Ecology Quiz

biotic factors

living things

abiotic factions

non living factors (air, water, rock, temperatures)

what communities are dominated by biotic factors

organism dense communities

what communities are dominated by abiotic factors

extreme habitations

grass adaptation to sand dunes

• thick waxy cuticle → reduce transpiration

• stomata in indentations → humid air can remain

• leaves roll up in droughts → humid chamber

• carb accumulation in root+leaf cells → increase osmotic potential

tree adaptations to mangrove swamps

• secretion of excess salt from salt glands in leaves

• cable roots grow close to surface for more O2

• large buoyant seeds carried by ocean

abiotic variables affecting plant species distribution

temp, water, light, soil pH and salinity, availability of mineral nutrients

abiotic variables affecting animal species distribution

water and temp

transects

investigate tolerance ranges of species

transects examples

line intersect sampling, belt transects, observational transects

sensors

record levels of a parameter

• data loggers

conditions required for coral reef formation

depth: less than 50 so light can reach

pH: above 7.8

salinity: 32-42 parts per thousand

clarity for light

temp: 23-29 degrees celsius

biome

all ecosystems of a specific type

ecological niche

every species in an ecosystem fulfills a unique role

species can’t survive unless all niche dimensions are satisfied

what do zones of tolerance determine

habitat

requirements of obligate aerobes

continuous O2

only live in oxic environments

examples of obligate aerobes

all animals and plants

requirements of obligate anerobes

no O2

only live in anoxic environments

examples of obligate anerobes

clostridium tetoni

methanogenic archaea

requirements of facultative anaerobes

use of O2 if available

live in oxic or anoxic environments

examples of facultative anaerobes

e.coli, yeast

modes of nutrition

photosynthesis, holzoic, mixotrophic

what is the energy in sunlight used for

fix CO2, produce sugars/amino acids/other carbon compounts

what uses photosynthesis as a mode of nutrition

plants

eukaryotic algae

some bacteria groups

holozoic nutrition in animals

food is swallowed before digestion

1. ingestion

2. digestion

3. absorption

4. assimilation (synthesize macromolecules)

5. egestion (voiding undigested material)

heterotrophic as holozoic nutrition

carbon compounds come from organisms

mixotrophic nutrition in some protists

autotrophs, protists, facultative mixotrophs, obligate mixotrophs

autotrophs

make their own carbon compounds

protists (mixotrophs)

both auto and heterotrophs

falcultative mixotrophs

can’t synthesize the carbon compounds they inject

auto, hetero, or mixotrophs

eg, euglena

obligate mixotrophs

auto and hetero

ecological niche types

fundamental, realized, competative exclusion, saphotropic nutrition

fundamental niches

potential range is defined by tolerance range and adaptations, only if no competition

realized niches

subset of fundamental niche, reductions due to overlaps with the niches of other competitor species

actual extent of potential range, due to competition

competative exclusion

2 species fundamental niches overlaps, if one species outcompetes the other in all parts, the second species is excluded

saprotrophic nutrition

secrete digestive enzymes into dead organic matter, digest externally, and absorb product

includes some fungi and bacteria, aka decomposers

diversity of nutrition in archaea

diverse in every source used for ATP production

• phototrophic, chemotrophic, heterotrophic

adaptations for dention and diet of herbivores

large and flat teeth to grind down fibrous plant tissues

adaptations of dention and diet for carnivores

defined canine teeth for tearing meat

adaptations of dention and diet for omnivores

mix of different types

adaptations of herbivors to resistance in plants

ex, insect mouth parts

• jaw like for biting off, chewing, and investing leaf pieces (beetles)

• tubular for piercing leaves/stems to reach ploem sieve and feed on sap (aphids)

plant adaptations

thorns and other physical structures

toxic secondary compounds in seeds and leaves

• some animals have metabolic adaptations for detoxifying these, like milkweed aphids tolerate milkweed toxins

adaptations of predators for finding, catching, killing prey

physical: vampire bats have molars to pierce prey

chemical: black mamba produces paralyzing venom

behavioral: grizzly bears ambush migrating salmon

adaptations of prey for resisting predation

physical: moths resemble broken birch twigs

chemical: caterpillars feed on toxins and display warning stripes

behavioral: blue striped snappers swim in a tight group

adaptations of plants for harvesting light

• trees have dominant leading shoot for rapid growth

• lianas climb other trees for support to use less xylem

• epiphytes grow on trunks to receive higher light intensity, shade out tree leaves

• shade tolerant shrubs absorb light reaching forest floor

ecosystems that persisted for a long time

daintree rainforest in northern Australia - 180 million years

requirements for stability in ecosystems

• steady supply of energy

• nutrient recycling w/o leakages, resulting in nutrients leaving the ecosystem

• high genetic diversity in individual species to survive environmental selection pressures

