The Middle Proterozoic Jiuling Group, one of the most important geologic unit in the Northwest Jiangxi Terrain, is a kind of An-bearing formation with a An-Ag-As associahon, and itsgeotectonic sethng belongs to the AC...The Middle Proterozoic Jiuling Group, one of the most important geologic unit in the Northwest Jiangxi Terrain, is a kind of An-bearing formation with a An-Ag-As associahon, and itsgeotectonic sethng belongs to the ACM area. Granihfication can supply An with favorable com-plexing agents. Later granitification is of much more significance in boneralizahon. Regional Anmineralisahon includes two types: metamorPhic hydrothermal solo-An mineralization in the northernpart and magma hydrothermal superimposed polymetallic mineralization with An, Ag, etc, beingdominant in the southern part. Regional exploration should center around the Jiuling Group, smallgranite bodies of later periods and fault structures, while paying attention to the anomalies of trace elements such as Au, Ag, As, Pb, Zn, etc.展开更多
This study improved the application of the Holdridge life-zone model to simulate the distribution of desert vegetation in China which gives statistics to support eco-recovery and ecosystem reconstruction in desert are...This study improved the application of the Holdridge life-zone model to simulate the distribution of desert vegetation in China which gives statistics to support eco-recovery and ecosystem reconstruction in desert area. This study classified the desert vegetation into four types： （1） LAD： little arbor desert; （2） SD： shrub desert： （3） HLHSD： half-shrub, little half-shrub desert; （4） LHSCD： little halfshrub cushion desert. Based on the classification of Xinjiang desert vegetation, the classical Holdridge life-zone model was used to simulate Xinjiang desert vegetation＇s distribution and compare the Kappa coefficient result of the model with table of accuracy represented by Kappa values. The Kappa value of the model was only 0.19, it means the simulation result was poor. To improve the life-zone model application to Xinjiang desert vegetation type, a set of plot standards for terrain factors was developed by using the plot standard as the reclassification criterion to climate sub-regime. Then the desert vegetation in Xinjiang was simulated. The average Kappa value of the second simulation to the respective climate regime was 0.45. The Kappa value of final modeling result was 0.64, which is the better value. The modification of the model made it in more application region. In the end, the model＇ s ecological relevance to the Xinjiang desert vegetation types was studied.展开更多
文摘The Middle Proterozoic Jiuling Group, one of the most important geologic unit in the Northwest Jiangxi Terrain, is a kind of An-bearing formation with a An-Ag-As associahon, and itsgeotectonic sethng belongs to the ACM area. Granihfication can supply An with favorable com-plexing agents. Later granitification is of much more significance in boneralizahon. Regional Anmineralisahon includes two types: metamorPhic hydrothermal solo-An mineralization in the northernpart and magma hydrothermal superimposed polymetallic mineralization with An, Ag, etc, beingdominant in the southern part. Regional exploration should center around the Jiuling Group, smallgranite bodies of later periods and fault structures, while paying attention to the anomalies of trace elements such as Au, Ag, As, Pb, Zn, etc.
文摘This study improved the application of the Holdridge life-zone model to simulate the distribution of desert vegetation in China which gives statistics to support eco-recovery and ecosystem reconstruction in desert area. This study classified the desert vegetation into four types： （1） LAD： little arbor desert; （2） SD： shrub desert： （3） HLHSD： half-shrub, little half-shrub desert; （4） LHSCD： little halfshrub cushion desert. Based on the classification of Xinjiang desert vegetation, the classical Holdridge life-zone model was used to simulate Xinjiang desert vegetation＇s distribution and compare the Kappa coefficient result of the model with table of accuracy represented by Kappa values. The Kappa value of the model was only 0.19, it means the simulation result was poor. To improve the life-zone model application to Xinjiang desert vegetation type, a set of plot standards for terrain factors was developed by using the plot standard as the reclassification criterion to climate sub-regime. Then the desert vegetation in Xinjiang was simulated. The average Kappa value of the second simulation to the respective climate regime was 0.45. The Kappa value of final modeling result was 0.64, which is the better value. The modification of the model made it in more application region. In the end, the model＇ s ecological relevance to the Xinjiang desert vegetation types was studied.
