Ecology Exam 3

many different species interacting make up

community ecology

how has monarch butterfly overwintering population size been changing? why?

declining / increase of herbicides sprayed kills of native plants that monarchs use for nectar, to lay eggs, and to reproduce

how does the amount of habitat/plant interaction affect diversity of a species

increased habitat means increased density

the practice of growing a single crop, plant species, or organism over a wide area

monoculture

homes that have monoculture yards are considered ecological (__)

wastelands

What did Douglas Tallamy discover about species diversity to sustain wildlife with native plants

need a lot of species and those species should be native

list an example of important of plant choices, exotic vs. native

exotic tree of heaven only supports 6 species while native oak supports 532 species

association of interacting species inhabiting some defined area

community

community structure is based on what 3 parts

number of species (richness), relative species abundance, and species diversity

t or f: Preston studied how common or rare species are in relationship to one another

t

what is the relationship between number of species and percent of plant cover

few plants have very low or very high coverage, most have intermediate

what is the relationship between number of species and number of individuals

few bird species or abundant, most species are moderately abundant

what is the scale between percent coveral intervals in lognormal distribution graph

next interval twice preceeding one

shape of Preston’s distribution was

lognormal (bell shaped/normal)

what did the study with Canadian prairie moths show about lognormal curve sampling

you need a large sample size to see lognormal curve

model that defines the number of samples needed to likely record all or almost all species at location of interest

species rarefaction curve

what two factors define species diversity and say what they are

species richness (number of species) and species evenness (relative abundance of species)

what does species evenness mean

more equally distributed

what is the formula for Shannon wiener index

-sump_ilnp_i

quantitative index of species diversity is the

shannon wiener index

how does species evenness relate to uncertainty and index of species diversity

more evenness means more uncertainty and higher diversity index

what does index of species diversity really measure

uncertainty in predicting ability of randomly bumping into select species

example of how environmental complexity affects species diversity

MacArthur found the warbler diversity increased as vegetation stature (complexity/volume) increased

for animals, species diversity is determined by complexity of (__), which is called (__), established by Hutchinson when he studied lakes and phytoplankton

plant habitat / Paradox of the plankton

what did Tillman discover to help explain the various niches within lakes

nutrient ratios in different parts of lake creates niches for different species

both NO3 concentration and soil moisture show great (__) over short distances

heterogeneity

what is the relationship between soil fertility and number of species and why?

high soil fertility means less species because uniform abundance of fertilizer leads to competition and then dominant plant drives out others. low soil fertility allows for many different niches and thus more species

portrays relative abundance and diversity of species within community by plotting relative abundance against rank in abundance

rank-abundance curve

rank-abundance curves show that plant diversity (BOTH richness and evenness) as been progressively (__) since beginning of long term fertilizing in 1856

declining

example of experiment that showed that plant diversity declines with fertilizing

Park Grass Experiment

discrete, punctuated, killing, displacement, or damaging of one or more individuals that directly or indirectly creates an opportunity for new individuals to be established

disturbance

established by Connell, predicts that intermediate levels of disturbance promote higher levels of diversity

intermediate disturbance hypothesis

why do low levels of disturbance reduce diversity?

competition causes one species to dominate

example of effect of disturbance and diversity

intermediate disturbance of prairie dogs (clip and dig vegetation) lead to most grass and forb diversity in South Dakota

removing prairie dogs removes (__) from plant diversity

heterogeneity

tree density (__) bird and plant species richness

promotes

summary of the feeding interactions within a community. one of the most basic and revealing descriptions of community structure

food web

antartic food web bottom to top

phytoplankton (diatoms) / krill / small fish / emperor penguin / seal / killer whale

phytoplankton are (__) organisms what kingdoms make up phytoplankton? include examples?

photosynthetic / Kingdom Protista (diatoms) and Kingdom Bacteria (blue-green algae)

zooplankton protozoan, multicellular, example that eats phytoplankton

krill

what do animals use to feed on krill? what animals feed on krill?

baleen / fish, squid, penguins, seabirds, seals, whales

reductions in one component of the food web, called (__), can ave drastic effects on other species in the community

perturbations

species that have substantial influences on community structure as a consequence of their high biomass

dominant or foundation species

list an example of an abiotic factor affecting food web relationships

global warming and climate change warming ocean water and negatively affects phytoplankton populations. this then affects bottom up the food chain, causing penguin populations to decline

examples of abiotic factors that can affect food webs

temperature, nutrients, water availability

give an example of strong and weak interactions within food web

wetland reed is foundation species. fly attack reeds and develop larvae in ricegrain galls. parasitoid moth also attacks reeds and larvae bore into stems which cause side shoots and allows for more flies to lay larvae. parasitoid wasps attack flies and blue tit bird pecks eats larvae

presence/absence of this species is critical to stability of the food web; they have inordinate influence on community structure

keystone species

occurs when the activities of one species, through an intermediary species, benefits another species without itself being helped or harmed

indirect commensalism

negative impacts are the result of two species sharing a predator or herbivore or by one species facilitating populations of a predator or herbivore of the second species

apparent competition

what was Paine’s hypothesis on the relationship between percent of community that is predators and the number of species in community

higher proportion of predators means higher diversity of prey

did the atlantic ocean or sargasso sea have more species and why?

sargasso sea because higher percentage of predators

list an example of an experiment that showed that predators are important to number of species

