Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2021-01-26 Cooperative journals: 《干旱区研究》
Abstract：本文以2 a生小胡杨2号幼苗为研究对象，采用盆栽持续干旱的方法探究其光合及生理特征对干旱逆境的响应，结果表明：（1）随干旱胁迫程度加剧，小胡杨2号主动调节自身光合机制以适应逆境条件，其净光合速率（Pn）等参数日变化曲线均由双峰型变为单峰型；同时，小胡杨2号积极调整水分利用策略，维持高水分利用效率以应对干旱环境。（2）轻度及中度干旱胁迫提升了小胡杨2号对强光的利用效率；重度干旱胁迫下苗木降低呼吸消耗保存光合产物、提高对弱光的利用能力以抵御干旱逆境。（3）经回归拟合，小胡杨2号Pn、蒸腾速率（Tr）、水分利用效率（WUE）与土壤含水量存在相应数学关系，确定适宜小胡杨2号幼苗生长的最优土壤水分范围为7.3% ~ 11.0%。（4）小胡杨2号通过积累渗透调节物质与提高抗氧化酶活性来减轻干旱胁迫的伤害作用，但重度干旱也会使其保护酶活性受到抑制，最终使膜脂过氧化程度加深。综上，小胡杨2号作为抗旱性良好的喜光树种，可广泛用于固沙造林、植被恢复等，在干旱半干旱地区林业建设中具有良好的推广前景。
Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-10 Cooperative journals: 《干旱区研究》
Abstract：内蒙古西部是东亚及全球重要沙尘源, 为揭示2000年以来该区沙尘活动空间分布特征及其成因，对区域地貌类型，地表沉积物组分，沙尘暴、扬沙和浮尘日数，以及大风日数等数据进行统计分析。结果表明：富粉沙、黏土组分的干盐湖与分布众多盐湖的边缘沙漠及沙地为高频沙尘活动区，如额济纳、拐子湖、腾格里沙漠南缘、毛乌素沙地西北边缘等区域；粉沙、黏土组分含量高, 而地表水分含量或植被盖度较高的地表，沙尘活动的频次较低，如河套灌区及鄂尔多斯高原东南边缘高盖度植被分布区; 地表粉尘含量较高, 且有一定盖度植被覆盖的地表，在较强风力作用下，沙尘事件也频发，如白云鄂博、乌拉特后旗等区域。综上所述，受区域大地貌背景的影响，地表沉积物机械组分、水分、植被以及风力等自然因素的空间差异，导致该区域沙尘活动发生频次具有显著的空间变异性。
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2018-09-03 Cooperative journals: 《干旱区研究》
Abstract：基于对乌兰布和沙漠刘拐沙头黄河沿岸相近株距（10~15 cm）、不同行距（1 m、2 m）、不同留茬高度（10 cm、30 cm）巨菌草的防风阻沙试验的观测数据分析。结果表明：① 巨菌草留茬沙障的防风固沙效益与沙障的高度和行距有直接关系，高度一定，行数越多，带距越小，防护效果越好，但所需材料增加。② 巨菌草留茬沙障内输沙量主要集中在地表15 cm以下，近地表0~5 cm处沙障对风沙流的阻碍能力较强。沙障行距为1 m、2 m时，高10 cm的沙障分别经9 带、12 带后风速降至起沙风速以下；高30 cm的沙障对风的阻碍能力增强，分别经7 带、9 带后地表无流沙运动。③ 沙障的设置应在保证高效的前提下降低成本。行距2 m、高30 cm的巨菌草留茬沙障，气流经过9 个条带（18 m宽）后，风速可降至起沙风速以下，此设置模式宜在干旱地区推广。
Subjects: Biology >> Botany >> Plant ecology, plant geography submitted time 2016-05-03
Abstract： Aims Forest carbon storage in Inner Mongolia plays a significant role in national terrestrial carbon budget due to its largest forest area in China. Our objectives were to estimate the carbon storage in the forest ecosystems in Inner Mongolia, and to reveal its spatial pattern. Methods In the study, field survey and sampling were conducted at 137 sites, which were nearly evenly distributed in most forest types in the study region. At each site, the ecosystem carbon density at each site was estimated thorough sampling and measuring pools of soil (0–100 cm) and vegetation, including biomass of tree, grass, shrub, and litter. Regional carbon storage was further calculated with the estimated carbon density for each forest type. Important findings Carbon storage of vegetation layer in forests in Inner Mongolia was 787.8 Tg C, with the biomass of tree, litter, herbaceous and shrub account for 93.5%, 3.0%, 2.7% and 0.8%, respectively. Carbon density of vegetation layer was 40.4 t?hm–2, with 35.6 t?hm–2 in trees, 2.9 t?hm–2 in litter, 1.2 t?hm–2 in herbaceous and 0.6 t?hm–2 in shrubs. In comparison, carbon storage of soil layer in forests in Inner Mongolia was 2449.6 Tg C, with 79.8% distributed in the first 30 cm. Carbon density of soil layer was 144.4 t?hm–2. Carbon storage of forest ecosystem in Inner Mongolia was 3237.4 Tg C, with vegetation and soil accounting for 24.3% and 75.7%, respectively. Carbon density of forest ecosystem in Inner Mongolia was 184.5 t?hm–2. Carbon density of soil layer was positively correlated with that of vegetation layer. Spatially, both carbon storage and carbon density were higher in the eastern area, where the climate is more humid. Forest reserve construction and artificial afforestation can significantly improve the capacity of regional carbon sink.
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