Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-11 Cooperative journals: 《干旱区地理》
Abstract：准确、高效地掌握草原土壤属性的空间分布能够为草地资源境管理提供基础信息和参考依据。相比于传统土壤调查方法，基于模糊逻辑的土壤—环境推理能够提高野外采样效率和预测制图精度，被广泛应用于数字土壤制图。但由于土壤自身的空间变异性及其与环境条件间的非线性，现有推理模型的稳定性较低，尚未在高寒草原区进行应用。选择新疆巴音布鲁克典型亚高山草原地区约4 km2区域为研究区，以高程、坡度、坡向、沿剖面曲率、沿等高线曲率、地形湿度指数6个地形因子为土壤环境因子，采用模糊[WTBX]C[WTBZ]均值聚类（Fuzzy C-means Clustering，FCM）方法对环境因子聚类，得到9个环境因子组合，并在隶属度值高的环境因子组合中心共设置18个典型点。运用土壤—环境推理方法模拟研究区表层土壤pH值空间分布，其变化范围在7.170~8.186之间。选取35个独立样本进行精度检验（均匀采样点16个，横截面采样点9个，垂直带采样点10个），模拟结果与实测值基本吻合，且基于模糊聚类和土壤—环境推理方法的模拟精度高于普通克里格法和反距离权重法。通过基于模糊逻辑和土壤—环境推理的数字土壤制图方法在小尺度区域的运用验证，结果表明基于典型点的采样方案能够快速、有效地对区域土壤属性进行空间模拟，该方法对于类似小尺度的研究区同样有效。
Subjects: Geosciences >> Geology submitted time 2022-12-20 Cooperative journals: 《干旱区研究》
Abstract：
With the basis of climate change, nitrogen deposition will have an impact on N2O emissions between the soil and atmosphere in the alpine wetland in the arid region of Northwest China. Taking the alpine wetland at Swan Lake of Bayinbuluke in the middle of Tianshan Mountain as a study area, three nitrogen addition treatments (0, 10, and 20 kg·hm− 2 ·a − 1 ) were set in different water conditions (perennial seeper area, seasonal water area, and perennial dry area). The measurement of N2O was made via static chamber-gas chromatography during the growing season. The relationship between N2O emissions and main environmental factors was explored. The results showed that the following: (1) increased N significantly contributed to N2O emissions under different water conditions in the alpine wetland ecosystem (P < 0.05). Under 0 kg·hm− 2 ·a − 1 treatment, the N2O accumulation showed an uptake from the ecosystem with the growing season. Under 10 and 20 kg·hm− 2 ·a − 1 treatments, the N2O accumulation were emitted. The cumulative N2O emissions increased significantly when nitrogen deposition increased in different water conditions. Increased nitrogen deposition influenced the wetland ecosystem from N2O to sink to the N2O source. (2) nitrogen application significantly affected the rate of N2O emissions from the ecosystem (P < 0.01). In seasonal water area, the relationship between the average N2O emission rate (F), nitrogen addition (N), and soil temperature (T) at a depth of 5 cm was in accordance with the multiple first- order equation (F = −2.763 + 0.209N + 0.151T, R2 = 0.483, P < 0.01). Therefore, N deposition increases N2O emissions in the alpine wetland in the arid region of Northwest China.
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2018-06-28 Cooperative journals: 《干旱区研究》
Abstract： 由于对陆地生态系统土壤、植被碳蓄积量了解的缺乏，故在预测气候变化中存在较大分歧，因此很有必要对不同生态系统碳分布情况进行研究。本文以干旱盐湖为研究对象，探究盐湖生态系统碳分布特征。结果表明：土壤有机碳密度分布随土层深度的增加而降低，土壤无机碳呈无规律分布；100 cm土层内有机碳密度介于7.55~15.75 kgm-2之间，平均为12.54 kgm-2，占植物群落和土壤总有机碳密度的97.84%。黑果枸杞和铃铛刺为盐生群落的优势种，地上平均生物量为261.38 gm-2，占总生物量的70.49%，草本植物群落平均生物量仅为109.45 gm-2；灌木和草本层地上生物量显著高于凋落物层（84.819.22）gm-2和（79.768.61）gm-2。盐生植物地下生物量随土层的增加而降低，0~100 cm土层总地下生物量为77.74 gm-2。盐生植物总生物量碳密度为276.48 gm-2，其中地上、凋落物和地下生物量分别占62.09%、25.75%和12.16%；地上植被和凋落物碳密度显著高于草本植物，根系生物量碳密度在剖面上分布不均，96.55%集中在0~50 cm土层。盐生植物地上地下以及凋落物平均碳含量43.09%，与经验系数（50%）换算得到碳密度相比实际碳密度高出13.80%，这将对植被碳储量的估算产生较大的偏差。
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