t2 lec1

What are the three levels of ecosystem organisation described in the lecture?

Individual, Population, Community.

What is an individual-level process essential for producing more animals?

Individual survival and fitness.

What key biological processes occur at the individual level?

Growth, metabolism, activity, thermoregulation, reproduction.

How is a population different from a species?

A population ≠ a species (they are not the same).

What is a community?

An assemblage: a collection of interacting populations in the same geographic area

What is carrying capacity?

The amount of resources available in a habitat that limits population size.

What are density-independent population controls?

Stressors that affect individuals regardless of population size (e.g., flooding, volcanic eruption).

What are density-dependent population controls?

Predation, parasitism, disease, and competition.

What is dispersal?

Departure, travel, and settlement.

What is migration?

Regular and directional movement between two locations.

What are benefits of dispersal/migration?

Finding resources, better conditions, reducing competition, avoiding inbreeding depression.

What are costs of dispersal/migration?

Energy cost, increased predation risk, lack of settlement.

What is competition?

Negative effects when one organism consumes or controls access to a limited resource

When two populations rely on one resource, what are the two possible outcomes?

Coexistence (ecological differentiation) or elimination (one species outcompetes the other)

What traits describe good competitors?

Broad distributions, abundant, influence distribution of other species, success based on traits and stress/disturbance trade-off.

What are the results of competition for dominant vs subordinate species?

Dominant = preferred conditions; subordinate = suboptimal conditions.

What is the fundamental niche?

The set of resources under which organisms could survive.

What is the realised niche?

The set of conditions under which organisms actually survive.

What type of relationship exists between corals and zooxanthellae?

Mutualism/symbiosis.

What ecosystem services do coral reefs provide?

Habitat for fisheries, tourism & culture, coastal protection, climate regulation, medicine/drug discovery, biodiversity.

How much of the ocean floor do coral reefs cover, and what proportion of marine species do they support?

<1% of the ocean floor; ~25% of all known marine species.

What are major stressors leading to coral bleaching?

Sea surface temperature increases, prey overabundance (anoxia), silt deposition (anoxia), increased solar irradiance, CO₂ emissions/climate change, ozone depletion, deforestation, overfishing.

What is noted about coral evolution in relation to environmental change?

Coral radiations and extinctions correspond to rapid, cataclysmic environmental changes; current extinction risk is high ("Next extinction? – NOW").

How much of the ocean is effectively protected, and what challenges remain?

9.6% protected; 2.8% effectively protected; 1% fully “no take.” Main driver of bleaching is climate change.