Spatial Distribution Of Tianshan Mountains Forest’s Soil Organic Carbon And Its Influencing Factors

It has long been a focus of academia to estimate the soil organic carbon contentof forest and to study its influencing factors. Soil organic carbon and its componentsspatial distribution affected by various thermal gradient of water and forestdevelopment, in previous work carried out in mixed forests cannot accurately reflectthe variation of forest soil organic carbon along the hydrothermal gradient due to aninability to distinguish the effects from multiple community types. The Piceaschrenkiana forest is a pure forest (lower elevation from1750m above sea level to2760m at its upper limit), presenting zonal distribution on the huge TianshanMountains from west to east with variable soil organic carbon along the hydrothermalgradient. So effects caused by community type changes of mixed forest can beexcluded. Therefore,in this study there ara greater scientific value of the Tianshanmountains Picea schrenkiana forest’s soil organic carbon and its physical componentsspatial distribution for this study area.According to the standards of climate, topography, forest growing communitystructure, the Tianshan divided into eastern Tianshan (as represented by the Kumulregion), middle (as represented by the Urumqi region)and western Tianshan (asrepresented by the Ili region). In the three study areas of eastern, middle, westernsection of Tianshan, every200m per elevation gradient series plots were set up, inwhich there are three plots on the northern slope of the eastern Tianshan and itselevation of2100m from the lower to the upper limit of the forest altitude2760m,and the northern slope of the middle Tianshan there are five plots, its elevation of1760m from the lower to the upper limit of the forest altitude2760m, there are fiveplots on the northern slope of the western Tianshan and its elevation of1700m fromthe lower to the upper limit of the forest altitude2760m. Set up three plots on each ofthe elevation gradient to dig a unified normative soil profile standards in each sample on the ground, on each soil profile by0-20cm,20-40cm,40-60cm,60-100cm,stratified soil samples. Soil samples back to the lab after dry to sieved, It used apotassium dichromate-oxidation external heating method to test soil organic carboncontent, relative density fractionation method to test light and heavy fraction organiccarbon content, particle size grouping method to test particulate organic carboncontent.Through the analysis of experimental data to explore the thermal gradient inthe water vertical distribution of Tianshan Picea schrenkiana forest soil organiccarbon and its physical components (along an altitudinal) and horizontal distribution(from east to west), and analyzed by hydrothermal forest growing relationshipbetween the ratio of the Tianshan Picea schrenkiana forest soil organic carbon spatialregularity of the combined effects of its differentiation.The results showed that:(1) In1m depth standard soil profile, eastern, middle and western Tianshanmountains of the organic carbon content of each altitudinal gradient presented adecreasing trend with increasing profile depth, the soil organic carbon of eachaltitudinal gradient was mainly concentrated on the soil surface at a depth of0—40cm,accounting for about70%—80%and the depth of40—100cm, accounting for about20%—30%of the whole section, it had obvious surface assembly;(2) With increasing altitude, the total soil organic carbon content of the standardprofile of eastern Tianshan showing an increasing trend after the first decrease, middleand western part of the Tianshan mountains’forest, from the lower elevation limit tothe upper limit presented an indistinctive bimodal change which decreased, increasedand then decreased;(3) On the0-1m standard soil profile, eastern, middle and western Tianshanmountains of the total organic carbon content of each altitudinal gradient presented inthe middle section> the western section> the eastern section of the law, in which themiddle and western part of the difference was not significant, but eastast Tianshanspruce forest altitudinal gradient of each soil organic carbon were significantly lower than in the middle and western section.(4) In the0-1m standard profile, light and heavy fraction organic carbondistribution consistence with the distribution of total organic carbon, however, theparticulate organic carbon showing a phenomenon that each soil evenly distributed;(5) Tianshan Picea schrenkiana forest on the standard soil profile each elevationgradient, heavy organic carbon accounting for about60%—70%, light fractionorganic carbon accounting for about20%—30%and then particulate organic carbonto total organic carbon ratio of10%;(6) With increasing altitude, the eastern Tianshan forest soil organic carbon,lightand heavy organic carbon showed decrease frist and then an increasing trend, whilethe POC was the first increase and then decrease trend; western part of the Tianshanmountains’forest, from the lower elevation limit to the upper limit presented anunique change which decreased, increased and then decreased;(7) Western Tianshan component of organic carbon(light and heavy fraction andparticulate organic carbon) always more than eastern organic carbon, this differencewas seen in the soil surface, but there was no significant difference in the deep soil.(8) Tianshan Picea schrenkiana forest spatial distribution pattern of soil organiccarbon is a common result of climatic conditions and forest growing, soil organiccarbon was positively correlated with precipitation, and negatively correlated withtemperature, while soil organic carbon was positively correlated with diameter atbreast height.This type of research breakthroughs of the community can not be ruled outchanging their predecessors impact on soil organic carbon, has study physicalcomponents of soil organic carbon and total organic carbon in the Tianshan Piceaschrenkiana forest vertical differentiation patterns and levels of differentiation law,the law is fully can be considered only by the growing influence of climatic factorsand the forest, which is on a large-scale study of climate on soil organic carbon spatial variation and it can be important reference to the study area correlated with scientificsearch.