Ecology and Climate Change Practice Flashcards

Flashcards covering population ecology metrics, community interactions, energy flow, and the mechanisms of climate change.

Population

A group of individuals of the same species living in the same area and capable of interacting and reproducing.

Population Density

The number of individuals per unit area, represented by the formula $D = \text{Population size} / \text{Area}$.

Clumped Dispersion

A spacing pattern where individuals occur in groups due to patchy resources, suitable habitat, or social behavior.

Uniform Dispersion

A spacing pattern where individuals are evenly spaced, often caused by territoriality or competition.

Random Dispersion

A spacing pattern with no predictable pattern, occurring when resources are evenly distributed and individuals neither attract nor repel each other.

BIDE Model Formula

$1N = (B + I) - (D + E)$ where population size changes through births, immigration, deaths, and emigration.

Instantaneous Rate of Increase ($r$)

A measure where $r > 0$ indicates population growth, $r = 0$ indicates a stable population, and $r < 0$ indicates a population decline.

Exponential Growth

Population growth under ideal conditions with unlimited resources, characterized by a J-shaped curve and the formula $\frac{dN}{dt} = rN$.

Logistic Growth

Population growth that slows as the population approaches carrying capacity ($K$), characterized by an S-shaped curve and the formula $\frac{dN}{dt} = rN\left(\frac{K-N}{K}\right)$.

Carrying Capacity ($K$)

The maximum sustainable population size that is determined by available resources.

Density Dependent Factors

Factors whose effects become stronger as population density increases, such as disease, competition, and predation.

Density Independent Factors

Factors that affect populations regardless of their size, such as hurricanes, floods, droughts, and wildfires.

r-Selected Species

Species that maximize reproduction by having many offspring, small body size, and little parental care; they typically exhibit Type III survivorship.

K-Selected Species

Species that compete near carrying capacity, characterized by few offspring, high parental care, and large body size; they typically exhibit Type I survivorship.

Type I Survivorship Curve

A curve showing high survival early in life with a sharp decline later, common in humans and elephants.

Type II Survivorship Curve

A curve representing constant mortality throughout life, shown as a straight diagonal line on a graph.

Type III Survivorship Curve

A curve where many individuals die young and few survive to adulthood, common in fish, oysters, and plants.

Community

All populations of different species living and interacting in an area.

Abiotic Factors

Non-living physical and chemical components of the environment, such as temperature, water availability, pH, and light.

Biotic Factors

Living components of the environment, including food, predators, competitors, and parasites.

Niche

The role of a species in its ecosystem, including its abiotic and biotic requirements and its effects on other organisms.

Fundamental Niche

The full potential range of habitats a species could occupy if there were no competition or other restrictions.

Realized Niche

The range of habitats a species actually occupies, which is usually smaller than the fundamental niche due to biological interactions like competition.

Competitive Exclusion

An interaction where one species outcompetes another for resources, leading to the local elimination or extinction of the less competitive species.

Niche Partitioning

The division of resources by species to reduce competition, allowing them to coexist.

Character Displacement

An evolutionary process where species living in sympatry evolve differences in traits, such as beak size, to reduce competition.

Mutualism

An interaction where both species benefit ($+ / +$) and the benefits of the relationship outweigh the costs.

Commensalism

An interaction where one species benefits while the other is unaffected ($+ / 0$).

Amensalism

An interaction where one species is harmed while the other is unaffected ($- / 0$), such as a boar trampling on grass.

Obligate Mutualism

A relationship where species cannot survive without each other, such as Coral and Zooxanthellae.

Trophic Cascade

A phenomenon where changes at one trophic level, such as the addition or removal of a predator, affect multiple other levels.

Keystone Species

A species that has a disproportionately large impact on its ecosystem relative to its abundance, helping to maintain biodiversity.

Second Law of Thermodynamics

The principle that energy transfers are inefficient, meaning energy is lost as heat, sound, or movement during transformations.

Photosynthesis Equation

$$CO_2 + H_2O + \text{Sunlight} \rightarrow C_6H_{12}O_6 + O_2$$

Cellular Respiration Equation

$$C_6H_{12}O_6 + O_2 \rightarrow CO_2 + H_2O + ATP$$

Trophic Efficiency

The percentage of energy transferred between trophic levels, which averages approximately $10\,\%$.

Albedo

The percentage of incoming sunlight reflected by a surface, ranging from $0\,\%$ (pure black) to $100\,\%$ (pure white).

Greenhouse Effect

A natural process where greenhouse gases such as $CO_2$, $H_2O$, and $CH_4$ trap heat in the atmosphere by absorbing outgoing infrared radiation.

Ice Cores

Samples from ice sheets that contain trapped air bubbles, providing a direct measure of ancient atmospheric $CO_2$ concentrations.

Ocean Acidification

The process where atmospheric $CO_2$ dissolves into seawater, reacting to form carbonic acid ($H_2CO_3$) and lowering the ocean pH.