Lecture Final Exam Review Sheet (54-56) Flashcards
occurs when species compete for a resource in short supply
interspecific competition interaction (-/-)
what can strong competition lead to?
competitive exclusion
what is competitive exclusion?
local elimination of a competing species
what does the competitive exclusion principle state?
two species competing for the same limiting resources cannot exist in the same place
refers to an interaction in which one species, the predator, kills and eat the other, the prey
predation interaction (+/-)
what are some feeding adaption of predators?
claws, fangs and poison
what defensive adaptions do prey display? (2) (BMM)
1) behavioral adaption
2) morphilogical and physiological defensive adaption
3) mechanical and defense protects species such as skunks and porcupines
what type of behavioral adaptions do prey display? (5) (HFFSA)
1) hiding
2) fleeing
3) forming herds or schools
4) self-defense
5) alarm calls
what can animals with effective chemical defense often exhibit?
bright warming coloration called apesomatic coloration
what makes prey difficult to spot?
cryptic coloration or camouflage
in some cases how may species gain significant protection?
by mimicking the appearance of another species
what is a batesian mimicry?
when a palatable or harmless species mimics an unpalatable or harmful model
what can mimicry also be used by?
predators to approach prey
what is an example of mimicrys being used for predators to approach prey?
the mimic octopus can take on the appearance and movement of more than a dozen marine animals
what is a mullerian mimicry?
two or more unpalatable species resemble each other
what is an example of a mullerian mimicry?
the yellow jacket and cuckoo bee
refers to an interaction in which an herbivore eat part of a plant or alga
herbivory interaction (+/-)
what has herbivory interaction led to?
evolution of plant, and chemical defenses and adaption in herbivores.
what is symbiosis?
a relationship where two or more species live in direct and intimate contact with one another.
what is a species fundamental niche?
potentially occupied by that species
what is a species realized niche?
the niche actually occupied by that species
as a result of competition what may happen?
a species fundamental niche may differ from their realized niche
what is an example of a species fundamental niche differing from their realized niche as a result of competition?
the presence of one barnacle species limits the realized niche of another niche
when one organism, the parasite derives nourishment from another organism, its host which is harmed in the process
parasitism interaction (+/-)
parasites that live within the body of their host
endoparasites
parasites that live on the external surface of the host
ectoparasites
what do many parasites have?
complex life cycles involving a number of hosts
how do some parasites change the behavior of their host?
in a way that increases the likelihood that the parasite will be transmitted to the next host
what can parasites significantly effect?
the survival, reproduction density of their host population
an interspecific interaction that benefits both species
mutalistic symbiosis or mutualism interaction (+/+)
what can mutualism interaction be?
obligate or facultative
when one species cannot survive without the other
obligate
where both species can survive alone
facultative
when one species benefits and the other is neither harmed nor helped
commensalism interaction (+/0)
what is true of commensalism interaction and why?
it’s hard to document in nature because any close association likely affects both species
variety of species that make up a community
species diversity
two components of species diversity
1) species richness
2) relative abundance
what is species richness?
the number of different species in the community
what is relative abundance?
the portion that each species represents of all individuals in the community
what can two communities have when it comes to species diversity?
the same species richness but a different relative abundance
what do food chains link?
tropic levels from producers to top carnivores
the feeding relationships between organisms in a community
trophic structure
what is a key factor in community dynamics?
trophic structure
what is a food web?
a branching food chain with complex trophic interactions
how are food chains and food webs shaped?
food chains are linear and food webs are web shaped
what may species play a role at in a food web?
more than one trophic level (reason for food web)
how can a food web be simplified? (2) (GI)
1) grouping species with similar trophic relationships into broad functional groups
2) isolating portion of a community that interacts very little with the rest of the community
how big is each food chain in a food web?
only a few links long
what does the energetic hypothesis suggest?
that the length of a food chain is limited by inefficient energy transfer
how can the energetic hypothesis be tested?
by manipulating productivity
what is an example of the energetic hypothesis manipulating productivity?
researchers varied the amount of leaf litter available to consumers in tree-hole communities and measure the number of links in the chain
the sequence of community changes after a disturbance
ecological succession
when does primary succession occur?
when no soil exists when succession begins
what is primary succession a result of?
changes induced by the vegetation itself
on the glacial moraines what do pioneer species facilitate?
later arrivals by increasing soil nitrogen content
where does secondary succession begin?
in an area where soil remains after disturbance
what is an example of secondary succession?
abandoned agricultural land may return to its original state through secondary succession
what is an ecological niche?
the sum of species’ use of biotic and abiotic resources
what can an ecological niche also be thought of as?
