1. Ecosystem Ecology

2. Ecosystem Ecology I. Introduction
- Ecosystem: an assemblage of organisms, together with their chemical and physical environments

3. Ecosystem Ecology I. Introduction
- “Box Models” of Exchanges (“fluxes”) between “reservoirs”

4. Ecosystem Ecology
I. Introduction
II. Energy Flow

5. Ecosystem Ecology I. Introduction II. Energy Flow A. Productivity
1. Gross Primary Productivity
Total photosynthetic productivity:
CO2 + H > Glucose + O2

6. 2. Net Primary Productivity:
- energy stored in biomass
- Global Patterns

8. Ecosystem Ecology I. Introduction II. Energy Flow A. Productivity
3. Net Secondary Productivity
- Net Production Efficiency = P/A

9. Ecosystem Ecology I. Introduction II. Energy Flow A. Productivity
0.5%
Birds
Ecosystem Ecology
I. Introduction
II. Energy Flow
A. Productivity
0.7%
Shrews
3. Net Secondary Productivity
- net production efficiency = P/A
6-10%
Most
Mammals
Up to 75% for sedentary poikilotherms

10. Ecosystem Ecology I. Introduction II. Energy Flow Productivity
Trophic Pyramids
- ecological efficiency: NSP/NPP (5-20%)
NPP of Secondary Carnivores
Loss due to 2nd Law
NPP of Primary Carnivores
NPP of HERBIVORES
NPP of Producers (PLANTS)

11. a. trophic "pyramids"
This is why large carnivores are RARE, and why they have large RANGES
NPP of Secondary Carnivores
Loss due to 2nd Law
NPP of Primary Carnivores
NPP of HERBIVORES
NPP of Producers (PLANTS)

12. Ecosystem Ecology I. Introduction II. Energy Flow Productivity
Trophic Pyramids
Detrital Foodchains
Predators
Herbivores

13. Ecosystem Ecology I. Introduction II. Energy Flow Productivity
Trophic Pyramids
Detrital Foodchains
BAR
Human Concerns

14. E. Human Concerns

15. E. Human Concerns: NPP

16. E. Human Concerns: NPP

17. E. Human Concerns
A doubling of meat production per capita

18. E. Human Concerns
6-10 lbs of feed for 1 lb increase in cattle weight
2-5 lbs of fish meal for 1 lb increase in farmed fish weight

19. input calories converted to calories able to be utilized by humans
Edible kilocalories produced from kilocalories of energy required for cultivation are:
18.1% for chicken,
6.7% for grass-fed beef,
5.7% for farmed salmon
0.9% for shrimp.
123% for potatoes
250% for corn
415% for soy
input calories converted to calories able to be utilized by humans
E. Human Concerns
So, for every 100 calories of energy we put in to raise chickens, we get 18 calories of energy produced in chicken meat cal into soy, 415 calories out.

20. E. Human Concerns
Food production, per capita
(400 kg per year is healthy minimum)

21. SO HOW DID WE DO IT?

22. E. Human Concerns
EXTENSIFICATION – MORE AREA

23. E. Human Concerns
47% of historical forested land has been cut

24. E. Human Concerns
INTENSIFICATION

25. E. Human Concerns

26. E. Human Concerns
The best land has already been used; further expansion in marginal areas is costly and requires more supplementation

27. E. Human Concerns
Global NPP (dry mass) = 224 billion tons. 59% is terrestrial, and of this, 35-40% is controlled by humans, either eaten directly or fed to animals we will consume

28. Ecosystem Ecology
I. Introduction
II. Energy Flow
III. Biogeochemical Cycles

29. III. BIOGEOCHEMICAL CYCLES
A. Overview
Small reservoir
“Turns fast”
FLUX
“Turns slow”
Large reservoir

30. B. The Water Cycle

31. B. The Water Cycle
All values in teratons (x 1018 g)
  Atmosphere (13)
OVER OCEAN OVER LAND  Rain Evaporation Rain Evaporation (385) (425) (111) (71)  
Oceans - 97% Runoff and Groundwater (40) (1,380,000) Lakes and Rivers (100)
Water content in sedimentary
rock near surface
(210,000) 
Biosphere (1)

32. B. The Water Cycle

33. B. The Water Cycle - Effects of Life
1. Plant biomass pumps water out of the soil into the atmosphere, increasing evaporation rates.
2. Volatiles act as nuclei on which raindrops can form ("Smoky Mountains"), increasing local precipitation. Large forests stimulate the rainfall they depend on.

