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南疆三地州贫困人口的精准识别及影响机制
No full textThe three southern districts of Xinjiang is one of the most severe poverty situation areas in 14 concentrated poverty areas, and analysesing the influence mechanism on the precise identification and causes of poverty of the poor is the core work of the precise poverty alleviation of poverty. In this paper, the minority Kepinaike in Kashgar Districts and Brazil Qiawage in Hotan Districts are chosen as a typical case of three prefectures poor village. It obtains 448 farmers basic family information as data support through surveys and questionnaire survey. And it optimizes the current system and verificates the new with exploring the advantages and disadvantages of the current system about the precise identification of poverty. At the same time, it concludes the main poverty in southern Xinjiang three prefectures poor households and its influencing factors using A-F mechanism of Multidimensional Poverty Measurement and classical statistics method. Finally, combined with the statistical analysis of farmers' willingness to increase income from poverty, it puts forward policy suggestions on the three southern states of poor households out of poverty in rural areas - precise path from the perspective of farmers -agriculture.The main results are as follows: (1) the current system in evaluation framework have the disadvantages which is that relates to content index is not comprehensive and the poor type has not been effective defect recognition.its optimization direction includes that: the refinement in the evaluation index of the original evaluation dimension, the added evaluation dimension in the third industry development status and the status quo of the ecological environment, and the appropriate adjustment in the weight. The optimized identification system has the following virtues: less capital and labor quality of poor households and the poverty types due to illness and school are effectively to get accurate recognition. While the farmers lower exchange ability and the weak modern production management organization are reflected as an important factor affecting poverty in the three southern districts. (2)cross factors leading to the multidimensional poverty has been ordinary phenomenon about the three prefectures poor households,in addition, the highest incidence of income poverty, lack of arable land, labor, capital, technology development costs and burden of disease have been the major poverty factor.(3) The poverty factors about the three prefectures hoseholds can be summarized as natural factors and family factors.local natural elements are the root causes of regional poverty,while lack of housing, the prevalence of disability, lack of labor skills and the level of education is low family factors aggravate the external causes of poverty.what’s more, backward production organization and industrial structure is the direct reason for the poverty.