rates.

Primary Productivity

Rate of organic matter creation by producers.

Algal Blooms

Rapid algae growth from nutrient excess.

Tundra Biome

Cold, treeless region with permafrost.

Chaparral Biome

Vegetation adapted to periodic fire.

Volcanic Islands

Islands formed from volcanic activity, e.g., Galapagos.

Northernmost Ecosystems

Ecosystems located in Arctic regions.

Organic Matter

Carbon-based compounds produced by living organisms.

Permafrost

Frozen soil layer limiting plant growth.

Seasonal Changes

Variations in climate affecting ecosystem dynamics.

Pond Succession

Pond evolving into marsh and solid land.

Lichens

Pioneer species that colonize bare rock.

Temperate Deciduous Forest

Located in the Midwest US, south of tundra.

Black Bears

Large mammals found in temperate forests.

Moose

Large herbivores native to northern forests.

Temperate Grasslands

Can experience hot or cold climates.

Sahara Desert

Largest desert in the world, less than 25 cm rain.

Savanna

Tropical grasslands with warm temperatures year-round.

Tropical Rain Forests

High biodiversity with nutrient-poor soils.

Aquatic Biomes

Include freshwater and marine ecosystems.

Freshwater Biomes

Comprise rivers, streams, and lakes.

Marine Biomes

Cover most of Earth's surface with saltwater.

Photic Zone

Layer where sunlight penetrates, allowing photosynthesis.

Aphotic Zone

Depth where no light penetrates, no photosynthesis.

Neritic Zone

Coastal ocean area from low tide to open sea.

Coral Reefs

Require warm, shallow, salty waters for growth.

Estuaries

Nutrient-rich areas where freshwater meets saltwater.

Water Cycle

Process of water evaporating, condensing, and precipitating.

Nitrogen Cycle

Cycle of nitrogen through ecosystems via various processes.

Limiting Factors

Nutrients that restrict growth in ecosystems.

Mangrove Swamps

Tropical wetlands dominated by salt-tolerant trees.

Salt Marshes

Temperate wetlands with salt-tolerant grasses.

Deep Sea Zone

Cold, high-pressure area with no sunlight.

Benthic Zone

Lowest layer of aquatic ecosystems, often nutrient-rich.

Grazing

Prevents succession in grassland and forest biomes.

Nitrification

Conversion of ammonia to nitrates (NO3).

Nitrogen Fixation

Process of converting N2 into usable nitrogen forms.

Ammonification

Decomposition of organic nitrogen into ammonium (NH4).

Eutrophication

Excess nutrient enrichment in water bodies.

Denitrifying Bacteria

Convert nitrates back to nitrogen gas (N2).

Mutualism

Symbiotic relationship where both species benefit.

Commensalism

One species benefits, the other is unaffected.

Parasitism

One species benefits at the expense of another.

Exponential Growth

Population growth in ideal conditions, J-shaped curve.

Logistic Growth

Population growth limited by environmental factors.

Carrying Capacity

Maximum population size environment can support.

Density-Dependent Factors

Population size limits based on population density.

Density-Independent Factors

Population size limits unrelated to population density.

Biogeochemical Cycles

Processes recycling nutrients through ecosystems.

Photosynthesis

Process converting light energy into chemical energy.

Respiration

Process of breaking down glucose for energy.

Decomposition

Breakdown of dead organisms by bacteria and fungi.

Symbiotic Relationships

Interactions between different species in an ecosystem.

Community Interactions

Constant interactions among organisms in an ecosystem.

Population Density

Number of individuals per unit area.

Human Activities

Actions like mining and deforestation affecting ecosystems.

Biological Processes

Natural processes like photosynthesis and respiration.