Studied by 3 people
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
Note 
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