(4) The age of the poor households out of poverty development will focus on different, the export of labor services, the development of aquaculture and engaged in building decoration has become the first choice of the majority of poor households' income approach to development. To provide Chinese agricultural technology, training and policy needs of poor households is a free clinic common reaction. (5) Local farmers in three southern districts of Xinjiang out of poverty path could think deeply in three steps: accurate identification—accurate poverty alleviation—accurately out of poverty
H2O2杀灭水华蓝藻效率优化及胞外聚合物作用分析
No full textCyanobacterial bloom is one of the hot environmental issues which should be resolved for domestic and international researchers. Many freshwater lakes in China at present are in a state of moderate or severe eutrophication, and faced with blooms outbreak constantly, H2O2 has strong oxidizing properties, and can generate strong killing-effect to water bloom cyanobacteria, the final products are H2O and O2, which will not cause environmental pollution. Ferric salts can catalyze H2O2 to generate much more ·OH, consequently enhance the oxidation properties significantly, therefore a small amount of iron addition can not only reinforce the algae-killing effect of H2O2, but also save the dosage of H2O2, this process provides a new approach for the control of water bloom cyanobacteria.Dominant species include many common and specific water-blooming cyanobacteria when the blooms break out in china lakes, and the algicidal effect of H2O2 to specific water-blooming cyanobacteria is different. the catalysis of ferric salt and light is quite important during controlling algal bloom, and exopolymers also play a key role in the algicidal process of H2O2, it’s therefor necessary to study the impact of above-mentioned factors.the aim of this research is to investigate the algicidal effect of H2O2 with organic and inorganic iron as a catalyst. Chlorophyll fluorescence Fv/Fm is regarded as an index, this assay also studies the function and changes of extracellular polymers(EPS) and cell membrane during H2O2 killing the cyanobacteria by batch experiments , the main results were as follows:(1) The effectiveness of iron salts is assessed by Chlorophyll fluorescence, the algicidal effect of H2O2 is ralatively poor with FeSO4 as catalyst, while the effect of H2O2 to kill algae under light with EDTANaFe as catalyst is quite good. Light radiation can significantly enhance the algicidal effect of H2O2 in the process of algae control.(2) Algae-killing effect of H2O2 with FeSO4 as catalyst is not good, the reason is summarized as follows; at neutral or slightly alkaline condition, Fe2+ is oxidized into Fe3+ and the partical size of solution increases, consequently forming precipitation when adding FeSO4, and leading to interruption of Fenton reaction, while EDTANaFe can keep the iron at the state of complexation, and mantain the Fenton reaction.