锡林郭勒荒漠草地种子植物区系研究

通过对锡林郭勒荒漠草地种子植物的组成特征、区系地理成分的分析,结果表明：该区有种子植物55科180属348种,被子植物占优势。科属组成分析表明,区系优势现象较明显,优势科、大属和较大属均以温带分布占优势;属种的地理成分分析表明,温带分布属、种占优势,热带分布的属、种所占比例很小,表明温带属性是该地区植物区系的基本属性,...     

浑善达克沙地药用种子植物区系分析

本文应用植物区系地理学的基本原理,对浑善达克沙地药用种子植物的科、属组成和属的地理成分进行了统计分析,结果表明:(1)本区有药用种子植物78科,270属,504种。(2)优势科现象明显;单种属、寡种属数量最多,属级水平的多样性丰富。(3)该区系包含14个分布区类型,温带性质的成分占绝对优势,热带性质的成分不多,特有程度低。(4)资源区域间分布差异大;有一定的古老成分。     

新疆乌恰康苏肖尔布拉克自然保护区种子植物区系

经初步查明,新疆乌恰县康苏肖尔布拉克自然保护区计种子植物65科282属635种(含亚种、变种),裸子植物3科3属12种,被子植物62科279属623种。对282属635种种子植物的地理成分分析表明,该地区植物分布区类型有12个型14个变型。其中,北温带分布有95属259种,占该地区植物总属、种数的40.25%和53.40%,表明温带属性是该地区植物区系的基本特点。同时,该地区植物区系与地中海―西亚―中亚及旧世界温带交流最多,其次与热带有一定的交流,而与温带亚洲和东亚交流很少。     

阿拉善荒漠区种子植物区系特征分析

阿拉善荒漠区地处典型的内陆干旱区,属温带荒漠气候,是亚非大陆戈壁荒漠区的东翼。本文对阿拉善荒漠区种子植物区系的组成、特点及性质进行了分析,并与邻近地区的植物区系进行了比较分析。经统计本区有种子植物(包括部分栽培种)87科377属1091种,野生种子植物82科367属1073种。主要结论为:1)植物种类较丰富;2)特有成分突出,共有中国特有属14个,其中当地特有属5个,分别是:四合木、绵刺、革苞菊、连蕊芥、百花蒿,多为单种属或寡种属;3)区系起源古老;4)与蒙古、古地中海、华北或东亚以及青藏高原植物区系关系密切。     

宁夏大罗山自然保护区种子植物区系特征

据统计，大罗山自然保护区种子植物有６５科、１６４属、２６３种。其中裸子植物有３科、６属、７种；被子植物有６２科、１５８属、２５６种。     

内蒙古大青山种子植物区系研究

大青山种子植物共有88科,391属,874种,其中裸子植物3科7属12种,被子植物85科,384属,862种。植物生活型多样,多年生草本占优势(65.22%),一二年生草本也占有一定比例(18.19%)。中生植物为主,占72.09%,旱生植物其次,占23.00%,由于生境的多样化,也有一些湿生和水生植物分布。地理成分复杂,东亚成分优势明显,蒙古成分也较多,反映出与周边地区的联系,温带亚洲、北温带、旧大陆温带成分均占有较高的比例,表现出明显的温带性质。     

中国-巴基斯坦喀喇昆仑公路沿线植物区系

2009年9月对中巴喀喇昆仑公路沿线分布的植物和植被进行了考察,经初步整理和统计,该地区共有野生维管束植物52科223属489种。其中,蕨类植物1科1属1种,裸子植物2科2属5种,被子植物49科220属483种。对222属488种种子植物的地理成分分析表明,该地区植物分布区类型有10个正型13个变型。其中,北温带分布有86属227种,占该地区植物总属、种数的45.75%和61.36%,表明温带属性是该地区植物区系的基本特点。同时,该地区植物区系与地中海-西亚-中亚及旧世界温带交流最多,其次与热带有一定的交流,而与温带亚洲和东亚交流很少。     

