Flashcards in LECT 21 Deck (76):
patchy distribution of resources
or death rate, is a measure of the number of deaths (in general, or due to a specific cause) in a particular population, scaled to the size of that population, per unit of time.
is a group of subjects who share a defining characteristic (typically subjects who experienced a common event in a selected time period, such as birth or graduation).
_____ have worldwide ranges
Photosynthesis and respiration, nectar production, phenology* adjustments, expenditure of energy stores
short generation time
Migration other than natural dispersal
illustrate carrying capacity.
logistic growth patterns
types of survivorship curves
Type I, II, III
are those that emphasize high growth rates, typically exploit less-crowded ecological niches, and produce many offspring, each of which has a relatively low probability of surviving to adulthood
rafts in form of floating vegetation may also carry species to new land
Three major aspects of population ecology
–Population range: area over which a population occurs
–Patterns of spacing within a range
–Changes in sizes of populations over time
are factors whose effects on the size or growth of the population vary with the population density. There are many types of density dependent limiting factors such as; availability of food, predation, disease, and migration. However the main factor is the availability of food.
density dependent factors
show probability of survival for each cohort
distinct populations that still interact, exchange individuals
a situational decision that involves diminishing or losing one quality, quantity or property of a set or design in return for gains in other aspects. In simple terms, a tradeoff is where one thing increases and another must decrease
reproductive growth versus vegetative growth
key enviromental challenges
three aspects of population ecology
2. distribution within range (pattern of spacing)
3. changes in populations over time
Plant popula'on numbers and/or produc'vity more driven by ___ than anything else
describes a specific process, the biological changes an animal or plant makes in response to a change
diffrent dispersal strategies; seed adaptations for dispersal
Wind blown, adherent and fleshy fruits
Spatial segregation of the sexes:
–More male willows in dry channels than females
–More female willows in wet channels than males.
____ is higher for female plants
–“Cost of reproduc'on”: impact on future repro by current repro
–Alternate-‐bearing in plants
states that individuals can maximize lifetime reproductive success by trading-off the allocation of resources to current offspring against the production of future offspring, and their own needs
cost of reproduction
is the potential for reproduction of an organism or population, measured by the number of gametes (eggs), seed set, or asexual propagules. ____is similar to fertility, the natural capability to produce offspring.
Group of interacting members of a single species
The maximum number of individuals of a populaGon that a given environment can sustain indefinitely.
____is the ability of a population of living species to increase under ideal environmental conditions – sufficient food supply, no predators, and a lack of disease. An organism's rate of reproduction and the size of each litter are the primary determining factors for _____
a form of alternate bearing that features produc'on of many seeds by a plant every two or more years in regional synchrony with other plants of the same species –Oak trees, for one, tend to do this –Defense against seed preda'on
reproduce over many seasons (perennial plants)
–Advantages for plants? Drawbacks? Most common climate/habitat?
Traits maximizing number of surviving offspring:
–Longer length of reproduc've life span
–Higher # of young produced each year
Distribu'ons of the individuals in a popula'on vary according to resource distribu'on and compe''on
Patchiness of resources High levels of compe''on Uniform resource distribu'on ClumpedNear-‐Uniform or Regular Random Lack of strong interac'ons
patchy resources, can apply to species of plants and animals
Cost of reproduction reflected by sexual dimorphism
–Woody dioeciousspeices: female is generally ______
–Herbaceous dioecious species: female generally ______ Why
or diagonal curves are an intermediate between Types I and III, where roughly constant mortality rate/survival probability is experienced regardless of age. Some birds and some lizards follow this pattern.
dynamics of species populations and how they interact with the environment
___ possess relatively stable populations and tend to produce relatively low numbers of offspring; however, individual offspring tend to be quite large in comparison with
me between birth of individual and birth of its offspring
stronger, larger populations replenish weaker ones
source sink metapopulations
_______ of range can occur serendipitously: unusual weather condi'ons, currents, altera'on of habitats
____ lives one year, more or less. When is the highest mortality? When is highest fecundity? Is that when the most seeds are produced in the population?
high levels of competition
Even, near-‐uniform or regular:
a group of interacting individuals of one species at time or place
The geographic distribu'on of a population
or concave curves have the greatest mortality (lowest age-specific survival) early in life, with relatively low rates of death (high probability of survival) for those surviving this bottleneck. This type of curve is characteristic of species that produce a large number of offspring (see r/K selection theory). This includes most marine invertebrates. For example, oysters produce millions of eggs, but most larvae die from predation or other causes; those that survive long enough to produce a hard shell live relatively long.
___ are those confined to limited ranges
describes plant mortality because of competition in crowded even-aged stands.
Plants have a variety of life spans, ranging from a month or two to 5000 years. Can be generally classified as ______
annuals, biennials, and perennials.
refers to processes that limit the size of a species' population in a given area
: uniform resource availability, lack of strong interactions/competition
_____ are mostly r-‐selected, ______ mostly K-‐selected, though there are weedy perennials and large, rela'vely slowly-‐developing annuals... •r-‐selected species oQen the “pioneer” species in succession
Cattle egrets thought to have reached the Americas from Africa via a trans-‐Atlan'c crossing
ability to alter behavior, physiology, and morphology itself
is the difference between (births + immigra'on) – (deaths + emigra'on)
Rela'onship between N and K and popula'on growth rates
dN = r(K -‐ N) dt K
reproduce once and die (annual plants) –What climates par'cularly favor annual plants? What other situa'ons?
Defined by density-‐dependent factors: abundance or lack of necessary resources and amount of harm caused by crowding (disease, parasites)
dis'nct popula'ons that exchange individuals
_____ changes over time
how populations change over time
Demography and demographics:
is a graph showing the number or proportion of individuals surviving to each age for a given species or group (e.g. males or females). Survivorship curves can be constructed for a given cohort (a group of individuals of roughly the same age) based on a life table.
ocean currents carry propagules to other con'nents
the differences in appearance between males and females of the same species, such as in colour, shape, size, and structure, that are caused by the inheritance of one or the other sexual pattern in the genetic material.
Can populations grow infinetely
_____ is mechanism for self-‐burial
____ and ____ determine population ranges over time
Natural selection and tolerance
or convex curves are characterized by high age-specific survival probability in early and middle life, followed by a rapid decline in survival in later life. They are typical of species that produce few offspring but care for them well, including humans and many other large mammals.
Type I survivorship curve