塔里木河中游天然植物群落结构与数量特征分析

运用典型样地法,对塔里木河中游30个天然植被样地的群落结构和数量特征做了调查分析。结果表明:(1)塔里木河中游沙吉力克、沙子河、乌斯满、阿其河、铁依孜五个断面的天然植物隶属11科,20属,22种。(2)塔里木河中游植物群落结构可分三层,即乔木层、灌木层与草本层,但这种乔、灌、草的三层现象不明显。生境条件差,植物对环境利用不充分。(3)荒漠植物群落物种多样性水平较低,群落结构简单,物种组成单一。从多样性指数的数量特征来看,Simpson多样性指数的变化范围为0.47~0.609,Shannon-Wiener指数变化范围0.849~1.302;Menhinick丰富度指数的变化范围为2.309~3.175,Margalef 2.731~5.461;JSW均匀度指数的变化范围为0.6~0.778,JSI指数的变化范围0.633~0.805。五个断面盖度的变化范围是0.259~0.563。     

饮马河流域典型湿地植物净化河流水环境效果研究

采取单种及混种方式,通过小型湿地模拟实验,研究松花江支流饮马河流域河流湿地中常见的芦苇、香蒲、槽秆荸荠、藨草、慈姑、花蔺、菱角、紫背浮萍和金鱼藻9种湿地植物及其组合对河流水体中化学需氧量(COD_(cr))、氮、磷等的净化效果。结果表明:所选湿地植物,在模拟环境条件下均能有效提升取自河流水体的水质;不同的湿地植物对污水中各污染物净化具有明显的差异,花蔺对总磷(TP)、COD_(cr)和氨氮(NH_3-N)净化效果最好,去除率依次为99.65%、68.22%和99.54%;香蒲、菱角、金鱼藻混合组对总氮(TN)的净化效果最好,去除率是66.19%;槽杆荸荠、芦苇和金鱼藻对亚硝酸盐氮(NO_2-N)的净化效果最好,去除率是83.64%。两种植物混种后对某一种污染物指标的处理效果弱于分别独种时的处理效果,但对多种污染物指标的综合处理效果一般要好于独种时的处理效果。     

板寨地下河大型水生植物调查及其固碳评价

为深入研究板寨地下河流域水生植物种类及其固碳潜力,于2014―2016年在植物高生长期和生长结束期对流域内水生植物进行物种鉴定及优势水生物种确定。最终通过对优势种群开展生物量及δ13Ｃ测试,推算其固碳潜力。结果表明：1）该地下河有大型水生植物28科、35属、41种,按其经济价值来分,可食用的6种,药用的33种,观赏的20种,具有较大经济开发潜力。2）流域内黑藻（Hydrilla verticillata）、竹叶眼子菜（Potamogeton malaianus）、小眼子菜（Potamogeton pusillus）、普生轮藻（Chara vulgaris）和金鱼藻（Ceratophyllum demersum）为优势种群,其生物量依次为136.70、225.00、16.00、172.00、17.00 g/m2。3）板寨地下河水生植物光合作用的固碳能力竹叶眼子菜最大,为111.83 gC/（a·m2）,小眼子菜最小,为7.95 gC/（a·m2）。4）板寨地下河水生植物利用作用碳源的比例平均为23.21％,即板寨地下河出口至下游无机碳年通量的损失量中,约23.21％是被水生植物固定下来,其固定的碳量为14.39 gC/（a·m2）,说明水生植物光合作用与岩溶作用相结合表现出巨大的固碳潜力。     

石羊河中下游流域植被的演替历史

以参考历史文献、实地调查和访问当地居民的方法,研究了石羊河中下游流域的植被演替。结果表明,该流域2000多年前为湖泊、沼泽和平原景观,后来由于气候和水文演化、人类活动加强和干旱加剧,导致湖泊与河流逐渐消失、绿洲因水系的变迁而向东南移动、早期的绿洲农田逐渐沙漠化,也使植被从水生、沼泽、草甸植物向沙旱生、强旱生、超旱生方向演替,物种大量消失,已演化成现在的沙漠、戈壁与绿洲景观。目前, 该流域红崖山水库以南的一些河道中尚有常年流水,河漫滩和湿地中还有水生、沼泽、草甸和中生植物种类,物种相对丰富;而水库以北的古河床及广大荒漠区植被稀疏,且多为沙旱生和强旱生植物种类,生物多样性低,稳定性差,沙漠化过程加强。要恢复流域植被、遏制土地沙漠化,应当采用调水、引水和节约用水的方法,加强绿洲保护,使地下水位恢复至植物可吸收利用状态。     

