Vertical distribution characteristics of dust aerosol mass concentration in the Taklimakan Desert hinterland

The different height mass concentrations of dust aerosol data from the atmosphere environment observation station （Ta- zhong Station） was continuously observed by instruments of Grimm 1.108, Thermo RP 1400a and TSP from January of 2009 to February of 2010 in the Taklimakan Desert hinterland. Results show that： （1） The mass concentration value of 80 m PMl0 was higher, but PM2.5 and PM1.0 concentrations at 80 m was obviously lower than 4 m PMl0, and the value of 80 m PM1.0 mass concentration was the lowest. （2） The PM mass concentrations gradually decreased from night to sunrise, with the lowest concentration at 08：00, with the mass concentration gradually increased, up to the highest concentration around 18：00, and then decreased again. It was exactly the same with the changes of wind speed. （3） The high monthly average mass concentration of TSP mainly appeared from March to September, and the highest concentration was in April and May, subsequently gradually decreased. Also, March-September was a period with high value area of PM monthly average mass concentration, with the highest monthly average mass concentration of 846.0 p.g/m3 for 4 m PM~0 appeared in May. The concentration of PM10 was much higher than those of PM2.5 and PM1.0 at 80 m. There is a small difference between the concentration of PM2.5 and PM~ 0. Dust weather was the main factor which influenced the concentration content of the different diameter dust aerosol, and the more dust weather days, the higher content of coarse particle, conversely, fine particle was more. （4） The mass concentration of different diameter aerosols had the following sequence during dust weather： clear day 〈 blowing dust 〈 floating and blowing dust 〈 sandstorm. In different dust weather, the value of PM~o/TSP in fine weather was higher than that in floating weather, and much higher than those in blowing dust and sandstorm weather. （5） During the dust weather process, dust aerosol concentration gradually decreased with particle size decreasing. The dust aerosol mass concentration at different heights and diameter would have a peak value area every 3-4 days according to the strengthening process of dust weather.     

南极菲尔德斯半岛多环境介质中多环芳烃分布特征及环境行为研究

对南极菲尔德斯半岛地区采集的水体、土壤、苔藓、粪便和生物介质中16种多环芳烃(PAHs)进行了分析,考察了不同环境介质中PAHs的含量分布特征及其环境行为。结果表明,水体、土壤、苔藓、粪便和生物中∑PAHs浓度分别为34.9—346 ng·g-1(mean=184)、68.9—374 ng·g-1(mean=188)、122—894 ng·g-1(mean=251)、197—293 ng·g-1(mean=245)和137—443 ng·g-1(mean=265)。与其他地区相比,5种介质中2+3环PAHs的比例超过0.5,而5+6环PAHs的比例则0.2,说明大气传输是菲尔德斯半岛地区PAHs来源的主要途径。通过PAHs在土壤-苔藓(logQSM)、生物-海水(logQOW)和企鹅肌肉-企鹅粪土(logQPD)中的浓度比值与其理化参数的研究发现,logQSM与logpoL和logKOA成显著线性关系,logQOW和logQPD与logKOW成显著线性关系,表明不同环境介质间污染物浓度比值可以看作PAHs在极地偏远地区气-固分配行为以及在生物体内分配行为的镜像。     

滴灌条件下盐地碱蓬(Suaeda salsa)种植年限对盐碱地土壤盐分离子分布的影响

采用时空转化的方法研究了滴灌条件下不同盐地碱蓬种植年限(0 a、1 a、2 a和3 a)对重度盐碱地土壤盐分及盐离子在0～120 cm土壤剖面的分布特征的影响,为盐地碱蓬在盐碱地中的改良利用提供理论依据。试验结果表明:滴灌种植盐地碱蓬后土壤盐分在剖面的分布发生明显变化,根区(0～40 cm)土壤含盐量随种植年限增加而下降,根底(40～120 cm)土壤则先增加后下降;Na⁺和Cl^-因容易被水淋洗和植物选择性吸收多,根区土壤中Na⁺和Cl^-含量随种植年限增加有显著降低,Ca²⁺和SO₄^2-不易随水移动,淋洗程度低,HCO^-₃和Mg²⁺第2 a和第3 a的淋洗效果明显好于第1 a;经过3 a种植后土壤中毒害离子Na⁺与Cl^-和在表层盐分组成中的比例下降,Ca²⁺比例上升,钠吸附比(SAR)值显著降低。     