克拉玛依种子植物科属的区系地理成分分析

克拉玛依有种子植物44个科198属369种,通过对该地区种子植物科属的区系地理成分分析,表明该地区的种子植物单种科,单种属多,区系优势现象明显:本地区中的7种优势科,虽只占克拉玛依植物区系总科数的15.91%,但所含种数占总种数的67.75%。特有种比例低,珍稀濒危保护植物种类较少,且植物区系主要以温带为主:温带分布科占总科数的57.80%,植被分布符合该地区地带性特点。     

江西大岗山森林植物区系研究

本文在野外调查、查阅标本、文献考证及分类处理的基础上，对江西大岗山植物区系进行分析，结果表明：(1)江西大岗山地区种子植物共约782属、1796种，包括12个分布区类型和17个亚型。亚热带至热带分布成分356属，温带成分239属：(2)中国特有成分26属，具有一定的区系残遗和特化现象；(3)大岗山地区植物区系起源古老，地理成分复杂，以热带～亚热带成分占优势，并与世界各个热带植物区系有着广泛的联系；(4)本区系间断分布类型多样，残遗植物类群丰富，在珍稀濒危种类颇多，这都与地史变迁、大陆漂移和人类活动等影响密切相关；(5)大岗山植物区系足典型的亚热带植物区系，有由热带成分向温带成分过渡的特点，成为许多热带性属的分布北界。该区具有由泛热带、亚洲热带、温带和亚热带植物区系成分在发生上是统一的。     

Estimation of net primary productivity and its driving factors in the Ili River Valley,China

Net primary productivity(NPP), as an important variable and ecological indicator in grassland ecosystems, can reflect environmental change and the carbon budget level. The Ili River Valley is a wetland nestled in the hinterland of the Eurasian continent, which responds sensitively to the global climate change. Understanding carbon budget and their responses to climate change in the ecosystem of Ili River Valley has a significant effect on the adaptability of future climate change and sustainable development. In this study, we calculated the NPP and analyzed its spatio-temporal pattern of the Ili River Valley during the period 2000–2014 using the normalized difference vegetation index(NDVI) and an improved Carnegie-Ames-Stanford(CASA) model. Results indicate that validation showed a good performance of CASA over the study region, with an overall coefficient of determination(R2) of 0.65 and root mean square error(RMSE) of 20.86 g C/(m~2·a). Temporally, annual NPP of the Ili River Valley was 599.19 g C/(m~2·a) and showed a decreasing trend from 2000 to 2014, with an annual decrease rate of –3.51 g C/(m~2·a). However, the spatial variation was not consistent, in which 55.69% of the areas showed a decreasing tendency, 12.60% of the areas remained relatively stable and 31.71% appeared an increasing tendency. In addition, the decreasing trends in NPP were not continuous throughout the 15-year period, which was likely being caused by a shift in climate conditions. Precipitation was found to be the dominant climatic factor that controlled the inter-annual variability in NPP. Furthermore, the correlations between NPP and climate factors differed along the vertical zonal. In the medium-high altitudes of the Ili River Valley, the NPP was positively correlated to precipitation and negatively correlated to temperature and net radiation. In the low-altitude valley and high-altitude mountain areas, the NPP showed a negative correlation with precipitation and a weakly positive correlation with temperature and net radiation. The results suggested that the vegetation of the Ili River Valley degraded in recent years, and there was a more complex mechanism of local hydrothermal redistribution that controlled the growth of vegetation in this valley ecosystem.     

