Ecology (AP Biology)

Ecology

Ecology

study of organisms & interactions with their environment

Abiotic

nonliving or physical factors (water, O2, light, temp)

Biotic

living factors (protists, fungi, plants, animals, etc)

Organismal

study of physiology & behavior interacting with environmental challenges

Population

a group of organisms; same species; live together

Community

group of organisms; different species; live together

Ecosystem

all living & nonliving things in an area

Biome

group of ecosystems; similar climates & communities

Biosphere

portion of planet that supports life

Dispersal

movement of organisms from High to Low population densities

Law of Conservation

Energy/matter cannot be created or destroyed, only transformed

Law of Entropy

in all energy transformations disorder (entropy) occurs (heat)

Importance of Abiotic Factors

determine which organisms can survive where

Importance of Biotic Factors

Invasive species, interactions w/ other species, predation, competition

Macroclimate

global, regional, and local level climate patterns

Microclimate

fine patterns in communities (pill bugs under a log)

Homeostasis

maintaining a steady-state internal environment, despite changes in the external environment

Regulators

maintain internally constant environment

Conformers

allow internal environment to vary (in organisms whose environment is stable)

Physiological Response

changing function of body

Morphological Response

changing anatomy of body (dogs growing thicker fur)

Behavioral Response

changing behavior to adapt to change

Rachel Carson

started first modern environmental movement

humans concerned w/ impact of actions on environment

DDT & biomagnification

Principle of Allocation

organisms have a limited amount of energy that can be spent on obtaining food, escaping predators, etc.

Thermal Stratification

colder/heavier water goes to bottom & warmer/ lighter water floats over (summer)

cold water to top and warm water to bottom (winter)

Density-dependent

has an effect if population is large or small

Density-independent

factors unrelated to population size

Density

number of individuals per unit area or volume

Dispersion

pattern of spacing among individuals within the boundaries of the population

Population Ecology

focuses on factors affecting population size over time

Clumping Distribution

most common; favored by reproductive patterns (mechanism against predation & to trap prey

Uniform Distribution

results from competition or antagonism (rare)

Random Distribution

no competition or aggregation (rare)

Adaptive Radiation

evolution of many diverse species from a common ancestor

Carrying capacity

max number of individuals that an environment can support over a long period of time (K)

determined by limiting factors (space food oxygen, etc.)

point where graph “levels off”

K-selected populations

larger, live longer, produce fewer offspring, live at carrying capacity (elephants)

r-selected populations

smaller, shorter life span, produce more offspring, swings in population size (frogs)

Mark-and-recapture

A method used in ecology to estimate an animal population's size. It involves capturing individuals, marking them, releasing them back into the environment, and then recapturing a sample later. The proportion of marked to unmarked individuals in the second sample helps estimate the total population.

Dominant Species

most abundant

Keystone Species

strong effect on composition of community (removal causes decrease in species richness)

Mutualism

symbiotic relationship where both species benefit

Commensalism

symbiotic relationship where one benefits and the other is neutral

Ecological niche

total of an organism’s use of biotic & abiotic resources in its environment

Fundamental niche

set of resources a population is theoretically capable of using

Realized niche

resources a population actually uses

Interference aggression

direct, aggression over resources

Exploitative competition

indirect, consumption/use of similar resources

Apparent competition

indirect, between 2 species both preyed upon by the same predator