大青沟国家自然保护区地面苔藓植物分布格局

用双向指示种分析（TWINSPAN）、除趋势对应分析（DCA）和典范对应分析（CCA）研究了大青沟国家自然保护区32个样地36种地面生苔藓植物分布格局。TWINSPAN和DCA分析结果显示,地面生苔藓植物群落可以分成双色真藓（Bryum bicolor）-小石藓（Weissia controversa）群落、西伯利亚瘤冠苔（Mannia sibirica）+小石藓（Weissia controversa）群落、密叶绢藓短柄变种（Entodon compressus var.zikaiwiensis）-密叶绢藓（Entodon compressus）+反扭藓（Timmiella anomala）群落、绒叶青藓（Brachythecium velutinum）-鳞叶藓（Taxiphyllum taxirameum）+尖叶匐灯藓（Plagiomnium cuspidatum）群落和地钱（Marchantia polymorpha）+曲肋薄网藓（Leptodictyum humile）-鳞叶藓（Taxiphyllum taxirameum）-柳叶藓（Amblystegium serpens）+平肋提灯藓（Mnium laevinerve）群落5组,对应分布在羊草（Leymus chinensis）草地、西伯利亚杏（Prunus sibirica）灌丛、大果榆（Ulmus macrocarpa）林、蒙古栎（Quercus mongolica）林和水曲柳（Fraxinus mandschuria）林。CCA分析结果显示,影响苔藓植物分布的主要因子有土壤水分、乔木盖度、空气湿度、凋落物盖度、草本层盖度等。     

试论沙冬青属的染色体地理*

沙冬青属是我国西北干旱地区及中亚东部荒漠的一个特有属,是我国荒漠中唯一的旱生常绿阔叶灌木,本文采用细胞学的方法,研究沙冬青属2种植物及其近缘属──黄花木属和黄华属在青藏高原的代表种(黄花木、紫花黄华)的核型、酯酶同工酶,进而探讨沙冬青属的演化趋势、地理分布及与环境的关系。本文是植物染色体地理的试验研究。     

旧石器时代至商周时期贵州遗址空间分布及其自然环境背景(英文)

This study presents an analysis of the spatial-temporal distribution of 230 archaeological sites in Guizhou Province, Southwest China for three selected time periods from the Paleolithic Age to the Shang-Zhou Dynasties. The relationship between archaeological sites distribution and environmental changes is also discussed based on paleo-environmental proxies of δ18O and δ13C recorded in stalagmites from Southwest China. The results show that: in the Paleolithic Age(260–10 ka BP), archaeological sites were concentrated in the central, northwestern and southwestern parts of Guizhou, where the high-altitudinal karst landforms with many natural caves suitable for human habitation are developed. In the Neolithic Age(10–3.6 ka BP), most of human settlements were concentrated in the central, northwestern and southwestern parts, while, a fewer sites were found on river terraces in the southern and eastern parts, and the intermontane basins in the central and western Guizhou. During the Shang-Zhou Dynasties(3.6–2.2 ka BP), the sites were mainly distributed in the intermontane basins and on river terraces, which were suitable for primitive aerial farming. The analysis of paleo-environmental proxies of δ18O and δ13C since 260 ka BP suggested that climate fluctuations had little impact on human settlements in this study area. The distinct physical environment, especially the spatial patterns of karst landforms and arable land played an important role in the archaeological sites distribution of Guizhou.     

