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