Ecology Exam 1

functional traits

morphological, physiological, or phenological characteristics affecting survival, growth, and reproduction

Endemism

a species that only exists in one specific geographic area in the world

where are the highest levels of endemism

in marine ecosystems - life evolved there first

the hydrologic cycle

dynamic movement of water among reservoirs at the global scale and the processes that cause water to move among reservoirs

reservoirs

locations that hold water within the hydrologic cycle

Reservoir turnover time

the time required for the entire volume of a reservoir to be renewed.

Reservoir turnover time for atmosphere

9 days

Reservoir turnover time for rivers

12-20 days

Reservoir turnover time for lakes

days to centuries

Reservoir turnover time for oceans

over 3000 years

Types of aquatic environments

Marine environments, transitional environments, freshwater environments

estuaries

freshwater to saltwater

salt marshes

saltwater to land

mangrove forests

saltwater to land

freshwater wetlands

freshwater to land

intertidal zones (marine environment)

occur globally where the ocean meets the land between high and low tides

what do intertidal zones create

creates microhabitats subject to highly variable conditions, causes species to live in the different zones based on their tolerance to conditions

Kelp forest structure (marine environment)

there is a canopy at the water’s surface, stipes extend from the canopy to the ocean floor Epi

stipes

kelp stems

Epipelagic zone

0-200m ; sunlit zone, photosynthesis possible, most surface life

Mesopelagic zone

200-1000 m ; twilight zone, light fades, no photosynthesis

what animals may live in the Mesopelagic zone

sperm whale, octopus

Bathypelagic zone

1000-4000m - midnight zone, completely dark, high pressure

Abyssal zone

4000-6000m, near ocean floor, cold, high pressure, sparse life

hadal zone

6000-11,000m ; deepest trenches, extreme pressure

gyres

wind created, are large circulation systems that move water across latitudes in a circular motion

thermohaline circulation

driven by differences in water density

what drives gyres

wind patterns and the Coriolis effect

5 major gyres

Indian, North Pacific, South Pacific, North Atlantic, South Atlantic

Upwelling

occurs when surface water is moved by some force (like wind) which allows deeper water to rise to the surface

what does upwelling do

brings cold, deep water with lots of nutrients to the surface

What drives thermohaline circulation

variation in temperature and salinity, resulting in density changes

• cold/salter water is dense and sinks

• warm/fresher water is less dense and rises

Variability of salinity

is less variable than temp and oxygen, varies with latitude and is relatively constant in one area

• related to regional rainfal

where is oxygen concentration the greatest

at the surface due to photosynthesis of marine plants and agitation by the wind

which transitional environments are land to sea

salt marsh and mangroves

which transitional environment is river to sea

estuaries

what transitional environment is land to freshwater

freshwater marsh

land to sea transition factors

low oxygen soil, high salinity. dominated by salt-tolerant plants

land to sea ecosystem services

• protect coastlines from erosion/storms

• trap nutrients in sediments

• support biodiversity

Estuary factors

freshwater from rivers mix with seawater, creates strong physical and biological gradients

• very productive

freshwater marsh factors

wetland dominated by grasses

• occur close to lakes, rivers

• very productive and essential for birds, etc

Lakes salinity factor

more variable than ocean

rivers and streams salinity factor

salinity varies with soil type

Human threats to ocean

• coastal pollution

• warming and acidifying of oceans

• freshwater pollution

Coral bleaching

corals lose their symbiotic algae due to elevated temperature. vulnerable to disease and death

ocean acidification

excess CO2 from atmosphere increase acidity in ocean. Harms marine life

Eutrophication

when high amounts of nutrients (usually from runoff) cause a dense algal bloom. Algae bloom uses up oxygen, leading to deoxygenation and animal deaths

Ecology

the study of relationships between organisms and the environment

Evolution

the change in gene frequencies (underlying phenotypic variation) within populations across time (generations)

Ecological situations can be viewed as:

forces driving evolutionary solutions to ecological problems

Evolution by natural selection

occurs when the interactions organisms have with their environment lead to changes in the traits of populations of organisms over generations

Tenets of Evolution by Natural Selection (5)