(3) By comparison of killing effect between main eight kinds of cyanobacteria with H2O2 using EDTANaFe as catalyst, we find that the algicidal effect of H2O2 differences along with various algae, Microcystis ichthyoblabe is scarcely damaged by H2O2 and EDTANaFe(H2O2=10 mg L-1, Fe2+=3 mg L-1), Microcystis aeruginosa is also not easy to damaged by H2O2 and EDTANaFe, while other cyanobacterias are strongly damaged by H2O2 and EDTANaFe .(4) Extracellular polymers (EPS) play an important role when H2O2 kills algae, cyanobacteria cells without EPS are quite sensitive to H2O2, but the damage of H2O2 to them is still different among the species. As for Microcystis ichthyoblabe, H2O2(10mg L-1) has little impact on it even though the aglae has been extracted EPS, but for other algaes, the decline in Fv/Fm of Cell-EPS is 1.5~2 times of that of Cell+EPS after adding same H2O2, which shows that EPS could scavenge about half of H2O2. (5) H2O2 can increase the permeability of cell menbrane as well as damage the cell membrane, and the level of damage is positively correlated with the decilne in Fv/Fm, therefore the permeability change of cell membrane can be regard as an index of damaging to algae(6) TOC changes little during the algicidal process by low-concentration H2O2, while half of protein and parts of polysaccharide are suffered structure changes including the decrease in molecule weight
塔中油田地下水位变化趋势与模拟
No full textThe Tazhong oilfield in the hinterland of Taklimakan Desert has a rich oil and gasresource, groundwater resources are particularly important due to extreme droughtconditions. The regional groundwater hydrological process is taken as the research object,in the paper, the temporal and spatial variation of groundwater depth was observed, and thehydrogeological parameters were calculated by GIS technique and pumping test toestablish the prediction model of groundwater flow system, and to clarify the mechanismof water movement. The numerical model of groundwater response process wasestablished on the condition of high strength pumping to determine and predict theresponse of the groundwater situation change situation in the future to solve thecontradiction between the resources development and water resources utilization, andconduct the scientific countermeasures for sustainable utilization of groundwater in thestudy area. The goal of this study is to explore the method to improve the accuracy ofgroundwater simulation model in the study area, and to provide scientific basis forsustainable utilization of groundwater resources in the study area. The main results are asfollows:(1) In the study area, the groundwater level decreases with the increase of time. Thevariation of water level is closely related to the pumping project and temperature. Thewater level was higher during the winter break period of 11-2 months, and the water levelshowed a downward trend due to the rise of temperature and the interference of humanactivities. The article used the regression deconvolution method to calculate the pressure ofthe unsteady flow pumping test in the unconfined aquifer, three non pressure models areused to calculate the hydrogeological parameters. The results show that except the Boultonmodel can not run successfully, the other two parameters are obtained. The Theis withJacob model to calculate the water conduction coefficient T = 8.96 E2 m2/d, water storagecoefficient S = 6.11 E -2; and the results of Neuman model for T = 8.76 E2 m2/d, Sy = 5E-1, Kv/KH = 1.12 E-3, Sy/S = 1 E1, calculated the permeability coefficient of K were13.6m/d and 13.3m/d.