Ecology Concepts from Video Notes CH 54-55

Vocabulary flashcards covering disturbances, cycles, energy flow, interactions, and production from the lecture notes.

Disturbance

An event (e.g., flood, drought, storm, human activity) that disrupts an ecosystem, changing resources and community structure; effects on diversity depend on disturbance level.

Intermediate disturbance hypothesis

Idea that moderate disturbances can maximize species diversity by preventing competitive exclusion and creating new niches.

Primary succession

Succession that begins in an area with no soil or life, such as bare rock.

Secondary succession

Succession that follows a disturbance in an area where soil remains and a community can be reestablished.

Evapotranspiration

Evaporation from soil and transpiration from plants; deforestation can reduce these rates by removing vegetation.

White-band disease

Coral disease causing tissue to slough from base to tip, reducing coral habitat for other marine species.

Zoonotic diseases

Diseases that are transferred from animals to humans.

Vector

An organism (e.g., ticks, lice, mosquitoes) that transmits pathogens between hosts.

First law of thermodynamics (ecology context)

Energy cannot be created or destroyed; it can only be transformed or transferred (e.g., plants convert solar energy to chemical energy).

Carbon cycle

Movement of carbon through the atmosphere, living organisms, soils, and oceans; photosynthesis reduces CO2, respiration and combustion release CO2.

Photosynthesis

Process by which autotrophs convert light energy into chemical energy (organic molecules).

Cellular respiration

Process by which cells break down organic molecules to release usable energy (ATP) and CO2.

Nitrogen cycle

Movement of nitrogen through the atmosphere, soil, and organisms; essential for amino acids and nucleic acids; includes fixation, assimilation, nitrification, and dentrification.

Nitrogen fixation

Conversion of N2 gas into usable forms (e.g., ammonia, nitrate) by bacteria or certain natural processes.

Phosphorus cycle

Movement of phosphorus through rocks, soils, water, and organisms; essential for nucleic acids, phospholipids, and ATP; no atmospheric phase.

Biological magnification

Build-up of harmful substances in higher trophic levels through the food chain.

Detritivores

Organisms that feed on detritus (dead organic matter), helping recycle nutrients.

Decomposers

Organisms (e.g., bacteria, fungi) that break down dead matter and waste, returning nutrients to the ecosystem.

Gross primary production (GPP)

Total amount of chemical energy produced by photosynthesis in an area.

Net primary production (NPP)

GPP minus autotrophic respiration (Ra); the energy stored as biomass.

Limiting nutrients

Nutrients that limit primary production; commonly nitrogen and phosphorus.

Algal blooms

Rapid increases in algae in aquatic systems, often fueled by excess nutrients (e.g., nitrogen).

Eutrophication

Nutrient enrichment of water bodies leading to excessive plant/algal growth and oxygen depletion, harming aquatic life.

Secondary production

Biomass generation of heterotrophs (primary consumers) through consumption of primary producers.

Water cycle

Cycle of evaporation, condensation, precipitation, transpiration, and surface/groundwater flows.

Mutualism

+/+ interactions where both species benefit and reproductive success increases for both.

Predation

+/- interaction where the predator benefits and the prey is harmed.

Competition

-/- interaction where two or more species compete for a shared resource, limiting survival and reproduction.

Commensalism

+/0 interactions where one species benefits and the other is largely unaffected.

Ecological niche

The role and position a species has in its environment, including the resources it uses and its interactions.

Competitive exclusion

If two species occupy the same niche, one will outcompete and exclude the other from that niche.