BIOL 1108 Unit 1 Mount St. Helens

Species

organisms that can produce fertile offspring

Population

all of the individuals of a single species that interact/breed

The unit at which evolution acts

Community

all of the populations of living things that interact in a place

Ecosystem

biological community of interacting organisms and their physical environment

Abiotic and biotic factors

Abiotic Factors that Define Ecosystems

Climate

-Averages and seasonality

Geology

-Bedrock, water, soils, topography

Disturbance

-Natural, human

-Scale and frequency

Biotic Factors that Define Ecosystems

Biodiversity

Species Interactions (Predator-Prey, Mutualism, Commensalism, etc.)

Presence of Invasive or Keystone Species

Ecosystems cannot be defined by

size

boundaries

Mt. St. Helens

Volcano that is part of Cascade Mountains that erupted in Washington state causing massive damage in 1980

-in temperate rainforest biome

Pre-Eruption Mt. St. Helens Ecosystem

Old Growth forest

-Never been logged

-Diverse forests and species

Rich soils

-Stimulated plant growth with lots of available nutrients

Heterogenous ecosystem that changed with elevation

temperate rainforest

Post-Eruption Mt. St. Helens Ecosystem

Forests scorched up to 17 miles from mt. st helens

Pumice Plain covered in ash so low nutrient levels in soil

Why do Mountain ecosystems have such high biodiversity?

As elevation increases, temp, O levels, precipitation levels, and biodiversity change and the ecosystems change

Elevation and Latitude: Differences in elevation in an area allow multiple biome

Effect of the eruption of MSH being lateral?

Northern slopes decimated, but southern slopes relatively unaffected

Scorch Zone

outermost forest

-defoliated trees

-surviving ground vegetation due to snow on the ground

debris avalanche

riverbeds where melt water and mud was washed in

Pumice Plane/Pyroclastic Flow

closest to blast zone

-Feet of volcanic ash (tephra/rock dust)

-No life

-small portion of the affected landscape

Blowdown Zone

largest zone

-Blast knocked over trees

-Not much surviving ground vegetation

Spirit Lake

flooded with muddy ash water and logs

-Murky water, limited visibility

What affects the order of reestablishment?

What can reach the area first?

-By wind(spores/seeds)

-What can survive there?

The first to survive there will be the first to reestablish

Plant Dispersal

how seeds/spores are spread from the parent plant

-Purpose: increases chance of survival by limiting competition for resources (soil nutrients..)

-Methods: wind, animal, water, gravity

Wind Dispersal

A method of dispersal where lightweight seeds catch the wind

-Long distances, random

Animal Dispersal

Seeds have hooks attached to them that attach to fur. Other seeds are eaten and pass through the digestive tract. can be carried far distances but varies

Water Dispersal

Seeds fall into the water and float away

-Splashes or long distance

Gravity Dispersal

Heavy nuts fall to the ground and roll

Example: Ballistic Dispersal

Ballistic Dispersal

plant catapults/ejects seeds

Ex. lupine

Seed Coat

protection and can impact dispersal

-Thickness varies (example. Walnuts vs. sunflower seeds)

-Thicker seed coats offer better protection from animals and dehydration

-Thinner seed coats don't cost as much energy to produce, can migrate fast

Cotyledon

food storage of fats, proteins, and oils

-Can be big or small

-Bigger cotyledons can offer more storage and last longer before germination (sprouting), higher survival rates, can grow quickly to overtop competitors

-Smaller cotyledons allow the seed to disperse farther and faster(lighter), takes less energy to produce (plant can produce more seeds)

Evolutionary Tradeoff

a trait increases fitness in one condition, while decreasing fitness in another

-explains why large-seeded plants produce relatively few seeds

per capita survivorship

probability of survival for any one seed

-decreases with the size of the seed (big seeds take more energy to produce but are more likely to survive)

Fitness

the ability to pass on genes to subsequent generations

Macronutrients

needed in large quantities to make nucleic acids and amino acids

-Primary (N, P, and K) and secondary nutrients

-Examples: Nitrogen, Phosphorous

Micronutrients

needed in small quantities, coenzymes

-Come from soil

-Example: Zinc

Where do plants get C?

air

Where do plants get H?

soil

Where do plants get O?

soil and air

What are plants made of?

