<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman, new york, times, serif;font-size:14pt">Dear all<br>The purpose of categorizing soils into low activity clay and high activity clay is to simplify soil carbon stock estimation. In most of temperate soils you have Montmorillionite and illite as High activity clays. In most of tropical soils you have kaolinite as a low activity clay.You can have vertisoils that contain high activity clay in both temperate and tropical environment. Unfortunately the type of clay is not usually given by soil analysis. <br>For the practical case of M. Gevorgyan, as you have a soil map of Armenia, you can use the carbon content of your different soil units to calculate the carbon stock at 30 cm depth. This will be more accurate than trying to correlate Armenian soils with low and high activity clay.<br>For the second issue. the World Reference Base
for soils differentiates Histosols from mineral soils. Histosols comprise soils formed in organic material.<br>Common names are peat soils, muck soils, bog soils and organic soils.<br>You can use base saturation of your soils to distinguish between nutrient poor and nutrient rich. A base saturation lower than 50 % can be considered nutrient poor and a base saturation equal or higher to 50 % can be considred nutrient rich.<br>Working with soil scientists of your country can help solve all these difficulties.<br><br>Regards<br>Mamadou<br><div> </div><div><em><font style="color: rgb(0, 0, 191);" face="arial black">Dr Mamadou Khouma <br></font><font face="arial black"><span style="color: rgb(0, 0, 191);"> Ingénieur Agronome</span><br></font></em><font face="arial narrow">B.P. 50037 Dakar, R.P. Senegal <br>Tel bureau : (221) 869 39 53 <br>Cellulaire : (221) 632 13 88</font></div><div style="font-family: times new roman,new york,times,serif;
font-size: 14pt;"><br><br><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;">----- Message d'origine ----<br>De : Artur Gevorgyan <arturgv@yahoo.com><br>À : discuss@ghgnetwork.org<br>Envoyé le : Mardi, 2 Octobre 2007, 9h52mn 15s<br>Objet : [GHG Network] Harmonization of soil classification systems<br><br><div>Dear GHG Inventory Experts<br><br>Attention: Land Use, Land–Use Change and Forestry<br>Experts<br><br>Being engaged in the national GHG inventory, for Land<br>Use, Land–Use Change and Forestry in Armenia for<br>preparation of the SNC under the UNFCCC, presently an<br>issue to harmonize national soil type classification<br>with the international WRB or USDA ones is being<br>faced, in order to estimate emissions/removals from<br>the mineral soils, due to land use/land use change,<br>management regime and input level at the Tier 1 level.<br><br><br>I assume that this task might also be of interest
of<br>those Eastern European and Commonwealth of Independent<br>Countries (post soviet union), which have similar<br>national soil classification systems and pursuing<br>estimation of carbon stock changes from mineral soils<br>at the default level. Please see the attached the<br>sample local soil map of Armenia.<br><br>In addition, I am looking for any numerical value or<br>other supporting threshold to distinguish properly<br>organic soils into nutrient poor or nutrient rich<br>ones, as requested by the GPG 2003. <br><br>Appreciating any support to handle with the raised<br>issue, I would like to highlight, that the objective<br>of the request is not the comparison of different soil<br>classification systems, their +/-, but creating<br>linkages among them, enabling using of relevant IPCC<br>default factors and reference soil organic carbon<br>data. Of course, the problem can easily be solved<br>applying GPG 2003 Tier 2 level; however at
present<br>there is a lack of sufficient local data for its<br>application. <br><br>Thank you. I look forward to tackle the raised issues<br>with your help.<br><br>Best regards,<br>Artur Gevorgyan<br><br><br> ____________________________________________________________________________________<br>Don't let your dream ride pass you by. Make it a reality with Yahoo! Autos.<br><a target="_blank" href="http://autos.yahoo.com/index.html">http://autos.yahoo.com/index.html</a><br> <br><br></div></div><br></div></div><br>
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