1. variation exists

2. variation has a genetic basis

3. more individuals are born than survive to reproduce

4. survival is non-random

5. survivors reproduce

6. speciation

1. variation exists

individuals in a population differ in traits

2. variation has a genetic basis

some traits are passed from parents to offspring through genes

3. more individuals are born than survive to reproduce

therefore not all genetic material is passed on

4. survival is non-random

some traits increase organism fitness and survival rates

5. survivors reproduce

therefore adventageous traits are more likely to be passed on to offpsring

6. speciation

given enough time and changes, populations can diverge into new species

Phenotype

the observable characteristics of an organism that result from the interactions between the genetic makeup of the individual and its environment

gene

a sequence of DNA or RNA which codes for a molecule that has a function

allele

a variant form of a gene

genotype

the genetic make up of an individual

phenotype

the characteristics an individual displays as a result of their genotype

Heritability

The measure of how much of the variation in a trait among individuals comes from genetic differences rather than environmental factors.

• Natural selection can only produce evolutionary change within a population when traits are heritable.

  • passed down genetically from parents to offspring

natural selection

refers to differential survival and/or reproduction among phenotypes

fitness

an organism’s ability to survive, mate, and pass its genes on to the next generation

speciation

the process by which one population splits and evolves into two or more distinct groups due to accumulated genetic differences over time

Which form of natural selection is this

Stabilizing selection

Which form of natural selection is this

Directional stability

Which form of natural selection is this

Disruptive selection

Stabilizing selection

favors average phenotypes and selects against extreme variations

Directional selection

leads to changes in the population mean by favoring an extreme phenotype in the population.

Disruptive selection

occurs when two or more extreme phenotypes are favored over the average within a population

Macroclimate

prevailing climatic conditions over large areas and long time periods. Interacts with local landscape to produce microclimatic variation

Microclimate

small, specific area where the climate differs from the surrounding regional weather

Are macro or microclimates more relevant to most organisms

microclimates

Describe the factors that affect microclimate 

• altitude

• aspect

• vegetation

• ground color

• boulders/stones/rocks

• burrows

Altitude affect on microclimate

higher altitude = lower temperature due to low air pressure

aspect def

the direction a slope or surface faces

• some aspects are shaded, some exposed to direct sunlight - impacts temperature

aspect affect on microclimate

Hills, valleys, and cliffs influence local microclimates. Alters temperature, moisture, radiation

vegetation affect on microclimate

creates cooler, less variable temperatures

how do ground color, boulders, and burrows influence microclimates

• ground color = dark absorbs and retains heat better than light colored ground

• burrows - moderate temperature and minimized temp variation

• undersides of boulders/stones create microclimates

Principle of allocation

Organisms have limited energy and resources. Therefore, if an organism allocates more energy to one function, such as growth or reproduction, it reduces the amount of energy available to other functions

Why do most species perform best in a narrow range of temperatures

enzymes - have optimal temps at which they work best

• can shift optimal temp over time

• species from diff locations have diff optimal temperatures

Heat balance equation

Hs in heat balance equation

total heat stores in an organism

Hm in heat balance equation

gained via metabolism

Hcd heat balance equation

Gained/lost via conduction (contact)

Hcv heat balance equation

Gained/lost via convection (wind/water)

Hr heat balance equation

Gained/lost via radiation (sun)

He heat balance equation

Lost via evaporation

Conduction

heat is directly transmitted from the environment to an organism

convection

heat travels to/from the organisms via movement of air or water

evaporation (heat balance equation)

water from the environment or sweat turns into vapor and carries away heat

Poikilotherm or Heterotherm

 species whose body temperature varies with the

environment 

Homeotherm

species that maintain a relatively stable body temperature

Ectotherms

species who rely on external sources of energy for regulating body temperature (ex=reptiles)

Endotherms

species that rely on internally derived metabolic heat energy (ex=mammals)

how did the experiment with bacteria demonstrate the principle of allocation

In an experiment with E. coli bacteria, bacteria that allocated more energy toward reproduction had less energy available for survival and maintenance. This demonstrated that organisms have limited resources, so investing more in one function means less for another.

What happens to enzymes when temp is too cold

they work slowly