| This paper does investigations on six natural poplar and willow forest stands of Ergis river in Aletai Xinjiang:Populus nigra,P.laurifolia,P.jrtyschensis,P.alba, P. canescens and Salix alba, and focuses on stand biomass estimate, organic carbon ratio measures of tree layer, shrub layer and herb layer, litter fall carbon ratio measures, carbon density and spatial distribution characteristic, growth law and diameter distribution law.1. Using sample plot and stem analysis method to measure stem analysis in standard land, we studied growth law and diameter distribution law of wild forest in Ergis river.Growth of six natural poplar and willow forest trees accord with common growth law of trees. Growth curve of tree height, DBH and volume were"S"pattern and growth curve of volume was most typical.The mature period of tree height, DBH and volume growth of six species in Ergis were inconsistency. The mature period of tree height was the earliest(10～25a),and then was DBH(22～38a), volume was the latest(30～50a).In the sequence of diameter Structure and density structure in six forest stands: P.canescens>P.nigra>P.jrtyschensis>P.laurifolia>S.alba>P.alba,density of six forest stands are reasonable.2.By method of sample plot and empirical model, we studied community and individual biomass distribution law of tree layer structure, shrub layer, herb layer and litter layer, the horizontal distribution pattern of environmental gradient were as follows:In the sequence of community biomass of six forest stands P.nigra, P.laurifolia, P.jrtyschensis,P.alba,P.canescens and S.alba were 175.303, 145.018, 143.224, 188.400, 152.889, 148.134 t·hm-2; In the sequence of tree layer biomass: 160.416,128.978,131.979,178.575,148.478,141.362 t·hm-2; In the sequence of shrub layer biomass: 10.875,11.243,7.164,5.618,0.448,4.319 t·hm-2; In the sequence of herb layer biomass: 3.469,4.336,3.744,3.129,2.581,1.799 t·hm-2; In the sequence of litter fall biomass: 0.543,0.461,0.337,1.078,1.382,0.654 t·hm-2.Biomass vertical distribution of natural poplar and willow forest in Ergis river, biomass of tree layer took advantage ratio 88.94%～97.71% in community biomass; Biomass of shrub layer account for 0.29%～7.75%; Biomass of herb layer account for 1.21%～2.99%; Biomass of litter layer account for 0.23%～0.90%.With the horizontal distribution pattern of environmental gradient change, community biomass increased along with distance increased. Tree layer and shrub layer biomass presents a single peak, The ratio of herb layer biomass account for total biomass decreases gradually and presents horizontal distribution characteristics.With mathematical models correlations and results showed simulate regression equations about individual tree biomass M and DBH, M=aDb the correlations are prominent, and the simulative of Power equation is best 0.884～0.984.3.The sintering method was used to measure carbon content rate of 6 forest stands and combined with community biomass to analysis carbon density of six forest stands.Carbon content rate of tree layer of Six forest stands in Ergis river were P.nigra 0.4561, P.laurifolia 0.4598, P.jrtyschensis 0.4585, P.alba 0.4641, P.canescens 0.4491, S.alba 0.4508.Mean carbon content rate of shrub layer is 0.4570,herb layer 0.3382, litter layer 0.4165.In the sequence of carbon density of tree layer of six forest stands P.nigra, P.laurifolia, P.jrtyschensis,P.alba,P.canescens and S.alba were 74.6699, 60.5297, 61.2832, 83.9391, 67.4913, 64.0599 t·hm-2; In the sequence of carbon density of shrub layer 4.802, 4.9606, 3.1625, 2.4825, 0.1977, 1.9058 t·hm-2; In the sequence of carbon density of herb layer 1.1340, 1.4317, 1.2242, 1.0346, 0.8602, 0.5932 t·hm-2; In the sequence of carbon density of litter layer: 0.2207,0.1874,0.1370,0.4382,0.5618,0.2659 t·hm-2.This research provided the scientific basis that people know the forest biomass and productivity characteristic,for protecting and using the forest living resources of Ergis river reasonably; Provided the basis for evaluating the adaptability which the main species growing of natural poplar and willow forest in Ergis river, for the species choice of vegetation restoration and the allocation reasonable structures, moreover has important reference values to evaluate the growth effect and the ecological effect of Ergis river natural poplar and willow forest;This dissertation filled the research vacaney on forest biomass, carbon density and growth law of north forest in Ergis river in Xinjiang; Provided some basic data for research on carbon cycle of forest ecosystem in Xinjiang of China.
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