Help
Options
Question
Population:
click to flip
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't know
Question
Distribution:
Remaining cards (89)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Ecology Test 2 UA
Benstead UA
| Question | Answer |
|---|---|
| Population: | a group of individuals of a single species inhabiting a specific area |
| Distribution: | size, shape, and location of the area occupied |
| Density: | the number of individuals within a given area due to age distribution, birth and death rates, immigration and emigration, and rates of growth |
| Distribution of individuals at small spatial scales | patterns that are random, regular, or clumped. |
| Cause of spatial scales | These patterns are produced both by the kinds of interactions that go on within a population and by the structure of the physical environment |
| Increasing competition for resources seems to result in what spacial pattern? | ‘regular’ pattern in ‘older’ communities |
| Distribution of populations at broad scales | clumped (due to resources like water) |
| Organism size and population density | Population density declines with increasing body size (inverse relation) |
| Natural populations are | not static in abundance or distribution |
| Cause of flux in natural populations | population dynamics: births, deaths, immigration and emigration |
| Effect of dispersal on local populations | increase (immigration) or decrease (emigration) |
| Dispersal is most common among what stage? | Juvenile |
| Three main ways of estimating patterns of survival within a population | – Cohort life table – Static life table – Age distribution |
| cohort | A group of individuals born at the same time |
| static life table | record the age at death of a large number of individuals |
| age distributions | proportion of individuals of different ages within a population |
| limitations of age distributions | Populations must not be growing or declining or subject to migration produces a static life table |
| survivorship curve | Plotting survivorship against age |
| How do survivorship curves relate amongst differs taxa? | Relatively similar |
| constant rates of survival | survivorship curves for some species are nearly straight lines individuals die at a constant rate throughout life Ex. Birds and mud turtles |
| High infant mortality | organisms produce large amounts of eggs with very high rates of mortality |
| Type I Survivorship Curve | High survival of young followed by death at old age (line shows little slope until old age and then quickly falls) |
| Type II Survivorship Curve | Constant survival (linear negative line) |
| Type III Survivorship Curve | High juvenile and low adult mortality (sudden drop and then levels out) |
| age distribution of a population reflects its? | history of survival and reproduction, as well as its potential for future growth |
| stable populations | population is juvenile dominant meaning the older trees will be replaced |
| unstable populations | middle aged individuals dominant meaning that there are not enough young to replace the old |
| life table | survival and age distribution with reproductive rates, we can actually make quantitative predictions about future population growth or decline |
| fecundity schedule | tabulation of birthrates for females of different ages in a population |
| life table combined with a fecundity schedule can be used to estimate: | – net reproductive rate (R0) – geometric rate of increase (lambda) – generation time (T) – per capita rate of increase (r) |
| net reproductive rate, R0 | survivorship curve with its seed production (in a fecundity schedule) also requires: number of individuals (nx) in each age class (x) and the seed production of each age class (mx) |
| geometric rate of increase (lambda) | ratio of the population size at different times Nt+1/ Nt |
| generation time, T | the average time from egg to egg |
| per capita rate of increase for the population (r) | birthrate minus death rate value of 0 would indicate a stable population |
| Robert Whittaker | pioneered research on the distribution of plants along the often steep environmental gradients associated with mountain ranges |
| range expansion | africanized bee-human induced very fast eurasian collared doves- no human interference, short distance dispersion of individuals trees- 100-400 m a year, similar to elk |
| geometric rate of increase | calculate total seed production, we multiply the initial number of plants in the populations (996) by the net reproductive rate (2.4177), we get 2,408. number of seeds the population will start with next year |
| generations overlap | not every female mud turtle lays eggs. The total number of offspring is less than the number of adult females so the population is declining |
| geometric population growth | any population with pulsed reproduction (a single generation per year) differ by a constant ratio (lambda,the geometric rate of increase) |
| exponential population growth | overlapping generations growth is continuous, not pulsed growth rate has to increase as populations get larger |
| max subscript on r (rmax) | maximum rate of increase achieved under ideal conditions intrinsic rate of increase |
| What are the necessary conditions for exponential growth? | low initial population densities |
| Slowing of growth | geometric growth and exponential growth cannot be maintained |
