Plantation Wood Yield
I reckon that to maximise production of fuel wood, trees should be planted, allowed to grow, then cut as soon as their rates of growth start to slow to about 0.707 (the reciprocal of the square root of 2) of their maxima. The problem is finding a non-labour intensive means of measuring individual growth rates.
The yields below, in dry tonnes per hectare per year, were taken from a table published by Oak Ridge National Laboratory in the USA for particular managed plantations. They also list data for some tropical trees.
|poplar||43||9-20||East & Pacific NW US|
From this I guess that a sensible ball-park expectation for managed tree plantations in temperate latitudes would be about 10 dry tonnes per hectare per year.
The annual yield is had by harvesting trees annually. Enough trees which have past their maximum rate of growth are selected. They are then ring-barked as soon as they have come into full leaf in the Spring. They are then left to 'season' until the Autumn when they are cut, trimmed and stacked. The trimmings and saw dust are then passed through a bacteriological process to reduce them to biomass or wood dust to fire a heat engine.
© January 2001 - Robert John Morton