Biomass and Nutrients Flashcards
What is the typical tonnes / ha of biomass in temperate forests?
What about tropical?
temp. 60-2000, mean of 350 tonnes/ha
trop. 60-800, mean of 400 tonnes/ha
What is the difference between shrub bimass distribution and tree?
Shrubs have more biomass in the below ground portion.
What is a very large portion of forest ecosystem biomass and nutrient content concentrated?
in the soil organic matter (litter)
How does nutrient content in trees vary?
By forest type, by species
How much of the terrestrial earth surface is forested?
1/3
What are the relative requirements of nutrients in plants if N=100
K=65 P=13 S=9 Mg=8.5 Ca=7 Fe=0.2
micronutrients (Mn, B, Zn, Cu, Mo) less than 0.05
What is Liebigs law of the minimum?
A concept that states that tree growth is controlled by the most limiting factor. Ex. if site is high in N but low in P, trees will be limited by P availability.
What is the basic flow of the nitrogen cycle?
Atmospheric nitrogen is fixed into Ammonia (NH3 and NH4) which are further nitrified by bacteria into Nitrate (N03-) ions which can be assimilated by plants. Plants then decompose and plant nitrogen is converted back to Ammonia again.
When is N most vulnerable to leaching?
When nitrogen is in the nitrate form after nitrification by bacteria.
What are some other sources of nitrogen?
- Anthropogenic sources
- fertilizer
- fossil fuel emissions
- Agriculture practices
- Abiotic Fixation (Lightning fixes some nitrogen)
What is the N distribution in a typical conifer forest?
10% in tree
3% in shrub
20% in Humus
67% in upper Mineral soil
Why do temperate conifer forests have such high biomass?
Long living trees = larger trees
What % of tree biomass is in the stem?
~60%
Where is most N in a tree?
50% in foliage and branches
