Surely you also have to consider whatever vegetation your are replacing? It's the net increase in net primary productivity which matters
A On Jun 7, 2013 12:33 AM, <[email protected]> wrote: > Dr. D.and list > > I am not an expert in this area, but try to follow the subject closely > - because it is a hugely important topic for biochar and you should get an > answer. You asked below *"My guess is that many group members here might > [think] this is among the least effective "geo-engineering" efforts. Am I > wrong? *" > > My answer: we need more data. By no means "least" yet.. > > Googling found this Wiki statement (emphasis added): > *'They grow at such a rate as to produce roughly 40 cubic feet (1.1 m3) > of wood each year, approximately equal to the volume of a 50-foot-tall tree > one foot in > diameter.[7]<http://en.wikipedia.org/wiki/List_of_largest_giant_sequoias#cite_note-NPS2009-7>This > makes them among the fastest > growing organisms on Earth, in terms of annual increase in mass. " > > > * This is encouraging but meaningless in CDR (NPP) terms until we > know the associated tree age and land area. If the above hypothetical > tree had unity density [barely floated] of about half carbon, we could say > about 0.55 tonnes C/yr per tree. If there were 100 such trees per hectare > (each occupying 100 sqm) or spaced about 10 meters apart, then we could > say the NPP was about 55 tonnes C/ha-yr or about 5.5 kg C/sqm-yr. This > would be astoundingly good. But could be off easily by a factor of10 if the > 40 cu ft related to a 250 ft tall tree (maybe this growth statistic is > for land with fewer than 10 trees per ha??). Anyone up on these numbers > for giant sequoia? An actively managed planted forest might start off with > 100 times as many trees per ha (one per sqm) - and slowly reduce the > density to get the maximum annual dollar yield from the initial planting > - the thinned little guys going to energy and biochar "of course". There > are numerous forestry experts who know this proper (maxmum profit) planting > and thinning schedule for different species. The growth follows a sigmoid > curve shape - so we need data on that as well. If the maximum growth > period is 500 years off, that is not so good. > > Speaking of biochar, millions of seedlings are now finding better > growth and economics with char replacing vermiculite or similar starter > "soil". > > Ron > ------------------------------ > *From: *"Dr D" <[email protected]> > *To: *[email protected] > *Sent: *Thursday, June 6, 2013 1:49:34 PM > *Subject: *[geo] Nice but unrealistic carbon capture project? > > Instead of sharing a paper, below is a 5 min video from the New York > Times.... > > > http://www.nytimes.com/video/2013/06/06/science/100000002262388/reaching-for-the-sky.html > > The Archangel Project wants to take cuttings from giant trees (Sequoias), > propagate them in the millions, and plant thousands of arces of them > throughout the US (e.g. New England). The idea is to capture carbon and > store if for thousands of years. > > My guess is that many group members here might this is among the least > effective "geo-engineering" efforts. Am I wrong? > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/geoengineering?hl=en. > For more options, visit https://groups.google.com/groups/opt_out. > > > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/geoengineering?hl=en. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
