绵阳市湿地植物资源调查研究

通过实地调查对绵阳市湿地植物的种类、生活型、植被类型进行了初步研究。初步确定绵阳市湿地植物有80 科295 种, 大部分为草本植物, 其中含较多属和种的科是禾本科(Gramineae)和菊科(Compositae), 含较多种的属是蓼属(Polygonum)。绵阳市湿地资源植物较丰富, 国家重点保护植物有3 种; 入侵植物或外来植物较多, 有17 种, 以喜旱莲子草(Alternanthera philoxeroides)、鬼针草(Bidens pilosa)危害最为严重。全市湿地植物可划分为6 个生活型、3 个生态型; 湿地植被类型大致分为5 个植被型组、11 个植被型和59 个群系。     

四种湿地植物在人工湿地的生长特性研究

研究了表面流人工湿地中香根草(Vetiveria zizanioides)、风车草(Cyperus flabelliformis)、芦苇(Phrogmites australis)和水鬼蕉(Hymenocallis littoralis)4种植物的根生物量和生长量、根系分布、地上部分的生长情况.风车草、香根草和水鬼蕉根系及地上部分的生长节律相似,9月或10月前生长较快,以后生长减慢甚至停止;芦苇则不同,7月以前生长缓慢,以后生长加速,冬季也保持较快的生长.全年根生长量和根生物量以水鬼蕉最大,显著高于其它植物(P<0.01),香根草最小,显著低于其它3种植物(P<0.01).香根草的根系垂直向下生长,分布较深,而其它3种植物的根系主要分布在浅层土壤中.风车草分株最多,叶面积指数最大.香根草叶面积指数最小.结果表明,在构建多种植物人工湿地群落时,可以考虑将芦苇与大多数湿地植物搭配以保证湿地全年保持较好的净化效果;水鬼蕉可以作为底层植物,和风车草等生长早、植株较高的植物构建多种湿地群落.     

安徽湿地维管植物多样性及植被分类系统

通过野外实地调查并结合相关文献资料,对安徽湿地维管植物多样性进行了研究,系统地分析了安徽主要的湿地植被类型及分类系统。结果表明:(1)安徽省湿地维管植物共有95科303属682种(含种下分类单位),其中蕨类植物10科11属16种,种子植物85科292属666种;种子植物中裸子植物2科5属7种,被子植物83科287属659种(其中双子叶植物62科208属451种,单子叶植物21科79属208种);湿地维管植物主要是由草本植物组成,科、属的优势现象明显,以莎草科(Cyperaceae)、禾本科(Gramineae)、菊科(Compositae)和蓼科(Polygonaceae)为优势科;以蓼属(Polygonum)、苔草属(Carex)、眼子菜属(Potamogeton)、飘拂草属(Fimbristylis)、莎草属(Cyperus)等为优势属,属的组成相对较为分散,寡种属和单种属占总属数的93.4%;(2)从分布区类型看,在科级水平上有7个类型,在属级水平上有13个类型,表明该区系地理成分复杂,分布区类型多样;总体上温带成分略多于热带成分,说明了安徽湿地维管植物的分布与本地所处的气候带相适应,反映出从热带向温带过渡的区系特点;(3)依据中国湿地植被的分类原则和分类系统,结合安徽湿地植被的生境特征和群落学特征,可将安徽湿地植被划分为3个植被型组、7个植被型、7个植被亚型和141个群系。     

长江河口九段沙下沙湿地植物N、P、K的分布特征与季节动态

2005年4—12月逐月对长江河口九段沙下沙湿地生态系统主要湿地植物群落进行样方调查与样品采集,通过对海三棱藨草(Scirpus mariqueter)、互花米草(Spartina alterni-flora)和芦苇(Phragmites australis)3种植物样品中N、P、K元素含量分析与生物量测定,揭示了下沙主要类型湿地的植物N、P、K元素的含量、分布、贮量与动态变化特征。结果表明:3种湿地植物N、P、K元素含量、分布、贮量与动态特征均各具特点。不同植物以及同一植物不同构件营养元素含量与分布均存在较明显的差异。营养元素在不同植物与同一植物不同器官含量排序的差异明显。N、P、K贮量分布特征因湿地植物种类、构件以及生物量不同而异。植物中营养元素含量与贮量的分布特征存在差异,其原因在于,与营养元素含量相比,生物量是制约植物营养元素贮量的主要因子。下沙湿地3种湿地植物及其构件的营养元素含量与贮量一般都低于上沙湿地。3种湿地植物营养元素均表现出明显的季节动态,一般生长初期营养元素含量高,生长停滞期含量低。3种湿地植物N、P、K含量的动态特征存在差异,总趋势为N、P、K含量随生长过程的进行而下降,相对下降速度排序为:KNP。受局地环境条件影响,上沙与下沙湿地的植物N、P、K元素的含量、分布、贮量与动态变化特征存在差异。     

