Ecology and Species Classification: Key Concepts and Tools

Ecology

The study of interactions between organisms and their environment.

Biome

A large geographical area with a characteristic climate, flora, and fauna.

Biosphere

The global sum of all ecosystems; all life on Earth and the environments they inhabit.

Ecosystem

A community of organisms interacting with each other and with their physical environment.

Community

All the different populations living and interacting in a specific area.

Population

A group of individuals of the same species living in the same area.

Individual

A single organism.

Species

A group of organisms that can interbreed and produce fertile offspring.

Binomial Nomenclature

The two-part scientific naming system using genus and species.

Dichotomous Key

A tool that helps identify organisms using a series of paired, opposite statements.

Genus

A taxonomic group containing one or more species that are closely related.

Organism

Any living thing.

Morphological Species

A species defined by physical characteristics (appearance/form).

Genetic Species

A species defined by genetic similarity and DNA analysis.

Ecological Species

A species defined by its ecological niche and role in the environment.

Taxonomy

The science of naming, classifying, and organizing organisms.

Classification of Species

The arrangement of species into groups based on shared characteristics.

DNA Surveys

Methods that analyze DNA to identify species present in an environment.

Biotic

Living components of an ecosystem.

Abiotic

Non-living physical and chemical components of an ecosystem.

Biotic Features of the Environment

Living factors such as plants, animals, fungi, and bacteria.

Abiotic Features of the Environment

Non-living factors such as temperature, light, soil, pH, and water.

Secchi Disk or Turbidity Tube

Tools used to measure water clarity (turbidity).

Light Meter or Lux Meter

Device used to measure light intensity.

Digital Thermometer or Temperature Probe

Instrument used to measure temperature accurately.

PH Probe or PH Test Kit

Tools used to measure acidity or alkalinity.

Soil Sieve Set or Sedimentation Test

Methods used to separate and analyze soil particle sizes.

Soil Moisture Probe or Gravimetric Method

Methods to measure soil moisture content.

PH

A measure of acidity or alkalinity (0-14).

Dissolved Oxygen

Amount of oxygen available in water for organisms.

Wave Action

Impact of waves on aquatic environments.

Turbidity

Cloudiness of water caused by suspended particles.

Salinity

Concentration of salt in water or soil.

Flow Velocity

Speed at which water flows in a river or stream.

Organic Content

Amount of decomposed organic material in soil or water.

Nitrates

Plant nutrients; high levels may indicate pollution.

Parasites

Organisms that live on or in a host and harm it.

Ecological Niche

An organism's role and interactions within its ecosystem.

Predation

A predator hunts and eats prey.

Herbivory

Animals feeding on plants.

Symbiosis

A close, long-term relationship between two species.

Mutualism

Both species benefit.

Commensalism

One benefits, the other is unaffected.

Parasitism

One benefits at the expense of the other.

Competition

Organisms compete for the same limited resources.

Intraspecific Competition

Competition within the same species.

Interspecific Competition

Competition between different species.

Competitive Exclusion Principle

No two species can occupy the same niche indefinitely.

Density Dependent Factors

Factors that intensify as population density increases.

Density Independent Factors

Factors that affect populations regardless of density.

Density Dependent Control

Regulation driven by density-dependent factors.

Density Independent Control

Regulation driven by non-density-dependent factors.

Limiting Factors

Factors that restrict population growth.

Carrying Capacity

The maximum population size an environment can support.

J-Shape Curve

Exponential population growth pattern.

S-Shape Curve

Logistic growth pattern leveling at carrying capacity.

Sampling Strategies

Methods for collecting data from a population.

Random Sampling

Every individual has an equal chance of being selected.

Systematic Sampling

Samples taken at regular intervals.

Transect Sampling

Sampling along a straight line to observe changes.

Motile Organisms

Organisms capable of movement.

Capture-Mark-Release-Recapture

Method to estimate population size.

Lincoln Index Formula

(N1 × N2) ÷ M2.

Pitfall Trap

Container used to trap small ground organisms.

Sweep Net

Net used to capture insects in vegetation.

Tree Beating

Shaking branches to collect falling organisms.

Tullgren Funnel

Device extracting organisms from soil or litter using heat.

Kick Sampling

Collecting aquatic organisms by disturbing substrate.

Camera Traps

Motion-triggered cameras to monitor wildlife.

Habitat

The natural environment where an organism lives.

Biomass

Total mass of living organisms in an area.

Keystone Species

A species with a disproportionately large effect on its ecosystem.

Tipping Point

A threshold where small changes cause major, irreversible shifts.