Trends in Ecosystems based on Temperature and Precipitation P/PET Ratio is important! PET: Potential Evapotranspiration P: Precipitation Limitation by Temperature No limitation by Temperature Hi P/PET Lo P/PET

Life Zones Figure Where are Deserts? 40% Land Surface Drier/Colder

Major Terrestrial Climates Colder

Major Terrestrial Biomes

Smaller-Scale effects: Impact of Slope Position/Aspect on Vegetation SouthNorth WetterDriest Wettest Hi PET Lo PET

Hunshandake Sandy Land, Inner Mongolia

Smaller-Scale effects: Impact of Cold Air Drainage Cold Air Sinks at Night

Frost Damage to a Haas Orchard Smaller-Scale effects: Impact of Cold Air Drainage

NE Rockies

Smaller-Scale effects: Impact of Cold Air Drainage

LIFE & ECOSYSTEMS

Ecosystems and Biomes Last Universal Common Ancestor LUCA Prokaryotes Protista 1-2 Bya

Ancient records of life Stromatolite ~2 Ga Prokaryotes Ediacara ~550 Ma Eukaryotes T-Rex 67 Ma Eukaryotes Trilobite ~545 Ma Eukaryotes Calcite Aragonite Silica Hydroxyapatite

Early Life on the Planet Probably originally evolved in water Continents were (originally) sterile, there was no organic material in the soil The early atmosphere had no O 2 and hence, no ozone (O 3 ) to protect plants/animals from UV radiation from the sun Bacteria colonize the land, who knows when… O 2 increases ~ 2 Ga Land plants arrive ~ 500 Ma Land animals arrive ~ 440 Ma

Life on the planet now: Ecosystems

Energy Balance of the Biosphere

Energy is lost when consumers consume

So, from an energy perspective, should we eat meat? NO: –Its more efficient to consume primary producers YES: –We can’t grow primary producers that we can eat everywhere (e.g. wheat). Animals eat things that we aren’t able to. –An inefficient system means there’s more slack should a crisis arise

The Basic Chemical Players Photosynthesis 6 CO H 2 O + light --> C 6 H 12 O O 2 Respiration C 6 H 12 O O 2 --> 6 CO H 2 O + light Also showing… –Chlorophyll A green dye that absorbs the light for photosynthesis

The Basic Chemical Players Also showing… –Water Part of the chemical reaction Also the main constituent of cells The transport solvent through plants –Nitrogen Usually absorbed as NO 3 - or NH 4 + Needed for Chlorophyll, Protein, DNA, RNA –Phosphorus Needed for Protein

The Keeling Curve

Variations in CO 2

Respiration & Photosynthesis Respiration Soil Organic Matter (with Organic N) H 2 O: Precipitation Soil Moisture Cloud H 2 O: Evaporation H 2 O: Transpiration H 2 O: Uptake Light: Absorption Microbes and Fauna: Respiration N Mineralization CO 2 in Atmosphere CO 2 : Fixation CO 2 : Emission CO 2 : Emission CO 2 : Emission Organic C: Deposition Organic C: Root Turnover N 2 : In Atmosphere N 2 : Fixation Mineral N: Uptake Organic N: Deposition Organic N: Root Turnover Mineral Soil Atmosphere Other Nutrients: Absorption Other Nutrients: Absorption Other Nutrients: Absorption

How the system works

Sometimes its not so good to be the King

Food Webs