云南石林长湖湿地植物区系研究

论述云南石林县长湖湖泊湿地范围内湿地植物的植物区系组成及地理成分特点,为保护和利用湿地资源提供科学依据。结果表明:(1)有湿地植物20科47属56种,种类多样性较突出;(2)植物区系统计,广布的科、属、种分别占95%、40.4%、19.6%,湿地植物的广布性突出;(3)科级区系中热带分布占5%,属级区系中热带分布占38.2%、温带分布占21.4%,种级区系中热带分布占32.2%、温带分布占42.8%,属级和种级区系显示亚热带区系的区域性;(4)种级区系中特有分布占5.4%,且为当地特有变种,显示出较高特有性。     

广西滨海湿地盐生维管植物区系研究

基于野外实际调查及参考相关文献资料, 对广西滨海湿地盐生维管植物及其区系进行研究, 结果表明: (1) 广西滨海湿地盐生维管植物有36 科63 属77 种, 含2 变种, 其中引种或栽培的5 科5 属5 种, 相比其他省份种类相对较少。(2) 种子植物区系地理成分较复杂、热带性质明显, 科的分布有4 个类型和2 个亚型, 属的分布有7 个类型和3个亚型。(3) 草本植物发达, 红树林植物及其伴生种为重要组成部分。(4) 单种科、单种属多, 无特有现象。     

广州地区湿地维管植物资源调查与分析

共调查记录了广州地区湿地维管植物42科,93属,112种,大部分为被子植物,其中含有较多属和种的科是禾本科(Gramineae)和菊科(Compositae),含有较多种的属是蓼属(Polygonum)和莎草属(Cyperus).出现频率较高的物种主要有空心莲子草(Alternanthera philoxeroides(Mart.)Griseb.)、少花龙葵(Solanum americanum Miller)和鸭跖草(Commelina communis Linn.),这三个种在70%以上的调查点中有分布.水生植物有15种,占总数的13.39%,大多数为单子叶植物;湿生植物有27种,占总数的24.11%;喜湿植物有70种,占总数的62.50%.调查到的植物有不少已广泛应用于湿地园林景观和人工湿地,也有一些具有一定的应用潜力.     

南京城市湿地维管植物资源调查分析

对南京 9 处典型城市湿地维管植物群落进行实地调查, 共记录南京湿地维管植物 68 科 160 属 223 种。结果表明: 南京城市湿地维管植物物种组成丰富, 优势科属为禾本科和菊科。区系成分可划分为 14 个分布区类型和 5 个变型。其中, 温带分布属 95 个, 占总属数(除世界分布属)的 64.19%; 热带分布属有 51 个, 占 34.46%, 中国特有分布属有 2 个, 占 1.35%。该区湿地维管植物具有广布植物多、区系组成结构复杂、分布区类型丰富、温带热带过渡性质等特征。从生活型组成看, 该区湿地维管植物主要由草本植物组成, 占总种数的 86.55%, 处于绝对优势。从生态型组成看, 该区水生植物有 25 种, 占总数的 11.21%, 大多数为单子叶植物, 湿生植物有 60 种, 占总数的 26.91%, 喜湿植物有 138 种, 占总数的 61.88%。调查发现 24 种外来植物, 其中空心莲子草和凤眼莲等入侵危害严重。最后, 探讨南京城市湿地维管植物面临的问题, 并提出南京城市湿地维管植物保护对策。     

