ecosystems

Flows of Energy and Materials in Ecosystems

Thermodynamics

1. energy not created or destroyed,

2.entropy not

Energy Budget crea

radiant energy at earth's surface 10%uv, 45% visible, 45% infrared

40% energy received by forests used in evapotranspiration

30% worlds solar energy drives hydrological cycle

1-5% photosynthesis

40-50% dissipated as heat

L70% of IR reflected,

2.

entropyrgy not created or destroyed, 2.

Photosynthetically Active Light
radiation=380-780nm
70% absorbed

Photosynthesis

Photosynthesis

Photosynthesis as a function of light intensity

Leaves as photosynthetic panels
monolayers vs. perforated leaf

Light diffuse after 100 diameters

Light on an inclined plane

Light Under the Canopy

1-5% reaches forest floor

sunflecks=70% of light reaching the forest floor

Plants in the Shade
compensation intensity adaptations

Energy Flow (kcal/m²)
sun(10⁶) > plants(10⁴) > herbivores(10³) > predators >(10²)

Energy Drives Material Cycles
gross primary production

net primary production

net community production

2 Basic Materials Cycles
1. gaseous with large atmospheric storage. eg. N

2. sedimentary with large reservoir in the earth's crust. eg. P

Carbon Cycle

Nitrogen Cycle

Phosphorous Cycle

Water Flow matrix from column to row 10³ km³yr^-1

	LAND	AIR	OCEAN
LAND	0	111.1	0
AIR	71.4	0	424.7
OCEAN	39.7	385.0	0