伊犁河谷察南灌区土壤盐分空间变异研究

以伊犁河谷察南灌区为研究区,运用EM38电导率仪测定及室内分析相结合的手段,获取土壤电导率值及0~30 cm、30~60 cm、60~100 cm土壤盐分含量。一方面对各土层土壤盐分含量进行了简单的盐渍化分级统计,另一方面应用地统计学方法,对土壤盐分特征因子进行半方差函数分析及空间插值分析。初步研究表明:察南灌区土壤电导率变异系数为1.31,各土层土壤盐分含量变异系数分别为1.31、1.10、1.49,均呈现空间强变异;0~30cm、30~60 cm、60~100 cm土层土壤中,盐化土所占比例分别为25.37%、21.79%、12.11%,形成了比较明显的盐渍化趋势;在空间分布上,土壤电导率及土壤盐分含量自灌区西北至东南方向总体呈现减小的趋势。另外,研究发现灌区各土壤盐分因子具有强烈的空间相关性,空间变异格局主要是结构性因素作用的结果。     

新疆伊犁地区野果林的群落特征及保护

新疆伊犁地区是我国野果林分布的主要地段.通过野外调查和资料收集,共获得67个野果林群落样方,分析了新疆伊犁地区野果林的群落结构及其分布特征.结果表明:野果林林下物种丰富,共记录维管束植物46科141属207种.群落分类将野果林划分为野核桃林、野苹果林、野杏林和野生樱桃李林4种类型.野杏林和野生樱桃李林的物种丰富度显著高...     

Pleniglacial millennium-scale climate variations in northern China based on records from the Salawusu River Valley

Situated in the Salawusu River Valley, southeast of China's Mu Us Desert, the MGS2 (Milanggouwan section) portion of the Milanggouwan stratigraphic section records 5.5 sedimentary cycles consisting of alternations between dune sand deposits and fluvial or lacustrine facies. We analyzed the grain-size and CaCO 3 distributions in MGS2, and found that Mz (mean particle diameter) and σ (standard deviation) displayed clear variations in peaks and valleys within different sedimentary facies. The CaCO 3 content averaged 0.4% in the dune sand deposits, 1.43% in the fluvial facies, and 8.82% in the lacustrine facies. Both the grain-size distribution and CaCO 3 contents, which equal the indicators for the alternation among the sedimentary facies, suggest the occurrence of 5.5 cycles. These results suggest that the observed cycles mainly resulted from fluctuations between a cold and dry winter monsoon climate and a warm and humid summer monsoon climate, and that the MGS2 portion experienced at least 5.5 fluctuations between these two extremes. This high-frequency climatic fluctuation indicates a strong influence of millennium-scale variations in the strength of the East Asian winter and summer monsoons in our study area during the Pleniglacial.     

新疆玛纳斯流域生态环境需水分析

本文从生态系统、生态环境的概念出发,就西北地区的一个典型的流域代表玛纳斯河(以下简称玛河)流域的生态特点与问题,提出玛河流域的生态环境需水概念,并概述了国内外生态环境需水的现状。根据玛河流域生态环境需水的定义,本文从降水———径流的发生与演变出发,按山区和平原生态圈层结构分层次计算玛河流域生态需水,并区分生态需水的水源组成(降水、径流)。分析计算结果,对玛河流域生态需水计算结果进行供需平衡分析。     

新疆巩乃斯河中岛屿植物成分的组合结构

在新疆巩乃斯河中岛屿所设的3个样地54个样方中,共有62种植物,隶属于28个科,6个株生长型,3个根生长型,5个生活型,5个水分生态类型和5个饲用价值类型。其中,菊科和禾本科种类最多,各占14.5%,豆科占9.7%。株生长型结构以直立型种类最多,占50%。根生长型结构以直根型的种类最多,占56.5%。生活型结构以地下芽植物最多,占41.9%。水分生态类型结构以中生型种类最多,占59.7%。饲用价值类型结构以良等的种类为多,占22.6%。以上结论表明,巩乃斯河中岛屿植物群落具有如下特点:①生长型和生活型结构表明岛屿植物群落具有中温带草本群落植株和根系特点,也具有典型的地下芽植物气候特征。②水分生态型和饲用价值类型的统计分析说明,岛屿植物群落具有中生生境条件、饲用价值类型高的特征。     