四川邛海湖湿地水生维管植物的现状调查

本研究对邛海湖湿地水生维管植物种类及分布状况进行了调查.结果表明,邛海湖湿地现有水生维管束植物77种,隶属于25科50属.其中,蕨类植物5种,隶属2科3属;被子植物72种,隶属23科47属.从植物生态类型和生活型方面来划分,邛海水生维管束植物可分为湖区水生维管植物、河口滩涂植物和湿生植物三种类型.它们主要分布在湖泊的北面、西面和南面.区系分析结果表明,邛海水生维管束植物共有7种分布类型,其中以世界性分布型植物种最多.邛海湿地自然着生的水生植物群落破坏严重,挺水植物以上群落基本消失,浮水植物和沉水植物分布区锐减,分布深度退缩,分布密度减小.针对邛海湿地水生维管束植物存在问题,笔者提出了相应的解决方法和建议.该研究为邛海湿地的恢复和重建提供了理论依据.     

海南羊山湿地的传粉网络及其季节动态

传粉网络是植物和传粉者之间形成的网状相互作用关系, 为理解群落物种多样性形成与维持机制提供了全新的视角。湿地是典型的群落交错区, 环境异质性与物种多样性都很高, 传粉网络可能比草地和森林等生态系统具有更复杂的结构。该研究针对海南岛海口市南郊的羊山湿地, 比较4个样地在旱季(5月)与雨季(8月)的传粉网络及其动态变化, 揭示湿地生态系统的传粉网络结构特征以及在干湿季的变化规律。结果表明, 羊山湿地传粉网络共有71种开花的植物, 131种传粉者, 传粉网络呈现低连接度、高嵌套度、中等网络特化程度的结构特征。在季节动态方面, 4个样地旱季的植物与传粉者种类高于雨季; 而传粉网络的连接度、嵌套度与网络特化程度没有明显的季节差异。白花鬼针草和水角等多个物种可同时在雨季和旱季开花, 使得植物-传粉者的种间关系虽然存在季节变化, 但传粉网络在旱季与雨季间的动态变化不大。总体而言, 羊山湿地物种多样性较高, 边缘效应较明显, 传粉网络结构较稳定。     

Ski slope vegetation at Snoqualmie Pass, Washington State, USA, and a comparison with ski slope vegetation in temperate coniferous forest zones

Ski slope vegetation at Snoqualmie Pass in Washington State, USA, was surveyed in order to identify community types and to compare it with vegetation development patterns in Japan. Ski slopes in Japan, most of which were constructed after 1960, underwent heavy land recontouring, while those at Snoqualmie Pass were constructed before 1950 with less modification. Three points apply to Japanese ski slope vegetation and differentiate these slopes from those at Snoqualmie Pass: (i) grasslands of introduced species are widespread and persistent; (ii) unvegetated patches are uncommon; and (iii) wetland vegetation has developed. These differences are mainly derived from the intensity of human impact, history of the slope and its scale: namely, ski slopes in Washington are older and larger than those in Japan. Ski slope vegetation in Washington was primarily differentiated by a soil moisture gradient. The large size of Washington ski slopes permitted the inclusion and development of wetland habitats, whereas most ski slopes in Japan are constructed on ridges and do not contain wetlands. Most introduced species in Japan are eliminated soon after seeding. In contrast, the long-term management of ski slopes decreased soil erosion and/or unvegetated patches in Washington and created relatively permanent grasslands composed of introduced species. Tsuga heterophylla and Abies amabilis were found established on the ski slopes in Washington, whereas in Japan the pioneer tree species are shade-intolerant broadleaved species. These differences may be a result of the different disturbance histories of ski slopes in the two countries. In addition, along with the conifers, early successional forbs such as Anaphalis margaritacea and Epilobium angustifolium are well established on Washington ski slopes. Results show that disturbances created by ski slope development greatly affect the vegetation, even on older, less heavily impacted ski slopes.     