Environmental factors and pattern of riparian vegetation along the downstream sections of the Lower Ogun River,Nigeria

The River Continuum Concept (RCC) is an existing theory regarding the distribution of plant communities along riverbanks. This study is concerned with the pattern of riparian vegetation along the Lower Ogun River (LOR) in relation to the observed downstream variation of various environmental factors (bank height, width, gradient, distance, cross‐sectional area and particle size). The LOR transits between undisturbed and disturbed sections. Forty‐eight cross sections were established at bankfull stage along the river channel stretch of about 90 km. Environmental variables distribution were determined using standard field procedures. Gradient was estimated from a 1:50 000 topographical map. At each corridor along the study sites, a 0.1 ha sampling site was chosen, in which 10 transects of 100 m² were demarcated. In all, 332 individuals stratified under 80 species were recorded across the transects. The study revealed that total species richness (TSR) downstream decreases exponentially. TSR is significantly correlated with channel width, suggesting that hydraulic variable contributes more to the variation in TSR. The downstream total environmental factors revealed that width is inversely significant with downstream distance, suggesting that the river channel is narrower downstream. This affects plant life form distribution downstream and confirms why there is appearance of anthropogenic induced species downstream as against those in the upper course.     

皖江滩地杨树抑螺防病林下植物多样性分析

以时空互代的方法,对皖江段滩地不同林龄的杨树人工林林下植物多样性进行了调查。结果表明:①杨树人工林林下以草本植物为主,居于前4位的优势科分别是菊科(9种)、禾本科(6种)、豆科(5种)、蓼科(5种),优势种以萝藦、菱叶鹿藿、无辣蓼、葎草为主。木本植物有桑科桑树、蔷薇科野蔷薇;②滩地造林后,林下植物的丰富度、多样性指数、均匀度指数均高于无林滩地上以芦苇为主的群落;③随着人工林林龄的增加,多样性指数表现出了先降低后上升的趋势,3年生的人工林丰富度(S)、多样性指数(D,H′)最高,20年生的人工林均匀度指数最高。滩地造林后植物多样性有一定程度增加,但成林后植物多样性又逐年减少。     

黑河下游尾闾区植物群落物种多样性与稳定性格局

黑河下游尾闾区作为西北干旱区典型的脆弱生态系统,其植物群落物种多样性与稳定性对维持该地区生态安全和可持续发展具有重要意义.以黑河下游尾闾区荒漠植被为研究对象,采用K-Means聚类,基于距河道距离及其对应的土壤含水量数据,将黑河下游尾闾区垂直于河道0-4 km区域可分为距河0-0.3 km(T0-03)、0.3-1.7...     

Historical trends affecting accumulation of sediment and phosphorus in Lake Pepin,upper Mississippi River,USA

This study was conducted to collect historical land use information that would help explain the historical patterns in accumulation of sediment and phosphorus in Lake Pepin documented by Engstrom et al. (J Paleolimnol, this issue). A wide range of historical factors including cropping systems, phosphorus applications from fertilizer and manure, human and animal populations, river flows and phosphorus discharges from waste water treatment plants were studied using statistical methods. Results showed that sediment losses from the Minnesota River basin are significantly correlated with historical increases in river flows, row crop production acreage and basin population. Total phosphorus accumulations in the sediments of Lake Pepin are significantly correlated with increased phosphorus discharges from metropolitan area wastewater treatment plants, and increases in row crop acreage and river flows. Total phosphorus inflows to Lake Pepin are significantly correlated with increases in river flows, row crop acreage and phosphorus fertilizer applied to agricultural lands. This is one of eight papers dedicated to the “Recent Environmental History of the Upper Mississippi River” published in this special issue of the Journal of Paleolimnology. D. R. Engstrom served as guest editor of the special issue.     

