BIOL 1108 Springthorpe UGA - Exam 2

Weather vs Climate Example

Weather - severe thunderstorm/hurricane

Climate - An upward trend over the 30-year average of the frequency of thunderstorms

Weather vs Climate

Weather - what is happening now

Climate - Recorded patterns over decades

Climate Change is always caused by humans (T/F)

False

The Greenhouse Effect

How earth traps heat near the surface, this is don by converting the high energy solar radiation into IR and heat, the lower energy radiation cannot escape

Greenhouse Gases (Top 5)

•Carbon Dioxide (CO2)

•Nitrous Oxide (N2O)

•Methane (CH4)

•Fluorinated Gases (F-gases) (always anthropogenic)

•Water Vapor (not anthropogenic)

Earth's Gas Composition

78% N2

21% O2

.9% Argon

.1% Trace Elements

What Makes A GHG a GHG?

Certain gases absorb IR

•Unless at 0 K, all molecules are constantly vibrating

•"the wiggles"

•Stretching and Bending

•When they do this, IR-active molecules will have a change in dipole moment that allows absorption of IR

Why do we talk about CO2

largely because it is the GHG in the highest proportion in our atmosphere. But, other molecules are capable of absorbing far more IR and it comes down to their structures.

Carbon Pools

Where Carbon is Stored

•Rocks / Fossil Fuels

•Soils

•Atmosphere

•Biosphere (Anything alive)

Ocean (Surface and Deep Ocean often considered separately)

Processes/Flux

How carbon moves between pools

•Photosynthesis

• Respiration

• Soil Respiration

•Combustion

•Vulcanism

• Decomposition

• Diffusion

•Sedimentation

GWP

Global Warming Potential

GHG's GWPs

•Carbon Dioxide: 1 GWP

•Nitrous Oxide: ~300 GWP

•Methane: ~30 GWP

•Fluorinated Gases: Average ~ 5000 GWP

N2O vs NOx

•NOx is an indirect greenhouse gas

•NOx produces ozone (O3)

NOx has a 100 year-GWP = 10

Ozone

•Ozone absorbs UV-B

•Causes sunburn/DNA damage in humans

•Ozone in the troposphere acts as a potent GHG

•~1000 GWP

•Ozone is incredibly short lived

•Half-Life: 10-60 min in air

Ozone does more good than harm

Climate Impact

GWP x quantity of gas

Measures the overall contribution to Climate Change

CO2 is...

The most impactful, 64%

Carbon Cycle

How carbon changes and moves with Pools and Fluxes (Processes)

A vast majority of anthropogenic CO2 emissions come from...

the burning of fossil fuels

Feedbacks

agents of stability or rapid change

Negative Feedbacks

Promote changes that lead back toward equilibrium

"overshoot, undershoot, overshoot, undershoot"

Ex. Predator/ Prey Dynamics

Positive Feedbacks

Systems that promote further change toward an extreme.

Amplification of a stimulus

"build, build, build, CRASH"

Ex. Labor , Avalanche

Albedo

Ability of a surface to reflect light

Albedo Feedback

As atmospheric temperatures rise, ocean water warms, melting sea ice. This exposes low-albedo seawater, which absorbs more sunlight, further warming the ocean and accelerating ice melt in a growing cycle.

Water Vapor Feedback

Rising GHGs warm the air, increasing evaporation. Warmer air holds more water vapor, a greenhouse gas that traps heat, further boosting evaporation and warming in a cycle.

water cycle

1)Condensation - water vapor in the air condenses into clouds

2)Precipitation - water in clouds falls back to earth as rain, snow, sleet, etc.

3)Transpiration- water lost from plants into the atmosphere. Can be thought of as evaporation from plants through their stomata

4)Evaporation - liquid water that is converted into water vapor from the surface of lakes and oceans and soil. Sometimes this is combined with transpiration to identify the amount of water vapor put into the air as evapotranspiration

What are the effects of climate change on the water cycle?