Dew amount and its long-term variation in the Kunes River Valley,Northwest China

Dew is an essential water resource for the survival and reproduction of organisms in arid and semi-arid regions. Yet estimating the dew amount and quantifying its long-term variation are challenging. In this study, we elucidate the dew amount and its long-term variation in the Kunes River Valley, Northwest China, based on the measured daily dew amount and reconstructed values (using meteorological data from 1980 to 2021), respectively. Four key results were found: (1) the daily mean dew amount was 0.05 mm during the observation period (4 July-12 August and 13 September-7 October of 2021). In 35 d of the observation period (i.e., 73% of the observation period), the daily dew amount exceeded the threshold (>0.03 mm/d) for microorganisms; (2) air temperature, relative humidity, and wind speed had significant impacts on the daily dew amount based on the relationships between the measured dew amount and meteorological variables; (3) for estimating the daily dew amount, random forest (RF) model outperformed multiple linear regression (MLR) model given its larger R² and lower MAE and RMSE; and (4) the dew amount during June-October and in each month did not vary significantly from 1980 to the beginning of the 21^st century. It then significantly decreased for about a decade, after it increased slightly from 2013 to 2021. For the whole meteorological period of 1980-2021, the dew amount decreased significantly during June-October and in July and September, and there was no significant variation in June, August, and October. Variation in the dew amount in the Kunes River Valley was mainly driven by relative humidity. This study illustrates that RF model can be used to reconstruct long-term variation in the dew amount, which provides valuable information for us to better understand the dew amount and its relationship with climate change.     

新疆玛纳斯河流域生态系统稳定性研究

玛纳斯河为天山北麓准噶尔盆地最大的内陆河,玛纳斯河流域生态系统独特,且具有干旱区生态系统的特点。近50年来,玛纳斯河流域由于受到人类活动的影响,生态系统稳定性发生了很大变化。通过运用生态学和系统学理论,使用AHP法对玛纳斯河流域生态系统稳定性进行了研究,确立了玛纳斯河流域生态系统稳定性评价指标体系,使用多个指标对流域生态系统进行了指标权重评定,通过计算认为玛纳斯河流域生态系统目前较为稳定。     

新疆伊犁河流域植被变化动态监测与评价

基于2000-2013年MODIS/NDVI数据和研究区内气象站点资料,分析了伊犁河流域植被生长季NDVI时空变化特征及其与气候因子的关系。结果表明:1)研究区植被整体呈微弱的退化趋势,年退缩率为-0.8×10-3a-1,其中草原的退化趋势较草甸、灌丛和林地略显著。2)2000-2013年研究区植被退化区面积占研究区总面积的11.45%,主要分布在特克斯河中下游、巩乃斯河周边地区;植被改善面积占全区总面积的8.38%,主要分布在伊宁市及霍尔果斯河周边地区。3)研究区伊宁站周边植被生长季NDVI与同期气温及降水存在不显著相关性,昭苏站周边植被生长季NDVI与同期气温及降水分别存在显著负相关和极显著正相关。气候的暖干化趋势可能是导致伊犁河流域植被生长退化的主要原因。     

新疆伊犁皮里其河流域表层土壤养分特征

以新疆伊犁皮里其河流域为研究区,采用野外调查与实验分析相结合的方法,选取土壤养分的7个指标:有机质、全N、全P、全K、有效N、有效P和速效K为分析参数。应用主成分分析法,对研究区土壤养分的主要因子进行识别,并应用聚类分析法对样地进行分类。主成分分析表明,该区土壤第一主成分主要反映土壤综合养分水平;第二主成分反映土壤P肥水平;第三主成分反映K肥水平。聚类分析表明,第一聚类样地因子得分较高,该类土壤养分主要受有机质、全N和速效K的影响较大,土壤较为肥沃;第二聚类样地土壤养分普遍低于第一聚类,有机质、全N含量低于第一聚类,土壤养分一般;第三聚类样地由于土壤环境较为特殊,因子得分最低,土壤相对贫瘠。最后,针对3个聚类不同类型土壤,提出具体的保护措施。