(2) The study area is in the interland of desert, groundwater recharge mainly rely onSouthern meltwater supply, the water depth in there is more than 5m, the phreaticevaporation is 0.986mm/a gaind by the equation of evapoeration , we can see that althoughthe climate is extremely dry, but due to the depth of water level is relatively deep, the vauleof phreatic evaporation is small, and the ground water is mainly used for human activities.(3) the MODFLOW software is used to simulate the change of groundwater level inthe study area and the development plan is assumed to predict the groundwater flow fieldin the future. The results show that the pumping process does not have a significant impacton the groundwater flow field in the hinterland of the hinterland. In this paper, by assumingthat the 5 schemes, the results are as follows: in the water supply capacity, the scheme 5>scheme 4> scheme 2> scheme 3> scheme 1; the cost, the scheme 5> scheme 3> scheme 4>scheme 2> scheme 1; all of the water supply schemes were not have no obvious influenceon the groundwater level. Through comprehensive consideration, when the water demandis very large, the choice of program 4 is the most optimized, if the water demand in thecontrol of the program 2, then select the most appropriate program 2
荒漠城市生态系统对未来气候变化响应的模拟研究与可持续评估
No full text作为人类活动的热点区域，城市突出反映了人类对自然环境的改造和控制；城市区域内大规模的物质生产、消费活动正在（或已经）改变陆地表面覆被状况、生物
退化野果林表层土壤理化特性与微生物群落特征
No full textIn the present study, soil microbial community was used as the object to investigatethe community structure and diversity characteristics and their under the degeneratedwild apple forest dominated by Malus sieversii in the wild fruit forest improvementstation of Xinyuan county , Xinjiang . The result showed that 1. Soil organic carbon(SOC), total nitrogen (TN), total phosphorus (TP )soil physical and chemicalproperties of the main indicators in the degenerated area and health range was notsignificantly different (P > 0.05). 2. By means of the coarse cultivation, actinomycetes,fungi number three groups at different distances from the trunk had no obviousregularity, but the numbers of three groups of microbes in degraded areas weresignificantly higher than that under alive trees crown (P < 0.05). By plate cultivationmethod, we found that the number of bacteria, actinomycetes and fungi exhibited noobvious regularity among different distances to the tree trunk. However, the numbersof bacteria, actinomycetes and fungi under dead wild apple trees crown were insignificantly higher than those under alive wild apple trees crown(P < 0.05). Theculture-dependent fungi can be divided into 3 phyla, 6 classes,8 orders,10 familiesand11 genera.The shared fungi genera