Ecology Lecture Notes

Flashcards generated from lecture notes on ecology, covering topics from species diversity to ecosystem dynamics.

What factors determine species diversity?

Richness and evenness.

How are richness and evenness defined?

Richness is the number of species; evenness is the distribution of individuals among species.

What is the purpose of a rank-abundance curve?

To visualize species richness and evenness.

What does the Chao1 index estimate?

Species richness, accounting for rare species.

What level of diversity does alpha diversity measure?

Diversity within a single habitat.

What does beta diversity quantify?

The difference in species diversity between habitats.

What scope of diversity does gamma diversity measure?

Overall diversity for a region.

What does Jaccard’s index measure?

Similarity between two communities based on shared species.

What is functional diversity?

The range of functional traits of species in a community.

What kind of relationships does phylogenetic diversity measure?

Evolutionary relationships between species.

What theory is described by the ideal free distribution?

How organisms distribute themselves among habitats to maximize fitness.

What is the nature of a metapopulation?

Spatially separated populations connected by migration.

What dynamics does the Levins metapopulation model describe?

Metapopulation dynamics based on colonization and extinction rates.

What process is described by source-sink dynamics?

Movement from high-quality (sources) to low-quality (sinks) habitats.

What ecological process is habitat fragmentation?

The division of large habitats into smaller patches.

What is the function of ecological corridors?

To connect fragmented habitats for species movement.

What does the equilibrium theory of island biogeography predict?

Species richness based on island size and distance.

What effect does intermediate disturbance have on species diversity?

It increases species diversity.

What type of succession occurs on newly exposed surfaces?

Primary succession.

Where does secondary succession occur?

In damaged ecosystems where soil remains.

What is the role of pioneer species?

To colonize disturbed areas.

What characterizes climax species?

They dominate at the final stage of succession.

What is a seral stage in ecological succession?

An intermediate stage found in ecological succession

What effect do disturbances have on ecosystems?

They alter structure, diversity, and resource availability.

What is defined as community stability?

The ability of a community to maintain structure and function over time.

What is community resilience?

The speed at which a community returns to its original state after disturbance.

What is community resistance?

The ability of a community to withstand disturbance without changing.

What does Net Primary Production (NPP) measure?

Carbon uptake after subtracting plant respiration from gross primary production.

What is net secondary production?

The energy accumulated in consumer biomass.

What do biomass and energy pyramids illustrate?

The distribution of biomass or energy among trophic levels.

What is ecological efficiency?

The percentage of energy transferred between trophic levels.

What part of available energy is consumed by organisms, according to consumption efficiency?

The proportion of available energy consumed by organisms.

What does assimilation efficiency measure?

The proportion of ingested energy that is assimilated.

What efficiency is defined by the ratio of biomass produced to assimilated energy?

Net production efficiency.

What is biomass residence time?

The average time biomass remains in a trophic level.

What is the hydrologic cycle?

The movement of water through the atmosphere, hydrosphere, and biosphere.

What does the carbon cycle describe?

The circulation of carbon between the atmosphere, oceans, and living organisms.

What is moving in the nitrogen cycle?

Nitrogen moving between the atmosphere, soil, and living organisms.

What is cycled in the phosphorus cycle?

The movement of phosphorus through rocks, water, and living organisms.

How does human activity influence the carbon cycle?

Burning fossil fuels increases atmospheric CO₂.

What characterizes the Anthropocene?

Significant human impact on Earth’s geology and ecosystems.

What was restored by wolf reintroduction in Yellowstone?

Ecosystem balance.

What do prawn reintroductions control?

Populations of snail hosts for parasites.

How were black-footed ferrets saved?

Through captive breeding and reintroduction efforts.

What is bottom-up control in ecosystems?

When nutrient availability determines the structure of an ecosystem.

What is top-down control?

When predators regulate the abundance of lower trophic levels.

What kind of interactions are present with direct effects?

Direct interactions between two species, like predation or competition.

What interactions occur with indirect effects?

Interactions mediated through one or more intermediary species.

What models describe trophic relationships?

Food chains and food webs.

What is the latitudinal gradient of species richness?

Species richness typically decreases from the equator to the poles.