Chapter 5 - Ecosystems and Living Organisms

growth rate

(r) the change of a population's size, expressed in percent per year. Calculated as the birth rate minus the death rate

ecosystem

a biological community and its abiotic environment.

population ecology

a branch of biology that deals with the numbers of a particular species found in an area and how and why those numbers change/dont over time. determine processes common to all populations, study how it respondes to environmental changes, etc.

community

an association of different populations of organisms that live and interact in the same placeat the same time

density independent factor

an environmental factor that affects the size of a population, but is not influenced by changes in population density. typically abiotic, such as weather events that kill a lot.

density dependent factor

an environmental factor, whose effects on a population change as the population density changes. as density increases, these slow population growth by increasing d or decreaing b. examples are prefation, disease, and competition

warning coloration

an evolved defense against predation, prompts avoidance by experienced predators that there is a presense of poison

limiting resource

any environmental resource that, because of its scarce or unfavorable levels, restricts the ecological niche of an organism

symbiosis

any intimate relationship or association between members of two or more species, includes mutualism, commenalism, and parasitism. typically one of the species lives in or on the other species

evolution

culmulative genetic changes that occur over a time in a population of organisms, evolution explains many patterns of distribution and abundance displayed in the natural world.

logistic population growth

curve has an S shape, occurs when the growth rate decreases as the population reaches carrying capacity.

Henry Cowles

developed the concept of succession

James H Brown

ecologist, studied species competition and diversity in a long term, showed that species richness is decreased when one species is dominent over others.

emigration

(e) a type of dispereal, individuals leave a population and decrease its size

immigration

(i) a type of disperal, individuals enter the population and increase its size

carrying capacity

(k) the maximum number of individuals of a given species that a particular environmentcan support for an indefinite period, assuming there are no changes in the environment. leveling out of the population typically occurs at this number, changes in response to environmental things.

Eukarya

eukaryotes, organisms with eukaryotic cells, includes 4 different kingdoms - plants, animals, protists, fungi, have a high degree of organization including a nuclei and organelles

source habitats

habitats that increase the likelihood of survival and reproductive sucess for the individuals living there. generally have greater population densities than less sourcy habitats, and surplus may have to disperse

r selection

have traits that contribute to a high population growth, the species emphasize having a shit ton of babies so that at least some survive and make it to adulthood. high r - small body size, early maturity, short life span, large broods, little to no parental care. low long term survival chances

K selection

have traits that maximize the chance of surviving in an environment where the to # of individuals is close to carrying capacity, basically have a little amount of kids and try to keep them alive. high K - long life spans, slow development, late reproduction, large bodies, low reproductive rates,

ecosystem services

important environmental benefits that ecosystems provide to people, include clean air to breath, clean water to drink, and fertile soil to grow crops. ecosystems with better species richness have better ecosystem services

epiphytes

involved in a commenalism relationship between tropical tree, types of smaller plants like mosses which live attached to the tree bark, but does not feed off of it, only uses the position to help live

sink habitats

lower quality habitats, local brith rate is less than local death rate, population declines until extinction occurs. vacant and can be moved in by a species better suited for the habitat

disperal

movement of part of the population from one region or country to another, considered when population changed on a local scale are calculated. not included in birth and death rates

mycorrhize

mutualistic relations between fungi and the roots of about 80% of all plants, grows around and in the root area so the plants grow better and the fungi can live

competative exclusion

one species excludes another from a niche as a result of competition, meaning that two species with the exact same niche cannot coexsist

environmental resistance

organisms cannot produce forever at their intrinsic rates, because the resources in the environment set a limit on how many organisms can be supported. includes unfavorable conditions like lack of food water shelter, more disease. Negative feedback mechanism

ecological succession (succession)

process of the community developing over time, species in one stage being replaced by a different species, organisms that initially occupy the areas are replaced over time

GF Gause

russian ecologist, grew a population of a single species in a test tube, only supplying limited food. showed population increasing exponentially at first, then declining to 0 and leveling off. showed carrying capacity/environmental resistance

