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Effects of shrub species and microhabitats on dew formation in a revegetation-stabilized desert ecosystem in Shapotou, northern China

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Journal of Arid Land 2014年第4期6卷 389-399页

作者： yanxia pan XinPing WANG Shapotou Desert Experimental Research Station Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences

Dew is an important supplement water source in arid and semi-arid areas. In order to determine the dew formation on different kinds of soils associated with various shrub species and microhabitats, we performed measurement of accumulated dew formation amount and duration in October 2009 in a revegetation-stabilized arid desert ecosystem in Shapotou area, northern China. The results indicated that the accumulated dew formation amount was four times larger at open spaces as compared to under the canopy, and it was nearly twice as much under living Artemisia ordosica plants（L.A.） as compared to under living Caragana korshinskii plants（L.C.）. The opposite characteristics were found for dew duration between different microhabitats. Dew amounts at different vertical heights around the shrub stands were in the order of 50 cm above the canopy〉the canopy edge〉under the canopy. Dew amount continued to increase after dawn, and the proportion of average accumulated dew amount after dawn accounting for the average maximum amount increased from above the canopy to under the canopy. Dew formation duration after sunrise accounted for more than 50% of the total formation duration during the day time. Contrary to the distribution characteristics of dew amount, dew duration after dawn and total dew formation duration during the day time were both highest under the canopy, followed by at the canopy edge and then at 50 cm above the canopy. The portion of dew duration after dawn accounting for the total dew duration during the day time increased from above the canopy to under the canopy. From these results, we may conclude that dew availability as a supplemental water resource for improving the microhabitats in water-limited arid ecosystems is position dependent especially for the plant microhabitats at different stands layers.

关键词： dew amount dew duration shrub species microhabitat soil surface type

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Effects of shrubs and precipitation on spatial-temporal variability of soil temperature in microhabitats induced by desert shrubs

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Research in Cold and Arid Regions 2013年第2期5卷 197-204页

作者： YaFeng Zhang XinPing Wang Rui Hu yanxia pan Shapotou Desert Research and Experiment Station Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences University of Chinese Academy of Sciences

Soil temperatures at 0, 5, 10 and 20 cm depths were monitored cominuously at different microhabitats （beneath shrub canopy （BSC）; bare intershrub spaces （BIS）） induced by xerophytic shrub （Caragana korshinskii Kom.） canopy, respectively. We mainly aimed to assess the effects of shrub canopy and precipitation on the spatial-temporal variability of soil temperature. Results indi- cate that both precipitation and vegetation canopy significantly affect soil temperature. In clear days, soil temperatures within the BSC area were significantly lower than in the BIS at the same soil depth due to shading effects of shrub canopy. Diurnal variations of soil temperature show a unimoclal sinusoidal curve. The amplitude of soil temperature tended to decrease and a hysteresis of di- urnal maximum soil temperature existed at deeper soil layers. Vertical fluctuations of soil temperature displayed four typical curves. In the nighttime （approximately from sunset to sunrise）, surface temperature within the BSC area was higher than in the BIS. In rainy days, however, soil temperatures were affected mainly by precipitation and the shrub canopy had a negligible effect on soil temperature, and little difference in soil temperature at the same soil depth was found between the BSC area and in the BIS. Diurnal variations in soil temperature decreased exclusively as rainfall continued and the vertical fluctuations of soil tempera~＇e show an increased tendency with increasing soil depth.

