Principles of Ecology Practice Flashcards

A comprehensive set of vocabulary flashcards covering basic ecology, environmental factors, population dynamics, community structure, and ecosystem processes based on BIOL 3086 lecture materials.

Ecology (Etymology)

Derived from two Greek words ‘Oikos’ meaning ‘home’ and ‘logous’ meaning to study; the term was first used by Ernest Haeckel in 1869.

Autecology

A branch of ecology that deals with the population dynamics of species and how they interact with the environment.

Synecology

A sub-discipline of ecology that studies the distribution, abundance, demography, and interactions between coexisting populations (e.g., forest, grassland, or marine ecology).

Palaeoecology

The study of organisms and their habitat in the geological past.

Abiotic Factors

Non-living components of the environment, such as temperature, light, water, gases, wind, soil, and physiographic factors.

Physical Resources

Absolute abiotic factors required for life; examples include sunlight, water, carbon dioxide, and nutrients for plants, and oxygen, water, and nutrients for animals.

Physical Factors

Abiotic factors that limit the quality of life of an organism, such as pH of water, degree of salinity, and temperature.

Justus Von Liebig's Law of the Minimum (1840)

States that even if an organism gets several abiotic factors, only one of these factors limits the optimization of the organism’s growth; this factor is the limiting factor.

Victor Shelfold's Law of Tolerance (1913)

States that the amount of physical factors an organism requires has specific upper and lower tolerance limits.

Eurythermal

Organisms characterized by a wide temperature tolerance.

Stenothermal

Organisms characterized by a narrow temperature tolerance.

Vernalization

The phenomenon where specific seeds, such as those of carrots, normally germinate in the spring or summer after exposure to cold.

Poikilothermic (Ectothermic)

Animals commonly referred to as 'cold-blooded'.

Homothermic (Endothermic)

Animals commonly referred to as 'warm-blooded'.

Photoperiod

The difference in the relative duration of daylight and darkness which influences stem elongation, flowering, and fruit growth.

Short-day plants

Plants that flower only if the light exposure is less than a critical duration of about $14$ hours; examples include Nicotiana, Chrysanthemum, and Xanthium.

Phototropism

The directional growth of plants in response to light where the direction of the stimulus determines the direction of growth.

Phototaxis

The movement of a whole organism in response to a unilateral light source where the stimulus determines the direction of movement.

Photokinesis

Variation in the intensity of locomotory activity of animals dependent on light intensity, but not direction.

Photonasty

Movement of parts of a plant in response to light where the direction of the stimulus does not determine the direction of the movement.

Hydrophytes

Plants that grow in water and waterlogged areas.

Mesophytes

Plants that grow in areas with moderate water requirements.

Xerophytes

Plants adapted to grow in deserts or dry areas where water source is a serious problem.

Edaphic Factors

Factors related to the soil, including texture, aeration, temperature, water, solution, pH, organisms, and decaying matter.

Loam Soil

A mixture of sand and clay particles that is well aerated, warms up quickly, and is easy to cultivate.

Hygroscopic Water

Water that occurs as a thin film around each soil particle.

Capillary Water

Water held in the small spaces between soil particles.

Gravitational Water

Water that drains downwards through the soil.

Physiographic Factors

Factors associated with the physical nature of an area, such as altitude, slope of land, and position in relation to the sun.

Entrainment

The process of light bringing the circadian rhythm of organisms into phase with the 24-hour period of the external environment.

Hibernation

A state of dormancy where animals collect resources like fat and become inactive during winter and autumn.

Aestivation

Dormancy in animals during warm and dry conditions.

Intrinsic Rate of Increase ($r_{max}$)

The maximum per capita rate of increase achieved by a species under ideal environmental conditions.

Exponential Population Growth Model

Represented by the formula $dN/dt = r_{max}N$, describing growth in an unlimited environment.

Logistic Population Growth Model

Represented by the formula $dN/dt = r_{max}N(1 - \frac{N}{K})$, describing growth that slows as resources are depleted.

Carrying Capacity ($K$)

The maximum number of individuals of a particular population that the environment can support.

Type I Survivorship Curve

A curve where the young have a high survival rate and typically live a long life (e.g., humans).

Type II Survivorship Curve

A curve indicating a relatively constant death rate throughout the life span (e.g., squirrels, honey bees).

Type III Survivorship Curve

A curve found in species where most young die very early in life (e.g., plants, oysters).

K-selected Species

Organisms with low reproductive rates, long life spans, and extensive postnatal care, inhabiting stable environments.

r-selected Species

Organisms with high reproductive rates, small body size, early maturity, and little to no parental care, inhabiting unstable environments.

Gause’s Principle of Competitive Exclusion

States that only one of two competitors for the same limiting resource will survive, leading to the exclusion of the other.

Interference Competition

Direct competition between individuals via aggression or preventing physical establishment in a habitat.

Exploitation Competition

Indirect competition occurring through the depletion of a common limiting resource.

Apparent Competition

Indirect competition between two species that are both preyed upon by the same predator.

Scramble Competition

A type of intraspecific competition where all individuals share available resources equally, which may result in none getting enough for growth.

Contest Competition

A type of intraspecific competition where some individuals claim enough resources for survival while denying others.

Parasitoidism

An interaction where a 'weak' organism attacks a 'strong' host by laying eggs in its body, where larvae feed on tissues until the host dies.

Species Richness

The number of species or taxonomic groups present in a particular community.

Relative Abundance

The relative number of individuals of each species in a particular community.

Keystone Species

Species whose presence is critical to the integrity of the community and which have a disproportionate effect on its structure (e.g., Starfish Pisaster).

Succession

The directional change in community structure through time.

Sere

The sequence of communities from grass to shrub to forest through time.

Primary Succession

Succession that begins on sites that never have supported life, such as rock outcrops, dunes, or glacial till.

Secondary Succession

Succession that occurs on previously occupied sites following a disturbance.

Net Primary Productivity (NPP)

The measure of net energy gain by autotrophy; calculated as Gross Primary Production minus energy lost to respiration.

Eutrophication

A condition where inland waters are polluted with nitrogen and phosphorus run-off, leading to explosive algae growth.

Demographic Transition

The transition of human population from high birth and death rates to low birth and death rates through three stages.

Nitrification

A biological process where ammonia is oxidized to nitrate by bacteria like Nitrosomonas and Nitrobacter.

Denitrification

A process where fungi and bacteria (e.g., Pseudomonas) reduce nitrates to gaseous nitrogen ($N_2$).

Dendroclimatology

The analysis of tree ring growth patterns to determine past climate variations.

Palynology

The study of contemporary and fossil palynomorphs, including pollen, used to infer past geographical distribution of plants.