江汉水生植物群落的结构与数量特征

汉江是长江的第一大支流,是我国实施南水北调工程的重要对象。目前,有关汉江水生植物群落方面的研究尚未见报道。因此,在1998-2000年,运用植物群落学研究的理论和方法,对汉江沿途6个江段水生植物群落的结构和数量特征进行了定位研究。在汉江上游与下游各江段,群落水平分布格局为斑块状,不象湖泊或池塘系统那样表现出明显的均匀分布或带状分布特征,而在中游局部江段中表现为小范围的带状分布。群落垂直分布格局,在上游江段,以沉水层为主,浮叶层和挺水层不发达或缺乏;在中游各江段,群落表现出完整的垂直结构层次：挺水层、漂浮层、浮叶层和沉水层;在下游江段群落结构常为两层或一层结构,以浮叶层和挺水层为主,而沉水层在下游江段发育不充分且生物量很小。另上,对汉江上、中、下游的典型植物群落的数量特征进行了分析。研究表明,在汉江的不同江段,群落的组成、结构和数量特征等都不同,而水位、流速、基质状况、人为干扰是影响汉江水生植物群落生长和分布格局的主要因子。     

高原湿地纳帕海水生植物群落分布格局及变化

采用3S技术与植物群落研究法,对高原湿地纳帕海24a来的湿地植物群落分布格局及变化的研究结果表明：与24a前水生植物群落相比较。纳帕海水生植物群落类型、数量改变,原生群落不断减少或消失,耐污、喜富营养类群如水葱群落（Com．Scirpus tabernaemontani）、茭草群落（Com．Zizania caduciflora）、穗状狐尾藻群落（Com．Myriophyllum spicatum）、满江红（Com．Azolla imbricata）群落等大量出现;群落总数由24a前的9个增至当前的12个,其中挺水植物群落增加2个,浮叶植物群落增加1个,挺水植物群落增幅最大。由东向西、由南向北,纳帕海水生植物群落分布大致呈现出浮叶群落、挺水群落、沉水群落斑块状依次配置的水平格局规律。挺水植物群落分布面积最大,达528．42hm^2,其次是沉水植物群落,分布面积为362．50hm^2,浮叶植物群落分布面积最小,为70．23hm^2。随沉水群落、浮叶群落向挺水群落的演替,群落伴生种数量增加、优势种优势度减小、层次类型改变,群落结构变得更为复杂。纳帕海湿地水生植物群落分布格局及变化是对湿地环境变化的响应,表明了在人为干扰作用影响下,纳帕海湖岸线内移、水量减少、水质恶化等湿地水文条件的改变,致使湿地生态系统功能不断退化。     

汉江中下游水生植物群落及演替

水生植物是河流生态系统的重要组成部分, 研究河流水生植物群落组成及演替对于河流生态系统健康诊断具有重要意义。该研究采用野外生态学研究方法, 于2013年9月和2014年6月2次对汉江中下游12个典型代表性江段的水生植物群落的组成、分布和生物量等进行调查。调查结果表明, 现阶段汉江中下游的主要水生植物共有69种, 隶属28科49属, 其中优势种主要是穿叶眼子菜(Potamogeton perfoliatus)、竹叶眼子菜(P. malaianus)、芦苇(Phragmites australis)、南荻(Triarrhena lutarioriparia)和喜旱莲子草(Alternanthera philoxeroides)等。结合早期的研究表明, 汉江中游江段沉水植物优势群落变化明显; 下游则呈现出由沉水植物群落向挺水植物群落演替的格局。挖沙和污染等人类干扰以及水位波动、河流底质和植物繁殖策略等自然因素可能是导致汉江中下游水生植物优势种变化和群落演替的主要因素。该研究结果可为汉江中下游的水生植物多样性保护和生态修复提供科学依据。     

