Bio220Exam2
Order by
109 terms
Terms | Definitions |
|---|---|
 ecology | the study of the distribution and abundance of organisms |
| abundance | the total number of individuals of a species present in a specified area |
| number of individuals in a population, number of individuals per unit area (density), density of one population relative to another (relative density) | three ways of estimating abundance |
| relative density | the density of one population relative to another |
| population size | this can only be assigned biological meaning when the population is circumscribed (well-defined-boundaries) |
| density | this is a biologically meaningful measure of abundance when no definite boundaries exist on a population |
| index of density | a reliable substitute for an actual measure of density |
| linearly | ideally indices of density are related to actual density in this way |
| non-linear | an antelope can poop four to ten times a day, therefore, eight poop piles can indicate one or two antelopes. This is an example of what kind of relationship between index of density and actual density? |
| total count | this measure of abundance requires defined boundaries, skilled counters, angle of view and standard conditions |
| accuracy can be less dependent on skill of observer, measurement is easier to standardize among observers and the act of observing does not influence what's observed | advantages over counting individuals to measure abundance |
| there is a less direct relationship to actual density, it can take skill to identify species and numbers of individuals | two disadvantages to using indices of density |
| geographic range, habitat tolerance, local population size | commonness and rarity can be classified based on combinations of these three factors |
| eight | there are this many possible combinations of the three commonness and rarity factors |
| Rarity 1 | this type of rarity has one limited rarity factor |
| Rarity 2 | this type of rarity has two limited rarity factors |
| Rarity 3 | this type of rarity has two limited rarity factors |
| extensive, broad, large | the most abundant species has [extensive/limited] geographic range, [broad/narrow] habitat tolerance, and [large/small] local populations |
| age structure | the number of individuals in each age class |
| age distribution | consists of the proportion of individuals of different ages in a population |
| births, deaths, immigration, emigration | four factors influencing the expansion/decline of populations |
| BIDE | this model expresses the change in population size |
| cohort | a group of individuals born in the same population in the same year |
| longitudinal study | following a cohort throughout its life (across geographical space at same pt. in time) |
| cohort analysis | individuals born in same year |
| latitudinal study | cohort study that is conducted across a geographical space at the same point in time |
| continuous breeding, overlapping generations | two requirements for the most reliable method of quantifying age-specific survival and mortality |
| static life table | this life table provides a snapshot of survival within a short period of time |
| 1- age class, 2- number of survivors at the beginning of the year, 3- the number of deaths in each age class by the end of that year | the columns of life tables show these |
| substract the number of deaths per age class from the number surviving at the beginning of the year | how can we estimate age-specific survivorship? |
| survivorship curve | these curves graph the relationship between age and survival |
| type 1 | this type of survivorship has high juvenile survival and most mortality in the old |
| type 2 | this type of survivorship has equal rates of survivorship and death regardless of age |
| type 3 | this type of survivorship has high juvenile mortality and high adult survival |
| decreasing | if there is a large number of older individuals, the population will be [increasing/decreasing] |
| increasing | if there is a large number of younger individuals, the population will be [increasing/decreasing] |
| N sub x | in a life table, this variable indicates the number of organisms alive in each age class |
| x | in a life table, this variable indicates the age class |
| pulsed dispersal | in this kind of dispersal, juveniles disperse only short distances before becoming established, although some can disperse far |
| functional response | in this kind of response, the rate of predators killing changes with prey density |
| numerical response | in this kind of response, the abundance of predators changes in relation to the abundance of prey |
| dispersal-mediated numerical response | in this response, the abundance of predators in an area decreases with decreasing prey density due to emigration rather than death |
| l sub x | in a life table, this variable indicates the proportion of individuals surviving to age x (or the probability of surviving to age x--number surviving over the total number of organisms) |
| m sub x | in a life table, this variable indicates the average number of offspring produced per individual |
| lxmx | the proportion of individuals surviving to a given time period times the number of offspring per individual |
| R sub 0 | net reproductive rate: (can not be negative) average number of offspring produced by an individual within its lifetime |
| values of R sub 0 < 1 | indicates that a population is declining |
| R sub 0 = 1 | population is stable |
| R sub 0 > 1 | population is increasing |