黄河三角洲新生湿地植物群落分布格局

为阐明黄河三角洲新生湿地植被群落的分布格局,以1996年后新淤积形成的湿地植被为研究对象,选取9个典型植被群落过渡带,测定分析其群落数量特征,以期能为更好的保护与管理黄河三角洲新生湿地提供数据支持。调查结果显示：黄河三角洲新生湿地植被群落沿河向海的方向呈同心环状发展,呈现出较明显的条带状。自河岸向海岸,植物的耐盐性逐渐提高。草本植物自河岸、海岸向中心陆地演替,而木本植物则由中心陆地向河岸、海岸演替。物种丰富度及香农-威纳（Shannon-Wiener）多样性指数自河岸向海岸,先升高后降低。土壤含盐量的变化与植物群落的组成结构之间具有密切关系,这说明土壤含盐量是影响黄河三角洲新生湿地植被分布格局的主要因子。     

西藏日喀则流沙固定的几个问题

1995年首次在西藏日喀则进行固沙植物的引种试验,大多数中国内地固沙植物不适应该地的流动沙丘,沙面高温和生长季短是主要制约因素。沙木蓼和籽蒿表现最好;油蒿种子不能成熟,因此不能做后续植物;乡土植物砂生槐在播种当年出苗率低、生长缓慢,只能用做后期植物。在西藏日喀则,有效的植物固沙程序是:在保护措施(草方格沙障、砾石层)下,在流动沙丘上播种外来种沙木蓼、籽蒿和油蒿或移栽籽蒿,同时播种乡土植物砂生槐。在沙木蓼和籽蒿种群衰退、油蒿种群未衰退但不能靠天然下种自行更新时,砂生槐开始发挥固沙作用,并最终凭其适沙特性和长寿命接替先锋固沙植物有效地固定沙丘。选择乡土固沙植物应将重点放在蒿属和锦鸡儿属上。     

黑河下游绿洲植被优势种生物量空间分布及蒸腾耗水估算

基于典型样点试验,建立了研究区植被优势种柽柳、胡杨与苦豆子地上生物量与其生态参数关系模型;利用高分辨率遥感影像Geoeye-1对植被优势种进行分类得到生态参数,实现了其地上部分生物量空间分布估算;最后利用生物量与蒸腾系数关系,估算植被优势种蒸腾耗水。结果显示：植被优势种总生物量为2.53×10⁶t,河流距离对生物量影响显著。根据试验测得的植被优势种蒸腾系数估算出总蒸腾耗水量为10.89×10⁸t,柽柳、胡杨与苦豆子所占比例分别为12.94%,82.93%与4.13%。     

Riparian plant species richness along lateral and longitudinal gradients of water stress and flood disturbance, San Pedro River, Arizona, USA

Diversity theory predicts that species numbers should be highest at intermediate levels of both disturbance and environmental stress. We examined woody and herbaceous plant species richness and cover in the San Pedro River flood plain, along lateral gradients of water availability (ground-water depth), flood disturbance (inundation frequency), and distance from and elevation above the channel, and along longitudinal gradients of water availability (ground-water depth, surface flow permanence, and rainfall) and flood disturbance (total stream power). Herbaceous species were recorded during four sampling periods, and spatial patterns for this group were time-dependent, reflecting temporal variation in limiting factors. During the summer dry season of a dry year, when overall richness was low, richness and cover of herbaceous species declined laterally from the stream channel with increasing ground-water depth, consistent with the idea that low resource levels can limit species richness. Following the summer monsoon rains and floods, when water was less limiting and annuals were seasonally abundant, lateral patterns shifted such that herbaceous species richness and cover increased with increasing plot location above or from the channel. The relationship of herbaceous species richness with tree canopy cover also varied seasonally, shifting from positive (greater richness under canopy) in dry seasons to negative (lesser richness under canopy) in wet seasons. Longitudinally, herbaceous species richness and cover were limited primarily by stream flow and/or ground-water availability during the summer dry season of a dry year. Following the summer monsoon rains and floods, patterns were weighted by the seasonally abundant annuals, and richness increased among sites primarily with distance upstream (and related rainfall gradients). Richness and cover patterns also varied between years with different flood conditions. During the two sampling seasons in the year following a large flood, herbaceous species richness increased with flood disturbance intensity but declined at the few most intensely disturbed sites, consistent with intermediate disturbance theory.For woody species, richness within plant functional groups varied in opposing ways along the lateral gradients: hydromesic pioneer species decreased and hydromesic and xeric competitors increased with distance from or above the channel, with no overall change in species richness. Among sites, woody species richness patterns were related to water availability, but not to flood disturbance. However, richness of woody hydromesic pioneer species increased with both increasing site moisture and flood disturbance. Woody and herbaceous species richness both increased among sites as a function of increasing flood-plain width, likely due to species–area effects. Overall, results indicate that flood disturbance and water availability both influence species richness of riparian plants in the flood plain of this semi-arid region river, with the relative influence of each factor varying among plant groups and over time.     