an organism’s ecological role
how can ecologically similar species coexist in a community?
if there are one or more significant differences in their niches
differentiation of ecological niches, enabling similar species to coexist in a community
resource partioning
what are dominant species?
most abundant species or have the highest biomass
what does hypothesis’ suggest about dominant species? (2)
1) they are most competitive in exploiting resources
2) they are most successful at avoiding predators
why may invasive species, typically introduced to a new environment by humans might become dominant?
because they lack predators or disease
what is one way to discover the impact of a dominant species?
remove it from the community
what is an example of removing a dominant species from a community to discover its impact?
introduction of chestnut blight to Eastern North America killed most of the dominant American chestnut trees
what type of effect does removing dominant species from community?
a small impact on some and a severe impact on others
what are keystone species?
exert strong control on a community by the ecological or niches
how does keystone species contrast from dominant species?
they aren’t necessarily abundant in a community
what do field studies of sea stars illustrate?
their role as a keystone species in intertidal communities
what does the bottom-up model propose?
an undirectional influence from higher to lower trophic levels
what does the bottom-up model represent?
the presence of mineral nutrients (N) controls plant (V) numbers which control Herbivore (H) numbers in which control predator (P) numbers (N->V->H->P)
what does the bottom-down model propose and what else is it known as?
that control comes from the trophic level above and is also known as trophic cascade model
what does the bottom-down model represent?
predators limit herbivores, and plants limit nutrient levels (N
what is the intermediate disturbance hypothesis?
states that moderate levels of disturbance can foster greater diversity than either high or low levels of disturbance.
examples of interspecific interactions (3) (PHFSC)
1) predation
2) herbivory
3) facilitation
4) symbiosis
5) competition
types of symbiosis (3) (PMC)
1) parasitism
2) mutualism
3) commensalism
what do high levels of disturbance exclude?
many slow-growing species
what do low levels of disturbance allow?
dominant species to exclude less competitive species
Explain why species richness declines along an equatorial-polar gradient
species richness generally declines along an equatorial polar-gradient and is especially great in the tropics. two factors in equatorial-polar gradient are probably evolutionary history and climate.
what are zoonotic pathogens transferred from?
other animals to humans
what can the transfer of pathogens be?
direct or through an intermediate species called a vector
what are many of today’s emerging diseases and what are some examples?
zoonotic (lyme disease, Zika and HIV)
what can identifying the community of hosts and vectors for a pathogen help prevent?
disease
what is an example of identifying the community of hosts and vectors to prevent disease?
recent studies identified two species of shrew as the primary hosts of the pathogen or lyme disease
what is the avian flu?
a highly contagious virus of birds
what are ecologists studying about the avian flu?
the potential spread of the virus from Asia to North America through migrating birds
explain how the first law of thermodynamic apply to ecosystems?
amount of energy is constant. energy is passed in food chains Either it is stored or released to the environment.
explain how the second law of thermodynamic apply to ecosystem?
energy is degraded when it is used. Most is lost as heat. 90% of the energy is lost at each trophic level.
what is Gross Primary production (GPP)?
an ecosystem’s total primary production
what is net primary production (NPP)?
GPP minus energy used by primary producers for respiration.
what is only available to consumers?
NPP
what do ecosystems vary greatly in?
NPP and contribution to the total NPP on Earth
what is standing crop?
the total biomass of photosynthetic autotrophs at a given time.
why does energy flow in an ecosystem?
energy enters most ecosystems as sunlight and then is converted to chemical energy by autotrophs, passed to heterotrophs through organic molecules that make up food and finally dissepated as heat.
why does nutrients cycle within an ecosystem?
chemical elements, including carbon and nitrogen, are cycled among biotic and abiotic components of an ecosystem.
what elements do photosynthetic organism incorporate into their biomass and then what is it consumed by?
air, soil and water and then is consumed by animals
how are the elements that are incorporated into the biomass returned to the environment?
by the metabolism of plants and animals, as well as by bacteria and fungi.
what factors may limit primary production in aquatic ecosystems?
light and nutrients
how does light limit primary production in aquatic ecosystems?
the depth of light penetration affects primary production in the photic zone of an ocean or lake.
how does nutrients limit primary production in aquatic ecosystems?
more than light, nutrients limit primary production in geographic regions in oceans and in lakes
what are typically the nutrients that most often limit marine production?
nitrogen and phosphorous
where are concentrations of nitrogen and phosphorous very low and why?
in photic zones because they are taken up rapidly by phytoplankton and because detritus tends to sink
where are nitrogen and phosphorous common?
in freshwater lakes
what is primary production?
the amount of light energy converted to chemical energy by autotrophs during a given time period
in marine and freshwater ecosystems, what controls primary production?
light and nutrients
what is secondary production?
amount of chemical energy in food converted to new biomass during a given period of time.
when a caterpillar feeds on a leaf, how much of the leaf’s energy is used for secondary production?
only about one sixth
what is production efficiency?
the fraction of energy stored in food that is not used for respiration
what is trophic efficiency?
the percentage of production transferred from one trophic level to the next
what does trophic efficiency usually range from?