34. -Effects of Life:
Cut forest – reduce evapotranspiration, increase runoff and river discharge
Eventually, reduce precipitation, and reduce river discharge.

35. B. The Water Cycle
- Effects of Humans

36. B. The Water Cycle Effects of Humans
1. Control 50% of surface runoff of planet
- 70% agriculture
- 20% industry
- 10% personal use

38. Most population growth is in tropical/arid areas where more water is needed to grow the same amount of crop, because
PET > Precipitation

39. 98% of water ‘footprint’ for animals is for their feed.
30% of all water used for animals is for beef cattle
Another 20% for dairy cattle

40. B. The Water Cycle Effects of Humans
1. Control 50% of surface runoff of planet
- 70% agriculture
- 20% industry
- 10% personal use
2. Dams

41. 2. Dams – Three Gorges, Yangtze River
Ship locks

42. 2. Dams – Three Gorges, Yangtzee River
1.5 miles wide, 600 feet high
Largest dam in the world – largest engineering project in the world.

43. 1.5 miles wide, 600 feet high
Reservoir 570 feet deep and nearly 400 miles long.

44. Energy = 18 nuke plants. At full power, reduces coal consumption by 31 million tonnes per year, avoiding 100 million tonnes of greenhouse gas emissions
100

45. Regulate a deadly, flood-prone river:
The 1998 flood (before the dam): 3,704 dead, 15 million homeless and $26 billion in economic loss. A staggering 25 million acres (~Kentucky) were evacuated, 13.3 million houses were damaged or destroyed.

46. Displaced 1.2 million people
Cover 1300 important archeological sites

47. 2. Dams – Problems:
- Flood upstream habitats
- release toxins into water
- cause eutrophication
- reduce oxygen content of water
- sediment buildup decreases “head” and power generation
- sediment trap starves downstream of sediment and nutrients – erosion of river delta and loss of productive estuary - reduce fisheries productivity
“The construction of dams is increasingly regarded as the biggest conservation threat to aquatic and riparian biodiversity in many river basins throughout the world.”
J. Wu, J. Huang, and X. Han Science 302:

48. B. The Water Cycle Effects of Humans
1. Control 50% of surface runoff of planet
- 70% agriculture
- 20% industry
- 10% personal use
2. Dams
3. Overtapped Rivers
Major rivers like the Colorado, Nile, Ganges, Yellow
don’t reach the ocean for months at a time – all the
water is drawn off by humans upstream.

50. Glen Canyon – 710 ft
Hoover – 726 ft tall

51. Cohen, et al (2001). A preliminary water balance for the Colorado River Delta, J. Arid Environments 49:35-48.
Hoover Dam
Glen Canyon Dam

52. 3. Overtapped Rivers
The Aral Sea, Kazakhstan:
once the 4th largest inland sea in world
Has lost 60% of its water, drawn off for agricultural purposes.
- Salinization increased, killing the productive fisheries industry
- Agriculture – salt increased 6X by 1994 the productivity had dropped by 20-50%.

53. 1989 2014 3. Overtapped Rivers The Aral Sea, Kazakhstan:
- salt and dust in air became a significant health problem
1989
2014

54. 1. Control 50% of surface water
2. Dams
3. Overtapped Rivers
4. Overtapped groundwater
- In Punjab (Indus Valley):
Wealthy can dig deeper wells, lowering water table, making it inaccessible for shallow wells.

55. 1. Control 50% of surface water
2. Dams
3. Overtapped Rivers
4. Overtapped groundwater
- In Punjab (Indus Valley):
pumping from wells exceeds recharge by 27%. Water table falling 0.7 m/yr
Wealthy can dig deeper wells, lowering water table, making it inaccessible for shallow wells.

56. Landsat image, North Texas, 2010

57. 3. Overtapped Rivers
Other Problems of "overtapping" rivers...
1. Reduced water availability
2. Salinized soils (20% worldwide)
3. Regional Conflicts
- The Jordan River (Jordan and Israel)
- The Indus (India and Pakistan)
- The Ganges (India and Bangladesh)
- The Colorado: Colorado, Utah, Arizona,
Nevada, California

58. Water Confict Events per Year, 1927–2015
Water Confict Events per Year, 1927–2015 Data from the Water Confict Chronology List 2015.
Peter H. Gleick Science 2016;354:
Published by AAAS