Robert MacArthur

studied warblers in north america which demonstrated resource partitioning

life tables

tables that show the likelihood of survival for indviduals of different times during their lives. orginially developed by insurane companies

community stability

the absense of change, assumed that it was a consequence of community complexity. result of resistance and resiliance

exponential population growth

the accelerating population growth that occurs when optimal conditions allow a constant reproductive rate over a period of time. when a population gets larger, it can grow even faster. demonstrated by the boom in population on our planet

primary succession

the change in species composition over time in a previously uninhabited environment

secondary sucession

the change in species composition that takes place after some disturbance distroys the exsisting vegitation, soil is already present

predation

the consumption of one species by another. uncludes animals killing and eating other animals, and animals eating plants. resulted in the coevolution of predator strategies (more efficient way to catch prey), and prey strategies (more efficient ways to escape a predator)

intrinsic rate of increase

the exponential growth of a population that occurs when resources are not limited. also called biotic potential. this is the maximum rate that the population could increase at. different species have different rates, and several factors effect this.

pioneer community

the initial community that develops during primary succession. typically things like lichens on bare rock, which secrete acids to break it apart

competition

the interaction among organisms that vie for the same resources (such as food or living space) in an ecosystem

coevolution

the interdependent evolution of two interacting species, symbiosis and the result of this

habitat

the local environment in which the organism lives

birth rate aka natural increase

the number of births per 1000 people per year (b)

death rate

the number of deaths per 1000 people per year (d)

population density

the number of individuals of a species per unit area or volume at a given time

sustainable harvest

the number of individuals that can be harvested from a population each year without reducing the total population. this is important to farming/fishing to ensure sustainable food sources.

species richness

the number of species in a community. varies greatly from one community to another. several factors effect this, such as abundance of potential niches, closeness in margins to other communities, species dominance, habitat stress, geological history

symbionts

the partners of the symbiotic relationship, can benefit from, be harmed by, or be not effected at all by the relationship.

fundamental niche

the potential, idealized niche of an organism. factors like competition make this typically unavalible

survivorship

the probability a given individual in a population will survive to a particular age. three main survivorship curves recognized by ecologists

type III

the probability of death greatest early in life, and then those that avoid that death have an increased chance of living once they are older.

type II

the probability of survival does not change with age, probability of death is always equally likely

natural selection

the process in which the best adapted individuals, those with a combination of genetic traits better suited for environmental conditions, are more likely to survive and reproduce, increasing their proportion in the population

realized niche

the resources that makes up the actual niche that organisms have

adapatation

the result of evolution, an evolutionary modification of a population that improves each individuals chances of survival and reproductive sucess in the environment occupied by the population

r = (b-d) + (i-e)

the total growth rate = (birth rate minus the death rate) + (immigration rate minus the emigration rate)

ecological niche

the totality of an organisms adaptations, its use of resources, and the lifestyle to which it is fitted. every organism has their own role in the structure and function of an ecosystem

type I

the young and those at reproductive age have a high chance of living, probability decreases more rapidly with age, death at late life

mutation

variations among offspring, changes in their nucleotide base sequence of their DNA which provides the genetic variability for natural selection in evolution. some mutatione beneficial, some harmful, beneficial ones will be selected for

cryptic coloration

when animals blend into their surroundings to hide from predators

resouce partitioning

when coexsisting species realized niches differ from each other in 1+ ways

population

a group of individuals of the same species that live in the same geographic area

archea

a kingdom of prokaryotes, live in oxygen deficient environments and are often adapted to harsh conditions

bacteria

a kingdom of prokaryotes, the ones that arent archea, typically live in more normal conditions

Charles Darwin

a naturalist, basically the father of evolution, who proposed that natural selection was the mechanism that evolution used. proposed that inherited traits that were better for survival would be preserved

pathogen

a parasite that causes disease and sometimes the death of the host, can occur in plants such as crown gall disease

metapopulation

a set of local populations among which individuals are distributed in distinct habitat patches across a landscape. distribution of local populations occurs because of difference in eleveation, precip, temp, etc.

keystone species

a species, often a predator that exerts a profound influence on a comunity in excess of tht expected by relative abundance. Special species vital to determining the nature and structure of the entire ecosystem

zooxanthelle

a symbiotic algae that lives inside the cells of coral and they photosynthesize and provide the animal with carbon and nitrogen compounds

parasitism

a symbiotic relationship in which one organism benefits and the other is adversley affected

mututalism

a symbiotic relationship where both partners benefit

ecotone

a transitional zone where two or more communities meet, contains all or most of the ecological niches of the two communities as well as some unique ones, highly species rich

commenalism

a type of symbiosis in which one orgnaism benefits and the other one is neither harmed nor helped

modern synthesis

a unified explanation of evolution- combines principles of genetics, natural selection, classification, fossils, developmental biology, and ecology all combined for their parts into a unified whole explanation

intraspecific competition

competition between different populations

interspecific competition

competition between population members