Chapter 1 (Introduction to Ecology)

Learning Objects/ Slides

ecology

the study of the distribution and abundance of organisms, the interactio between organism, the interaction between organism and their environment, and structure and function of ecosystems

1995 Minnesota with the frogs

Parasites and Pesticides
Upon examination of the
frogs, it was discovered that
ALL deformed amphibians
had a parasite called
Ribeiroia ondatrae

individual approach

understands how adaptations, or characterisitcs of an individual’s morphology, physiology, and behavior enable it to survive in an environment

population approach

examines variation in the number, density, and composition of individuals over time and space

community approach

understands the diversity and interactions of organisms living together in the same place

ecosystem approach

examines the interrelationships among the living organisms, physical features, bio-chemical processes, natural phenomena, natural phenomena, and human activities in ecological communities

types of ecology experiments

• laboratory

• small-scale field

• large-scale field

• replication

• random assignment of treatments statistical analysis

abiotic

relating to or resulting from non-living factors in an environment, such as temperature, water, sunlight, soil, air, and minerals.

biosphere

the global sum of all ecosystems, where all plants, animals, microorganisms, and humans live and interact with the air, water, and soil.

control group

the group in an experiment that does not receive the treatment or experimental condition. It is used as a baseline for comparison to see the effect of the variable being tested.

3 reasons to why we care about ecology

1. the products obtained from ecosystems

2. necessary for the production of all other ecosystem services

3. benefits obtained from the regulation of ecosystem processes

advantages and disadvantages of using field observations

advantages:

• cost effective

• direct data collection

• minimal interference

disadvantages

• lack of control

• observer bias

• limited repeatability

advantages and disadvantages of using lab experiments

advantages

• high control over variables

• easier to replicate

• faster results

disadvantages

• ethical concerns

• artificial setting

• expensive equipment and setup

advantages and disadvantages of using field experiments

advantages

• real world setting

• natural behavior

• useful for social research

disadvantages

• cost

• low control over variables

• replicability issues

importance of hypotheses

importance of controls

importance of replication

importance of data analysis

two reasons why amphibians are important

factors that affect formation of deformities in frogs and how they are interrelated

how ecology can be studied on different spatial and temporal scales

How to interpret the results of a scientific study

most important PHYSICAL factors for where an organism lives

temperature and water

others: light and ocean pressure

most important CHEMICAL factors for where an organism lives

salinity, pH, oxygen

others: carbon dioxide, nutrients, toxins

weather

current conditions (temperature, precipitation, humidity, cloud cover)

temporal scale: minutes to weeks

climate

long-term description of weather, based on averages and variation measured over decades

temporal scale: decades to centuries

continentality

inland= greater of temperature swings

mountains i

block moisture dude to rain shadwo

warm air is ___ dense than cold air

less dense

there is a ___ atmospheric pressure at the equator than at 30 degrees North latitude

lower

air cools as it _____

expands

what areas will have high humidity

0 degree latitude (equator)
subpolar low (60 degrees latitude)

what areas will have low humidity

30 degree latitude (descending dry air from hadley and Ferrel cells, deserts)
Poles (90 degrees latitude) → cold, descending air

what areas will have high pressure

low humidity areas (dry) = high pressure zones = descending air → the air is sinking and pressing down on the surface

- 30 degrees (subtropical highs)
- 90 degrees (poles)

what areas will have low pressure

high humidity areas = low pressure zones = rising air → the air is moving upward and away from the surface

- 0 degrees (equator)
- 60 degrees (subpolar lows)

atmospheric circulation cells

determine Earth’s major climate zones

temperature differences drive what?

atmospheric and oceanic circulation

winds flow from areas of ___ pressure to ____ pressure

high to low

winds moving towards the equator will always bend to the ____

west

winds at the equator will always bend to the ____

east

winds appear deflected due to rotation of earth

coriolis effect

within the same tropical rainforest, predict what the temperature and precipitation profiles will look like at the same longitude, equal distances above and below the equator?

at 30 degrees S latitude we would expect

low humidity and high pressure

winds that are moving from the poles towards the equator

bend to the east in the northern hemisphere and to the west in the southern hemisphere

what would happen if the Earth wasn’t tilted

the seasonal changes would be more extreme

if the average temperature on Earth increased, what effect would this have on the distribution of boreal forests in the northern hemisphere

The southern edge of the boreal forests would move northward

what is the main reason earth has different climates and seasons

The tilt of earth’s axis stays the same but this tilt causes variation

at 30 degrees S laitude, you would expect

high pressure, little humidity

intertropical convergence zone (ITCZ)

where the two hadley cells meet

gulf stream

bring warm water from equator to poles

California current

brings cold water from the poles to equator

heat capacity

a physical property of matter, that is defined as the amount of heat supplied to a material to produce a unit change in its temperature

biome

large-scale terrestrial communities shaped by physical environment, categorized by plant forms. determined by climate (both averages and seasonal variation)

convergent evolution

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

what type of radiation does the sun emit

shortwave

What type of radiation does the earth emit

longwave

albedo

= .32
proportion of solar radiation being reflected by a surface

positive feedback

a change in a system causes more changes in the same direction, making the effect stronger or bigger

negative feedback

a change in a system triggers a response that reduces or reverses that change, helping system stay balanced or stable

climate envelope

a range of conditions over which a species occurs; can predict response to climate change

acclimatization

adjusting to stress through behavior or physiology
- short term

• reversible process

adaptation

Individuals with traits that enable them to cope with the stress are favored; over time, these genetic traits become more frequent in the population
- long term

• genetic response

endotherms

produce their own heat

ectotherms

rely on heat from the environment