ecology u1

ecology

study of relationships between living organisms & their physical environment

dynamic steady states

when gains & losses of ecological systems are in balance

ecosystem hierarchy in order

individual, population, community, ecosystem, landscape, biosphere

natural selection

the differential survival & reproduction of individuals based upon genotype/phenotype

evolution

change in the frequency of [heritable traits] in a population over time

*selecitve pressure

any environmental factor that increases or decreases the survival and reproduction of certain traits in a population

*genetic bottlenecking

a sharp reduction in population size that drastically reduces genetic diversity, leaving the surviving population with a limited gene pool

parasite

lives on host without killing it

parasitoid

lives on host and kills it

detritivores

decomposers

habitat

the place, or physical setting, in which an organism lives

niche

range if abiotic & biotic conditions that an organism can tolerate

models

empirical:based on data you can observe (no theories)

phenomenological: describe patterns w out explaining why (some theories)

mechanistic: explains what happens & why

greenhouse effect

the process of solar radiation (short wave) striking earth, being converted to infrared radiation (long wave), & being absorbed & re-emitted by atmospheric gases

also not man made

albedo

fraction of solar energy reflected by an object

solar equation

changed throughout the year (through, above, through, below)h

Hadley cells

describe air circulation between the equator and 30 degree N and 30 S latitudes

ITCZ

a band near the equator where warm, moist air rises because trade winds meet, causing frequent clouds and heavy rainfall (intertropical convergence zone; changes throughout the year)

the ___ effect influences wind patterns

Coriolis

ocean currents

affect distribution of climates

GYRES

large-scale water circulation between continents

upwelling

relatively cold water raises near warmer

ENSO

The el nino-sothern oscillation

shows what can happen w a change in conditions

thermohaline circulation

• driven by thermal & saline gradients

• redistributes energy & nutrients among the oceans of the world in a trip that can take hundreds of years

landscape features

influence climate & weather

UHI

urban heat island

when a city’s temp is significantly warmer than surrounding rural areas

urban rainfall effect

when cities generate their own storms due to the UHI

convergent evolution

phenomenon in which 2 species descended from unrelated ancestors look similar bc they have evolved under similar selective forces

biomes

geographic regions that contains communities composed of organisms w similar adaptations

9 major terrestrial biomes are defined by

dominant plant forms that are associated with distinct patterns of seasonal temps & precipitation

mean annual temps

< 5 C: tundra & boreal forest

5-20 C: temperate

>20 C: tropical

name the 9 biomes

tundra, boreal forest, temperate rainforest, temperate seasonal forest, woodland/shrubland, temperate grassland/cold desert, tropical rainforest, tropical seasonal forest/savanna, subtropical desert

tired bears take tasty warm treats; tigers travel south

tundra

coldest biome characterized by a treeless expanse above permanently frozen soil

*permafrost

frozen soil so hard for trees to grow & nutrient poor

boreal forest (taiga)

densely populated by evergreen needle-leaved trees, w a short growing szn & severe winters

temperate rainforest

mild temps & abundant precipitation dominated by evergreen forrest

temperate seasonal forest

moderate temp & precipitation conditions dominated by deciduous trees

woodland/shrubland

hot, dry summers & mild, wet winters, a combo that favors the growth of drought-tolerant grasses & shrubs

temperate grassland/cold desert

hot, dry summers & cold, harsh winters & dominated by grasses, nonwoody flowering plants, & drought-adapted shrubs

tropical rainforest

high precipitation, never freezes, evergreen vegetation in multiple layers

tropical seasonal forest/savannah

warm temps w pronounced wet & dry seasons, deciduous trees

subtropical deserts

hot temps, scarce rainfall, long growing seasons, & space variation

3 factors of water

salinity, flow, depth

streams & rivers

characterized by flowing fresh water (=lotic)

riparian zone

bond of terrestrial vegetation alongside rivers & streams that’s influenced by seasonal flooding & elevated water tables

headwater streams are

shaded, nutrient poor, more O2, and allochthonous

allochthonous

inputs, such as leaves, that cone from outside the ecosystem

downstream river

open, wide, nutrient rich, & autochthonous

autochthonous

inputs come from algae & aquatic plants inside the ecosystem

lakes & ponds

characterized by non flowing fresh water (=lentic) w at least some area of water that is too deep for plants to risk above the water’s surface

littoral zone

rooted vegetation/shallow

limnetic zone

sunlight still reaches

profundal zone

deep, no sunlight

benthic zone

surface below the water

thermocline

transition between warm & cold weather

freshwater wetlands

contains standing fresh water (=lentic), or soils saturated with fresh water for at least part of the year, & is shallow enough to have emergent vegetation throughout all depth

salt marshes

saline environment, contain non woody emergent vegetation, often within an estuary

mangrove swamps

occur along tropical & subtropical coasts & contain salt-tolerant trees w roots submerged in water

intertidal zone

narrow bond of coastline between the levels of high tide & low tide

tide pools

fluctuate dramatically in temp & salinity, but can have lots of life within them

coral reefs

in warm, shallow waters that remain at 20 deg. C year round

open ocean

part of the ocean that is away from the shoreline & coral reefs

photic zone

sunlight still reaches

aphotic zone

no sunlight

3 thermal properties of water

• high specific heat means that it changes temps slowly

• resistant to changing states

  • densest at 4 deg. C

the thermal properties of water …

influence how it responds to changes & the environment it provides for organisms

the density of water…

influences how organisms move through it

viscosity

the thickness of a fluid that causes objects to encounter resistance as they move through it

different water depths present …

different challenges to aquatic organisms

---

is a powerful solvent

water

solute ____ as you move towards the ocean

concentrations

calcium carbonate

limestone

some solutes reach ___ & can

saturation; precipitate out of solution

acidity

the concentration of H ions in a solution

pH equation

-log(H+ concentration)

osmosis

movement of water across a semipermeable membrane

osmotic potential

force w which an aqueous solution attracts water by osmosis [MPa]

osmoregulation

mechanisms that organisms use to maintain proper solute balance

semipermeable

barrier/filter that allows for movement for some variables & not others