水生植物的应用与管理

水生植物具有观赏、净化以及生物多样性高的特点,在城市环境建设中得到广泛应用。针对应用中出现的一些问题,结合水生植物个体生态学特征、群落结构和发育动态等,提出了科学应用水生植物的基本要求。     

油蒿不同部位水分关系研究

应用植物PV技术研究油蒿（Artemisia ordosica Krasch）不同部位（营养枝、生殖枝、1年生枝、2年生枝、3年生枝、根系）的持水性能及其在SPAC系统的水分运移中的作用。结果表明：油蒿不同部位具有相似的水分生理特点,但各参数差异比较明显。随着木质化程度的增加,枝条（除生殖枝）饱和时最大渗透势（Ψ100π）、初始质壁分离时的渗透势（Ψ0）、相对水分亏缺（D0RW）、相对渗透水分亏缺（D0ROW）、束缚水含量（Vb）、细胞组织最大弹性模量（εmax）及ΔΨ（Ψ100π－Ψ0）逐渐增大,而自由水含量（Vf）则逐渐减小。生殖枝的Ψ100π、Ψ0、D0RW、D0ROW则大于其他枝条,根系的Ψ100π、Ψ0、D0RW、D0ROW、Vb、εmax均大于枝条,而Vf和ΔΨ小于枝条。随木质化程度增加,枝条的总水容（C）逐渐减小。C表现出两段性,在膨压消失前,枝条的水容（C1）变化不大,而在膨压消失后枝条水容（C2）随木质化程度增加而减小;总体来看,生殖枝的水容大于其他枝条,而根系水容最大。在水分胁迫条件下,木质化程度低的枝条,其较小的束缚水含量（Vb）及弹性模量（εmax）和较大的水容（C）不利于其保持体内水分以及较高的水势和膨压;而木质化程度高的枝条,其较高的束缚水含量及坚硬厚实的细胞壁则有利于其保持体内水分;根系较大的Vf和C,表明其容易失水的特性,有利于SPAC系统水分传输。     

高寒湿地生态系统土壤有机物质补给及地-气CO2交换特征

海北高寒湿地植物地上、地下生物现存量较高,2004年海北高寒湿地植物净初级生产力为1799.7 gC·m^-2.由于家畜对湿地植物采食量低,每年将有大量的枯黄植物残留于地表,表现出地上、地下生物量以及苔鲜均成为土壤有机物质的补给源.由于区域温度低,积水严重,对植物残体分解缓慢,导致湿地土壤有机质含量很高,形成了厚达2 m左右的泥炭层.观测结果表明,海北高寒湿地净生态系统CO₂交换量具有明显的季节变化,年内4月和10月存在两个CO₂释放高峰期,夏季的7~8月为一个强吸收期,全年来看为一个巨大的碳源.2004年净生态系统年碳交换量为76.7 gC·m^-2.计算结果表明,植被的呼吸消耗量每年为1199.8 gC·m^-2,其植物总固碳量为2999.5 gC·m^-2,而土壤呼吸为1876.4 gC·m^-2.     

大型火电厂热排放对邹县环境气温影响的初步研究

对1960—2009年邹城和兖州温度及温度日较差的年、季变化趋势进行分析,对比邹县电厂现况发展,研究电厂热排放对环境气温的影响程度和相对贡献。结果表明：近50 a来,邹城和兖州年平均气温呈上升趋势,年增温速率分别为0.326 ℃∕10 a和0.124 ℃∕10 a,且邹城显著增温时间与火电厂投产时间一致。1960—1994年,热排放增温率均为正值,年最低气温高达0.51 ℃∕10 a,年日较差为-0.35 ℃∕10 a,多个季和年值增温贡献为100%。1995—2005年,热排放增温率为正值,平均气温为0.209 ℃∕10 a,年最低气温为0.118 ℃∕10 a,年最高气温为0.056 ℃∕10 a,年日较差为-0.100 ℃∕10 a,表现为热排放对平均气温和最低气温影响显著,对最高气温影响较弱,多个季增温贡献有所降低,仍显示出热排放对环境温度有相当程度的贡献。     

遥感技术在新疆民丰区域寻找地下水中的应用

针对南疆民丰戈壁沙漠地区,应用遥感技术,在地貌、水系、构造、古河道等系列解译的基础上,根据不同植被的影象特征建立了找水模型：以鲜艳大红色彩者,划分为喜淡水湿生型植物群落,表明以叶绿素含量极高阔叶植被为主,主要分布在河床、河漫滩与古河道地带,属淡水,水位埋藏较浅,且丰富稳定;以褐红色、紫红色影象特征者,划分为喜感 水湿生型植物群落,表明为耐盐碱性极强的叶子很小、叶杆多刺植被,主要分布在沼泽或盆地、属     

赣北前震旦纪微古植物组合及其时代讨论

本文在对赣北前震旦纪微古植物进行系统归纳、总结的基础上,参考有关研究资料,建立了该区前震旦纪４个微古组合,对各微古组合进行了综合分析与对比,并对所属地层时代提出新的意见。     