关键词： desert shrub precipitation soil temperature shading beneath shrub canopy bare intershrub spaces

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Intrastorm stemflow variability of a xerophytic shrub within a water-limited arid desert ecosystem of northern China

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Research in Cold and Arid Regions 2017年第5期9卷 495-502页

作者： YaFeng Zhang XinPing Wang yanxia pan Rui Hu Shapotou Desert Research and Experiment Station Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou Gansu 730000 China

An increasing number of studies in recent years has elucidated distinguishable effects of stemflow on hydrology and biogeochemistry within a variety of ***,no known studies have investigated the temporal variability of stemflow volume within discrete rainfall events for xerophytic ***,stemflow was monitored at 5-min intervals using a tipping-bucket rain gage during the 2015 growing season for a xerophytic shrub(Caragana korshinskii)within a water-limited arid desert ecosystem of northern *** characterized the stemflow temporal variability,along with rainfall,and found the temporal heterogeneity of rainfall clearly affected the timing of stemflow inputs into basal soil within discrete rainfall *** rainfall threshold value for stemflow generation is not a constant value but a range(0.6~2.1 mm,with an average of 1.1 mm)across rainfall events and is closely associated with the antecedent dry *** lags existed between the onset of rainfall and the onset of stemflow,and between rainfall peaks and stemflow *** findings are expected to be helpful for an improved process-based understanding of the temporal stemflow yield of xerophytic shrubs within water-limited arid desert ecosystems.

关键词： stemflow temporal variability xerophytic shrub antecedent dry period time lag

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Revisit of event-based rainfall characteristics at Shapotou area in northern China

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Research in Cold and Arid Regions 2016年第6期8卷 477-484页

作者： XinPing Wang YaFeng Zhang RuiHu yanxia pan HaoJie Xu Wei Shi yanxia Jin Hiroshi Yasuda Shapotou Desert Research and Experiment Station Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Arid Land Research Center Tottori University

Distribution of rainfall event sizes and interval lengths between events are important characteristics of arid and semi-arid climates. Understanding their importance will contribute to our ability to understand ecosystem dynamics in these regions. Rainfall event timing and magnitude are important drivers of ecosystem processes and are instrumental in creating land-scape heterogeneity in arid and semi-arid regions. Rainfall event characteristics were analyzed using an automatic tip-ping-bucket rain-gauge record across the entire summer monsoon season from 2008 to 2015 at the arid desert area of Shapotou in the Tengger Desert, China. Changing the minimum inter-event time （MIT） from 30 min to 24 h alters the number of rainfall events from 64 to 25 for the event depth larger than 0.1 mm. The mean rainfall intensity declined from 0.95 mm/h to 0.53 mm/h, and the geometric mean event duration rose from 0.55 h to 4.4 h. The number of rainfall events, mean rainfall intensity, and geometric mean event duration differed under different criteria of individual rainfall depths, except that for an individual rainfall depth of 0.5, 1.0, and 5.0 mm. The aforementioned features differed only at the lowest range of the mean rainfall intensity and depth for MIT=3 and 6 h. These findings suggest that identification of event-based rainfall in this specific arid region can be better achieved by setting the MIT at six hours. The wide variation in rainfall event properties indicate the need for paying more attention to the proper selection and reporting of event criteria in studies that adopt event-based data analysis. This is especially true in quantifying effective rainfall for soil water replenishment in terms of rainfall depth and intensity with infrequent rainfall events.

关键词： arid and semi-arid regions desert ecosystems rainfall event Shapotou area in northern China

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Variation in water source of sand-binding vegetation across a chronosequence of artificial desert revegetation in Northwest China

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Research in Cold and Arid Regions 2020年第5期12卷 306-316页

作者： yanxia pan XinPing Wang Rui Hu YaFeng Zhang Yang Zhao Shapotou Desert Research and Experiment Station Northwest Institute of Eco-environment and ResourcesChinese Academy of SciencesLanzhouGansu 730000China