河湟地区乡村聚落位序累积规模模型的实证研究

科学确定乡村聚落体系是落实乡村振兴战略和促进农业农村现代化的关键之一,研究乡村聚落规模分布规律有助于乡村聚落体系优化。基于理论假设推导出了位序累计规模模型的准确表达及其规律,在此基础上,比较研究了位序累计规模模型和乡村位序—规模法则在河湟地区的适用性和准确性,厘清了河湟地区乡村聚落规模分布的特征和演变规律。研究显示：① 位序累积规模模型是一个单调递增的凹函数（P ≥ 1）,函数表达式随着聚落规模分布的帕累托系数变化而变化。当1 ≤ P<1.20225时,S_i=aln(N_i)+b,拟合系数a与首位聚落规模呈正相关;当P ≥ 1.20225时,$S_i=be^{aln(N_i)}$,聚落规模变异系数和首位聚落规模与拟合系数a呈负相关关系,而与拟合系数b则呈正相关关系。② 位序累积规模模型在河湟地区乡村聚落规模分布研究中具有良好的适用性和准确性,而乡村位序—规模法则不适用。③ 河湟地区乡村聚落规模分布为接近于帕累托系数为2的均衡分布且总体趋于集聚。未来河湟地区应有序推进乡村聚落向自然和社会经济条件较为优越区域适度集聚,合理制定区域乡村聚落布点规划和实用性村庄规划,走人与自然和谐共生、城乡融合发展的具有河湟地区特色的乡村振兴道路。     

鄂尔多斯盐沼湿地土壤盐分特征对植物群落的影响

为研究内陆盐沼植物群落的分布对土壤盐分的响应特征,选取鄂尔多斯盐湖盐沼区作为研究区,筛选了肉质耐盐植物群落、苔草植物群落和禾草植物群落3类典型植物群落,开展了土壤含水量、pH、电导率以及Na⁺、K⁺、Mg²⁺、Ca²⁺、Cl^-、SO₄^2-、CO₃^2-和HCO₃^-测定,分析了区内典型植物群落对土壤水盐因子的响应规律。探讨了3类植物群落之间土壤因子含量的差异性;采用相关性分析和CCA分析,评价了3类植物群落多样性及物种分布随土壤因子的变化规律。结果表明,区内3类植物群落中,土壤盐分含量表现为肉质耐盐植物群落最高,苔草植物群落最低,禾草植物群落居中;植物多样性与土壤中含量最高的Na⁺和SO₄^2-的相关性最显著;植物分布同时受到土壤盐分、水分和pH的显著影响。研究结果可为鄂尔多斯盐湖区土壤盐...     

Study on the extremely cold winter of 1670 over the middle and lower reaches of the Yangtze River

The snow-cover days over the middle and lower reaches of the Yangtze River （MLRYR） in the winter of 1670 were extracted from Chinese historical documents. By these records, the winter temperature anomalies （compared to the mean of 1961-1990） recorded at seven meteorological stations and the regional mean winter temperature were estimated. The results show that： （1） There was an average of about 30 snow-cover days over the MLRYR region in 1670, ranging from 11-20 days in Shanghai and eastern Zhejiang to 5140 days in eastern Hunan Province. The snow-cover days averaged about 40 days in Anqing and Nan- cheng, and ranged from 30 to 40 days in Quzhou, Jingdezhen, and Nanchang; and （2） the regional mean winter temperature in 1670 was estimated to be approximately 4.0 ℃ lower than that of 1961-1990. The maximum negative anomaly of 5.6℃ occurred in Nanchang and the minimum anomaly of-2.8 ℃ was detected in Quzhou. Both of these were lower than that of the coldest winter during the instrumental observation period of 1951-2010. This research could not only provide a method to es- timate historical climate extremes, but also provide a background to understand the recent instrumentally climate extremes.     

察尔汗盐湖卤水自然蒸发过程中Ca2+分布规律研究

卤水中钙离子的存在会对盐湖化工生产及其产品质量造成较大影响,研究钙离子在卤水蒸发过程中的分布规律具有重要意义。通过室外自然蒸发及盐田实地采样,研究了察尔汗盐湖盐田生产过程中钙离子分布变化规律。结果表明,在自然蒸发实验中卤水钙离子浓度随蒸发量的增加逐渐减少,在盐田生产现场采样结果显示钙离子浓度随卤水蒸发而增加,结合生产实际,推断外界钙离子补给是造成这种现象的主要原因。因此,避免车间含钙尾水混入,阻止盐田卤水和周边土壤可溶性钙盐间离子交换是有效降低卤水钙离子浓度的主要方法。     