Seed Banks in Arid Wetlands with Contrasting Flooding,Salinity and Turbidity Regimes

Aquatic plant communities in arid zone wetlands underpin diverse fauna populations and ecosystem functions yet are relatively poorly known. Erratic flooding, drying, salinity and turbidity regimes contribute to habitat complexity, creating high spatial and temporal variability that supports high biodiversity. We compared seed bank density, species richness and community composition of aquatic plants (submergent, floating-leaved and emergent) among nine Australian arid zone wetlands. Germinable seed banks from wetlands within the Paroo and Bulloo River catchments were examined at nested scales (site, wetland, wetland type) using natural flooding and salinity regimes as factors with nondormant seed density and species richness as response variables. Salinity explained most of the variance in seed density (95%) and species richness (68%), with flooding accounting for 5% of variance in seed density and 32% in species richness. Salinity-flooding interactions were significant but explained only a trivial portion of the variance (<1%). Mean seed densities in wetlands ranged from 40 to 18,760 m⁻² and were highest in wetlands with intermediate levels of salinity and flooding. Variability of densities was high (CVs 0.61–2.66), particularly in saline temporary and fresh permanent wetlands. Below salinities of c. 30 g l⁻¹ TDS, seed density was negatively correlated to turbidity and connectivity. Total species richness of wetlands (6–27) was negatively correlated to salinity, pH and riverine connectivity. A total of 40 species germinated, comprising submergent (15 species), floating-leaved or amphibious (17 species), emergent (6 species) and terrestrial (6 species) groups. Charophytes were particularly important with 10 species (five Chara spp., four Nitella spp. and Lamprothamnium macropogon), accounting for 68% of total abundance. Saline temporary wetlands were dominated by Ruppia tuberosa, Lamprothamnium macropogon and Lepilaena preissii. Variable flooding and drying regimes profoundly altered water quality including salinity and turbidity, producing distinctive aquatic plant communities as reflected by their seed banks. This reinforces the importance of hydrology in shaping aquatic biological communities in arid systems.     

Understanding sitatunga (Tragelaphus spekii) habitats through diet analysis in Rushebeya‐Kanyabaha wetland,Uganda

Between January and December 2008, we assessed the diet and habitat selection of sitatunga, a highly endangered tropical wetland antelope threatened by habitat loss in Rushebeya‐Kanyabaha wetland. Microhistological faecal analysis and vegetative sampling methods were used to assess plant forms, species and seasonal changes in the sitatunga diet. Habitat use was indirectly determined by assessing feeding patterns, distribution of dung and trails within the wetland. Sitatunga fed mainly on herbs, sedges, grasses and shrubs. A total of 34 plant species were recorded as eaten by sitatunga. The most eaten plant species was Cyperus papyrus L. (22%). Malenthera scandens Schum. & Thonn., Polygonum senegalense Meisu (12%) and Polygonum pulchrum Blume (5%) were the most eaten herbs. Zea mays L. was the most eaten agricultural crop (58% of domestic crops), mainly during the wet season. Sitatunga feeding was mainly concentrated on the wetland edge habitat (46%) where most of its food (53%) was located. The other preferred habitat was the tall closed papyrus. We conclude that the long‐term survival of sitatunga requires a management plan focussing on the conservation of the most preferred plant species and habitats.     

Differences exist in bird communities using restored and natural wetlands in the Parkland region,Alberta, Canada

Wetland restoration is used to compensate for historic and ongoing wetland losses. We compared bird community composition in 24 restored wetlands and 36 natural wetlands in the Parkland region of Alberta. Natural wetlands ranged in exposure to agricultural activity and were binned into three classes (low, medium, and high disturbance). Although the abundance and average species richness of birds were similar between restored and natural wetlands (analysis of variance: p > 0.22), the avian community composition differed significantly among wetland types (multiresponse permutation procedure [MRPP]: A = 0.05, p < 0.001). The avifauna using restored wetlands was distinct from the avifauna using natural wetlands spanning a range of disturbance levels (A = 0.02–0.06; p ≤ 0.006). Notably, restored wetlands were surrounded by less shrub/forest cover and more open water than low‐disturbance, natural wetlands. The majority (58%) of species using the surveyed wetlands were not classified as wetland‐dependent. Interestingly, if only wetland‐dependent species are considered, the avifauna using restored wetlands is no longer distinctive (MRPP: A < 0.01, p = 0.187), although the abundance of wetland‐dependent birds was marginally higher in restored wetlands (n = 24) than in low‐disturbance, natural wetlands (n = 10; Tukey's honestly significant difference test: p = 0.041). Overall, restored wetlands had reduced beta diversity compared to natural wetlands, regardless of whether the avifauna were restricted to wetland‐dependent species or considered comprehensively. This draws into question the legitimacy of the assumption that restoration can fully offset continued losses of natural wetlands.     