•More episodic precip (less frequent)

•More intense (more precip in heavy rain events)

•Increasing Drought and Flooding

•Shifting weather patterns and stronger storms

•Less Snow

Permafrost Feedback

The Arctic warms faster than the rest of the world due to permafrost and albedo feedback. Permafrost, like a frozen soil popsicle, traps carbon but is now thawing, releasing greenhouse gases. Most decomposition here is anaerobic, producing methane—a far more potent GHG than CO2, with each pound of methane equating to 28 pounds of CO2, accelerating warming.

Migration

Moving across the landscape (different than seasonal migration)

Climate Envelope

The set of environmental/climatic conditions that an organism requires in order to survive

When envelopes move, species will try to move with them if they can.

Plants...

Struggle to migrate at the rate needed to stay in their envelope

Phenology

The timing of seasonal changes in plants and animals ex. Flowering, migration, calving, molting, etc.

The result of earlier spring / longer growing season

Phenological Mismatch

When the timing of events for interacting species no longer co-occur

If something can't migrate

Adapt/Evolve or go extinct

Kelp Forest

An aquatic ecosystem dominated by giant kelp (Macrocystis) which is a brown algae. They provide important food and habitat for many species.

Kelp are macroalgae

Have blades that that do most of the photosynthesis and vascular tissue, but they don't have stomata and gas exchange is through diffusion/active transport

kelp forests' complexity/info

far more complex than most other marine ecosystems

Extremely High Vertical Complexity

High Horizontal Complexity

High Resistance

High Resilence

High O2 content, and cold

Best Marine Ecosystems

are NOT at the equator

Temperature and dissolved oxygen

Are inverses of each other

Temperature has a strong impact on..

All Marine Ecosystems

How have Kelp Forests done in recent times

Drastically Declined

Regulator

keeps internal environment constant regardless of external environment

Conformer

internal environment matches external environment

Thermoregulation

•Temperature Control

-Includes special enzyme functions,

-must be careful of denaturation by heat

•Energetics (Confromer pro)

Thermoconformers don't need to spend energy regulating their internal temperatures >>> put that energy into other activities (finding food)

•Biochemistry (Regulator Pro)

Thermoregulators are always operating at biochemical optimum

Migration (Conformer Con)

•Thermoconformers may need to migrate to stay within an ideal temperature

brumination

similar to torpor/hibernation but the alligators will move when it gets warmer, low MBR

Types of Thermoregulation

Behavioral: Actions / decisions

Physiological: Internal changes (not visible)

Morphological: External characteristics

Strategies to Increase internal heat

Blubber

Thick Fur

Vasoconstriction

Countercurrent Exchange

Dormancy (Hibernation)

Body Positioning

Basking

Metabolism (Thermogenesis)

Strategies to decrease internal heat

Sweating

Panting

Vasodilation

Surface Area increases

Wallowing (mud, water, etc)

Body Positioning

Dormancy (Estivation)

Metabolism

•All of the chemical reactions in the body

1.Energy Conversion

2.Building Block Synthesis

3.Waste Elimination

Includes Anabolism - Synthesis

Includes Catabolism - Degradation

How do humans thermoregulate

We use metabolism to influence our temperature, metabolic rate increases as temperatures go up and down

Thermoneutral Zone

The temp range in which metabolic rate does not need to rise to maintain body temp

Respiration rate

how fast we burn calories

Homeotherm

•Have a very small range of tolerable internal temps

Poikilotherm

•Have a wide tolerable range of internal temperatures

•No permanent harm (though biochemical processes will speed up or slow down with temp)

Endotherm

- internal temp can be controlled by altering metabolic rate (all birds and mammals)

Ectotherm

body temperature cannot be controlled with metabolism (reptiles, amphibians, fish and invertebrates)

Main ideas from metabolic demands

Big animals require more energy (more biomass to move and maintain, etc.).

Between endotherms and ectotherms of a similar size, endotherms have higher BMRs.

Endotherms vs Exotherms Metabolism

Endotherms burn more calories in an effort to maintain their internal temperatures and to counteract heat loss to the environment. Ectotherms rely on the external environment to maintain temperature, so no calorie expenditure is required to maintain heat.

Larger animals TOTAL energy requirements

animals have more cells that need energy, they have to move more weight around. Higher total energy requirements

higher per kg requirements?

