Subjects: Geosciences >> Geography submitted time 2024-03-01 Cooperative journals: 《干旱区研究》
Abstract： The influence of different slope-facing environmental factors on the natural regeneration of Piceaschrenkiana in the middle section of the northern slope of Tianshan Mountains was investigated. A series of plotswere established on shady, semishady, semisunny, and sunny slopes at the same altitude, in a Picea schrenkianaforest to develop the structure equation model for the regeneration index which uses different slope- facingenvironmental factors. According to the environmental characteristics of the different slope- facings, therelationship between the survival status of Picea schrenkiana seedlings and environmental factors was analyzed.The results showed that the semishady and semisunny slopes were more suitable for the survival and growth ofseedlings, and the regeneration indexes of the two slopes (0.065 and 0.057) were significantly higher than thoseof the shady and sunny slopes. Litter was found to have a dual effect on the regeneration of Picea schrenkiana.The undecomposed litter layer was too thick to be beneficial to regeneration, while the rich organic matter couldpromote the formation of a high nitrogen environment in the soil, which was conducive to the regeneration ofseedlings. The influence of different slope-facing environmental factors on the regeneration index was in theorder of total nitrogen content (0.60) > adult tree density (0.46) > litter half- decomposed layer (0.37) > totalpotassium content (0.24) > organic matter content (0.23) > total phosphorus content ( − 0.16) > availablephosphorus content ( − 0.32) > litter undecomposed layer thickness ( − 0.34). Overall, the regeneration of Piceaschrenkiana seedlings in the region was best on the semishady and semisunny slopes with a closure degree ofapproximately 0.6 and litter thickness of approximately 2.5 cm, as well as high total nitrogen and total potassiumcontents in the soil.
Subjects: Biology >> Botany submitted time 2023-03-28 Cooperative journals: 《干旱区研究》
Abstract： This study aims to provide reference for quantifying the selection model of plant water sources. MixSIAR model and IsoSource model are commonly used to quantify plant water sources by combining hydrogen and oxygen stable isotope technology. However, different models yield varying quantitative results. Hence, choosing the best model is important to reduce the uncertainty of results. In this work, the hydrogen and oxygen stable isotope compositions of stem xylem water and each potential water source of two shrubs were measured from July to September in 2019 and 2021. The dominant tree species Cotoneaster melanocarpus and Berberis heteropoda in the premontane shrub zone of the northern slope of Tianshan Mountain were selected as subjects. MixSIAR and IsoSource models were used to quantify plant water sources, and their results were compared and evaluated according to the root mean square error (RMSE) and parameter R. Results showed (1) differences in the quantification results of the two models for the main potential water sources of plants. These differences were related to the calculation principles of the two models. (2) Under the premise that the two models quantify the same main potential water sources of plants, the IsoSource model quantifies larger values than the MixSIAR model. (3) The results of RMSE and parameter R showed that the error of IsoSource model in quantifying plant water sources was smaller than that of MixSIAR model possibly due to the large difference between C. melanocarpus and B. heteropoda In summary, the MixSIAR model may be more accurate in quantifying the similarity of plant water sources than the IsoSource model.
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2020-04-26 Cooperative journals: 《干旱区研究》
Abstract：雪水当量是一个能直观反映出积雪水资源量的重要指标，准确而全面地获取天山云杉树冠截留雪水当量信息，对于提高天山水资源量计算精度方面具有重要意义。本文以天山云杉树苗为研究对象，通过模拟降雪，进行降雪截留实验研究。利用数码照相机获取云杉的雪盖面积、高精度天平称量树冠上截留的雪水质量，进而建立起云杉树苗雪盖面积和雪水当量之间的关系。实验结果表明：多株云杉树苗多次模拟降雪，树冠截留的雪水当量和垂直朝下数字摄影获得的雪盖面积之间拟合曲线趋于一致，且拟合回归方程满足y=21.235x2-1.457x（R2=0.9925）；通过云杉多次模拟降雪实验，构建云杉雪盖面积与树冠截留的雪水当量模型，提出一套利用雪盖面积较为准确估算树冠截留雪水当量的科学方法，为天山云杉树冠截留降雪及其雪水当量提供高精度估算模型。
Subjects: Biology >> Ecology submitted time 2018-05-18 Cooperative journals: 《生态学报》
Abstract：采矿及矿产品运输过程会对环境造成重金属污染进而对生物体产生危害。为定量描述艾维尔沟矿区道路两侧重金属污染程度、明确雪岭云杉叶片对重金属的吸收富集效应，通过采集雪岭云杉叶片和土壤样品，测试其铅（Pb）、锌（Zn）、镉（Cd）、砷（As）、铜（Cu）、铬（Cr）的含量，分析重金属的富集效应和空间分异特征。结果表明：（1）雪岭云杉叶片和土壤中各重金属含量差异显著（P P < 0.05），平均达86.28 μg/g，土壤中Zn、Cu超过了国家土壤质量标准的一级限制值，而As比三级限制值大41%；（2）以背景区（板房沟林场）的土壤和雪岭云杉叶片重金属为评价标准，研究区雪岭云杉叶片重金属综合污染指数为2.05，属中度污染，其中As和Pb单项污染指数较高，达3.65和2.57。研究区土壤重金属综合污染指数为1.69，属轻度污染；（3）随距离增加，除土壤和叶片中Pb含量表现为负线性递减外，As和Cu均表现为先升高后降低，土壤中Cr、Zn逐渐升高，但叶片中Cr逐渐降低，Zn变化不大；（4）冗余分析（RDA）结果显示土壤中Cu、As、Pb与雪岭云杉死树胸径和树高呈正相关关系，而Cr、Zn与其呈负相关。采矿及运输已对土壤和雪岭云杉的生长造成影响，本文对天山雪岭云杉森林的生态修复与保育具有一定的借鉴作用。
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