Effects of an African grass invasion on vegetation,soil and interstitial water characteristics in a tropical freshwater marsh in La Mancha,Veracruz (Mexico)

Abstract

The transformation of freshwater wetlands to pastures is a common practice in Mexico. This rapid loss of wetlands contrasts with the scarce information that exists about these ecosystems. To identify the environmental factors that control vegetation structure of a freshwater wetland invaded by the African grass Echinochloa pyramidalis, we characterized the vegetation (species composition, cover and aerial biomass), soil (moisture, redox potential, bulk density and topography) and water (water depth level, electric conductivity and pH) in two seasons of the year (dry and rainy). In addition, we analyzed the soil and water of three vegetation areas in the wetland, one dominated by E. pyramidalis, another by Sagittaria lancifolia and a third by Typha domingensis. The parameters associated with the hydrology of the wetland (water level, soil moisture, redox potential and bulk density) explained the plant species distribution. The invasive grass dominated in the relatively drier areas in the wetland while native species such as S. lancifolia, T. domingensis and Pontederia sagitatta dominated wetter sites. Introduction of E. pyramidalis has caused negative changes in the wetland, in particular a decrease of the diversity of plant species. In addition, we believe that the invader grass, as a C4 species, has more efficient use of water than the native plants, as well as a larger biomass, characteristics that can change the hydrological pattern of this wetland.     

中国自然湿地螺类生态学研究进展

螺类是软体动物腹足纲的通称,是湿地生态系统大型无脊椎动物的重要组成部分。湿地螺类在维持湿地生物多样性和复杂食物网结构,保障湿地物质循环和能量流动等方面具有重要的生态功能。从基本组成、生活型、功能群方面归纳了螺类群落结构特征;分析了螺类的时空分布格局;重点讨论了影响螺类群落结构的温度、盐度、底质等非生物因子和植被、物种间影响等生物因子以及人类对螺类的影响;概述了湿地演替过程中螺类群落的变化和螺类的环境指示功能。依据目前中国自然湿地螺类的研究特点和国际研究动态,展望了未来我国螺类群落的生态学研究的重点。     

扎龙湿地藻类优势种生态位及其种间联结性动态分析

为了解扎龙湿地藻类群落结构的季节特征和演替规律，对扎龙湿地藻类群落进行了分析，主要涉及藻类优势度、生态位、MFG功能群划分、生态位重叠值及联结系数分析。结果表明：(1)在检出的8门311种藻类中，夏季种类丰富度最高，全年优势种为狭形纤维藻和啮蚀隐藻。(2)优势种种类和密度季节性差异较大，春季以金藻-绿藻种类为主，夏季以绿藻-隐藻种类为主，秋季以隐藻-绿藻种类为主。(3)生态位宽度值与MFG功能群划分结合分析表明，优势种可分为3个大类别，不同种类对资源利用情况的差异较大，各季节广生态位种能较好的反映扎龙湿地水体环境的季节变化趋势。(4)生态位重叠值在不同季节上有较大差异，O_ik>0.6的占比分别为42.86%(春)、28.57%(夏)和25.00%(秋),表明春季优势种种间资源的竞争最为突出，种间竞争强于夏、秋两季。(5)种间联结性检验结果显示，扎龙湿地藻类优势种间总体联结上呈正关联关系，但是种间联结较为松散，种与种之间相对独立。研究表明，扎龙湿地藻类群落结构生态位测度均存在明显的季节波动，较好反映出水环境季节变化特征，可用来指示湿地水体环境的变化。     