察尔汗盐湖别勒滩区段晶间卤水的主要离子分布特征

通过野外采集样品、室内实验分析,研究了察尔汗盐湖别勒滩区段晶间卤水的主要离子分布特征。采集了53个晶间卤水样品,通过分析,发现K+浓度一般随着深度的增加而减小,Li+浓度一般随着深度的增加而增加,Mg2+浓度随着深度增加浓度也在增加,但异常情况同样存在。Li+,B2O3在空间分布上有一个富集区域,越是远离这一区域离子含量就越低;K+含量则存在两个临界点,在临界点附近相关离子浓度和矿化度会变化。     

基于土地利用的中国人口密度模拟

土地利用数据综合了影响人口分布的众多因素的信息。根据分县控制、分城乡、分区建模的思路,建立基于土地利用的中国1km栅格人口模型。对农村人口采用线性加权模型进行模拟,根据全国12个农业生态区内人口与各类农业用地之间的相关关系选取指标,采用逐步回归计算各指标的回归系数,并结合土地的生产力及其与人口的相关性,确定各指标的加权系数。对城市人口,建立基于城镇规模的人口距离衰减加幂指数模型。结果分析表明,“胡焕庸”线以东人口占全国的94.58%,人口密度是该线以西的21倍;东部人口集中于黄淮海地区、四川盆地、长江中下游、东北平原及沿海地区,东南沿海又表现为“点轴”分布的特点。验证表明,模拟结果具有较高的精度。     

祁连山大野口流域青海云杉种群结构和空间分布格局

青海云杉（Picea crassifolia）是祁连山亚高寒山地森林植被的建群种之一。应用“相邻格子法”获得100 m×100 m样方内所有个体的调查资料,采用种群动态和胸径、树高和冠幅级频率分布及6种聚集强度指数分析了青海云杉的种群结构和空间分布格局。结果表明：（1）青海云杉种群动态分析表明,种群表现为增长型种群。（2）青海云杉种群胸径级频率分布呈“倒J”型,胸径级随个体数的变化符合对数方程y=-219.32ln(x)+482.67(R²=0.963 8,P＜0.01),胸径分异指数为0.48,种群个体胸径差异属明显分异;树高级频率分布呈“间歇”型,不同高度级与个体数之间可用二次方程y=0.795x²-31.23x+285.1(R²=0.603,P＜0.01)进行较好的描述,树高分异指数为0.55,高度差异属明显分异;胸径和树高两者之间符合对数方程y=5.912ln(x)-4.249 3(R²=0.603,P＜0.01);冠幅级与个体数之间可用三次方程y=5.317 6x³ -91.759x²+408.88x-173.87(R²=0.8355,P＜0.01)进行很好的拟合[WTBZ],冠幅分异指数为0.53,种群个体冠幅差异亦属明显分异。总体上看,青海云杉幼苗较为丰富,天然更新能力强,目前表现为成熟稳定型种群。（3）在空间分布格局上,青海云杉种群空间分布格局呈斑块状聚集分布,其扩散系数、丛生指标、聚块性指数、平均拥挤度指数、负二项式分布参数、Cassie指标分别为1.162、2.285、0.162、85.802、1.002和0.026。在不同发育阶段的分布格局有所差异,Ⅰ级幼苗和Ⅱ级幼苗为聚集分布,小树、中树和大树为均匀分布,随着龄级的增大,种群的聚集程度减小,即由聚集分布变为均匀分布,该种群表现出明显的扩散趋势。研究结果可为青海云杉的管理和经营提供理论依据。     

Vegetation impact on the thermal regimes of the active layer and near-surface permafrost in the Greater Hinggan Mountains, Northeastern China

The ground temperature and active layer are greatly influenced by vegetation in the Greater Hinggan Mountains in Northeastern China.However,vegetation,as a complex system,is difficult to separate the influence of its different components on the ground thermal regime.In this paper,four vegetation types,including a Larix dahurica-Ledum palustre var.dilatatum-Bryum forest（P1）,a L.dahurica-Betula fruticosa forest（P2）,a L.dahurica-Carex tato forest（P3） in the China Forest Ecological Research Network Station in Genhe,and a Carex tato swamp（P4） at the permafrost observation site in Yitulihe,have been selected to study and compare their seasonal and annual influence on the ground thermal regime.Results show that the vegetation insulates the ground resulting in a relatively high ground temperature variability in the Carex tato swamp where there are no tree stands and shrubs when compared with three forested vegetation types present in the area.Vegetation thickness,structure,and coverage are the most important factors that determine the insulating properties of the vegetation.In particular,the growth of ground cover,its water-holding capacity and ability to intercept snow exert a significant effect on the degree of insulation of the soil under the same vegetation.     

