Ecology is

The study of the distribution and abundance of organisms,

ANDthe flows of energy and materials

between abiotic and biotic components of ecosystems.

Scales of Ecological Organization

Element Cycling

Oxygen (O)Hydrogen (H)Nitrogen (N)Phosphorus (P) Potassium (K)Sulfur (S)Calcium (Ca)Sodium (Na)

Magnesium (Mg)Manganese (Mn)Molybdenum (Mo)Cobalt (Co)Zinc (Zn)Aluminum (Al)Copper (Cu)Iron (Fe)others

Carbon (C)

1. Nutrients, unlike energy, are retained within the ecosystem.

Element Cycling through Ecosystems

2. There is continual recycling between the organisms and the physical environment.

Element Cycling through Ecosystems

Element Cycling through Ecosystems

oxidized = low energy

reduced = high energy

Ecosystem Compartments

Air (Atmosphere)

Water (Hydrosphere)

Land (Lithosphere)

Organisms (Biosphere)

Ecosystem Compartments

PlantsAnimalsDetritus (dead organic)Microbes

AirWaterSoilSediments

Organic Compounds, Inorganic Compounds

1. assimilitory processes are transformations that incorporate elements into organisms

2. dissimilitory processes are transformations that release elements into the inorganic forms

Element Cycling through Ecosystems

1. If we were to follow any given nutrient through time, there would be a continual alternation between living and nonliving

compartments of the ecosystem.

Element Cycling: Overview

2. Time for cycling is directly proportional to the time spent in the largest compartment. ie, an imbalance can exist between

compartment sizes.

3. Gains and losses from outside of the ecosystem are small when compared to the rate at which nutrients are cycled within

the system.

Water Cycle

97% of the water in the globe resides in the oceans

22% of precipitation occurs over land, and is greater than losses by evaporation and transpiration

The processes of evaporation, transpiration,

and precipitation cycle water through ecosystems

78% of precipitation occurs over ocean, which is less than losses by evaporation

Water Cycle

The residence time of water in the atmosphere is 1.5 weeks

The oceans and land surface contain approximately 1,300,000 TT of water

The atmosphere contains 13 TT of water vapor, and each year there is approximately 496 TT of precipitation globally.

The residence time of water in liquid form on the oceans+land surface is 2,800 years

Global Warming

Greenhouse gases

Carbon dioxide is the largest single contributer

to climate forcing

Carbon dioxide contributes about half of total climate forcing from greenhouse

gases

Carbon Cycle

2. Exchange of carbon dioxide between the atmosphere and the oceans

3. Sedimentation of carbonates

1. Assimilatory and dissimilatory reactions, primarily photosynthesis and respiration.

Carbon Cycle

Pools of carbon in living organisms, soil organic matter and sediments = 2,650 Pg

Residence time = 31 years

Photosynthesis assimilates

approximately 223 Pg of C

each year (GPP, land +oceans).

Vegetation = 500 PgSoil = 1500 Pg

Atmosphere = 730 Pg

Carbon Cycle: Oceans

2. Dissolution rate depends on wind speed, ocean mixing

1. Dissolved carbon dioxide is the main reservoir = 30,000 Pg

3. Pool of vegetation (algae) is small (5 Pg) & not thought to change that much with human disturbance

Carbon Cycle: Lithosphere

Calcium carbonate precipitates from carbon dioxide dissolved in water, with calcium

CO2 + H2O => H2CO3

H2CO3 => HCO3- + H+ => 2CO3

- + 2H+

Ca2+ +CO32- => CaCO3

Precipitation is slow, <1 Pg per year

Carbon Cycle: Atmosphere

Carbon Cycle: Atmosphere

Carbon dioxide concentration in the atmosphere is higher now than it has been in the last 20 million years

Until the last 100 years, carbon dioxide concentrations had been stable for the last 1000 years

At times in the Earth’s history, CO2 concentration was much higher than today, but the climate was vastly different

Flask Network

Free Air CO2 Enrichment (FACE)