Hydrodynamically mediated macrophyte silica dynamics

In most aquatic ecosystems, hydrodynamic conditions are a key abiotic factor determining species distributions and abundance of aquatic plants. Resisting stress and keeping an upright position often relies on investment in tissue reinforcement, which is costly to produce. Silica could provide a more economical alternative. Two laboratory experiments were conducted to measure the response of two submerged species, Egeria densa Planch. and Limnophila heterophylla (Roxb.) Benth., to dissolved silicic acid availability and exposure to hydrodynamic stress. The results were verified with a third species in a field study (Nuphar lutea (L.) Smith). Biogenic silica (BSi) concentration in both stems and leaves increases with increasing dissolved silica availability but also with the presence of hydrodynamic stress. We suggest that the inclusion of extra silica enables the plant to alternatively invest its energy in the production of lignin and cellulose. Although we found no significant effects of hydrodynamic stress on cellulose or lignin concentrations either in the laboratory or in the field, BSi was negatively correlated with cellulose concentration and positively correlated with lignin concentration in samples collected in the field study. This implies that the plant might perform with equal energy efficiency in both standing and running water environments. This could provide submerged species with a tool to respond to abiotic factors, to adapt to new ecological conditions and hence potentially colonise new environments.     

Intra- and inter-specific effects of mast seeding on seed fates of two sympatric <Emphasis Type="Italic">Corylus</Emphasis> species

We released seeds of two sympatric tree species, Corylus mandshurica (seed with thinner seed hull, higher nutrition) and C. heterophylla (seeds with thicker seed hull, lower nutrition) in the masting year of C. mandshurica in 2008, and C. heterophylla in 2009, respectively, to investigate how seed masting of the two sympatric Corylus species affects seed removal and dispersal fitness of the two species differently at both intra- and inter-specific levels. At intra-specific level, the authors found mast seeding of both C. mandshurica and C. heterophylla significantly reduced seed removal, seed consumption, but increased seed dispersal distance and seed dispersal fitness of the released seeds. Mast seeding of C. mandshurica increased seed caching of C. mandshurica. At inter-specific level, the authors found mast seeding of C. mandshurica reduced seed removal of C. heterophylla, but mast seeding of C. heterophylla did not significantly reduce seed removal of C. mandshurica. Mast seeding of C. mandshurica reduced seed consumption of C. heterophylla, while mast seeding of C. heterophylla reduced seed consumption of C. mandshurica. We found mast seeding of C. mandshurica significantly reduced seed dispersal distance of C. heterophylla, while mast seeding of C. heterophylla significantly increased seed dispersal distance of C. mandshurica. We found that mast seeding of C. mandshurica significantly increased seed dispersal fitness of C. heterophylla, while mast seeding of C. heterophylla did not significantly increase seed dispersal fitness of C. mandshurica. More studies are needed to reveal the ecological consequences of mast seeding at inter-specific or community-level. Seed traits may attribute the differences of mast seeding at inter-specific level. Because seeds with thinner seed hull and higher nutrition were more harvested and eaten by rodents, mast seeding of C. mandshurica might have reduced seed removal and seed consumption, but increased dispersal fitness of C. heterophylla (seeds with thicker seed hull, lower nutrition). Therefore, synchrony among species is, or is not, selectively beneficial to the focus species depends on seed traits which determine gains from mast seeding at inter-specific level.     

Chemical oxygen demand,nitrogen and phosphorus removal by subsurface wetlands with Phragmites vegetation in different models

To improve the removal efficiency of subsurface wetlands vegetated mainly by Phragmites, pilot‐scale gravel‐based wetlands were used to treat sewage characterized by chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) pollution. For Phragmites vegetation, COD, TP and TN removal loads of wetland vegetation with Phragmites australis–Typha angustata–Scirpus validus as main species reached 0.517 g m^?2 d^?1, 0.277 g P m^?2 d^?1 and 0.023 g N m^?2 d^?1. The COD removal loads in pilot‐scale and medium‐scale (260 m² in area) wetlands with Phragmites‐monoculture vegetation were 0.62–0.64 g m^?2 d^?1, while that of P. australis–T. angustata–S. validus wetland reached 0.974 g m^?2 d^?1. Thus, the preferable poly‐culture model for Phragmites wetland vegetation was P. australis, T. angustata, S. validus and Zizania latifolia with stem density ratio of 8:1:5:1. After harvest, nitrogen and phosphorus standing stocks of wetland vegetations ranged only 2.2–9.93 g N m^?2 and 5.39–13.5 g P m^?2, respectively, as both the above ground biomass and the nitrogen and phosphorus contents of the wetland vegetation harvested in late autumn were low.