Ecology Exam 1 (UWL BIO307 Baines)

the scientific study of the relationship between organisms and their environment

Ecology

oikos

greek word for "house"

lokos

greek word for "scientific study"

dependent variable(s) in frog experiment

number of frogs with deformities

independent variable(s) in frog experiment

presence/absence of pesticide and the size of mesh used

what causes the deformities in frogs?

parasites and pesticides

(NO single factor!!)

population

a group of individuals of a single species that live in a particular area and interact with one another

community

an association of populations of different species living in the same area

ecosystem

a community of organisms plus the physical environment in which they live

biosphere

all organisms on Earth plus the environments in which they live

small spatial scale

soil microorganisms

large spatial scale

atmospheric pollutants

short temporal scale

leaf response to sunlight

long temporal scale

how species change over geologic time

model

simplified representation of a real system

(mathematical: quantitative) (word-based: qualitative)

mensurative study

measure natural variability of intact systems to generate and test hypotheses

manipulative study

generate hypotheses and then manipulate system before measuring variables and testing hypotheses (lab and field exp.)

experimental design

1. replicate! (perform each treatment more than once)

2. assign treatments at random

3. statistical analysis to determine significant effects

replication

used so that as the number of replicates increases, it becomes less likely that results were due to a variable that was not measured or controlled

linear regression

a way to test for a linear relationship between two variables

p-values

a non-signif. p-value means that we have failed to reject the null hypothesis!! (P>0.05)

coefficient of determination (R^2)

tells you about the goodness-of-fit: what proportion of the total variation is explained by the line

standard errors

useful way of representing variability of the mean (smaller with less variability) - is a 95% prob. that the true pop. mean lies within 2 SE of the calculated mean

ANOVA (*ANSWER ON TEST)

TESTS THE NULL HYPOTHESIS THAT SEVERAL GROUPS HAVE THE SAME MEAN

null hypothesis

there is no effect of the independent variable on the dependent variable

(manipulative: treatment has no effect)

(mensurative: no relationship between measured variables)

weather

current conditions! (temp, precipitation, humidity, clouds)

climate

long-term description of weather, based on averages (seasons) ---- determines where organisms can live! --- timing is also important

water vapor

cool air holds less water vapor than warm air! (cold air is more dense)

Hadley cell

cell that forms N & S of the equator, DRIVEN BY SOLAR RADIATION! (large-scale conviction in which air rises at the equator and sinks about 30 deg N&S)

Coriolis effect

result of Earth's rotation - causes moving particles (such as air) to be deflected RIGHT IN THE NORTHERN HEMIS. (larger to smaller circumference in flow of tilt) and LEFT IN THE SOUTHERN HEMISPHERE (smaller to larger, go against direction of spin)

subsidence

creates regions of high atmosphere pressure at 30 degrees N & S - once air temp. is similar to that of surrounding atmosphere, it descends towards Earth's surface

upwelling

deep ocean water rises to the surface! (force of coriolis effect causes surface waters to flow away from the coast and deeper, and colder ocean waters to rise and replace them)

regional climatic influences

vegetation and regional climate influence and feed back on one another

albedo

amount of solar radiation a surface reflects! (lighter colored surfaces have higher albedo, darker surfaces therefore absorb more radiation) -ice has higher albedo than water

evapotranspiration

water loss through transpiration by plants

ITCZ (Intertropical Convergence Zone)

the zone of max solar radiation and atmospheric uplift ---- if axis decreased, the ITCZ would move less!

stratified

oceans and lakes can become this - warm surface water on top of colder, denser water results in layers that do not mix --- determines movement of nutrients and oxygen

light and oxygen levels of open water (top to bottom)

Epilimnion

Thermocline

Hypolimnion

Benthos

*Eat that honey bee

Water properties

Warmer temp, solids dissolve more into ions, and with more ions, density increases

Warmer water, less oxygen (colder water, more oxygen)

Salinity

concentration of dissolved salts in water

River Continuum Concept

as streams increase in size, detritus from riparian vegetation decreases and becomes less important as a food source; macrophytes become more important!

human impact on streams

sewage/fertilizer/other pollutants

non-native species

deforestation

dams

pelagic zone

open water --- dominated by plankton

phytoplankton

photosynthetic - only in photic zone (which extends to about 200 m deep)

zooplankton

non-photosynthetic protists (tiny)

estuary

where rivers flow into oceans (salinity varies)

salt marshes

shallow coastal wetlands (dominated by grasses and rushes)

mangrove forests

dominate some tropical coastal zones

salt-tolerant

roots trap sediments!

rocky intertidal zones

provide a stable substrate for many organisms -- sessile organisms have a high tolerance for changes in salinity

coral reefs

restricted to warm, shallow water, biomass some of the highest in the world

pelagic zone

open ocean beyond the continental shelves

evolution

change in organisms over time

natural selection

individuals with certain heritable characteristics survive and reproduce more successfully

evolution mechanisms

1. mutation

2. natural selection

3. genetic drift

4. gene flow

5. Non-random mating

** Marissa never gets good naps

directional selection

individuals with one extreme of a heritable phenotypic trait

stabilizing selection

individuals with an intermediate phenotype are favored

distruptive selection

individuals at both phenotypic extremes are favored

frequency dependent selection

fitness of a phenotype is determined by its frequency (rare or common) in a population ********it is an advantage to be different

genetic drift

chance events determine which alleles are passed on to the next generation (significant for only small populations!)

gene flow

alleles are transferred from one population to another via movement of individuals or gametes

1. populations become more similar

2. new alleles can be introduced to a population

if equator was heated, hadley cells would..

become MORE pronounced and there should be LESS rain at 30 degrees N

Mountain zones (bottom to top)

Lower montane zone --- montane zone --- subalpine zone --- alpine zone

*elevation increases, temp decreases, precipiation increases

heterogeneity

the quality or state of consisting of dissimilar or diverse elements