50-75% H2O

-C, H, O (cellulose is C6H10O5, glucose is C6H12O6)

-N (big component of DNA and proteins)

-P (big component of phosphate backbone of DNA)

-Also some Magnesium (makes chlorophyll)

Nitrogen Cycle

(1) nitrogen fixation

-Nitrogen gas to ammonia

-carried out by bacteria typically

(2) nitrification

-ammonia to nirates and nitrites

-carried out by nitrifying bacteria typically

(3) denitrification

-nirates and nitrites to nitrogen gas and nitrous oxide

Tephra

-rock dust

-MSH soil

-missing nitrates

Importance of Nitrogen

-used to make proteins responsible for muscles,cellular communications and enzymes

-used for DNA's nitrogenous bases

-used to make chlorophyll

Protein Folding Steps

Primary structure, Secondary Structure, Tertiary Structure, Quaternary Structure

Proteins

Complex molecules made of amino acids

-Synthesized using ribosomes and an mRNA template (translation)

-Ex. digestive enzymes, helicase, muscle fibers

Primary structure: straight chain of amino acids, no folding, held together by peptide bonds

Secondary Structure:

Crimped (Beta Sheet)

Curled (alpha helix)

Tertiary Structure: multiple folds and bends of a single amino acid chain

Quaternary Structure: multiple tertiary structures

Primary structure

straight chain of amino acids, no folding, held together by peptide bonds

Peptide Bond

C-N polar covalent bond (e- shared) connecting AA (C from carboxyl group and N from amino group

-primary structure

Secondary Structure

Crimped (Beta Sheet)

Curled (alpha helix)

-H-bonds between Carboxyl and amino groups of AAs

Tertiary Structure

-multiple folds and bends of a single amino acid chain

-R- groups determine 3D structure

-IMFs, ionic bonds, and sometimes disulfide bridges determine exact folding pattern

quarternary structure

multiple tertiary structures

What can determine proteins shape?

-bonds, IMFs

-Can denature when too hot or wrong pH and lose its function

-mutations in an amino acid and that will change its function

Ionic Bond

-donate/take e-

-big differences in electronegativity in 2 molecules

-Permanent attraction between whole charged molecules (+1/-1)

-Anions: negative charge, extra electron, gained an e-

-Cations: positive charge, missing e-, lost an e-

Ex. NaCl

Covalent Bond

Share e-

-Low energy state

Ex. HCl

Polar Covalent Bond

E -shared unequally

-partial charge associated with a bond

Nonpolar Covalent Bond

E- shared equally

IMFs (intermolecular forces)

electrostatic charge attractions between molecules that can vary in permanence and strength

-H-bonds, Dipole-Dipole

Hydrogen Bond

strong temporary attraction between partial positive charges of H and partial negative N,O, F, Ex. H2O

-connects nitrogenous bases in DNA

Electronegativity

how tightly an atom holds onto its e-

components of amino acids

Amino Group

Carboxyl Group

R Group (determines AA interactions and protein shape)

What is the Limiting Resource in MSH soil?

Nitrogen

Liebeg's Law of the Minimum

Assumptions:

1) 1 limiting resource at a time

2) Too much of a nutrient isn't harmful

3) Ignore size limitations for organisms

-Can apply to individuals and populations: (states that they will grow only up to the point it runs out of a vital resource, even if there are surpluses of other resources)

-Only works with organisms with indeterminate growth

Indeterminate Growth

-don't have a maximum size, they grow until they die

Ex. trees, goldfish, lobsters, some snakes, etc.

Lupine

-1st to reestablish in MSH (pioneer species)

-improved the pumice plain by decomposing and enriching the soil, facilitating colonization of other plants

- has a mutualistic relationship with N-fixing bacteria that grows in its roots (plants get usable N and bacteria get habitat, glucose and other photosynthesis products)

Haber-Bosch Process

artificial way of producing N

-Caused huge agricultural revolution in the early 1900s

Types of Species Interactions

Mutualism(+/+), Predator/Prey(+/-), Parasitism(+/-), Herbivory(+/-), Commensalism(+/0), Altruism(-/+), Facilitation(-/+), Competition(-/-)

Mutualism (+/+)

Both species benefit from the interaction

Symbiotic Relationship

Live their lives in close physical proximity and evolved together (does not necessarily mean either organism is helped, harmed, or neither)

Ex. Clownfish and anemone (clownfish gets shelter and anemone is unaffected)

Ex. Mistletoe is a plant who sends root-like structures into the bark of a host tree like an oak in order to intercept and absorb the sugars and nutrients from its host. [Mistletoe and Oak trees]

Ex. Tick and dog (tick gets blood, dog is harmed)

Altruism

(-/+)one organism acts to increase the fitness of another organism at a cost to itself (decreasing its fitness)

Ex. Dog raises a litter of kittens

Facilitation

(-/+) One organism changes the environment, leading to its own eventual replacement

-Typically occurs in plants

-drives succession

Ex. Lupine improved the pumice plain by decomposing and enriching the soil allowing other species to colonize and take over

Ex. Blackberries and Hawthorns

Kin Selection

an organism increases the fecundity of a relative at a cost to its own reproductive capacity

-mutualistic

-Ants and bees

Competition

(-/-) limiting the other's potential

Types: Interspecific, Intraspecific

Interspecific Competition

competition between individuals of different species

Intraspecific Competition

competition between individuals of the same species

How to Plants Facilitate Each Others Growth?

