Ecology is The study of the distribution and abundance of organisms, AND
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Transcript of Ecology is The study of the distribution and abundance of organisms, AND
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)