Mukkaw Bay Washington State Paine experiment: top predator sea star was removed. this caused a decline in diversity from 15 to 8 species. mussels and gooseneck barnacles drove out other species

t or f: we used to think only predators were keystone species

t (now we found herbivores can be)

t or f: Lubchenko proposed to resolve the contradictory affects of herbivores increasing diversity, decreasing diversity, or sometimes doing both

t

snail preference for feeding?

tough, red algae OR

tender, green algae

tender, green algae

explain part 1 Lubchenko’s experiment on herbivores effecting local diversity

green algae dominated in pools without snails while red algae dominated in pools with the snails because the snails ate all of the green algae

how are the snail populations controlled to prevent them from eating all the green algae

snails eaten by green crab which are eaten by seagulls

what did Lubchenco find when she observed number of algal species in tide pools with different densities of snails

as density increased from low to medium, number of algal species increased. but then as density increased further from medium to high, number of algal species declined to create a curve

why did Lubchenco’s experiment result in the curve

at low density, snail feeding not enough to prevent green algae from dominating pool and crowding out other species. at medium density, snail feeding on green algae prevents competitive exclusion. at high densities, snail eats all green algae and less preferred algae

requirements for a species to be keystone

low biomass and high impact on community structure

give an example of a mutalistic keystone species and results of experiment

cleaner wrasse eats parasites from client fish. when the cleaner fish were removed, fish diversity declined 24%. when cleaner fish were added, diversity went up 24%

on reefs without cleaner wrasses, fish harbor (__) times the number of parasites as those living with cleaner wrasses

4

what disperses 30% of the seeds in the shrublands of the fynbos of South Africa?

ants

south Africa’s southern Cape where vegetation mainly shrubs, 8600 species, 68% endemic

Cape Fynbos

explain the mutalistic relationship of ants in South Africa? how do the ants do it so well?

ants disperse shrub seeds and in return feed on elaiosome food bodies / they bury seeds in sites safe from rodents and fire

Christian found substantial reduction in seedling recruitment by plants producing (__) seeds in areas invaded by (__). meanwhile, (__) seeded plants who are less affected by the invaders showed no reduction

large / argentine ants / small

what mechanisms for success did the garlic mustard use during its invasion

easily scape natural enemies and herbivores, release secondary compounds (release chemical in soil to keep other plants from growing), high phenotypic plasticity, high reproductive output

what impacts did the invasion of exotic garlic mustard have

decreased native plant diversity and growth, decrease mycorrhizal fungi abundance, decreased native butterfly survival, altered soil nutrient cycling

as the number of garlic mustard plants per plot increased, how did the shannon diversity index change

went down

there is growing evidence that the invasion of garlic mustard is (__) abundance of West Virginia (__). percentage of eggs that hatch on native garlic mustard leaves is significantly (__) than on toothwort leaves.

decreasing / white butterfly / lower

term proposed by Arthur Tansley for biological community plus all of the abiotic factors influencing that community

ecosystem

two parts of ecosystem ecology

energy flow and nutrient cycles

difference between energy flow and nutrient cycles

energy flows from producer to consumer and need constant new flow to fuel primary production while nutrients move in cycles

primary production generated by

autotrophs

source of energy FOR ALL ORGANISMS. quantity of energy that enters planet that can be captured and converted to chemical energy or biomass

primary production

primary production is derived from (__) during (__) and (__)

carbon fixation during photosynthesis and chemosynthesis

production of new, organic matter, or biomass, by autotrophs in ecosystem per unit area or volume during some period of time

primary production

total primary production by all primary producers in ecosystem

gross primary production

gross primary production minus respiration by primary producers

net primary production

production of biomass by heterotrophic consumer organisms feeding on plants, animals, microbes, fungi, or detritus during some period of time

secondary production

position in food web determined by number of transfers of energy from primary producers to that level

trophic level

rely on chemosynthesisindirectly through a symbiotic relationship with specialized bacteria living inside their bodies.

tube worms

bottom level of pyramid is (__)

primary producers

second level of pyramid is (__), which includes

primary consumers / herbivores and detritivores

third level of pyramid is (__), which includes

secondary consumers / carnivores and detritivores

fourth level of pyramid is (__), which includes

tertiary consumer / predators feeding on carnivores

t or f: all consumers depend on primary production for existence

t

tubeworms lack (__) and (_). they are highly vascularized tissues with specialized cells with large amounts of (__)

mouths / digestive systems / bacteria

has bacteria on itself that does chemosynthesis

yeti crab

about half of gross primary production carbon used for

cellular respiration

what 3 factors affect NPP

temperature, rainfall, and nutrients

relationship between precipitation and NPP

increased precipitation increases NPP

relationship between temperature and NPP

increased temperature increases NPP

what is the main factor affecting NPP in aquatic environments? and where is it higher?

nutrient availability / shallow water and heavy current (cycles nutrients)

rule that claims that nutrient in shortest supply is limiting factor for production

Liebig Law of the Minimum

What did Shaver and Chapin observe about NPP when they added commercial fertilizer with N, P, and K?

primary production doubled

whole-lake experiment: before fertilizing, the two lakes supported (__) phytoplankton biomass

after fertilizing, phytoplankton biomass (__) in the experimental lake

when fertilizing stopped, phytoplankton biomass (__) in experimental lake

similar / increased / decreased

an increase in nutrients often leads to an initial rise in primary production followed by a (__) in species diversity

decline

higher species diversity generally leads to (__) biomass production

higher

influences of physical and chemical factors of ecosystem are (__) controls on trophic cascade

bottom-up