BIOL 1040 FINAL

individual

single organism, fundamental unit of study

population

individuals of a single species that live/interact together

community

individuals of multiple species that live/interact together

ecosystem

biotic and abiotic factors interacting in a system

species richness

number of individuals in a community

biodiversity

loosely defined, human-centric (products/resources essential for human survival)

rarefaction curve

number of observations (X) vs number of species (Y)

rank-abundance plots

rank species from highest to lowest abundance (X) vs proportional abundance (Y)s

scale

size of area we study

semelparity

one reproductive event per lifetime, many low-survival progeny

iteroparity

multiple reproductive events per lifetime, extra investment increasing survival of progeny

synchronized reproduction

timed reproductive event that occurs when resources are most abundant

unsynchronized reproduction

occurs at random times throughout population

demographic stochasticity

changes in population abundance depend on timing of birth death, immigration, emigration; less important with larger populations

environmental stochasticity

fluctuations in lambda due to poor weather causing mortality or food shortages

density dependence

birth or death rates change with population density (ex. high population leads to food shortages, higher death rates)

carrying capacity

population size where birth and death rates are equal

exploitative competition

individuals reduce resource availability (ex. take up space, eat food, drink water)

interference competition

individuals prevent access to resources (ex. territories, nesting sites)

negative density dependence

population growth rate decreases as population density increases

r-strategists

fast end of continuum, greater # offspring, shorter lifespan, earlier reproduction/sexual maturation, lower investment (insects, bacteria, mice)

k-strategists

slow end of continuum, less offspring, longer lifespan, later reproduction/sexual maturation, greater investment

abiotic drivers

non-living aspects impacting where a species can grow (sunlight, temperature, climate)

biotic drivers

other species’ impact on where a species can grow (competition, predation, mutualism)

dispersal barriers

physical barriers preventing species from moving to certain areas (mountains, oceans, predators, roads, dams)

Hutchinsonian niche

set of environmental conditions permitting a population to grow

metapopulation

local populations coupled by movement (immigration, emigration) of individuals among patches

tri-trophic chain

chain of three species where A consumes B, B consumes Ct

trophic level

number of links between species and base of food web

Green world hypothesis

the world is dominated by plants since carnivores eat herbivores, releasing plants and allowing proliferation

bottom-up regulation

herbivores carrying capacity limited by plant concentration (amount of resources available)

top-down regulation

plants carrying capacity limited by herbivore concentration (predation) OR disease regulates species abundance

trophic cascade

each trophic level is regulated by the level above and below it (ex. wolves regulate elk which regulate willow trees)

exploitative competition

two species consuming a shared resource (negative interaction)

competitive exclusion principle

two species competing for same resource cannot coexist, the species that can tolerate the lower concentration of nutrient excludes its competitors

character displacement

differences among characteristics are accentuated in regions where they overlap geographically, to reduce competition for limited resources

conspecifics

individuals within its own species

heterospecifics

individuals of the other species (often a competitor)

niche complementarity

different species make more complete use of all available resources by using same resources in different ways (ex. birds inhabiting different parts of the tree)

selection effects

more species means a greater chance of finding one that is more reproductive

mutualism

mutually-beneficial positive interaction between pair of species

symbiosis

at least one species in a pair experience a benefit, neither experience harm

resource-based mutualism

when a pair of species shares resources when conditions make it difficult to acquire all resources independently (ex. fungal and algal parts of lichen)

nitrogen fixation

converting atmospheric nitrogen into usable compounds

parasitism

relationship that allows for parasite to benefit from detriment of host species

disease

condition impairing structure/function of an organism (internal or external factors)

zoonotic disease

diseases that can move between host species (ones we care about: malaria, ebola, covid, etc)

macroparasite

don’t multiply within host, zoonotic disease (can move between hosts)

microparasite

multiply within host, zoonotic disease

trophically transmitted parasite

makes host more likely to get eaten by the next host/predator

parasitic castrator

using host nutrients for growth

parasitoid

always kill their hosts

micropredator

smaller than their prey, doesn’t kill their victim

social predator

attack prey in packs (ex. wolves)

solitary predator

attack prey individually using stealth

virulence

negative impact of parasite on host

disease/parasite fitness

ability to infect new hosts

beta

transmission rate (susceptible individuals that become infected)

v

recovery at a constant per capita rate

R0

basic reproductive number, number of individuals infected by FIRST infected; beta*susceptible/recovery rate.

host behavioral manipulation

virus alters host’s behavior, leads to higher rate of transmission

viral shunt

bacteria productivity decreased by the fact that they are infected by virus

lambda

1+birth rate - death rate

ecosystem

complement of biotic, abiotic factors interacting in a system

flux

processes moving energy/matter between pools (respiration, decomposition, photosynthesis)

pool

states where energy/matter are stored (biomass, soil, atmosphere)

upwelling zones

most productive parts of ocean, where deep layer nutrients are brought to the surface

primary production

where energy enters ecosystems (ex. sunlight)

net primary production

energy produced by photosynthesis, accounting for respiration losses

gross primary production

total energy produced by photosynthesis

autotroph

get all energy from surrounding environment / PRODUCERS

heterotroph

get energy from food / CONSUMERS

leaching

loss of available nitrogen/phosphorous in environment

hubbard watershed

effect of draining out watershed, cutting all vegetation on nutrient concentration

residence time

amount of time nutrient spends within an ecosystem

occlusion

phosphorous released from rocks weathering is bound by metal ions (no longer available)

succession

pattern of development of terrestrial ecosystem

primary succession

bare rock to formation of new island

secondary succession

formation of ecosystem after its destroyed by fire/flood/drought

greenhouse effect

solar radiation that’s absorbed by soil/atmosphere is returned at a different wavelength