Recent changes in ground surface thermal regimes in the context of air temperature warming over the Heihe River Basin, China

Changes in ground surface thermal regimes play a vital role in surface and subsurface hydrology, ecosystem diversity and productivity, and global thermal, water and carbon budgets as well as climate change. Estimating spring, summer, autumn and winter air temperatures and mean annual air temperature（MAAT） from 1960 through 2008 over the Heihe River Basin reveals a statistically significant trend of 0.31 °C/decade, 0.28 °C/decade, 0.37 °C/decade, 0.50 °C/decade, and 0.37 °C /decade, respectively. The averaged time series of mean annual ground surface temperature（MAGST） and maximum annual ground surface temperature（MaxAGST） for 1972–2006 over the basin indicates a statistically significant trend of 0.58 °C/decade and 1.27 °C/decade, respectively. The minimum annual ground surface temperature（MinAGST） in the same period remains unchanged as a whole. Estimating surface freezing/thawing index as well as the ratio of freezing index to thawing index（RFT） in the period between 1959 and 2006 over the basin indicates a statistically significant trend of-42.5 °C-day/decade, 85.4 °C-day/decade and-0.018/decade, respectively.     

An exploratory analysis of benthic macroinvertebrates as indicators of the ecological status of the Upper Yellow and Yangtze Rivers

This study presents findings of the first systematic analysis of aquatic biotic assemblages in the source region of the Yellow and Yangtze Rivers. It provides an initial basis with which to select representative organisms as indicators to assess the aquatic ecological status of rivers in this region. Macroinvertebrates are considered to be good indicators of long-term environmental changes due to their restricted range and persistence over time. Field investigations of macroinvertebrates were conducted in August 2009 in the source region of the Yellow River, and in July 2010 in the source region of the Yangtze River. Altogether 68 taxa of macroinvertebrates belonging to 29 families and 59 genera were identified. Among them were 8 annelids, 5 mollusks, 54 arthropods and 1 other animal. In the source region of the Yellow River, taxa number, density and biomass of macroinvertebrates were 50, 329 individuals m2 and 0.3966 g dry weight m2, respectively. Equivalent figures for the source region of the Yangtze River were 29, 59 individuals m2 and 0.0307 g dry weight m-2. The lower benthic animal resources in the source region of the Yangtze River are ascribed to higher altitude, higher sediment concentration and wetland degradation. Preliminary findings of this exploratory study indicate that hydroelectric power stations had a weak impact on benthic dwellers but wetland degradation caused by a series of human activities had a catastrophic impact on survival of macroinvertebrates. Ecological protection measures such as conservative grazing and vegetation management are required to minimize grassland degradation and desertification, and reduce soil erosion rate and river sediment discharge.     

Water sources of plants and groundwater in typical ecosystems in the lower reaches of the Heihe River Basin

Stable oxygen and hydrogen isotopic compositions （δ18O and δD） of soil water and shallow groundwater of a riparian forest, an artificial shrub forest, and Gobi of the lower reaches of the Heihe River Basin are used to study the recharge water sources of those ecosystems. IsoSource software is used to determine the δ180 values for root water of Populous euphratica and Tamarix ramosissima in the riparian forest ecosystem, Haloxylon ammodendron in the artificial shrub forest, and Reaumuria soongorica in the Gobi, as well as for local soil water and groundwater, and precipitation in the upper reaches of the Heihe River Basin. Our results showed that soil water and shallow groundwater of the riparian forest and the artificial shrub forest were recharged by river water which originated from precipitation in the upper reaches, and strong evaporation occurred in the artificial shrub forest. Soil water of the Gobi was not affected by Heihe River water due to this area being far away from the river channel. The main water sources of Populous euphratica were from 40-60-cm soil water and groundwater, and of Tamarix ramosissima were from 40-80-cm soil water in the riparian forest ecosystem. In the artificial forest, Haloxylon ammodendron used 200-cm saturated-layer soil water and shallow groundwater. The Reaumuria soongorica mainly used soil water from the 175-200-cm depth in the Gobi. Therefore, soil water and groundwater are the main water sources which maintain survival and growth of the plants in the extremely arid regions of the lower reaches of the Heihe River Basin.     

