Carbon Storage Flashcards
Ecosystem carbon storage
= primarily in tree biomass or thick litter layer on forest floor across terrestrial biomes
Green plants - nearly 20% of C in biosphere stored in plants
Animals - biomass much smaller than plants due to insufficient energy transfers across trophic levels
Litter - undecomposed plant debris, majority leaves (70%) in forests
soil - humus remains in soil after organic material decomposed
Tropical rainforest carbon storage
e. g. Amazonian, African and Indo-malaysian
- competition for light, water risen due to multiple layers of vegetation
- evergreen plants and large-leaved trees maximises transpiration and growth
- carbon storage in animals relatively high due to number of different habitats provided e.g. Napo, Peru, 283 species of trees in area of a football pitch
Rainforest carbon storage and flows
- typical store of large forest = 180tnnes/ha above ground
- exchanges of carbon between atmosphere, biosphere and soil are rapid due to humid conditions, making decomposition and CO2 release rapid
- litter store proportionally small in this biome
- heavy rainfall - soils leached, only limited count of humus carbon retained
Physical factors affecting growth and storage in rainforest biome
light = concentrates dun ray's at this latitude, little seasonal variation. All year growth and sequestration. temp = high annual temps precipitation = heavy rainfall most days as sun heats air, no dry season
Temperate grassland carbon storage
mid-latitude grasslands e.g. N.American prairies (High plains of USA and Canada) , Eurasian Steppes (Ukraine through Russia)
- lack of rainfall limits growth of thick forest, short grasses dominate landscape
- narrow stems reduce heat gain, and root system traps moisture
- turf grasses with rhizomes (underground stems) associated with humid parts of biome
- bunch grasses, reproduce by seed, associated with drier parts of biome
- decrease in animal biodiversity and biomass, earthworms consume organic matter and excrete waste
Grassland carbon storage and flows
- 2-10tonnes/ha of Carbon above ground, double stored in roots
- soil carbon store around 100-200tonnes/ha
- warm humid conditions allows decomposition and quick release of CO2 in autumn
- litter store small
- exchanges vary in seasons, winter = photosynthesis causes as grasses die, spring = respiration through root increases
Change in biome stores due to deforestation
- rainforest timber used for furniture and flooring
- large scale agri-business accelerated removal of Amazonia, Africa and Indonesia rainforest
- food demand increase and more affluent population, soya beans grown on deforested soils in Brazil and in Costa Rica, 1/3 cleared forest used for cattle ranching
- increases overland flow and soil erosion, removing storage capacity of soils, loss of C store
- toxic haze developed in Sumatra, Indonesia due to forest fires and CO2 release as forest is cleared
Change in biome stores due to afforestation
- new trees act as carbon sinks, mitigate climate change
- reduce flood risk
- UN REDD scheme provide incentives for conservation of rainforests
- UK Forestry Commission established 1919, increase timber supplies using heather and moorland to grow coniferous trees
- carbon offsetting = aims to marry business principles with environmental goals
Change in biome stores due to agricultural activity
- affects biomass C storage on land and soil carbon presence
- excessive cultivation results in land being overworked, land degradation and soil erosion, e.g. Dust Bowl
- addition of manure, composts and biosolids from soils to agricultural soils beneficial as high in organic carbon content
- clearing vegetation for agriculture reduces soil organic carbon content, and further declines after poor management practice
- farm management increasing soil carbon storage:
crop management = irrigation and rotation
pasture management = fertiliser and grazing, introduce earthworms
organic amendments = animal manure, recycled plant remains
