Population and Community Ecology Overview

Population

Group of individuals of the same species.

Distribution

Area over which a population occurs.

Geographic Range

Total area inhabited by a species.

Abundance

Number of individuals in a population.

Population Density

Number of individuals per unit area.

Population Dispersion

Spacing of individuals relative to each other.

Random Dispersion

Individuals' positions are independent of each other.

Clumped Dispersion

Individuals occur in groups or patches.

Uniform Dispersion

Individuals are evenly spaced throughout the area.

Sampling Methods

Techniques to estimate population density.

Ecological System

Environment where populations interact.

Local Distribution

Specific area where a population is found.

Environmental Factors

Conditions affecting population distribution.

Intraspecific Competition

Competition among individuals of the same species.

Territoriality

Behavior to defend a specific area.

Habitat

Natural environment where a species lives.

Estimation Variability

Density estimates can vary based on sampling.

Grid Sampling

Counting individuals within defined grid cells.

Winter Temperature Limit

Northern limit for red maple at -40°C.

Rainfall Limit

Western limit for red maple due to low rainfall.

Standing Water Requirement

Necessary habitat for pond cypress trees.

Social Groups

Groups formed by species for survival.

Colonial Nesting Birds

Birds nesting close to reduce stress.

Chihuahuan Desert

A desert region in West Texas.

Clumped Dispersion

Population distribution where individuals are grouped together.

Mean Density

Average number of individuals per unit area.

Population Abundance

Total number of individuals in a population.

Endangered Species

A species at risk of extinction.

Acacia Trees

Trees providing habitat for certain plant species.

Uniform Dispersion

Evenly spaced distribution of individuals in an area.

Population Growth

Change in number of individuals over time.

Exponential Growth

Rapid population increase under ideal conditions.

Logistic Growth

Population growth that slows as resources become scarce.

Carrying Capacity (K)

Maximum population size an environment can sustain.

Growth Rate (r)

Rate of increase or decrease in population size.

Population Size (N)

Total number of individuals in a population.

K-strategists

Organisms adapted to stable environments with low reproduction.

R-strategists

Organisms adapted to unstable environments with high reproduction.

Life History Traits

Characteristics influencing reproductive strategies and survival.

Meta-population

Network of interacting local populations within a larger area.

Recolonization

Process of population re-establishment after extinction.

Local Extinction

Disappearance of a population from a specific area.

Habitat Patches

Isolated areas of suitable habitat within a landscape.

Poor Competitors

Species that struggle against others for resources.

Super Tramps

Another term for r-strategists, emphasizing dispersal ability.

Stable Population Size

Population size that remains consistent over time.

Unsuitable habitat

Ecosystem area lacking necessary conditions for species.

Low quality habitat

Area with reduced resources affecting population health.

Source population

Stable population providing individuals to sink populations.

Sink population

Population at risk due to low habitat quality.

Rescue effect

Process where source populations replenish sink populations.

Meta-population

Group of populations connected by dispersal.

Conservation

Efforts to protect endangered species and habitats.

Attwater's Prairie Chicken

Endangered bird reliant on captive breeding for survival.

Coastal tall-grass prairie

Ecosystem historically home to Attwater's Prairie Chicken.

Species diversity

Measure of species variety and abundance in a community.

Species richness

Count of different species in a community.

Tropical rainforest

Ecosystem known for exceptionally high species richness.

E. O. Wilson

Biologist known for ant species research and biodiversity.

Coral species

Diverse marine organisms, vital for reef ecosystems.

Great Barrier Reef

Home to 321 known coral species in Australia.

Biodiversity

Variety of life forms in a given ecosystem.

Human activity

Actions impacting ecosystems and biodiversity negatively.

Extinction

Permanent loss of a species from the ecosystem.

Ecological phenomenon

Natural events affecting species and habitat interactions.

Community ecology

Study of interactions among species in a community.

Taxonomic subset

Specific group of organisms within a larger classification.

Species count

Total number of species identified in a study.

Regional droughts

Extended dry periods affecting local ecosystems and species.

Prairie fires

Natural events that can reset ecosystem dynamics.

Temperate Ecosystems

Regions with moderate climates, including grasslands and deserts.

Species Richness

Total number of different species in an ecosystem.

Konza Prairie

Biological station with 480 vascular plant species.

Ontario Prairie Preserve

Site with 493 beetle species discovered.

North American Arctic

Home to 1100 vascular plant species.

Ecosystem Stability

High species richness leads to greater ecosystem resilience.

Relative Abundance

Percentage contribution of each species to total species.

Species Evenness

Equitable distribution of individuals among species.

Dominant Species

Species with higher abundance in a community.

Keystone Species

Species with disproportionate impact on community stability.

Competitive Exclusion Principle

Complete competitors cannot coexist in the same niche.

Interspecific Competition

Competition among individuals of different species.

Gause's Law

Proposed by Georgy Gause regarding competitive exclusion.

Carrying Capacity

Maximum population size an environment can sustain.

Ecological Requirements

Conditions necessary for a species' survival.

Community Attributes

Characteristics defining interactions and species composition.

Species Interactions

Relationships between species competing for resources.

Hypothetical Species Interaction

Example of competitive outcomes between two species.

Community A

Uneven relative abundance; 85% grass, 5% wildflowers.

Community B

Even relative abundance; 25% for all species.

Research Significance

Understanding species diversity helps assess ecosystem health.

Disturbance Resilience

Ability of an ecosystem to recover from disruptions.

P. aurelia

A species that outcompetes P. caudatum.

P. caudatum

A species that declines to extinction when competing.

Resource partitioning

Similar species utilize resources differently to coexist.

Interspecific competition

Competition between different species for resources.

Niches

Non-overlapping roles species occupy in an ecosystem.

Physical structure

Spatial distribution of populations creating community features.

Vertical structure

Layering of plant species in forest communities.

Zonation

Distribution of species based on environmental gradients.