Small organisms, they lose more heat bc of the higher surface area to volume ratio, so they need more food

Marine vs Terrestrial

Marine mammals have higher metabolic requirements than terrestrial mammals

How do sea otters thermoregulate

THICK fur

Thermogenesis

Skips ATP and generates heat

Needs high amounts of food

Homeostasis

A dynamic equilibrium which is actively regulated to maintain a variable (the health of an animal) at a constant level

Osmoregulation

The ability to regulate the amount of solute internally relative to external solute

Osmoconformer

does not regulate the amount of solute internally relative to external solute

Is osmoregulation constant?

No, it depends on the environvemt, and salinity of water

Cellular respiration

transforms the energy in organic molecules into ATP and heat

Energy is...

Stored inside of bonds as potential energy

Energy flows through biological systems according to

the laws of thermodynamics

1. Energy can be transferred and transformed, but not created or destroyed

2. Every energy transfer or transformation increases the entropy (disorder) of the universe

Only some of the energy that is released is useful

Most is "lost" as heat or waste

Food Webs

Energy diagrams that show how energy flows through an ecosystem based on what eats what, all organisms are not equal

Trophic level

where an organism is in the food chain

Autotrophs Carbon Source

Inorganic C (CO2)

Heterotrophs Carbon Source

Organic C (C & H) (Anything alive or used to be alive)

How much energy is retained by each trophic level

10%

Energy goes to

Feces

Growth

Cellular Respiration

Plankton

Anything that drifts with tides and currents

Often microscopic

What are the autotrophs in the kelp forest ecosystem?

phytoplankton

Phytoplankton

•"Plant plankton"

•Photosynthetic microorganisms/algae

•Contribute ½ of the world's oxygen

Zooplankton

•Usually just small invertebrates

•Eat phytoplankton or other zooplankton

The difference between choosing prey

ENERGY GAINED - ENERGY SPENT

Some have more calories, but take more energy to obtain

OPTIMAL FORAGING THEORY

Organisms use foraging strategies that maximize energy gain

Prey Switching

switching to the next best prey item when a preferred item becomes rare

Sea Urchins

•Invertebrates

•Related to sea stars (echinoderms)

•Mostly Herbivores

•Spines for protection

•Kelp is primary food source when available

Destroy Kelp forests if not regulated

Trophic cascade

when changes at one trophic level have dramatic effects throughout a food web

Keystone Species

an organism with an outsized influence relative to its abundance

Apex Predator

an organism at the top of the food chain

Why are Kelp Forests better than Urchin Barrens

•Carbon sequestration

•Vertical complexity

•Biodiversity

•Ecosystem stability

•Ecologically important Juvenile fish habitat

Alternative Stable States

•Ecosystems can have multiple stable modes that are difficult to transition out of.

It can be very difficult for the ball to move back to the original trough and requires another kind of very large disruption to do it.

K

Carrying Capacity

What are 2 pieces of evidence from the Estes et al. paper that implicate orcas?

•A small # of orcas could greatly decrease otter pop

•Only otter loss in open ocean

•No washed up sea otters

•No relocation of sea otters

•Increased orca attack sightings

pollutants that accumulate in organisms over time

•Metals/Metalloid*

•Hg, Pb, Cd, Cr, As*

•POP's - Persistent Organic Pollutants

•(PFAS, PCBs, DDT)

•Stored in fatty tissue

•passed on through blood and milk

Toxin accumulation causes excess mortality in 2 ways:

•Trophic level

•Age

Bioaccumulation

Toxins build up in an individual as it ages.

Biomagnification

Toxin concentrations increase as you move up through trophic levels

Can both happen at once

Yes, ex. Old Large Tuna (Apex predator trophic level, and by age)

persistent chemicals that biomagnify

Hg, Pb, Cd, As*, PCB's and DDT

Ocean Acidification (OA)

•Ocean water is usually basic, so it's becoming less basic (more acidic)

•More CO2 in atm. = more CO2 in ocean (diffusion)

•A result of increasing atmospheric CO2, not climate change directly