渭河咸阳城区段天然河滩与由河滩改造的湿地公园中6类野生动物分布对比

为了对比渭河城区段天然河滩与由河滩改造的湿地公园中野生动物的分布情况,进而对河流天然河滩的园林化改造进行评估。2016年5月至2018年4月,采用样带法、典型样方法和坑穴诱捕法,调查了渭河咸阳城区段天然河滩和被改造为湿地公园的河滩中鸟类的巢和蛇类、蛙类、刺猬类、兔形类、鼠类的分布及其数量。研究结果表明,在天然河滩采样地中,诱捕到的5类野生动物和鸟巢的数量都显著大于其在湿地公园中的数量(p<0.05),且天然河滩被改造为湿地公园后,蛇类、刺猬类和兔形类野生动物几乎消失。可见,将天然河滩改造为湿地公园,实现了城市人居空间的延伸,增加了游憩功能,但是,因其改变了原天然河滩的地形、土壤和植物群落,使得湿地公园失去了原天然河滩的大部分生态功能,野生动物失去了它们赖以生存的独特环境,其分布种类和数量皆显著减少。     

西藏雅鲁藏布江流域典型沙漠区生态修复植物群落物种多样性

为了深入了解和探讨西藏沙化土地治理区的植物群落的结构类型、组织水平和稳定程度,根据西藏雅鲁藏布江河谷沙地山南市全国防沙治沙综合示范区20个样地的调查资料,分析了西藏山南市全国防沙治沙综合示范区植物群落物种多样性特征。结果表明：西藏山南市全国防沙治沙综合示范区的植物有34种,藏沙蒿（Artemisia wellbyi）、花棒（Hedysarum scoparium）、桑（Morus alba）、沙打旺（Astragalus adsurgens）和沙蒿（Artemisia desertorum）占优势地位。综合示范区固沙植被平均盖度为31.6%±13.1%;平均生长高度为41.2±19.9 cm;平均生长密度为4.6±4.7株·m^-2。植物群落物种多样性H指数平均为0.99±0.54;物种多样性D指数平均为2.55±1.37;物种均匀度平均为1.76±0.75。     

土库曼斯坦物种多样性及其与中国新疆的比较

土库曼斯坦与中国新疆在地理地形、景观带以及气候特征等诸多方面具有相似之处,这些因素共同决定了二者在物种多样性方面的相似性与可比性,加之人类活动影响加剧,两地物种多样性均遭受着严重的威胁。在对土库曼斯坦和中国新疆现有物种多样性数据进行总结的基础上,分析了二者的物种多样性现状、珍稀动植物特征以及濒危种和入侵种相关研究进展,对比了二者在物种多样性年际尺度上的异同,总结了土库曼斯坦与中国新疆物种多样性保护现状与相关政策,以期为深入开展两地生物多样性合作与交流提供支持。     

塔克拉玛干沙漠南缘3种荒漠植物光合特性的比较

在2008年6、7和8月中旬,以塔克拉玛干沙漠南缘固氮植物骆驼刺（Alhagi sparsiftia Shap．）和非固氮植物柽柳（Tamarx ramossimaLedeb．）、花花柴（Karelinia caspica Less．）为研究对象,研究了两种类型植物的净光合速率、光响应、CO：响应模型参数、叶绿素和叶氮...     

Channel metamorphosis, floodplain disturbance, and vegetation development: Ain River, France

