Ricardo Carrere Instituto del Tercer Mundo Casilla de Correo 1539 Montevideo URUGUAY Dear Richardo: Thank you for your nice reply. I was unaware from your original article about the dangers of tree monocultures that you were also against any large-scale agricultural monoculture. I had incorrectly assumed that you were against the 0.6% of tree monocultures in Brazil but were not against the 70% food crop monocultures in Iowa. I was unaware that you were against high production rates (tons/ha) for any crop. I assume we both agree that water consumption rates/ha are high when any crop production rate is high. With regards to production rates, I was relieved to learn that many countries can now produce wood at rates of 40-50 metric tons/ha/yr. This will mean that less natural forests will have to be harvested for wood needs. For example, countries like Brazil consume/produce about 1.6 cubic meters/capita/year. If the population doubling time for Brazil is 30 years, annual wood consumption in 2024 may exceed 500,000,000 cubic meters. We need to decide today were wood in Brazil will be harvested from in 30 years (natural stands? polycultures? high yielding monocultures?). As foresters, we were both trained to have a long-term outlook on forest management. Where we differ is choosing the path which we believe will have the least detrimental effects. If a mean production of 50 cubic meters/ha/yr could be achieved, Brazil would only need 10,000,000 ha of plantation monocultures (1.2% of the land base) to supply the wood needs in the year 2024. If we do not rely on high yielding monocultures, how many hectares of natural stands will be harvested in 2024? A million hectares/year? I do not believe that 1.2% of the land base for Brazil is too much to have in tree monoculture. For example, the amount of plantations in Sweden is about 11% of the landbase. In comparison, I bet the amount of Brazil currently in row crops currently exceeds 5%. ------------------ In your note of 14 October, you stated: >"What can happen when instead of 1 hectare you have >hundreds of thousands of hectares of pine or eucalyptus >monocultures growing at 40-50 tons/ha/yr? This is now happening >in many countries in the world such as Brazil, Indonesia, South >Africa, Chile, Uruguay, and many others." I was aware that Aracruz Celulose in Brazil achieved such production rates on an operational scale. However, I am not aware of high production rates (40-50 cubic meters/ha/yr) from operational plantations in Indonesia, Chile, Uruguay and many others countries. Could you (or any netter) please send me references to support your claims? I need to update my list of production rates from intensively managed tree monocultures. Your claims make my current list out of date. I could use any reference (even if it is just from research plots and not from rates achieved from an operational scale). I need these references for a paper I plan to write. The following is my old list. Country cubic meters/ha/yr Brazil (Eucalyptus) 35 New Zealand (Pinus) 25 South Africa (Eucalyptus) 21 Chile (Pinus) 21 Congo (Eucalyptus) 20 South Africa (Pinus) 15 United Kingdom (Picea) 14 West US (Pseudotsuga) 14 Southern US (Pinus) 9 Will any netter please send me references to expand and update this list? p.s. I have assumed that one green [wet] ton of wood will convert to one 1 cubic meter. For example, the volume of one green ton of Eucalyptus grandis may be 0.94 cubic meter while one dry ton may be 1.47 cubic meters. Thanks again Ricardo. David South School of Forestry Auburn University, AL 36849-5418 dsouth@forestry.auburn.edu 205-844-1022 205-844-1084 (FAX)
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