were Penicillium, Fusarium, Aspergillus,Absidia, Nectria, Trichoderma, Metarhizium, the endemic genera under alive wildapple trees crown were Clonostachys, Purpureocillium and the endemic genera underdead wild apple trees crown were Leptosphaeria, Phoma.3. The soil harbored similarmicrobiota at the dominant taxonomic levels ( from phylum to genus). By the 16SrRNA gene sequencing and analysis, the soil bacterial microbiota can be divided into35 phyla, 104 classes,160 orders,199 families and 305 genera. At the phylum level，the microbiota were dominated by Actinobacteria, Proteobacteria, Crenarchaeota,Acidobacteria, Chloroflexi. The predominant families were Nitrososphaeraceae,Gaiellaceae, Hyphomicrobiaceae, Chitinophagaceae, Micromonosporaceae. At thegenus level, the microbiota were dominated by Candidatus Nitrososphaera,Rhodoplanes, Pseudonocardia. The tree dieback decreased the soil bacterialcommunity diversity（shannon and chao1 diversity index）but it showed no significant difference between alive wild apple trees crown and dead wild apple trees crown.4. By the ITS gene sequencing and analysis, the soil fungal microbiota can be dividedinto 6 phyla, 20 classes,79 orders,150 families and 361 genera. At the phylum level，the microbiota can be by Ascomycota, Basidiomycota , Zygomycota,Chytridiomycota , Rozellomycota, Glomeromycota and some unclassfied fungi. TheAscomycota was the dominant phylum with the relative abundance 77%-95%. Thepredominant families were Trichocomaceae , Herpotrichiellaceae , Nectriaceae,Lasiosphaeriaceae, Chaetomiaceae, Sporormiaceae. At the genus level, the fungicommunities were dominated by Penicillium, Exophiala, Mortierella, Fusarium,Ochroconis Trichocladium, Preussia, Podospora, Cyphellophora, Tetracladium. Thetree dieback decreased the soil fungal community diversity（shannon and chao1diversity index）but it showed no significant difference between alive wild apple treescrown and dead wild apple trees crown. 5. The degeneration of wild fruit forestdecreased the genetic diversity of topsoil microbiota. The microbial population oftopsoil under alive and dead apple trees crown showed a significant differentiation.6.The above study may indicate that a variety of aspects (soil nutrient, soil enzymeactivity, the number of cultivatable microorganisms, microbial community structureand diversity ) of the soil quality responded differently to the degeneration of the wildfruit forest. Compared to the soil physical and chemical properties, the soil microbiotaitself responded more sensitively to the degeneration of the wild fruit forest. When itcomes to the ecological restoration and conservation of the wild fruit forest in thefuture, it may not need to consider the soil nutrient status of itself in a short term. Itmay provide new thoughts for applying microbial agent to facilitate the ecologicalrestoration and conservation in the wild fruit forest
不同水肥管理措施对新疆绿洲棉田土壤CO2排放的影响
No full text目前，农田管理措施对农田生态系统碳循环和全球变暖的影响已成为研究的热点。如果能长期和准确的测定农田管理措施对于农田土壤碳库的影响，就能为评价陆地生态系统碳源、汇以及全球气候变化等方面提供强有力的依据。本研究基于新疆阿克苏站，以绿洲棉田土壤为研究对象，开展不同还田方式对棉花秸秆腐解速率的影响，棉花秸秆下土壤CO2时空分布特征，干湿交替（灌溉引起的）及秸秆和氮肥对土壤CO2排放影响的研究。本研究主要得出以下结论：