The purpose of this paper is to describe and explain channel metamorphosis of the Ain River in east-central France and the effects of this metamorphosis on floodplain disturbance and vegetation development. The Ain River is a 195 km long stream originating in the Jura Mountains which flows into the Rhône River between Lyon, France, and Geneva, Switzerland. The lower 40 km of the Ain River, beyond the mountain front, are situated in a valley of outwash deposits where the floodplain is 0.2 to 1.2 km wide. A complex mosaic of floodplain landscape units has developed. Maps dating back to 1766 and six sets of aerial photographs dated between 1945 and 1991 were used to document changes in channel pattern. Aerial photos and field surveys were used to compile maps of landscape units based on dominant vegetation life-forms, species, and substrate. Six maps dated between 1945 and 1991 were digitized in ARC/INFO and an overlay was generated to determine the changes in landscape units as related to channel disturbance. Change from a braided to a single-thread meandering channel probably took place in the period 1930–1950. The process of river entrenchment has occurred throughout the Holocene but has accelerated in the present century due to shortening of the river course, construction of lateral embankments, and vegetation encroachment following reservoir construction and cessation of wood-cutting and grazing. The increase in horizontal channel stability coupled with channel entrenchment have decreased floodplain disturbance and lowered the water table by approximately one meter. Pioneer and disturbance-dependent landscape units have experienced a more terrestrial-like succession to an alluvial forest. Abandoned channels have also been replaced by alluvial forests. On poorly drained soils, shrub-swamp communities of willow and hydrophytic herbaceous plants have been replaced by mixed forests of ash, alder, black poplar, and oak. On well drained alluvial soils, ash and oak dominated hardwood forests have declined in favor of mesophytic stands of black poplar. All types of vegetation, but particularly dry grasslands-shrublands, have been cleared for mines, campgrounds, agriculture, and other types of development. Using several measures, landscape diversity decreased between 1945 and 1991.     

水电项目对越南硒圣河地区社会经济发展及环境保护的影响

硒圣河是湄公河的主要分支之一,其集水区地形条件和水资源量均对水电开发十分有利。此外,无论从物种多样性还是生物量来看,硒圣河水生生物资源非常丰富。鱼类是当地人们的重要食物来源,粗略估计鱼类物种数量可能在200-300种之间,目前具有详细记录的鱼类大约为120种。截至目前,从越南境内硒圣河上游至越-柬边界总共开发了6个水电项目,兴建了一座4A级硒圣调蓄水库。流经柬埔寨的硒圣河部分,依据发展规划将兴建3座水电站,即硒圣5号电站（硒圣1号电站以下）、硒圣3号电站、硒圣2号电站。硒圣河水电项目对区域（越南和柬埔寨）社会经济的影响体现在：为地处偏远和困难的集水区创造了新的能源资源,改善了交通系统和农村地区的生活条件。与此同时,这些水电项目也对该区域自然环境产生了重大影响。例如,改变了下游流动机理变化,导致下游河道淤积,对沿河生态系统也产生了一定影响。     

北京白河湿地主要植物群落生态学研究

通过对北京白河植物群落的组成、结构、生物量、生活型及区系特征调查研究。结果表明,白河滩地共分布有水生、湿生植物33科98属178种;生活型以地面芽植物和一年生植物占优势;区系特征以世界广布和北温带分布型占主导。该调查区域共有18个湿地植物群落类型;主要植物群落的生物量秋季小香蒲(Typha minima)群落为3200g/m^2;芦苇群落(Phragmites australis)为3000g／m^2;有芒稗(Echinochloa crusgallii vat．caudata)群落为3500g／m^2;褐鳞莎草群落(Cyperus fuscus)为1300g/m^2。该地区主要植物群落的生物量、群落组织水平、多样性与人为活动干扰有密切关系。     

塔里木河下游植物群落分布格局及其环境解释

研究表明,塔里木河下游地区共有植物18种,分别隶属于9科、15属。其中藜科 (Chenopodiaceae)、柽柳科 (Tamaricaceae)、豆科 (Leguminosae) 3个科有10种,约占所有种数的56%,反映了干旱区旱生耐盐种类占优势的特点。样地排序结果表明,沿样地CA第一排序轴,所有18个调查样地可划分为3种类型,分别对应3种不同地下水位,即浅地下水位区 (<3 m)、中地下水位区 (3~5 m) 和深地下水位区 (>5 m),不同的植被类型组合亦分别对应不同类型的地下水位。CCA排序表明,影响该地区植物群落分布格局的环境因子主要是地下水位、土壤含水量、土壤pH值。CCA排序分析可将18种植物分为4个组,分别对应于不同的环境因子变化梯度。从管理的角度出发,在塔里木河流域下游地区进行受损生态系统的恢复与重建过程中,要重点考虑到上述提及的主要环境因子,尤其是重视水资源的合理开发与利用,采用适宜的灌溉方式,防止地下水位下降和土壤盐渍化的发生。