Ecology and Human Impact Study Guide - Vocabulary Flashcards

Vocabulary flashcards covering key ecology concepts from the notes.

Carbon Cycle

The circulation of carbon among the atmosphere, oceans, soil, and living organisms, driven by processes such as photosynthesis, respiration, decomposition, and combustion.

Cellular respiration

Metabolic process by which organisms convert glucose and oxygen into usable energy (ATP), releasing carbon dioxide.

Denitrification

Microbial process that converts nitrates into nitrogen gas, returning nitrogen to the atmosphere.

Volcanic activity

Natural source that releases carbon dioxide into the atmosphere.

Decomposition

Breakdown of dead material and wastes, recycling carbon and nutrients back to soil and air.

Burning fossil fuels

Combustion of coal, oil, and natural gas that releases CO2 and other pollutants.

Photosynthesis

Process by which producers convert light energy, CO2, and water into glucose, removing CO2 from the atmosphere.

Nitrogen cycle

Movement of nitrogen through air, soil, water, and organisms; includes fixation, uptake, ammonification, nitrification, and denitrification.

Nitrogen fixation

Conversion of nitrogen gas (N2) into ammonia or nitrates, primarily by bacteria or lightning.

Nitrates

Form of nitrogen usable by plants, taken up from soil or water.

Phosphorus cycle

Movement of phosphorus through rocks, soil, water, and organisms; has no significant atmospheric phase.

Weathering

Breakdown of rocks that releases phosphorus (as phosphate) into soil and water.

Biotic

Living components of an ecosystem (plants, animals, microbes).

Abiotic

Nonliving components of an ecosystem (air, water, minerals, climate).

Carbon sink

Reservoir that absorbs more carbon than it releases (e.g., forests, oceans).

Carbon source

Reservoir that releases more carbon than it absorbs (e.g., burning fossil fuels, high respiration).

Decomposers

Bacteria and fungi that break down dead matter, recycling nutrients.

Trophic levels

Positions in a food chain/web based on feeding relationships (producers, primary/secondary/tertiary consumers, decomposers).

Producers

Organisms that synthesize organic matter from light (plants) or chemical energy.

Primary consumers

Herbivores that eat producers.

Secondary consumers

Organisms that eat primary consumers (carnivores/omnivores).

Tertiary consumers

Top predators that eat secondary consumers.

Energy pyramid

Diagram showing energy transfer between trophic levels; about 10% of energy is transferred to the next level; rest is lost as heat.

Biomass pyramid

Diagram showing the mass of living matter at each trophic level, usually decreasing up the chain.

10% rule

Approximately 10% of energy is transferred to the next trophic level; the remainder is used for life processes or lost as heat.

Food web

Network of interconnected food chains showing who eats whom; energy flows through the network.

Predator-prey

Ecological relationship in which a predator hunts prey; affects population sizes.

Niche

The role or job of a species in its ecosystem, including resource use and interactions.

Biodiversity

The variety of life in an ecosystem; higher when different niches are occupied by diverse species.

Competition

When two or more organisms attempt to use the same limited resource.

Carrying capacity

Maximum population size an environment can sustain indefinitely given resources.

Exponential growth

Rapid population growth when resources are abundant (J-shaped curve).

Logical growth

Growth that levels off as resources become limiting (S-shaped curve); approaches carrying capacity.

Renewable resource

Resource that can be replenished naturally in a short time (e.g., solar, wind).

Nonrenewable resource

Resource that cannot be replenished on a human timescale (e.g., fossil fuels, minerals).

Global warming

Long-term increase in Earth's average surface temperature due to greenhouse gas emissions.

Ozone depletion

Thinning of the ozone layer caused by chemicals like CFCs, increasing UV exposure.

Bioaccumulation

Buildup of substances (e.g., pesticides) in an organism over time, often increasing up the food chain.

Eutrophication

Nutrient over-enrichment (N and P) leading to algal blooms and oxygen depletion in water bodies.

DDT

Pesticide that bioaccumulates and harms wildlife, especially top predators.

Deforestation

Removal of forests leading to habitat loss and decreased biodiversity.

Invasive species

Non-native species that disrupts ecosystems by outcompeting native species.

Population growth

Increase in the number of individuals in a population over time.

Urbanization

Expansion of urban areas; can fragment habitats and alter ecosystems.

Crop rotation

Agricultural practice of alternating crops to maintain soil fertility and reduce pests.

Stricter laws

Policies implemented to protect ecosystems and reduce pollution.