Exam 2 Notes - BIO 181

Ecology: the study of relationships between organisms and the environment

Organismal: the study of an organism’s relationship with it’s environment (biotic and abiotic)

Population: the study of interactions between members of same species

Abiotic factors: Non-living physical and chemical elements

Abiotic factors: water, soil, air, sunlight, minerals

Biotic factors: Living organisms

Biotic factors: Animals, plants, fungi, etc

Populations: groups of individuals of same species in one place.

Density-dependent factors: Predation, interspecific competition, intraspecific competition, accumulation of waste

Density-independent factors: weather, natural disasters, pollution, and other chemical/physical conditions

Population demography: quantitative study of populations, how size changes through time, population broken down into parts

Population growth is most influenced by what? number of females

Generation times: average birth interval between birth of an individual and birth of it’s offspring

Cohort: peer group (similarities); think similar ages and life stages

Fecundity: how able a female is to reproduce

Mortality: how man people are being removed from the group

Life table: probability of survival and reproduction through a cohort’s life

Survivorship: percent of original population surviving to given age

Survivorship curve: graph of a number of individuals surviving at each age interval

Exponential growth model applies to populations with what? No growth limits

The biotic potential of any population is what even when rate of increase remains constant? Exponential

Carrying Capacity (K): maximum number of individuals that environment can support

What is the K of earth? 8-10 billion people

Logistic growth: applies to populations as they reach K

Human growth potential is: exponential

Ecological footprint: measures the amount of biologically productive land and sea area of an individual, a region, all of humanity, or a human activity that compete for biologically productive space

Dominant species: most abundant

Keystone species: most influential with respect to trophic levels

Foundation species: allows other species to inhabit an area by altering the environment

Community ecology: the study of interacting populations of species living within a particular area or habitat

Intraspecific Competition: competition within a species

Interspecific Competition: Competition between different species

Interference: Direct, physical interactions over resources

Exploitative: interact indirectly by consuming the same resources

Competitive Exclusion Principle: two species cannot occupy the same niche in a habitat, different species can’t coexist in a community if they are competing for all the same resources

Niche: total range of conditions under which an individual (or population) lives and replaces itself

Realized Niche: actual set of conditions under which an organism exists

Fundamental niche: entire set of optimal conditions under which an organismic unit can live and replace itself

Resource partitioning: among similar species occupying the same geographic area, result of NS

Character displacement: differences in morphology between sympatric species, role in adaptive radiation

Predation: Consumption of prey by it’s predator

Predation: strong selective pressure; features that decrease predation strongly favored

Chemical defenses: monarch butterfly caterpillars feed on milkweed and dogbane families, incorporate cardiac glycosides from plants, and the birds get sick when they consume/eat the monarchs.

Strawberry poison dart frog uses: aposematic coloration

Striped skunk uses aposematic coloration to warn predators of the unpleasant odor it produces.

Camouflaged or cryptic animals: nonpoisonous and blend with surroundings and usually don’t live in groups

Batesian Mimicry: Harmless species imitate warning signals of harmful species

Müllerian Mimicry: Related or unrelated poisonous species that share a predator come to resemble one another’s warning signals

Müllerian Mimicry Example: Several unpleasant tasting Heliconius butterfly species share a similar color pattern with slightly better, but still unpleasant tasting varieties.

Commensalism: One species benefits and the other is just “meh”

Parasitism: One species is gaining something from the other - one benefit

Mutualism: Both are benefitted

Mutualism Example: Acaia trees and ants

Mutualism Example: Clown fish and anemone

Mutualism Example: Cleaner shrimp and fish

Mutualism Example: Ants and caterpillars

Mutualism Example: Termites and gut flagellates

Commensalism Example: Egrets and water buffalo

Commensalism Example: Remora and shark

Commensalism Example: Pea crab and tube worms or mollusks

Endoparasites: Live within body of hosts

Ectoparasites: Live on surface of hosts

Parasitoidism: Deposit eggs on/in host

Endosymbiont: Live inside another, but usually mutualistic

Four main abiotic biogeochemical cycles: water, carbon, nitrogen and phosphorous

Richness: number present

Abundance: number of individuals per species

Relative abundance: how common or rare relative to others

Diversity: species richness and evenness of species’ abundances

Evapotranspiration: the release of water into the atmosphere as water vapor, by evaporation, transpiration, and respiration.

How does energy exist in ecosystems? Heat, light, chemical-bond energy, motion.

First Law of Thermodynamics: Energy is neither created or destroyed; changes forms.

Second Law of Thermodynamics: Some chemical-bond or light energy converted to hear (entropy).

What is the major source of energy in an ecosystem? the sun

Autotrophs: Primary producers

Heterotrophs: Consumers

Autotrophs: self-feeders; assemble inorganic precursors into the array of organic compounds of which they are made

Photoautotrophs: gain energy from light

Chemoautotrophs: gain energy from inorganic molecules

Heterotrophs: obtain organic compounds by consuming other organisms; these animals eat plants and other organisms

Herbivores: first consumer level

Primary carnivores: eat herbivores

Secondary carnivores: eat primary carnivores or herbivores

Detrivores: eat decaying matter

Decomposers: Microbes that break up dead matter

Limiting nutrients: Nutrients in shortest supply and put a limit on growth

What is the limiting nutrient in terrestrial and aquatic ecosystems? Nitrogen and Phosphorous

What is the limiting nutrient in algal populations or 1/3 of the world’s populations? Iron

Gross primary productivity (GPP): Rate at which primary producers incorporate energy from the sun.

Net primary productivity (NPP): Energy that remains in primary producers after respiration and heat loss

About what percent per year of incoming solar radiant energy is captured by primary producers?

about 1% in chemical

Heterotrophs only have what energy left in primary producers? Chemical-bond energy

The amount of chemical-bond energy does what as energy as energy is passed from one trophic level to the next? Decreases

During the transfer of energy down trophic levels, how much energy is stored as biomass and is in turn available to the next trophic level? 10%