[Greenbuilding] [BULK] Re: Plybooboo comparative yields

[YankeePerm at aol.com]

That's interesting.   Now if you want a genus that should never be planted 
outside of its native Australia, it is Eucalpytus.   It poisons the soil for 
most other plants.   I'd also be interested to see if Eucalpytus can be 
monocropped indefinitely.   Many of those bamboo groves in China have been managed for 
nearly the full duration of Chinese history.   

Another factor, that probably doesn't eat up the large difference between the 
unnamed bamboo genera and Eucalpytus, is actual structural capacity.   A 
bamboo culm equals the strength steel half the diameter of the bamboo.   By 
weight, it is stronger than steel.   Being very strong but leightweight is a good 
feature for building, but the lightweight stucture of bamboo also means that the 
plant needs to produce less biomass to reach full size.   (It's hollow, or at 
least most Asian species are.)   The low biomass production means less 
fertility elements are removed with the wood, which probably contributes to the 
sustainability of bamboo groves. So if you are interested in biomass, carbon 
sequestering, then Eucalyptus outdoes bamboo by several times, but if you are 
interested in building materials over the long term, we need more data to make a 
decision.   In point of fact, what we would replace if we planted more bamboo in 
North America, would be mainly plantation pines with waning productivity, not 
Eucalyptus monocrops.   

An interesting note:   bamboo plantations in Australia, where the Eucalyptus 
species are native, are increasing rapidly.   Now this may not be rational, 
but it could be for good reasons, maybe.

Dan Hemenway

DH

In a message dated 2/8/07 8:20:52 PM, keith at earthsunenergy.com writes:


> In China’s Hunan province, reportedly the
> source of most bamboo flooring sold in the U.S., average bamboo culm
> yields of 5-8
> mt/ha/yr are reported. In comparison, documented production of wood by
> the most
> commonly planted eucalyptus species ranges from 7.9 to 35 mt/ha/yr (dry
> weight).
> 
> 





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