chapter 25 populations and ecosystems

population

community

ecosystem

operational habitat

abiotic

biotic

climate

soil factors

pioneers

a horizon

b horizon

c horizon

interactions

mutualism

competition

competition exclusion

niche

ecotypes

transplant experiments

common garden

frugivores

commensal relationships

predation

herbivores

herbivory

browsing or grazing

pathogenic

boundaries of the geographic range

limiting factor

random distribution

clumped distributions

uniform distributions

chemicals

allelochemics

allelopathy

age distribution

demography

generation time

intrinsic rate of fnatural increase or biotic potential

carrying capacity

r-selected species

k-selected species

physiognomic structure

life forms

species composition

trophic levels

primary producers

primary consumers

secondary consumers

decomposers

energy flow

carbon flow

an individual plant never exists in isolation in a habitat; instead , there are other individuals of the same species

rather coexists with numerous populations of other plant species as well as populations of animals, fungi, protists, and prokaryotes

nonliving environment

the physical size and shape of the organisms and their distribution in relation to each other and to the physical environment

pollinators are critically important aspects of the habitat for the plant species they pollinate, and any disease organisms or predators that prey on those pollinators are also important to the plant.

habitat

the set of conditions in which an organism completes its life cycle

nonliving and are physical phenomena: climate, soil, latitude, altitude, and disturbances such as fires, floods, and avalanches.

living factor: the plant itself, other plant species, and the species of animals, fungi, protists, and prokaryotes

the first plants that invades a new soil

tolerance range

between the low and high extremes

uppermost and is sometimes called the zone of leaching; it consists of litter and debris, and as this breaks down, rainwater washes nutrients from it downward into the next layer

zone of deposition, is the area where materials for the a horizon accumulates. it is rich in nutrients and contains both humus and clay

composed mostly of parent rock and rock fragments

each species is assumed to be adapted to a particular set of conditions

a situation in which tow populations do not grow as well together as they do separately because they use the same limited supple of resources

when several individuals, of either just one or several species, occur together, the possibility for interaction is created. if the interaction is basically benficial for both organisms

whichever species is les adapted is excluded form the ecosystem by superior competitors

which one species benefits and the other is unaffected, are also common between plants and animals

this could be the beginning of divergent speciation, of course, but long before the various subpopulations could be called subspecies

ex. beans frown in rich soil with adequate water are strikingly different from those grown in poor soil with little water and other stresses. to test whether ecotypes really exist

plants form each site are transplanted to the alternate site, and plants from both sites may be grown together

many interrelationships between plants and fungi or bacteria are harmful to the plant, but the fungi and bacteria

seed dispersal by fruit-eating animals, also benefits both species as long as the animal does not chew the seeds and digest the embryos

predation

a relationship in which one species benefits and the other is harmed

herbivores

herbivory

but more likely known as browsing or grazing

although most habitat components act on the plant simultaneously and most should be considered important, at any given time and locality, one factor alone determines the health of the plant

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used whenever there is no obvious, identifiable pattern to the position of individuals

those in which the spacing between plants is either small or large, but rarely average

the inhibition

the roots of one individual may establish a zone that prevents the germination or growth of others. zones can also be established, at least theoretically, by the release from the plant of chemicals that inhibit other plants

the length of time from the birth of one individual until the birth of its first offspring, affects the rapidity of population growth: annuals have a generation time of 1 year or less and can increase rapidly, whereas most conifers and angiosperm trees must be several years old before they produce their first seeds

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the number of offspring produced by an individual that actually live long enough to reproduce under ideal conditions.

the number of individuals in each population that can live in a particular ecosystem is limited

a population close to its carrying capacity, select for phenotypes very different from those that are beneficial in a disturbed habitat

typically are annuals or small shrubby perennials because the disturbed habitat gradually changes back into a crowded one that is no longer suitable for the pioneer

trees, shrubs, and herbs are the three most useful categories

temporal structure

the changes that an ecosystem undergoes with time; the time span can be as short as a day or can encompass season or decades

refers to the number and diversity of species that coexist in an ecosystem, and it depends on whether the climate is mild or stressful, the soil is rich or poor, and the species' tolerance ranges are broad or narrow

basically feeding levels

the steps of how the food energy level goes down each losing the energy they gained/lose

autotrophs, they are the first step of any food web

the herbivores that eat the primary producers

herbivores are preyed on by the carnivores, the secondary consumers

such as fungi and bacteria break down the remains of all types of organisms, even those of other decomposers