Water is the most important limiting factor in arid areas,and thus water resource management is critical for the health of dryland ***,global climate change and anthropogenic activity make water resource management more difficult,and this situation may be particularly crucial for dryland restoration,because of variation in water uptake patterns associated with artificial revegetation of different ages and vegetation ***,there is lacking longterm restorations that are suitable for studying this *** Shapotou area,Northwest China,artificial revegetation areas were planted several times beginning in 1956,and now form a chronosequence of sand-binding landscapes that are ideal for studying variability in water uptake source by plants over *** stable isotopesδ18O andδ2H were employed to investigate the water uptake patterns of the typical revegetation shrubs Artemisia ordosica and Caragana korshinskii,which were planted in different *** compared the stable isotope ratios of shrub stem water to groundwater,precipitation,and soil water pools at five layers(5−10,10−40,40−80,80−150,and 150−300 cm).The results indicate that Artemisia ordosica derived the majority of their water from the 20−150 cm soil layer,whereas Caragana korshinskii obtained water from the 40−150 cm soil *** main water sources of Artemisia ordosica and *** plants changed over time,from deeper about 150 cm depth to shallow 20 cm soil *** study can provide insights into water uptake patterns of major desert vegetation and thus water management of artificial ecosystems,at least in Northwest China.

关键词： artificial vegetation stable isotopes soil water xylem water water source

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高校图书馆报纸阅览室乱架问题研究

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图书馆建设 2010年第7期 81-83页

作者：潘艳霞青岛农业大学图书馆山东青岛266109

报纸是信息传递的快捷媒体之一,深受人们喜爱。报纸阅览室是高校图书馆中使用频率最高的部门之一,因此常常出现乱架现象,增加了报纸的查阅难度。青岛农业大学图书馆报纸阅览室针对乱架问题,在字顺排架法的基础上建立了明码暗字排架法。... 详细信息

报纸是信息传递的快捷媒体之一,深受人们喜爱。报纸阅览室是高校图书馆中使用频率最高的部门之一,因此常常出现乱架现象,增加了报纸的查阅难度。青岛农业大学图书馆报纸阅览室针对乱架问题,在字顺排架法的基础上建立了明码暗字排架法。这种排架方法便于报纸的取还与管理,简便易行,能有效预防乱架现象,可在高校图书馆报纸阅览室推广使用。

关键词：报纸阅览室乱架报纸排架明码暗字排架法

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吸湿凝结水对荒漠地区生物土壤结皮生态功能的影响综述

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地球科学进展 2022年第1期37卷 99-109页

作者：潘颜霞张亚峰虎瑞中国科学院西北生态环境资源研究院沙坡头沙漠试验研究站甘肃兰州730000

生物土壤结皮可以作为一种模式系统来研究复杂的生态学问题,而吸湿凝结水是生物土壤结皮在干旱期维持功能活性的基础,吸湿凝结水输入期间生物土壤结皮的生理活动会影响土壤中的碳交换和许多生物地球化学过程,因此,在荒漠生态系统中,地... 详细信息

生物土壤结皮可以作为一种模式系统来研究复杂的生态学问题,而吸湿凝结水是生物土壤结皮在干旱期维持功能活性的基础,吸湿凝结水输入期间生物土壤结皮的生理活动会影响土壤中的碳交换和许多生物地球化学过程,因此,在荒漠生态系统中,地表吸湿凝结水与生物土壤结皮的关系研究显得尤为重要。但由于吸湿凝结水的形成过程受下垫面特征以及诸多热力及气象环境要素的影响,需要基于土壤学、生物学、气象学、物理学和表面科学等学科的交叉集成研究。在综述国内外研究动态的基础上,根据吸湿凝结水形成的物理基础,对比分析了不同原理测量方法的优缺点及发展趋势,从吸湿凝结水对生物土壤结皮的作用机制和生物土壤结皮发育对吸湿凝结水形成的影响两方面总结和讨论了目前吸湿凝结水形成与生物土壤结皮关系研究的进展和不足,根据现有研究结果,阐述了在未来全球变化背景下,非降雨水输入特征的改变及对生物土壤结皮发育和荒漠生态系统功能的生态作用,并提出了当前研究中存在的问题及未来的研究重点,这些问题的解决将提高我们对荒漠生态系统稳定性和可持续性的科学认知水平。

