Post on 20-Dec-2015
Primary Productivity
Jason BroshearKatherine EchementZach MoningLeo Sack
Photosynthesis
Photosynthesis
Respiration
Carbon Cycle
SinkAmount in Billions of Metric
Tons
Atmosphere 578-766
Soil organic matter 1500 to 1600
Ocean 38,000 to 40,000
Marine sediments and sedimentary rocks 66,000,000 to 100,000,000
Terrestrial plants 540 to 610
Fossil fuel deposits 4000
Greenhouse Effect
Primary Productivity
Phytoplankton
Phytoplankton
• Single-celled plants
• Photosynthesis
• Lots of them – about half of plant biomass on the planet
Phytoplankton – nutrient influence
Biological Pump
Phytoplankton Distribution
• Where is the most phytoplankton productivity?
Arctic and Southern Oceans
• In high latitudes, most nutrients rarely used up
• Limiting factor: dissolved iron
• “Fertilize” these regions with iron, more productivity
• Solution to global climate change??
Problems with Iron Fertilization
• Zooplankton grazing also a limiting factor
• Much added iron “lost” – affects on other ecosystems?
• Limited effect on CO2 – most recycled in water, not sinking
• Not economically feasible solution
Boreal Forest: Background
• The northern boreal ecoregion accounts for about one third of this planet's total forest area.
• Is considered one of the largest carbon sinks.• Most dominant tree species are conifers which are well-adapted to
the harsh climate, and thin, acidic soils. • There are innumerable water bodies: bogs, fens, marshes, shallow
lakes, rivers and wetlands, mixed in among the forest and holding a vast amount of water.
• Fire is a crucial disturbance factor in the boreal ecoregion because it facilitates the destruction of old, diseased trees along with the pests that are associated with those trees.
• Some trees such as aspen and jackpine actually require fires to stimulate their reproductive cycles. Furthermore, the nutrient-rich ash left behind helps fuel plant growth.
Grasslands: Background
• Tropical grasslands (Savannas) and temperate
• Savannas have wet and dry seasons - heavy rain and seasonal fires
• Grasses are dominant, trees and large shrubs mostly absent
• Large and small mammals, reptiles, birds, etc.
Grasslands
Net Primary Productivity of Different Biomes
0
5
10
15
20
25
desert
semidesert
tundra
lake/stream
temperate grassland
boreal forestagriculture
temperate foresttemperate woodland
tropical savannatropical forest
wetland
Ecosystem
Area (10^12 m^2)
0
200
400
600
800
1000
1200
desert
semidesert
tundra
lake/stream
temperate grassland
boreal forestagriculture
temperate foresttemperate woodland
tropical savannatropical forest
wetland
Ecosystem
NPP (gC/m^2/yr)
Nitrogen Cycle
Phosphorus Cycle