5-10%
what is trophic efficiency multiplied over?
length of food chain
explain why worldwide agriculture could feed more people if all humans consumed only plant material?
most of the energy is wasted by feeding grain to farm animals. Hogs and chicken are more efficient at making meat than cattle and fish are more efficient than the other.
what are the four nutrient reservoirs? (WCNP)
1) water cycle
2) carbon cycle
3) nitrogen cycle
4) phosphorous cycle
what is the biological importance of the water cycle?
essential for all organisms
what forms of the water cycle are available to life?
liquid, vapor or frozen ice.
reservoirs for the water cycle
1) oceans contain 97% water
2) 2% bound in glacier and polar ice caps
3) 1% in lakes, rivers and ground water
key processes for the water cycle (4) (ECPT)
1) evaporation by H20 by solar energy
2) condensation of H20 vapor into clouds
3) precipitation
4) transpiration by plants moves volumes of H20 into atmosphere, surface and groundwater can flow into ocean completing cycle
biological importance of the carbon cycle
framework of organic molecule essential to all organisms
forms available to life in the carbon cycle
photosynthetic organisms utilize C02 during photosynthesis and convert carbon to organic forms used by consumers
reservoirs in the carbon cycle (7) (FSSOPAS)
1) fossil fuels
2) soils
3) sediments of aquatic ecosystems
4) oceans
5) plants and animal biomass
6) atmosphere
7) sedimentary lock is the largest (limestone)
key processes for the carbon cycle (3) (PVB)
1) photosynthesis by plants and phytoplankton remove atmospheric C02 (equal to the amount added by cellular respiration)
2) volcanoes are source
3) burning fossil fuels
biological importance of the nitrogen cycle
part of amino acids, proteins and nucleic acids and is a limiting plant nutrient
forms available to life of the nitrogen cycle (3) (TOB)
1) 2 inorganic forms: ammonium and nitrate
2) organic forms: amino acids
3) bacteria (animals use only organic forms)
reservoirs for the nitrogen cycle (4) (8SSB)
1) 80% is in the atmosphere as nitrogen gas
2) soils and sediments of lakes, rivers and oceans
3) surface and ground water
4) biomass of living organisms
key processes of the nitrogen cycle (7) (EFNPBBNR)
1) entrance is nitrogen fixation
2) fixed by lighting
3) nitrogen fertilizer
4) precipiation
5) blowing dust provides input of ammonium
6) nitrification converts ammonium to nitrate by nitrifying bacteria using nitrate as their metabolism instead of oxygen
7) releasing nitrogen gas
conversion of nitrogen gas by bacteria to forms that can be used to synthesize nitrogenous organic compounds
nitrogen fixation
biological importance of the phosphorous cycle
major constituent of nucleic acid, phospholipids, ATP and bones and teeth
forms available to life in the phosphorous cycle
phosphate which plants absorb and use in the synthesis of organic compounds
reservoirs for the phosphorous cycle (4) (SSOO)
1) sedimentary rocks (largest)
2) soils
3) oceans (dissolved)
4) organisms
key processes for the phosphorous cycle (5) (WSPRD)
1) weathering of rocks adds phosphorous to soil
2) some may leach into ground and surface water and reach the sea
3) phosphate taken in by producers may be eaten by consumers
4) returned to soil through decomposition of biomass or excretion by consumers
5) dust and sea spray move small amounts through atmosphere
explain why toxic compounds usually have the greatest effect on top-level carnivores
biological magnification
process in which accumulated toxins become more harmful as they become more concentrated in successive trophic levels of a food web
biological magnification
why does biological magnification occur?
because biomass at any given trophic level is produced from a much larger biomass ingested from the level below
describe the causes and consequences of ozone depletion
results mainly from accumulation of CFCs (chemicals used in refrigerators and manufacturing)
when breakdown of CFCs from these chemicals what happens?
they rise to the stratosphere, the chlorine reacts with the ozone, reducing molecular 02
where is thinning (ozone depletion) most apparant?