| why make cohort life table | to estimate total offspring production by a population during the period of a study |
| is R sub 0 or lambda ever negative | NO! |
| Geometric rate of increase | (lambda) the ratio of population size at two points in time: (N sub t+1)/N sub t |
| When does R sub 0 equal lambda | species with non-overlapping generations BECAUSE DISCRETE TIME MODEL (have eggs and then die before offspring reach reproductive age) |
| lambda not equal to R sub 0 in | species with overlapping generations and continuous reproduction |
| Generation Time | time between when mamma has baby and then baby has baby |
| what is r | per capita rate of increase, average rate of increase per individual in the population (can be negative): births - deaths |
| unlimited growth (two types) | occurs with abundant resources (geometric and exponential) |
| Geometric | discrete growth (line) -changes over fixed time interval: R sub 0 = geometric rate of increase |
| Exponential | continuous growth |
| Equation for Geometric Growth | Nt = N0 (lambda) ^ t |
| r<0 | declining |
| r = 0 | stable |
| r< 0 | increasing |
| Exponential Growth | Nt = N0 e ^rt |
| rmax | intrinsic rate of increase |
| population requires competition for survival because | if not would grow until use up all resources and all die |
| lambda is equal to | e ^ r |
| k | carrying capacity - sigmodial growth curve |
| logistic growth | sigmodial - results from carrying capacity which results from competition and resource limitations |
| N < k | r is positive |
| N = k | r is zero |
| N > k | r is negative |
| density dependent factors | usually biotic: dense population = high predation = more prey = more dense |
| density independent factors | earthquake, storm- lot or few animals and still all die |
| three types of interactions | competition (--), exploitation (-+), mutualism (++) |
| competition | interaction between individuals (over limited resource) that leads to reduction in the contribution of those individuals to next generation |
| intraspecific competition | among organisms of same species |
| interspecific competition | among orgainisms of different species |
| interference competition | individuals interact directly and prevent others from gaining access to a resource (fight for banana- one winner) |
| exploitation competition | individual remove resource needed by others (take straw) |
| apparent competition | individuals affect each other negatively via a shared natural enemy (acid monkey rock) |
| competitive symmetry | magnitude of the negative effect of competition is the SAME on both competitors |
| competitive asymmetry | magnitude of the negative effect of competition is GREATER on one competitor than on the other |
| Two ways to demonstrate that intraspecific competition occurs | show resources are limiting, fitness has decreased for one species |
| two ways to demonstrate that interspecific competition occurs | fitness decreased for BOTH species, and resources limiting |
| self-thinning | decline in population density in given population that occurs when biomass increases and intraspecific competition increases |
| ecological niche | combination of enviro factors (abiotic and biotic) that affect survival, growth and repro, (how makes living, how FUNCTIONS in ecosystem, how interacts with other species) |
| Competitive Exclusion Principle | two species can't occupy the same niche |
| Ecological niche (hutchinson definition) | N-dimensional hypervolume (summary of organisms tolerances and requirements)- each factor that effects niche is another dimension |
| Two types of niche | fundamental and realized |
| fundamental niche | everywhere organism could possibly live (does not consider competition from other species) |
| realized niche | where actually live once other organisms considered (competition) |
| 1-(N/K) | equation for carrying capacity |
| competition coefficients | alpha12 or alpha21 |
| alpha12 | this competition coefficient signifies the effect of one individual from species two on the population growth rate of species one |
| alpha21 | this competition coefficient signifies the effect of one individual from species one on the population growth rate of species two |
| < | if alpha12 is [>, >, =] then the effect of species two one species one is less than the effect of species one on itself |
| > | if alpha12 is [>, >, =] then the effect of species two one species one is greater than the effect of species one on itself |
| Lotka-Volterra | this model allows us to compare how populations affect each other |
| predator | this exploiter has a one:many enemy to victim ratio and kill its victim |
| biologically, predators will increase if there are lots of prey and decrease if there are few | predator isocline |
| prey will increase if there are few predators and decrease if there are many | prey isocline |
| handling time | the time the predator spends pursuing, subduing and digesting each prey item it finds |
| type one | in this functional response, there is a linear increase of food intake per exploiter as victim population increases |
| type two | in this functional response, as prey density increases, the predation rate asymptotes due to handling time |
| type three | in this functional response, the per capita consumption rate accelerates at low densities and saturates at high densities (S shape) |
| obligate and facultative | two type of mutualism |
| facultative | type of mutualism in which partners can live without each other if necessary |
| obligate | type of mutualism in which partners cannot live without each other |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.