AP Environmental Science & Ecology Review

Comprehensive practice flashcards covering conservation biology, island biogeography, ecological tolerance, natural selection, population growth dynamics, and ecological succession.

What is conservation biology?

A field of science that studies threats to biodiversity and develops solutions to protect, restore, and manage it.

Why is ecosystem diversity prioritized if only one level of biodiversity can be focused on?

Because ecosystem diversity supports the other levels of biodiversity.

What is the difference between species richness and species evenness?

Species richness is the number of different species present, whereas species evenness is the relative abundance of each species.

Who developed the theory of Island Biogeography in the 1960s?

Ecologists Robert MacArthur and E.O. Wilson.

According to Island Biogeography, what two main variables determine an island's species richness?

The rate of immigration and the rate of extinction.

What biodiversity characteristics are associated with an island that is small and far from the mainland?

Few new species reach the island, populations are smaller with fewer resources, species richness is lower, and there is a higher risk of local extinction with lost species being less likely to be replaced.

What biodiversity characteristics are associated with an island that is big and close to the mainland?

More species reach the island, there are more resources, space, and habitat types supporting larger populations, species richness is higher, and there is a lower risk of local extinction.

How are island size and island distance applied to conservation design?

Island size informs habitat size (protecting and restoring larger areas), while island distance informs habitat connectivity (building and maintaining habitat corridors to allow migration, recolonization, mating, and gene flow). Effective conservation areas should be both large and connected.

What is the Endangered Species Act?

A U.S. law that protects listed species and the ecosystems upon which they depend.

What is CITES?

The Convention on International Trade in Endangered Species of Wild Fauna and Flora, an international agreement regulating cross-border trade in protected wildlife, plants, and their products.

What is ecological tolerance (fundamental niche)?

The range of conditions, such as temperature, salinity, flow rate, pH, or sunlight, that an organism can endure before injury or death results.

What biological activities occur within an organism's optimal range?

Organisms survive, grow, and reproduce in this preferred niche.

What occurs to an organism in the zone of physiological stress?

Organisms survive but experience stress such as infertility, lack of growth, and decreased activity (marginal niche).

What happens to an organism in the zone of intolerance?

The organism dies from factors such as thermal shock, suffocation, or lack of food, water, or oxygen (unavailable niche).

What is a limiting factor in an ecosystem?

Even if all other factors are optimum, it is the single factor most likely to regulate population growth.

What are key limiting factors for soil and freshwater lakes and rivers?

Nitrogen, phosphorus, and potassium limit soil, while phosphorus limits freshwater lakes and rivers.

What two main observations challenged the pre-1800s belief that species were fixed?

1. Biogeography (the way organisms seemed highly adapted to their environments) and 2. The growing fossil record showing organisms that no longer exist alongside fossils similar to modern organisms.

What was Jean-Baptiste Lamarck's proposed mechanism of species change?

Organisms develop adaptations because they need them and pass down traits acquired during their lifetime to offspring.

What book did Charles Darwin publish in 1859?

On the Origin of Species.

What is the biological definition of evolution?

The change in the genetic make-up of a population over time.

What two mechanisms generate variation in traits within a population?

Sexual reproduction and random mutations.

What are the five steps or components of natural selection?

1. Variation, 2. Overproduction, 3. Competition, 4. Differential Survival and Reproduction, and 5. Heritability.

What is an adaptation?

Any inherited trait that allows an organism to better survive or reproduce (be more fit) in its environment.

What is biotic potential ($r$) and what curve represents it?

The maximum reproduction rate under ideal conditions with unlimited resources, represented by a J-curve (exponential growth).

What is carrying capacity ($K$) and what curve represents it?

The maximum population size an ecosystem can support long-term, represented by an S-curve (logistic growth).

What is population overshoot and what is its consequence?

When a population temporarily grows above its carrying capacity, resulting in severe resource depletion.

What is a population die-off?

A rapid crash caused by famine, disease, or starvation following an overshoot, operating as a negative feedback loop.

What is the lag in a predator-prey cycle?

The delay where the predator population peaks slightly after the prey population peaks.

What is ecological succession?

The gradual process where species composition in a community changes over time following a disturbance.

What conditions and causes characterize primary succession?

It begins on bare rock where no soil is present, is caused by events such as volcanic eruptions or glacial retreats, and takes hundreds to thousands of years.

What are the pioneer species in primary succession and what is their role?

Lichens and mosses, which break down bare rock into soil.

What conditions, causes, and pioneer species characterize secondary succession?

It starts where soil already exists, is caused by disturbances such as forest fires, clear-cutting, or abandoned farmland, takes decades, and features annual weeds and grasses as pioneer species.

How do early successional species and late/climax species differ in light adaptations?

Early species require full direct sunlight to grow, whereas late/climax species (such as oaks and hickories) are shade-tolerant trees that grow under a canopy.