Community Ecology and Population Dynamics

Vocabulary practice flashcards covering fundamental ecological concepts, community interactions, forms of succession, biodiversity levels, and population limiting factors from handwritten lecture notes.

Keystone species

Species that exert strong control on their community due to their ecological roles or niches, having a disproportionate effect on their ecosystems; if removed, the ecosystem will collapse.

Trophic cascades

Powerful indirect interactions that can control entire ecosystems, occurring when predators limit the density and/or the behavior of prey, thereby enhancing the survival of the next trophic level.

Disturbance

An event that changes resource availability and/or results in physical changes to the environment, such as fires, hurricanes, floods, storms, or volcanic eruptions.

Ecological succession

A series of relatively predictable events that occur in a community over time during its recovery.

Primary succession

Ecological succession that begins on newly formed rock (such as after a volcanic eruption) or in areas that have no remnants of an older community.

Pioneer species

The first species to colonize barren areas during ecological succession.

Secondary succession

Ecological succession that occurs when an existing community is not completely destroyed (such as after a wildfire); it occurs much faster than primary succession because existing soil remains.

Interspecific interactions

Interactions that occur between populations of different species and may help, harm, or have no effect on the species involved, including competition, predation, herbivory, and symbiosis.

Commensalism

A symbiotic relationship in which one organism benefits while the other is unaffected, such as hermit crabs utilizing discarded, empty snail shells for physical protection of their soft abdomen.

Mutualism

A symbiotic relationship in which both species benefit, such as oxpeckers eating ticks and blood-sucking parasites off mammals like rhinos, zebras, and giraffes while alerting them to approaching danger with loud noises.

Parasitism

A symbiotic relationship in which one organism feeds on another and causes harm, such as ticks and fleas latching onto the skin of animals (dogs, cats, deer) to consume blood and potentially transmit diseases like Lyme disease.

Predator adaptations

Specialized traits that assist predators in capturing and consuming prey, including claws, fangs, and venom.

Prey adaptations

Specialized defensive traits and behaviors that help prey avoid predation, including hiding, forming herds, alarm calls, claws, and camouflage.

Limiting factors

Scarce environmental resources that cause population growth to slow or stop as competition increases within a growing population.

Density-dependent factors

Biotic limiting factors whose effects on a population depend on and intensify with increased population density.

Density-independent factors

Abiotic limiting factors that affect a population regardless of its population density, such as natural disasters (fires, hurricanes, floods, temperature changes, and nutrient availability).

Genetic diversity

Heritable variation within the gene pool of a population or community.

Species diversity

The variety of different organisms that comprise an ecological community.

Ecosystem diversity

The variety of different habitats, biological communities, and ecological processes within an ecosystem, reflecting variation throughout its biotic and abiotic factors and conferring resilience to environmental disturbances.

Competitive exclusion principle

The ecological principle stating that two species competing for the exact same limited resource cannot stably coexist in the exact same place.