Physiological Ecology and Population Biology Flashcards

A comprehensive collection of vocabulary flashcards covering physiological ecology, population dynamics, life history strategies, behavioral ecology, and species interactions based on lecture notes.

Physiological Ecology

The study of individual dependence on and species' adaptations to the physical and biotic environment.

Acclimation

A short-term, reversible adjustment to environmental stress through changes in behavior or physiology.

Adaptation

A long-term, irreversible genetic response of a population where individuals with traits that cope with stress become more frequent over time.

Optimum

The specific value of an environmental variable at which an important physiological process is maximized.

Stress

A condition where an environmental change reduces the rate of a physiological process, lowering the potential for survival, growth, or reproduction.

Tolerance

A survival strategy involving physiological or morphological capacity to withstand and live through an environmental challenge.

Avoidance

A survival strategy where an organism gets away from an environmental challenge via mechanisms such as migration, dormancy, or microhabitat selection.

Climate Envelope

The range of climatic conditions over which a species occurs, commonly used to predict geographic distribution responses to climate change.

Fundamental Niche

The full range of physical environmental conditions under which a species could potentially survive and persist.

Realized Niche

The actual geographic and ecological distribution of a species, constrained by dispersal limitations and biotic interactions such as competition and facilitation.

Isozymes

Different structural forms of the same enzyme produced by a species that have distinct temperature optima to facilitate acclimatization across changing seasons.

Boundary Layer

A zone of still air adjacent to a leaf surface caused by friction, which influences convective and conductive heat transfer.

Pubescence

Leaf hairs that can reduce solar radiation absorption by reflecting sunlight or reduce convective heat loss by thickening the boundary layer.

Ectotherms

Animals that regulate their body temperature primarily through energy exchange with the external environment.

Endotherms

Animals that regulate their internal body temperature primarily through metabolic heat production ($H_{met}$).

Thermoneutral Zone

The range of environmental temperatures over which an active endotherm maintains a constant basal metabolic rate (BMR) with only minor behavioral or morphological adjustments.

Lower Critical Temperature

The ambient temperature threshold below which an endotherm must increase its metabolic heat generation to balance conductive and convective heat loss.

Torpor/Hibernation

The adaptive lowering of effective body temperature and basal metabolic rate during severe cold to conserve stored energy reserves.

Water Potential

A physical measurement of the energy state of water that governs the passive direction of water movement from areas of high potential to low potential.

Cavitation

The structural rupture or breakage of water columns within plant xylem vessels caused by severe water deficits.

Population

A group of individuals of the same species inhabiting a specific geographic area at a specific time that interact by competing, sharing pathogens, and reproducing.

Regular Dispersion

A spatial distribution pattern characterized by uniform spacing among individuals, commonly driven by intense resource competition or territorial defense.

Clumped Dispersion

A spatial distribution pattern where individuals are grouped together due to patchy resource environments, limited dispersal, or social aggregation.

Mark-Recapture Method

A technique used to estimate mobile animal population sizes ($N$) based on the proportional relationship $\frac{M}{N} = \frac{R}{C}$.

Species Distribution Modeling

An analytical approach combining known geographic occurrence localities with environmental layers to predict current and future suitable habitats.

Metapopulation

A set of spatially isolated local populations linked to one another by occasional dispersal events.

Source Population

A subpopulation within a metapopulation system that produces an excess of dispersers because reproductive rates exceed mortality rates.

Sink Population

A subpopulation within a metapopulation system where local mortality exceeds reproduction, requiring continuous immigration to persist.

Density-Independent Factors

Abiotic events or forces (such as floods, extreme temperatures, or natural disasters) whose effects on mortality or population growth rates are independent of population density.

Geometric Population Growth

A population growth model describing organisms with discrete, non-overlapping breeding seasons in unlimited environments ($N_t = N_0\lambda^t$).

Exponential Population Growth

A continuous population growth model describing organisms with overlapping generations reproducing continuously in unlimited environments ($\frac{dN}{dt} = rN$).

Density-Dependent Factors

Biotic mechanisms (such as resource competition, disease transmission, or space limitation) whose per-capita impacts change as population density varies.

Carrying Capacity ($K$)

The maximum sustainable population size that a specific environmental setting and its available resources can support indefinitely.

Logistic Growth

A model of density-dependent population growth where the per-capita rate of increase slows down as population size ($N$) approaches carrying capacity ($K$), formulated as $\frac{dN}{dt} = rN\left(1 - \frac{N}{K}\right)$.

Positive Density Dependence (Allee Effect)

A demographic phenomenon where individual fitness and per-capita population growth rates increase at higher densities when population levels are very low.

Type 1 Survivorship Curve

A demographic pattern characterized by high survival rates throughout juvenile and adult life, with mortality heavily concentrated in older age classes.

Type 2 Survivorship Curve

A demographic pattern characterized by a constant rate of mortality throughout the lifespan of the organism, independent of age.

Type 3 Survivorship Curve

A demographic pattern characterized by high mortality among young juveniles followed by high survival rates once maturity is achieved.

Life Table

An actuarial table summarizing age-specific survival, mortality, and fecundity schedules used to calculate reproductive and growth parameters.

$r$-Selected Species

Organisms adapted to uncrowded or frequently disturbed habitats characterized by high intrinsic growth rates, early maturity, small body size, and numerous small offspring.

$K$-Selected Species

Organisms adapted to crowded, competitive habitats near environmental carrying capacity characterized by slower development, delayed maturity, larger body size, and fewer, well-provisioned offspring.

Grime's CSR Scheme

A plant ecological framework classifying species into competitive (low stress, low disturbance), stress-tolerant (high stress, low disturbance), and ruderal (low stress, high disturbance) life history strategies.

Behavioral Ecology

The study of the ecological and evolutionary basis of animal behavior.

Proximate Cause

The immediate mechanistic trigger of a behavior, including physiological, neurological, genetic, or developmental factors operating within an individual's lifetime.

Ultimate Cause

The evolutionary advantage, adaptive significance, and historical fitness benefits that explain why a behavior evolved over generations.

Optimal Foraging Theory

A behavioral model predicting that animals forage in a manner that maximizes their net energy gained per unit of foraging time ($E_{net} = \frac{E_{gross}}{h + s}$).

Marginal Value Theorem

An analytical model predicting patch residence time, stating that foragers remain longer in higher-quality patches and stay longer in patches as travel time between patches increases.

Dilution Effect

A selective advantage of social group living where an individual's statistical probability of being targeted by a predator decreases as group size expands.

Parasitoidism

An ecological interaction ($+/-$) where an insect lays eggs in or on a host organism, and the resulting larvae consume host tissues and ultimately kill the host.

Constitutive Defense

A physical, morphological, or chemical anti-predator defense that is continuously produced and always present in an organism.

Induced Defense

A defensive structure or toxic secondary metabolite that is synthesized or mobilized only in direct response to herbivore damage or predator attack.

Plant Compensation

An adaptive growth response where partial removal of plant tissue by herbivores stimulates the production of replacement leaves, stems, or reproductive tissues.