Antartica and the hole is increased
what does CFCs do to earth?
increases intensity of UV rays reaching Earth’s surface, increasing lethal and nonlethal forms of skin cancer and cataracts in humans
what is conservation biology?
seeks to preserve life and integrates several fields
what fields does conservation biology integrate? (5) (EPMGE)
1) ecology
2) physiology
3) molecular biology
4) genetics
5) evolutionary biology
what is restoration ecology?
applies to ecological principles to return ecosystems that have been disturbed by human activity to a condition as similar as possible their natural state
what are the three major threats to biodiversity? (HIO)
1) habitat destruction
2) introduced species
3) overexploitation
how is habitat destruction a major threat to biodiversity and what is an example?
alteration of habitat
Ex: Prairie occupies less than 1% of original area in Wisconsin/ 93% of coral reefs have been damaged by human activities
how is introduced species a major threat to biodiversity and what is an example?
humans move them from native location to new geographic area
ex: brown-tree snakes arriving in Guam as cargo ship stowaway
how is overexploitation a major threat to biodiversity and what is an example?
human harvesting of wild plants or animals at rates exceeding ability of population of species to rebound
ex: fishing decreased population of bluefish tuna to feed human protein
what is the small-population approach?
studies processes that can make small populations become extinct.
what is a small population prone to?
interbreeding and genetic drift which draw it down an exctinction vortex
what is the key factor driving the extinction vortex?
loss of genetic variation neccesary to enable evolutionary responses to environmental change
do small population and low genetic diversity always lead to exctinction?
no not always
minimum population size at which species can survive
Minimum Viable Population (MVP)
what does the MVP depend on?
factors that affect a population’s chances of survival over a particular time
what does the MVP require?
determining the effective population size
what is the declining population approach?
focuses on threatened and endangered populations that show downward trend, regardless of population size
what does the declining population approach emphasize?
factors that caused a population to decrease
what steps does the declining population approach involve? (5) (CSDTA)
1) confirm that the population is in decline
2) study the species’ natural history
3) develop hypotheses for all possible causes of decline
4) test hypotheses in order of likeliness
5) apply the results of the diagnosis to manage for recovery
what is the total population size?
the number of organisms inhabiting an ecosystem
what is an effective population size?
a population’s breeding potential
describe the conflicting demands that may accompany species conservation?
conservation requires conflict between habitat needs and of endangered species and human demands
what is an example of conflicting demands accompanying species conservation?
US pacific Northwest Habitat preseravation is at odds with timber and mining industries
describe biodiversity hot spots
a relatively small area with an exceptional concentration of endemic species and large number of endangered and threatened species
why are biodiversity hot spots important?
good choices for nature reserves, but hard to identify (could be hot spot for more than one taxonomic group)
what are zoned reserves?
an extensive region that includes areas relatively undisturbed by humans surrounded by areas that have been changed by human activity and are used for economic gain.
what has become the world leader of establishing zoned reserves?
Small central American nation of Costa Rica
what do buffer zones provide?
a steady, lasting supply of forest products, water and hyroelectric power as well as support agriculture and tourism
what does Costa Rica hope to maintain?
at least 80% of its native species in its zoned reserves
what is bioremediation?
use of organisms, usually prokaryotes, fungi or plants to detoxify polluted ecosystems.
what do restoration ecologists use various type of to remove many different types of toxins from ecosystems?
organisms
what is an example of restoration ecologists using organisms to remove many different types of toxins from ecosystems?
Some plants adapted to soils containing heavy metals are capable of accumulating high concentrations of potentially toxic metals
what do restoration ecologists use to revegetate sites polluted by mining and then what do they do?
plants and then they harvest them to remove the metals from the ecosystem
what is biological augmentation?
uses organisms to add essential materials to degraded ecosystem
what does biological augmentation encourage the growth of and what does it speed up?
plants that thrive in nutrient-poor soils and often speeds up the rate of successional changes that can lead to recovery of damaged sites
what is an example of biological augmentation encouraging the growth of plants that thrive in nutrient-poor soils?
rapid growth of indigenous plants alongside roads in Puerto Rico after colonization of the areas by nonnative plant that thrives on nitrogen-poor soils
what did rapid buildup of organic material from the nonnative plants enable?
the indigenous plants to recolonize the area and overgrow the introduced species.
describe the concept of sustainable development
development that meets the needs of people today without limiting the ability of future generations that meet their needs
what must sustainable development connect?
life sciences with social sciences, economics and humanities.
explain the goals of the sustainable biosphere initiative (2) (DS)
1) defines and acquires the basic ecological needs to develop, manage and conserve Earth’s resources as responsibly as possible.
2) studies global change
how does the sustainable biosphere initiative study global change
1) interactions between climate and ecological processes
2) biological diversity and its role in maintaining ecological processes
3) ways in which productivity of natural and artificial ecosystems can be sustained.