关键词：生物土壤结皮凝结水测定方法生态意义

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干旱区春小麦发育期反照率变化及其不对称性

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农业工程学报 2011年第12期27卷 120-125页

作者：张亚峰王新平潘颜霞虎瑞中国科学院寒区旱区环境与工程研究所沙坡头沙漠试验研究站兰州730000 中国科学院研究生院北京100049

反照率是影响农田热量平衡的一个关键因子,也是作物生长监测和产量估测的一个重要参数。为了研究反照率随春小麦发育期的变化规律,探讨地表反照率日变化的不对称性及其影响因子,运用辐射仪对春小麦分蘖、拔节、抽穗、灌浆及成熟等不同... 详细信息

反照率是影响农田热量平衡的一个关键因子,也是作物生长监测和产量估测的一个重要参数。为了研究反照率随春小麦发育期的变化规律,探讨地表反照率日变化的不对称性及其影响因子,运用辐射仪对春小麦分蘖、拔节、抽穗、灌浆及成熟等不同发育期的地表反照率日变化进行了观测。结果表明,地表反照率变化的整体趋势是随春小麦发育期的变化而先升(分蘖期至抽穗期)后降(灌浆期和成熟期)。地表反照率的日变化随太阳高度角变化呈现上、下午不对称特征,当太阳高度角小于40°时,上午地表反照率要明显大于下午同样太阳高度角时的反照率,当太阳高度角大于40°时,上、下午地表反照率则逐渐对称。分析推测早晨春小麦叶片表面存在露珠是造成地表反照率日变化不对称的主要原因。研究结果为准确确定干旱区地表反照率及运用地表反照率进行作物生长监测提供一定参考依据。

关键词：作物监测生长春小麦地表反照率发育期日变化不对称

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新型磁控开关型故障限流器参数设计及模型机研究

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电工技术学报 2008年第11期23卷 59-64页

作者：潘艳霞凌志斌蔡旭姜建国上海交通大学电信学院上海200240

基于饱和铁心型高温超导故障限流器拓扑,提出了一种适用于中高压电网的磁控开关型故障限流器结构。通过工作原理分析,论证了此拓扑结构的可行性,建立了限流器的数学模型和简化电路模型,推导出这种限流器系统的设计公式,并在此基础上研... 详细信息

基于饱和铁心型高温超导故障限流器拓扑,提出了一种适用于中高压电网的磁控开关型故障限流器结构。通过工作原理分析,论证了此拓扑结构的可行性,建立了限流器的数学模型和简化电路模型,推导出这种限流器系统的设计公式,并在此基础上研制了一台220V/50A限流器模型机。试验结果表明,该故障限流器具有快速、有效的故障电流限制作用,且具有结构简单可靠,运行控制灵活的特点。

关键词：超导故障限流器故障电流电力系统

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中国沙漠微生物分布及特征

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中国沙漠 2023年第1期43卷 244-256页

作者：潘颜霞回嵘李新荣中国科学院西北生态环境资源研究院沙坡头沙漠研究试验站甘肃兰州730000

微生物是沙漠生态系统的重要组成部分,对生态系统功能和稳定性具有重要意义,目前中国对沙漠微生物的研究基本覆盖了主要的荒漠区。本文基于中国沙区已有研究成果对微生物学研究方法的进展、沙漠微生物群落组成及多样性变化规律、沙漠微... 详细信息

微生物是沙漠生态系统的重要组成部分,对生态系统功能和稳定性具有重要意义,目前中国对沙漠微生物的研究基本覆盖了主要的荒漠区。本文基于中国沙区已有研究成果对微生物学研究方法的进展、沙漠微生物群落组成及多样性变化规律、沙漠微生物群落分布特征及影响因子、沙漠微生物群落功能多样性和微生物资源等进行了总结,以期为沙区微生物资源开发利用提供重要依据。

关键词：中国沙漠微生物群落组成分布特征功能多样性

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