Terms : Hide Images
| 7232717115 | intrinsic growth rate (r) | has particular maximum potential for growth labeled (r) |  | 0 |
| 7232717116 | overshoot | when a population becomes larger than spring carrying capacity |  | 1 |
| 7232717117 | community | -incorporates all populations pf organisms within a given are -boundries maybe defined by state or federal agencies responsible for managing it -scientists who study this are interested in how species interact with one another -exist within ecosystems |  | 2 |
| 7232717118 | growth rate | number of offspring an individual can produce in given time period, minus deaths of individual or its offspring during the same period | 3 | |
| 7232717119 | die-off | -result of overshoot -population crash | 4 | |
| 7232717120 | population | -composed of all individuals that belong to the same species & live in a given area at a particular time -evolution occurs -scientists who study this are interested in factors that cause number of individuals to increase or decrease |  | 5 |
| 7232717121 | logistic growth model | -describes population whose growth is initially exponential but slows as population approaches carrying capacity of environment (K) -s-shaped |  | 6 |
| 7232717122 | age structure | -description of how many individuals fit into particular age categories -knowing this helps ecologists predict how rapidly populations can grow |  | 7 |
| 7232717123 | limiting resource | -resource that a population cannot live without & which occurs in quantities lower than a population would require to increase in size -if this decreases, so does population size that depends on it *water, nitrogen, phosphorous* |  | 8 |
| 7232717124 | s-shaped curve | logistic growth model *Gause Paramecium experiments* |  | 9 |
| 7232717125 | sex ratio | -ration of males to females -usually close to 50:50 -helps scientists estimate number of offspring a population will produce in the next generation *fig wasps=20 females:1 male* | 10 | |
| 7232717126 | population ecology | -study of factors that cause populations to increase or decrease -knowing these factors that affect population size helps implement measures to improve survival & reproduction | 11 | |
| 7232717127 | carrying capacity (K) | limit to how many individuals an environment can sustain |  | 12 |
| 7232717128 | j-shaped curve | -exponential growth model -populations not limited by resources, growth is rapid, as more births occur with each step in time |  | 13 |
| 7232717129 | k-selected species | -large organisms that reach reproductive maturity relatively late -produce few large offspring -provide parental care -pose challenge because populations grow slowly -endangered species cannot respond quickly to efforts to save it from extinction -because carrying capacity is denoted as k |  | 14 |
| 7232717130 | population density | -number of individuals per unit area (or volume) -helps scientists estimate whether species is rare or abundant *coyote=1 per square km:12 per square km* -useful measure for wildlife managers whi must set hunting or fishing limits on species *offer more hunting/fishing permits for high zones & fewer for low zones* |  | 15 |
| 7232717131 | population size | -total number of individuals within a defined area at a given time *california condor-combination of poaching, poisoning, flying into power lines=reduced but by captive breeding, increased |  | 16 |
| 7232717132 | density-independent factors | -have same effect on an individual's probability of survival & amount of reproduction at any population size -bird populations are regulated by these *tornado, hurricane, flood, fire, volcano* |  | 17 |
| 7232717133 | density-dependent factors | -influence individual's probability of survival & reproduction in a manner that depends on size of the population *amount of food available-food scarcity affect large populations over smaller ones* |  | 18 |
| 7232717134 | r-selected species | -exhibit rapid population growth that is followed by overshoots & die-offs -small organisms that reach reproductive maturity relatively early -produce many small offspring -reproduce frequently -provide little/no parental care -because intrinsic growth rate is denoted by r *house mice, roaches, small fish, insects, weedy plants* |  | 19 |
| 7232717135 | population distribution | -description of how individuals are distributed with respect to one another *random, uniform, clumped* |  | 20 |
| 7232717136 | clumped population distribution | -large group, feeding opportunities & protection from predators *school fish, flocking birds, herding mammals* |  | 21 |
| 7232717137 | uniform population distribution | -evenly spaced -plants produce toxins to prevent other plants of same species from growing close *nesting birds* |  | 22 |
| 7232717138 | random population distribution | -no pattern *trees* |  | 23 |
| 7232717139 | survivorship curves | -distinct patterns of survival over time *type I, II, III* |  | 24 |
| 7232717140 | type III survivorship curve | -low survival early in life & rarely reach adulthood *r-selected species* |  | 25 |
| 7232717141 | type II survivorship curve | -relatively constant decline *coral, squirrels* |  | 26 |
| 7232717142 | type I survivorship curve | -as they approach old age, start to die in large numbers *k-selected species* |  | 27 |
| 7232717143 | exponential growth model | -(N v t) = (N v 0) e ^ rt -e is base of natural logs, t is time -future size of population (N v t) depends on current size of population (N v 0), intrinsic growth rate of population (r) & amount of time (t) over which population grows -j-shaped |  | 28 |
| 7232717144 | corridors | -strips of natural habitat that connect separated populations -provide connectedness among populations |  | 29 |
| 7232717145 | metapopulation | -groups of spatially distinct populations that are connected by occasional movements of individuals between them -provide a species with some protection against threats such as diseases |  | 30 |
| 7232717146 | community ecology | -study of how interactions between species affect community structure & organization |  | 31 |
| 7232717147 | competition | -struggle of individuals to obtain a limiting resource |  | 32 |
| 7232717148 | competitive exclusion principle | -principle stating that two species competing for the same limiting resource cannot coexist |  | 33 |
| 7232717149 | resource partitioning | -situation in which two species divide a resource, based on differences in their behavior or morphology |  | 34 |
| 7232717150 | predation | interaction in which one organism kills & eats another |  | 35 |
| 7232717151 | parasites | -live in or on organism they consume, known as host -rarely cause death to host, since they consume only small fraction of host *tapeworms, protists that live in bloodstream & cause malaria |  | 36 |
| 7232717152 | pathogens | -parasites that cause disease in host *viruses, bacteria, fungi, protists, helminths |  | 37 |
| 7232717153 | parasitoids | -organism that lay eggs inside other organisms -when eggs hatch, larvae consume host from inside out, which leads to death *wasps, flies |  | 38 |
| 7232717154 | mutualism | -an interaction between species that increases the chances of survival or reproduction for both species -assist other species on order to benefit itself |  | 39 |
| 7232717155 | commensalism | -relationship between species in which one species benefits & the other species is neither helped nor harmed *bird use tree as perch, fish use coral as place to hide from predators |  | 40 |
| 7232717156 | symbiotic | -relationship of two species that live in close association with each other |  | 41 |
| 7232717157 | keystone species | -species that are far more important in their community than their relative abundance might suggest -exists in low numbers *predators, source of food |  | 42 |
| 7232717158 | ecological succession | -replacement of one group of species by another group of species over time -decades to centuries -in terrestrial community, can be primary or secondary |  | 43 |
| 7232717159 | primary succession | -ecological succession occurring on surfaces that are initially devoid of soil *parking lot, newly exposed rock from glacier retreat, newly cooled lava |  | 44 |
| 7232717160 | secondary succession | -succession of plant life that occurs in areas that have been disturbed but have not lost their soil -follows event like fire, hurricane -occur on abandoned agriculture field *New England farms |  | 45 |
| 7232717161 | pioneer species | -species that can colonize new areas rapidly & grow well in full sunshine *aspen & cherry trees |  | 46 |
| 7232717162 | theory of island biogeography | -demonstrates importance of both habitat size & distance in determining species richness |  | 47 |