卧龙自然保护区内海拔梯度上林窗如何影响植物多样性?（英文）

Understanding the underlying ecological processes that control plant diversity within(α-diversity) and among(β-diversity) forest gaps is important for managing natural forest ecosystems, and it is also a prerequisite for identifying the formation and maintenance mechanisms of forest plant communities. In this study, we focused on the interrelationships among habitat type(gap/non-gap plots), gap size, elevation and environmental factors, and we explored their effects on plant diversity(α-diversity and β-diversity). To do this, a total of 21 non-gap(i.e., closed canopy) plots(100 m2) and 63 gap plots, including 21 with large gaps(200–410 m2), 21 with medium gaps(100–200 m2) and 21 with small gaps(38.5– 100 m2),were selected along an elevational gradient in a subalpine coniferous forest of southwestern China. Using structural equation models(SEMs), we analyzed how forest gaps affected plant diversity(α-diversity and β-diversity) along an elevational gradient. The results showed that(1) as elevation increased, unimodal patterns of α-diversity were found in different-sized gaps, and β-diversity showed a consistent sinusoidal function pattern in different-sized gaps. The gap size was positively related to α-diversity, but this effect disappeared above 3500 masl. Moreover, the patterns of α-diversity and β-diversity in non-gap plots were irregular along the elevational gradient.(2) SEMs demonstrated that many environmental factors, such as the annual mean air temperature(AMAT), ultraviolet-A radiation(365 nm, UV-A365), ultraviolet-B1 radiation(297 nm, UV-B297), moss thickness(MT), soil carbon/nitrogen ratio(C/N ratio), NH4-N and NO3-N, were significantly affected by elevation, which then affected α-diversity and β-diversity. The photosynthetic photon flux density(PPFD), UV-A365 and UV-B297 were significantly higher in plots with forest gaps than in the non-gap plots. Moreover, the PPFD and UV-A365 were positively and directly affected by gap size. Surprisingly, except for the NH4-N and the C/N ratios, the below-ground environmental factors showed little or no relationships with forest gaps. All of these effects contributed to plant diversity. Overall, the above-ground environmental factors were more sensitive to gap-forming disturbances than the below-ground environmental factors, which affected α-diversity and β-diversity. The predicted pathway in the SEMs of the elevational effects on α-diversity andβ-diversity was relatively complicated compared with the effects of forest gaps. These results can provide valuable insights into the underlying mechanisms driving the diversity-habitat relationship in the subalpine coniferous forests of southwestern China.     

滇中高原火后更新森林植物和土壤水分含量的时空格局（英文）

Plant moisture content(PMC) is used as an indicator of forest flammability, which is assumed to be affected by climate drought. However, the fire-induced drought stress on PMC and its spatial and temporal variations are unclear. Based on a parallel monitoring experiment from 2014 to 2015, this study compared the PMCs and soil moisture contents(SMC) at five post-fire sites in central Yunnan Plateau, Southwest China. The number of years since last fire(YSF), season, topographic position, plant species and tissue type(leaf and branch) were selected as causal factors of the variations in PMC and SMC. A whole year parallel monitoring and sampling in the post-fire communities of 1, 2, 5, 11 and 30 YSF indicated that drought stress in surface soils was the strongest in spring within the first 5 years after burning, and the SMC was regulated by topography, with 64.6% variation in soil moisture accounted for by YSF(25.7%), slope position(22.1%) and season(10.8%). The temporal variations of PMC and SMC differed at both interannual and seasonal scales, but the patterns were consistent across topographic positions. PMC differed significantly between leaves and branches, and among three growth-forms. The mean PMC was lower in broad-leaved evergreen species and higher in conifer species. Season and soil temperature were the primary determinants of PMC, accounting for 19.1% and 8.3% of variation in PMC, respectively. This indicated phenology-related growth rather than drought stress in soil as the primary driver of seasonal changes in PMC. The significant variations of PMC among growth forms and species revealed that seasonal soil temperature change and dominant species in forest communities are useful indicators of fire risk assessment in this region.     

Quantitative Classification and Ordination of Plant Communities in the Upper and Middle Reaches of the Yarlung Zangbo River Basin

Based on vegetation survey data and environmental data of the Yarlung Zangbo River Basin, we conducted a quantitative ecological analysis of the vegetation community composition and the relationship between species and the environment in the study area. The results showed that 44 sampling sites and 68 plant species in the study area can be classified into seven subtypes: Artemisia minor + Stipa purpurea; Artemisia demissa + Stipa purpurea + Artemisia wellbyi; Kobresia pygmaea; Trikeraia hookeri; Sophora moorcroftiana + Cotoneaster multiflorus + Pennisetum centrasiaticum; Artemisia frigida; Potentilla fruticosa + Orinus thoroldii. Detrended correspondence analysis (DCA) indicated that both longitude and altitude play important roles in site and species distribution patterns. In addition, canonical correspondence analysis (CCA) revealed that in the upper and middle reaches of the Yarlung Zangbo River Basin, changes in temperature and precipitation caused by longitude are the main factors controlling the formation and transition of vegetation community types. Moreover, natural vegetation could be divided into three types: desert steppe community (source area), alpine steppe community (middle reaches region), and shrub community (confluence of Yarlung Zangbo River and Nyangqu River).     

潜在影响防城港核电冷源系统的藻类暴发特点及其监测防控技术

2014年底,在广西防城港核电厂一期工程1号机组热试期间,核电厂所在的冷源水取水海域钦州湾暴发了球形棕囊藻赤潮,赤潮严重时出现了冷却水系统堵塞现象,严重威胁到核电的安全。本次由藻类引发的威胁核电冷源安全的事件在国内尚属首例,以往人们更多关注核电的温排水对附近海域生物的影响,而反过来,生物对核电正常运行的潜在影响相比之下缺少研究。在此背景下,本文通过研究历史调查资料,对潜在影响防城港核电冷源系统的藻类及其暴发特点进行初步分析,以大规模暴发时易成囊、成团、成簇以堵塞核电冷源入水作为筛选标准,筛选出球形棕囊藻、束毛藻、夜光藻和浒苔几种潜在威胁种,进一步对潜在威胁种的预警监测和防控方法进行初步介绍,以达到早期预防、保障核电冷源系统安全用水的目的,并为其他核电厂提供参考。