Increased soil moisture

Soil building

Temperature and humidity regulation

Attracting pollinators

Soil Chemistry Alteration (N-Fixers like Lupine)

Succession

process of development that over time, gradually and predictably changes the biological community

Stages: Pioneer Stages, Intermediate Stages, Climax Community

Types: primary and secondary

-driven by facilitation

Pioneer Stages of Succession

1. Bare Rock

2. Lichen (can break down rock for nutrients, decompose and create soil)

3. Small annual plants, moss

4. Perennial herbs, grasses (stabilize soil)

Intermediate Stages of Succession

Shrubs, shade intolerant trees

Climax Community

stage that will persist as astatic ecosystem and will continuously regenerate itself until a disturbance

-Characterized by shade-tolerant trees (can grow without a lot of light, can grow in shade under established trees)

primary succession

succession starting with bare rock

Ex. succession beginning on mountain tops/granite outcrops, glacier retreats, parking lots,

secondary succession

Succession starting with soil

Ex. MSH

Mt. St. Helens Succession

secondary succession

Pioneer Stages

1. Lupine

2. Fireweed/Pearly Everlasting

Intermediate

3. Willows, Red Alder

Climax

4. Noble Fir, Douglas Fir, Red Cedar

What changes with Succession?

1. Complexity

2.Biodiversity

3.Soil Complexity

Complexity

habitat diversity

Types: vertical and horizontal

Increasing complexity —> increases habitat diversity —-> increases biodiversity

Vertical Complexity

Layers of a Forest

1.Soil

2.Forest floor

3.Understory/ Shrub Layer

4.Sub-canopy

5.Canopy

Horizontal Complexity

patchiness (more patches, more diversity, more stages of succession —> more horizontal complexity)

-increased by disturbances

Species Richness

the number of different species

Simpsons' Biodiversity of Index (S')

identifies relative abundance of species

0

Disturbance Regime

refers to the size(scale), type, and frequency of disturbances

Ex. MSH Disturbance Regime: volcanic disturbances (infrequent and large scale eruptions)

Dynamic Equilibrium

an ecosystem in a constant state of flux due to disturbance and succession over times

-Contains patches of different successional stages

-High biodiversity

-High horizontal complexity, varying vertical complexity

Ex. South slope of MSH

Ecosystem Services

economic benefits to humans provided by the natural environment and from healthy ecosystems

Ex. erosion control, pharmaceuticals, coastal hurricane protection

Why are some places more biodiverse than others?

1. Time (succession and Dynamic Equilibrium)

2. Ecosystem Complexity (Horizontal, vertical, topographic)

3. More energy (equator v. poles)

4. Environmental Harshness (Limiting Factors)

A plant that lives in a very dry place where suitable conditions for germination happen infrequently would most likely have evolved to have a _________ seed coat and a ___________ cotyledon.

thick , large

The plants that will be able to reach the interior of the pumice plain first are likely to be seeds with __________ cotyledons and have __________ dispersed seeds.

small , wind

Give an example of a species that will likely be the last to reach the interior of the pumice plain.

Cedar Trees

Charge of P in Phosphoric Acid (H3PO4) where P is central atom connected to 3 OH- groups and one O atom?

partial positive

If all of the hydrogen bonds in a protein were broken, which levels of protein structure would be altered?

Secondary structure

Tertiary structure

Quaternary structure

If 2 atoms share electrons in a covalent bond and their electronegativity difference is 0.3, what does that mean?

They do not share electrons evenly, but it's close enough that we consider the bond to be non-polar

Autotroph

get carbon from inorganic sources like CO2

Heterotroph

get carbon from organic sources (other organisms)like glucose

Are carnivorous plants autotrophs or heterotrophs?

autotrophs

What increases with succession?

Soil Carbon and Nitrogen

Biodiversity

Vertical Complexity

Resistance

Resilience

Shade-tolerant trees

Horizontal Complexity

Compare complexity of permaculture farm to organic farm.

Permaculture farm has high horizontal complexity and high vertical complexity compared to the organic farm

Biomass

the total weight of all the living things in an area

Ecosystem Resistance

ability to prevent impacts from disturbance (less impact of disturbances)

Increase in species richness/biodiversity/complexity —-> higher ecosystem resistance