• climatic variables remaining within tolerance levels

what species activity has a disproportionate effect on the structure of a community

keystone species

tipping point in ecosystem stability

level of disturbance causing ecosystem to cross ecological threshold

resulting in abrupt change

example of tipping point

amazon rainforest and deforestation as a positive feedback loop

models to investigate the effect of variables on ecosystem stability

• small experimental areas set up as ecological experiments

• fenced off enclosures

• mesocosms

mesocosms

small container w/ transparent sides for sunlight

• includes autotrophs, saprotrophs/detrivores to recycle nutrients

changes caused by humans that threaten stability

deforestation, fossil fuels, climate change, forest fires

what does sustainability of resource harvesting depend on

rate of harvesting must be lower than the rate of replacement so no depletion occurs

in ecosystems, what does sustainability rely on

nutrient availability, detoxification of waste products, energy availability

example of resource harvesting

brazil nuts in the amazon rainforest

overfishing cod in north atlantic

factors affecting sustainability of agriculture

soil erosion, leaching nutrients, supply of fertilizers + other inputs, pollution from agro chemicals, carbon footprint

bioaccumulation

concentration increase of a toxin in body tissues during an animal’s life

example of chemical in bioaccumulation

mercury, which is fat soluble

biomagnification

increase in concentration of toxin at each successive trophic level in the food chain

example of biomagnification

DDT (pesticide) in American kestral

eutrophication (nutrient enrichment) of aquatic and marine ecosystems due to leaching

nutrients from fertilizers/manure/urine contain water-soluble nitrates and phosphates

rainfall drains through soil → enters waterways → causes algae blooms that kill other plants → increase decomposition and biochemical O2 demand (BOD)

rewilding as a solution

encourages natural ecosystems to return by stopping human activities, distributing seeds of missing plants, reintroducing apex predators/keystone species, control of invasive species

what does degradation of ecosystems lead to

loss of biodiversity, rapid rates of species extinction, loss of ecosystem services

ways to rewild

carbon sequestration, climate regulation, flood protection, prevention of soil erosion, purification of air and water

what was improved at hinewai reserve in new zealand

town water supply improved, carbon sequestration, public access

what percentage and type of sun radiation is absorbed in atmosphere before reaching earth’s surface

25-30% short form radiation

what percentage of sun radiation reaches surface and is converted into heat

70-75%

what type of radiation in re-emitted

long wave radiation

what percentage of energy is absorbed by greenhouse gasses

70-85%

what temperature would the earth be w/o greenhouse effect

-18 degrees

causes of climate change

carbon dioxide, cellular respiration, combustion of fossil fuels and biomass, methane

• all amplified by positive feedback loops

methane

marshes/waterlogged habitats

landfills

extraction of fossil fuels

melting permafrost

increase in absorption of solar radiation

temp rises → arctic sea ice melts → dark oceans absorb more heat →

acceleration rates of decomposition of peat + organic matter

temp rises → permafrost thaws → CO2 and methane released into atmosphere from decomposition →

release of CO2 from deep ocean

increase temperature → gasses bubble from water, solubility decreases → increased CO2 in atmosphere

increase in droughts and forest fires

forest fires → increased dryness + drought bc of increased transpiration rates → increased temp and CO2

example of tipping point

net loss in carbon accumulation in boreal forest → may transition from carbon sink to carbon source

• cold temps reduce rate of cellular respiration and decomposition of detritus

• photosynthesis captures CO2 in tree biomass

• warmer temps/drier winters → droughts → fires

• releases CO2 and reduces capacity to store carbon

polar habitat change: landfast ice

landfast ice is attached to shore w/ variability in formation

• emperor penguins lose breeding ground and increased distance to food

polar habitat change: sea ice

arctic sea ice is decreasing

• walrus pups are in danger of trampling

changes in ocean currents

ocean is stratified, mixing between layers occurs due to wind and current

CC increases stratification and prevents nutrient upwelling

stratified

warmer, less salty water is on top

effect of stratification

decreases ocean’s primary production and energy flow through marine food chains

upslope range shifts of temperate species

tropical montane bird species in new guinea migrate to higher elevation and increase resource competition

poleward shifts of temperate species

northward spread in north America tree species

threats to coral reefs as an example of potential ecosystem collapse

corals need carbonate ions to make calcium carbonate

• hydrogen ions react w/ dissolved carbonate ions, reducing concentration → ocean pH has dropped by 30% since late 18th century

• corals can’t make skeletons and existing skeletons dissolve → increased temps cause coral bleaching

CC solution

Aforrestation, forest regeneration, restoration of peat-forming wetlands as approaches to carbon sequestration