ECOLOGY CHAPTER 1

Ecology

The scientific study of relationships among organisms and between organisms and their physical environment.

Environment

All biotic (living) and abiotic (nonliving) factors that affect an organism.

Abiotic factors

Nonliving components of the environment such as temperature, light, water, and soil chemistry.

Biotic factors

Living components of the environment, including other organisms, predators, competitors, and mutualists.

Biodiversity

The variety of life at all levels of biological organization.

Ecosystem services

Natural processes that support human life, such as clean water, climate regulation, and nutrient cycling.

Individual (Organism)

A single living organism studied in physiological and behavioral ecology.

Physiological ecology

The study of how organisms' physical and chemical processes help them survive environmental conditions.

Behavioral ecology

The study of how behavior contributes to survival and reproduction.

Population

A group of interbreeding individuals of the same species living in a defined area.

Population ecology

The study of factors that affect population size, growth, distribution, and regulation.

Community

An association of interacting species living in the same area.

Community ecology

The study of species interactions and how they affect community structure and coexistence.

Ecosystem

A biological community together with its physical and chemical environment.

Ecosystem ecology

The study of energy flow, nutrient cycling, and decomposition.

Landscape ecology

The study of exchanges of organisms, energy, and materials among ecosystems.

Biosphere

All regions of Earth that support life, including land, water, and atmosphere.

Observational research

Data collection without manipulating variables.

In situ

Research conducted in the natural environment.

Ex situ

Research conducted outside the natural environment, such as in labs or greenhouses.

Niche partitioning

The division of resources or space among species to reduce competition.

Stable isotope analysis

A technique that uses differences in atomic mass to trace nutrient and energy flow.

Experimental research

Research that involves manipulation of variables to test hypotheses.

Treatment

The experimental condition in which a variable is manipulated.

Control

The condition used for comparison where the variable of interest is not manipulated.

Fitness

An organism's ability to survive and reproduce, often measured by offspring or seed set.

Natural selection

The process by which traits that improve fitness become more common over generations.

Modeling

The use of representations to describe, explain, or predict ecological systems.

Conceptual model

A diagram or schematic showing relationships among components of a system.

Quantitative model

A mathematical representation of ecological relationships.

Simulation model

A computer-based model used to predict complex ecological outcomes.

Paleoecology

The study of past ecosystems using preserved biological evidence.

Lake sediment pollen analysis

A method used to reconstruct historical vegetation patterns.

Climate change

Long-term changes in temperature and climate patterns that affect ecosystems.

Evolutionary adaptation

Genetic changes that increase survival or reproduction under new environmental conditions.

Conservation ecology

The application of ecological principles to protect species and ecosystems.

Endangered species

Species at risk of extinction due to low population numbers or environmental threats.

CITES

An international treaty regulating trade in endangered species.

Endangered Species Act (ESA)

A U.S. law protecting threatened and endangered species and their habitats.