1基于尼龙网袋法研究不同还田方式对棉花秸秆腐解速率的影响，结果表明：1）棉花秸秆还田后腐解速率均表现为前期较快，后期较慢的特点；2）还田量对秸秆腐解速率无显著影响（P>0.05）。3）秸秆还田后90d内，表现为粉碎度越小，越有利于腐解，但在此后，粉碎度对秸秆腐解速率已无显著影响（P>0.05）。4）从棉花秸秆还田深度对秸秆腐解百分率的影响看，表层处理的腐解百分率最小，埋深10cm处理的腐解百分率居中，埋深20cm处理的秸秆腐解百分率最高。
2基于静态箱法和气井法，研究棉花秸秆还田下绿洲棉田土壤CO2浓度和通量的时空分布特征。结果表明：棉花秸秆还田下土壤CO2浓度与通量具有明显的时空变化特征。均表现为7月份出现峰值，10月份出现低值，但与NS（对照组）相比，棉秆还田处理的土壤CO2浓度与通量在5月份也出现峰值。土壤CO2浓度随土壤深度的增加而增加，但棉秆还田对土壤CO2浓度的垂直分布影响不大（0~30cm）。土壤CO2浓度和通量均随秸秆还田量的增加而增加，但加倍量棉秆还田的土壤CO2浓度和通量均显著高于其他处理（P < 0.05）。此外，不同处理的土壤CO2浓度与通量之间均呈现显著相关（P < 0.05），相关系数随棉秆还田量的增大而增大，即土壤CO2通量强烈依赖于土壤CO2浓度。
3通过室内模拟土壤含水量和干湿交替对土壤CO2排放的影响，结果表明：1）与60%WFPS（土壤充水孔隙度）处理相比，40%WFPS处理对土壤CO2排放起到显著抑制作用（P 0.05）。2）多次干湿交替循环后，干湿交替处理的土壤CO2累积排放量显著低于恒湿处理（P < 0.05）。在不同干旱强度处理中， SD（强度干旱）处理对土壤CO2排放速率造成的影响变化幅度显著大于MD（适度干旱）处理，但多次干湿交替循环后，SD处理的土壤CO2累积排放量却显著小于MD处理。随干湿交替循环次数的增加，对土壤CO2排放速率造成的影响幅度显著降低。干湿交替能降低土壤CO2排放量，降低量随干旱强度增大而增大。
4通过室内模拟秸秆和氮肥对土壤CO2排放的影响，结果表明：1）施加棉花秸秆显著增加了土壤CO2排放量和土壤有机碳含量（P 0.05）。2）以CO2形式排放出去的碳占秸秆腐解产生总碳量的百分比来看，在MS（适量秸秆）和LN（低氮量）水平下最高，分别为48.71和50.72%，而在H1S（高量秸秆）和0N（不施氮肥）水平下最低，分别为46.68和45.94%。3）从秸秆还田量和施氮量对EF（秸秆碳排放系数）的影响来看，在MS和0N水平下最高，分别为36.68和35.71%，而在H1S和HN（高氮量）水平下最低，分别为33.53和34.86%，但从每个处理来看EF不是一个常数
柽柳THNAC7基因响应高盐胁迫的调控机理研究
No full textNAC转录因子是植物所特有的并广泛存在于植物当中的一个超家族。其典型的特征是N端含有一个高度保守的NAC结构域，并且在其C端存在一个多变的转录调节区域。NAC转录因子参与包括花的发育、次生壁的生成以及细胞分裂、茎顶端分生组织的形成以及叶片衰老在内的多个过程，同时也在生物和非生物胁迫响应的过程当中发挥重要的作用。
本实验室从柽柳当中鉴定出一条响应盐胁迫的NAC基因，命名为ThNAC7（GenBank number：JQ974961)。此基础上，本研究首先通过转录激活实验证明，ThNAC7转录因子具有转录激活活性，其转录激活结构域由位于C端的连续三个独立的区域组成；然后通过构建了35S:ThNAC7过表达载体，并将其转化到拟南芥中，获得过表达ThNAC7的T3代转基因拟南芥幼苗。对其中的2个转基因株系（OE2和OE5）和野生型（WT）拟南芥进行NaCl和Mannitol胁迫，并对拟南芥的根长和鲜重等进行了统计与分析。结果表明，过表达株系的抗旱和耐盐能力明显强于野生型植株，表明过表达ThNAC7基因提高了转基因拟南芥的抗旱和耐盐能力；对OE2、OE5和WT进行100 mM NaCl胁迫，通过对SOD活性、POD活性、MDA以及叶绿素含量等生理指标的测定与分析，结果显示过表达株系OE2和OE5的SOD和POD酶的活性显著比WT高，MDA也比WT低，说明在盐胁迫下，过表达ThNAC7基因的细胞膜完整性好于野生型对照，进一步说明ThNAC7转基因拟南芥的耐盐能力较野生型显著提高。
为了快速鉴定基因的抗逆功能，本研究在已建立瞬时转化系统的基础上，以整株烟草为试材，通过分析不同菌液浓度、乙酰丁香酮浓度、Tween20浓度、蔗糖浓度、不同浸染时间、及有无激素对GUS基因表达的影响，研究其瞬时表达的最佳条件。结果显示：用OD600值为0.2的农杆菌侵染3 h，在1/2 MS培养基中添加120 μM的乙酰丁香酮，1.5 mg/L KT，0.5 mg/L NAA，3%的蔗糖，共培养3 d，能够得到高效的GUS基因瞬时表达。该体系的建立为利用瞬时转化体系快速分析柽柳基因的抗逆功能奠定了基础
干旱区典型流域植被净初级生产力的遥感估算研究
No full text陆地植被净初级生产力（NPP）是生态系统碳循环的重要组成部分，并且是反映植被对自然环境资源的利用程度。随着气候的变化和大规模的水土开发，生态系统的生产力发生巨大的变化，开展流域陆地生态系统净初级生产力研究，对干旱区实现流域农业可持续发展和提高陆地生态系统可持续性具有重要的科学意义。玛纳斯河流域属于干旱区山地生态系统，植被类型复杂多样，并且绿洲景观特色鲜明。因此，借助实验观测和模型模拟方法，开展流域陆地生态系统NPP研究，分析不同时空格局下的NPP特点以及尺度效应。本文得到以下结论：
（1）从整体上，生育期内碳通量动态变化均呈现单峰曲线。在整个生长季，棉花累积的NEE、Reco和GPP分别为-304.8 g C m-2, 706.18 g C m-2 和 1011.00 g C m-2。随着尺度的上升，GPP与Rn、Tair和SWC的相关性逐渐变强，其原因为生态系统的抗干扰性和稳定性。从分钟到日尺度，GPP与Rn的相关性比与Tair的相关性强；在日尺至月尺度上，反之。这主要取决于光合作用的生物化学特征。由于GPP对环境因子的响应与NPP对环境因子的响应相似，因此，NPP对环境因子有相同的响应。
（2）基于SEBAL模型和光能利用利用率模型的耦合，估算了干旱区天山北麓玛纳斯河流域2013年的植被NPP。本研究中的相关参数根据干旱区的特征进行了调整，并且其创新点在于水分胁迫系数的估算。本研究结果检验表明，SEBAL模型和光能利用率模型的耦合，对玛纳斯河流域山地-绿洲-荒漠生态系统植被NPP的模拟效果较合理，能较好地反映植被净初级生产力的实际情况，不仅提高干旱区植被NPP估算精度，还可以降低模型操作难度，是估算干旱区植被NPP的一种有效途径。