Glacier retreat and its effect on stream flow in the source region of the Yangtze River

There is growing concern over the effects of climate change on glacier melt and hydrology. In this article, we used two natural small-scale basins, Tuotuo River and Buqu River in the source region of the Yangtze River, China, to show the impacts of glacier melt on stream flow. Changes in the extent of glaciers and ice volume in 1970, 1992 and 2009 are evaluated using remote sensing images. Changes to the glacier surface area over the same time interval are estimated through the delineation of glacier outlines and positions using Landsat TM/ETM＋ imagery. By 2009, the glacier surface area had decreased by 20.83% and 34.81% of the 1970 values in Tuotuo River and Baqu River basins respectively. The total meltwater supply in each basin is estimated to be 2.56×10^9 m^3/yr and 1.24×10^9 m^3/yr respectively. Mass balance calculations show that glaciers in the study area suffered a constant mass loss of snow and ice, accumulatively approximately -24 m over the past 40 years. The annual and summer stream flow tended to increase in Tuotuo River basin from 1970 to 2009 while a negative trend of change was shown in Buqu River basin during 1970-1986. Glaciers became shorter, narrower and thinner under the effect of atmospheric warming. Streamflow increase has been recorded at Tuotuo River station in response to increased glacier and permafrost melt. However, streamflow decrease has been recorded at Yanshiping station on Buqu River, where glacier melt has lagged behind atmospheric warming. These results show a close but variable linkage among climate change, glacier melting and water resources in the source region of the Yangtze River.     

基于灰色关联模型对江苏省PM2.5浓度影响因素的分析

采用克里金插值法分析2014年江苏省PM_2.5浓度空间分布特征,运用灰色关联模型计算PM_2.5浓度与影响因素间关联度,分析主要影响指标因子与PM_2.5浓度空间分布的相互关系。结果显示：① 江苏省PM_2.5浓度具有沿海低、内陆高,南部高、北部低的空间分布特征;② PM_2.5污染来源指标层的权重值最大（w_i = 0.4691）,空气质量与气象要素指标层的权重稍大（w_i = 0.2866）,城市化与产业结构层的权重值最小（w_i = 0.2453）;③ 在27个指标因子中,与PM_2.5浓度关联度为中度的仅有公路客运量、房屋建筑施工面积、园林绿地面积、人口密度等4个指标因子,PM_2.5与其余指标因子均呈强度相关联,其中与PM₁₀、O₃、降雨量、公路货运总量、地区工业总产值和第二产业占地区生产总值比重等指标的关联度较高;④ PM_2.5污染源指标层与PM_2.5浓度关联度值较大的城市分别是南京、无锡、常州、南通、泰州市;城市化与产业结构指标层与PM_2.5浓度关联度值较大的城市分别是徐州、苏州、盐城、常州市;空气质量与气象要素指标层与PM_2.5浓度关联度值较大的城市分别是盐城、扬州、常州、南通市。综合分析可知,影响指标因子关联度值与PM_2.5浓度空间分布有较好相关性。研究表明,灰色关联模型可有效分析影响PM_2.5浓度的主要因素,能对PM_2.5浓度影响指标进行定量分析与评价。     

Lake Area Changes and the main causes in the hinterland of Badain Jaran Desert during 1973–2010,China

Lake area information in the Badain Jaran Desert in 1973, 1990, 2000, and 2010 was obtained by visual interpretation and water index analysis of remote sensing images, based on the spatial and temporal characteristics of lake area changes during 37 years. Results indicated that the nttmber of lakes declined from 94 to 82 and the total surface area was reduced by 3.69 km2 during 1973-2010. The desert lake area reduced by different degrees in different periods, but this occurred most rapidly during 1973-1990. According to the statistics of lake area changes, lake area decreases mainly occurred in the lakes with areas less than 0.2 km2, while the areas of lakes greater than 0.9 km2 only fluctuated. The changes of lake areas were probably due to changes in the quantity of underground water supplies rather than the effects of local climate change or human factors.