| Logistic population growth | resources are depleted by a growing population, its growth rate slows and eventually stops S- shaped, or sigmoidal, curve |
| carrying capacity, or K | population size at which growth stops birthrates equal death rates and population growth is zero |
| rmax occurs at __ during logistical growth? | very low population size |
| realized r (logistical growth) | r decreases as population increases |
| if N<K, r is? | positive and population grows |
| if N=K, r is? | 0 and population growth stops |
| N>K, r is? | negative and population declines |
| abiotic | rainfall, temperature density-independent factors |
| biotic | predation, competition, disease density-dependent factors |
| life history | life span, age at maturity, fecundity, offspring size |
| Offspring number versus size | larger offspring are limited to fewer individuals smaller offspring can afford to produce more, but small offspring have lower survival No organism can do both |
| adult survival is lower | reproduce at an earlier age and invest relatively more energy in reproduction |
| GSI | gonadosomatic index measures the proportion of energy allocated to reproduction Adult mortality rate was inversely related to age at maturity |
| higher mortality rates reproduce___? | earlier and allocate more energy to reproduction |
| r selection | per capita rate of increase, r Species in which selection favors a high population growth rate are r-selected ‘weedy’species (new or disturbed) |
| K selection | carrying capacity of a population, K Species in which selection favors a efficient utilization of resources populations are near their carrying capacity much of their time (i.e., low disturbance environments) |
| Variable/unpredictable environments result in___? | r selection and Type III survivorship curves |
| Constant/predictable environments result in___? | K selection and Type I or II survivorship curves |
| semelparity | single reproduction |
| iteroparity | repeated reproduction |
| r versus K selection | intrinsic rate of increase, competitive ability, Development rate, age at maturity and body size |
| Opportunistic | species maximize their ability to colonize new habitat in unpredictable environments by combining low juvenile survival, low numbers of offspring and early maturity |
| Equilibrium | species combine high juvenile survival, low numbers of offspring, and late reproductive maturity |
| periodic | combines low juvenile survival, high numbers of offspring, and late maturity |
| Charnov’s life history cube | dimensionless ratios to remove the effects of size and time relative size of offspring, proportion of lifetime allocated to reproduction, and the fraction of adult body mass allocated to reproduction over the lifespan |
| Summary of life history cube | illustrates the fundamental differences among fish, mammals, and altricial birds |
| Intraspecific competition | competition is strongest between individuals of the same species - they have very similar resource requirements |
| Self-thinning | Plant density typically decreases faster than biomass increases slope often averages -3/2 |
| Interspecific competition | competition among different species competition is more likely if two species have similar requirements or similar niches |
| niche | environmental requirements of a species how, where and when a species makes its living Grinnell and Elton |
| competitive exclusion principle | two species with identical niches cannot coexist indefinitely |
| fundamental niche | n-dimensional hypervolume, where n equals the number of environmental factors affecting a species survival and reproduction conditions a species would exploit in the absence of other species |
| realized niche | species subject to biotic interactions (competition, predation, disease, parasitism) |
| morphological niche | Differences in finch beak size are directly related to differences in diet |
| Lotka-‐Volterra competition model | express the population growth of two species of potential competitors with two logistic equations predicts coexistence of two species when, for both species, interspecific competition is weaker than intraspecific competition |
| competition coefficients | two terms -alpha12N2 and -alpha21N1 express the competitive effect of one species on another |
| alpha12 | he effect of an individual of species 2 on the rate of population growth rate of species 1 |
| alpha21 | is the effect of an individual of species 1 on the rate of population growth rate of species 2 |
| isoclines of zero population growth | combinations of N1 and N2 at which population growth of N1 (or N2) is zero, form strait lines |
| state space | species on each axis |
| outcomes of competition | extinction of species 1, extinction of species 2, and coexistence of the two species |
| Niche overlap and competition | competition for space between the two species |
| character displacement | Evolution toward niche divergence |
| allopatric | biological populations of the same species become isolated |
| sympatric | inhabiting the same geographic region |
| exploitative interactions | increases in fitness of one species with a decrease in fitness of the other ex. Predator-prey and parasite-host |
| biological control | moth used to control the cactus |
Created by:
dhmulder
Popular Biology sets