（3）玛纳斯河流域2013年植被NPP总量为7066.72 Mt C·a-1，平均值为278.06 g C·m-2·a-1，总体分布趋势是自南向北先增加-后减少-再增加-最后减少，随着地貌和土地利用类型的变化呈现明显的分布规律，且其月变化比较明显，7—8月达到最大值，占总量NPP的52.2%。植被净初级生产力随海拔和坡度的增加整体呈下降趋势，同时伴随着波动，这些波动主要由地表植被覆盖类型和环境因素所引起。随着尺度的扩展，玛纳斯河流域植被NPP呈下降趋势，产生尺度效应，其主要由地表覆盖类型引起。玛纳斯河流域未利用地NPP的最适尺度为30m，而模拟农田NPP的最适尺度为330-400m
胡杨BR信号通路中转录因子PeBZRI/PeBESI基因功能研究
No full textBR（Brassinosteroid）作为植物生长的必需激素，在调控植物的生长、发育和保护植物免受环境胁迫方面具有非常重要的作用，如促进细胞伸长和分裂，提高花粉育性，调节细胞壁结构和增强抗逆性等。目前BR 信号转导的研究主要集中于拟南芥、水稻、番茄等一年生草本植物，对于广泛存在于自然界的木本植物，其BR信号转导过程中的关键基因功能鲜有研究。本研究主要对胡杨(P. euphratica) BR信号通路中转录因子PeBZR1/PeBES1基因的功能进行了初步探究，以期初步阐明PeBZR1/PeBES1基因在抗逆能力方面的作用，同时也为利用PeBZR1/PeBES1基因进行改良林木和农作物提供一定的理论基础，研究结果如下：
（1）通过对干旱、盐和铜胁迫下胡杨和俄罗斯杨BZR1/BES1基因表达模式的分析发现，三种胁迫都能影响BZR1/BES1基因的表达，两个树种之间差异较大；在盐胁迫下，胡杨的BZR1/BES1的表达量保持相对稳定，俄罗斯杨表达量逐渐升高后降低。通过对组织表达差异分析发现BZR1/BES1基因在根茎叶中均有表达，BZR1基因在胡杨的根茎叶中表达量差异小，俄罗斯杨根中最少，叶片其次，茎中最多，BES1基因在胡杨中变化较小，俄罗斯杨的叶片中表达量显著高于其他组织。
（2）通过生物信息学预测PeBZR1/PeBES1基因编码蛋白的各种理化性质，构建了BZR1/BES1基因的系统进化树，并通过烟草原生质体观察两个转录因子的亚细胞定位，发现两个都在细胞核内表达；分析了PeBZR1/PeBES1启动子的功能元件，而且从胡杨中克隆出PeBZR1/PeBES1基因，并通过overlapping PCR得到了两个基因的功能获得型Pebzr1-1D和Pebes1-1D载体。
（3）将过表达载体35S::PeBZR1和35S::PeBES1转入烟草，通过对不同浓度盐胁迫下的生理生化指标分析发现：在盐胁迫下，与对照相比过表达的转基因烟草株系都显著提高了烟草的SOD、POD和CAT酶的活性，不同盐浓度下程度不同，各转基因株系之间也存在差异；渗透调节物质脯氨酸和可溶性糖的含量也变化显著，PeBZR1转基因株系明显高于PeBES1；与对照相比转PeBZR1/PeBES1基因株系的过氧化氢含量降低，可溶性蛋白含量升高；MDA含量也有降低的趋势；而NtNHX1和NtHAK1基因的表达量在不同浓度盐胁迫下差异显著，转基因株系的表达量显著高于对照，说明PeBZR1/PeBES1转录因子上调了这两个耐盐基因的表达，以上说明了转PeBZR1/PeBES1基因的烟草耐盐性明显高于对照，促进了烟草在盐胁迫下的正常生长, 转基因种子的在不同胁迫下的萌发实验也验证了转基因种子能够提高胁迫条件下的萌发率、根长及α—淀粉酶活力
绿洲化过程中塔北灌区农田土壤固碳速率及潜力研究
No full text绿洲化作为干旱半干旱地区的一种独特生态演变机制，是人类活动与自然条件共同作用下由荒漠向绿洲转变的过程。新疆塔北灌区作为典型的绿洲农业区，伴随着绿洲化过程，其农田土壤理化性质及有机碳含量发生改变，进而影响到农田土壤碳库的变化。本研究通过对不同时期塔北灌区农田样地土壤采样及剖面分析，同时结合第二次全国土壤普查和塔北灌区相关农业资料，利用Arc GIS软件分析农田土壤有机碳密度和储量的变化，揭示绿洲化过程中塔北灌区农田土壤有机碳库的演变规律，并分析影响土壤有机碳变化的主要因素，估算塔北灌区及南疆地区的农田土壤固碳潜力。研究旨在为塔北灌区改善土壤质量、提高农作物产量提供科学指导，对新疆乃至西北地区的碳估算提供理论支撑，从而服务于国家气候谈判。本研究主要研究结果如下：
（1）不同类型土壤有机碳含量差异显著
塔北灌区不同类型土壤有机碳含量（SOC）之间存在差异，从高到低依次为林灌草甸土、草甸土、潮土、盐土和风沙土，其中风沙土有机碳含量远低于该区平均水平。土壤剖面有机碳含量从上而下递减，这与长期耕作及农田管理等关系密切。塔北灌区土壤有机碳密度（SOCD）的空间分布差异显著，总体呈现出自西南向东北递减的分布格局；不同类型土壤有机碳密度（SOCD）差异显著，与SOC含量分布规律一致；对同一土壤类型而言，不同土属间有机碳密度（SOCD）差异不显著。塔北灌区的有机碳库总量约为87.64*107 kg。不同类型土壤的储碳能力从高到底依次为林灌草甸土、草甸土、潮土、盐土和风沙土；草甸土碳库是灌区最大的碳库，其有机碳储量为46.31*107 kg，所占比例高达52.85%。
（2）近30年（1981-2011年）有机碳含量呈增加趋势
30年来，塔北灌区有机碳含量及密度均呈上升趋势，西南、中南和东南部的SOCD增量明显，最高可达0.9503 kg·m-2，中北及东北部等区域则呈负增长。农田有机碳含量以不足0.01 kg·hm-2·a-1的变化速率缓慢增长，土壤固碳、丢碳、相对平衡面积分别占总面积的61%、25%和14%。
（3）土壤有机碳变化是多种因素综合作用的结果
影响农田有机碳固存的主要因素包括农田开垦年限、农田管理措施和土壤理化性质三个方面。农田开垦年限对土壤有机碳积累影响显著。以新开垦地为对照，耕作年限达30年以上的农田有机碳含量显著高于耕作年限小于30年的农田。以土壤有机碳含量为因变量（y），耕作年限为自变量（x），做回归分析，得y = 0.002x2 + 0.0737x + 1.9883，R² = 0.9014。农田管理措施是塔北灌区农田土壤有机碳固存的重要影响因子。较高的秸秆还田比例，有机肥及化肥的配施，充足的灌溉水源，均有效地提高了土壤有机碳的含量。土壤有机碳含量与容重、粉粒及黏粒含量呈显著正相关，与砂粒含量呈显著负相关；全氮、全磷、全钾及有效磷含量与土壤有机碳含量的相关性显著，pH值及速效钾对土壤有机碳含量影响不显著。土壤有机碳与养分元素相关性由高到为：全氮(TN)>全磷(TP)>有效磷(AP)>全钾(TK)>速效钾(AK)；建立土壤有机碳含量(y)与全氮(x1)、全磷(x2)、全钾(x3)和有效磷(x5)的最优回归方程，y=5.464x1+31.603x2+0.1771x3+23.552x5-3.184，R2=0. 653，P<0.001。
（4）农田土壤有机碳潜力巨大
塔北灌区不同类型土壤有机碳固碳潜力差异显著。盐土的固碳潜力为1.69 kg·m-2，远高于其他4种类型的土壤，因此要加强塔北灌区的次生盐碱化治理和盐碱土改良。塔北灌区5种土壤类型的总固碳潜力为59.32*107 kg，固碳潜力较大。总体而言，南疆地区的土壤有机碳固碳潜力巨大，为22.96*109 kg。固碳潜力最大的3种土壤类型依次为盐土（1.64 kg·m-2）、境漠盐土（1.06 kg·m-2）和灌淤土（0.98 kg·m-2），固碳潜力不足0.5 kg·m-2的为棕钙土，其他土壤类型的固碳潜力均在0.5~1.0 kg·m-2之间