CM L8 Flashcards
How is soil created
By the interaction of physical and chemical weathering of rock
Aspects of soils that determine biome and habitat productivity
- Physical component eg water, temperature
- Inorganic component eg bedrock, weathering
- Organic component eg soil microbes, protists
Productivity of an under-ground habitat is dependent on?
Functioning and efficiency of the organic component of the soil particularly the microbe
What is in the uppermost layer of the soil
Biological activity and nutrient cycling
How do soils develop?
Over time as bedrock weathers and biological activity increases
Where do soils form?
Around fragments of the bedrock directly below, other times glacial or river sediment dominates
What influences soil biological activity
Abiotic factors and the soil biota
What determines soil fertility
- inorganic components eg alumina- silicates, silica, calcium carbonate
- organic components: raw decomposing material
Mull organic matter
- fertile soils
- good aeration and temperature
- cycling of OM is rapid
- microbes and soil animals abundant
Mor organic matter
- forms in less favorable conditions (waterlogged soils)
- OM accumulates and acidifies (leaching)
- few decomposers, no nitrifying bacteria
How does soil drainage alter soil chemistry
By increasing waterlogging, decreasing aeration and pH
pH of soils wuth good drainage
Neutral-alkaline
Where can we find fertile soils
In the East and Southeast
How does nutrient availability change as soil acidity increases
It decreases
Impact of soil acidity can be seen where?
In the Arctic Tundra of Alaska