筑坝扩容下高原湿地拉市海植物群落分布格局及其变化

基于遥感与地理信息系统技术、结合实地调查与验证,对高原湿地拉市海筑坝扩容13a来湿地植物群落类型、物种组成、空间分布格局进行研究,对比分析筑坝扩容前后植物群落变化特征。结果表明,拉市海当前分布有水葱 (Scirpus tabernaemontani)、两栖蓼 (Polygonum amphibium) 等2个挺水植物群落,鸭子草 (Potamogeton tepperi)、菱 (Trapa bispinosa)等2个浮叶植物群落,穗状狐尾藻 (Myriophyllum spicatum)、篦齿眼子菜 (Potamogeton pectinatus)、菹草 (Potamogeton crispus)、穿叶眼子草 (Potamogeton perfoliatus)、小叶眼子菜 (Potamogeton pusillns)等5个沉水植物群落,草甸植被分布于湖周。湿地植物物种共计61种,隶属于25科、48属,物种丰富度随沉水→浮叶→挺水→草甸逐渐增加。沉水植物群落分布面积最大(615.08 hm²),其次是草甸(214.60 hm²)、浮叶植物群落(140.01 hm²),挺水植物群落分布面积最小 (9.34 hm²),群落垂直层次随沉水→浮叶→挺水呈复杂化的趋势。筑坝13a来,拉市海植物群落类型从单一的沉水型植物群落发展成为由沉水、浮叶、挺水型组成的、水平空间多样化配置的湿地植被系统,其中穗状狐尾藻、篦齿眼子菜、小眼子菜等植物群落在筑坝蓄水13a后没有发生演替得以保留,而扇叶水毛茛(Butrachium bungei)、马来眼子菜(Potamogeton malaianus)和轮藻(Chara spp.)群落发生演替而消失。研究掌握了筑坝扩容下拉市海湿地植物群落分布格局及其变化特征,为科学评估筑坝蓄水对湿地生态系统的影响提供了基础性数据,同时也为水文改变下高原湿地生态系统的保护、管理以及资源可持续利用提供了一定的理论依据。     

湖北斧头湖浮叶水生植物群落学研究：Ⅱ.荇菜群落的结构

本研究从三方面考察了斧头湖荇菜群落的结构,并对其进行了周年观察,荇菜群落内共有１３种植物,可归为５个生活型１１个生长型,其物种组成较贫乏,浮叶水植物群落的物种结构较挺水植物群落简单,荇菜群落呈带状和斑块状分布,荇菜种群的群聚规模从０．０８－０．６４ｍ＾２不等。群落的垂直结构分两层：浮叶植物层和沉水植物层,无发达的地下根茎系统和水上层。群落内荇菜种群在５月下旬达到最大现存量和生殖高峰,之后在一个低的     

汉江中下游水生植物多样性及南水北调工程对其影响

１９９７—２０００年对汉江中下游８个江段水生植物种类组成、分布、生物量做了调查。汉江中下游共有水生植物１８科２２属３４种,以世界广布种为主,Ｒ／Ｔ值为０．６７。中游以沉水植物群落为优势,建群种为轮叶黑藻（Ｈｙｄｒｉｌｌａ　ｖｅｒｔｉｃｉｌｌａｔａ）、穿叶眼子菜（Ｐｏｔａｍｏｇｅｔｏｍ　ｐｅｒｆｏｌｉａｔｕｓ）和微齿服于荣（Ｐ．ｍａａｃｋｉａｎｕｓ）;下游主要为挺水植物群落,建群种为东方香蒲（Ｔｙｐｈａ　ｏｒｉｅｎｔａｌｉｓ）和芦苇（Ｐｈｒａｇｍｉｔｅｓ　ｃｏｍｍｕｎｉｓ）,生物量为５７．５—２１００ｇ／ｍ＾２;α－多样性在丹江口最高（０．５４６）,老河口次之（０．５１７）,仙桃员低（０）;生活型多样性在中游丹江口最大（０．４０２）;β—多样性在时间梯度６—８月份在所有样点β＝０,水平梯度β＝０．７９,垂直梯度β＝１．４８;γ—多样性在汉江中游为２９种,在下游为１０种。中游地区水生环境适合水生植物生长,而下游人类活动导致水环境趋于恶化限制了水生植物分布。     

斧头湖挺水植被的群落学研究——Ⅱ.莲群落Com. Nelumbo nucifera的结构

本文从物种结构、水平结构和垂直结构三方面结合其时间特征对湖北省斧头湖莲群落的结构进行了分析,结果表明:①莲群落物种组成复杂,生长型类型多样,是一多优群落,挺水、浮水和沉水三个植被层都很发达;②莲群落中明显地表现出了优势种的替代过程,沉水植被层中菹草、黑藻和金鱼藻的替代尤为明显,各物种的个体生态学习性的差异是造成这种现象的主要原因;③莲群落内部表现出不同物种的种群分布在水平方向上的分化,莲的叶片和花果均表现出群聚分布的式样,是一种形态学格局;④莲群落垂直结构复杂,一般存在三个植被层,不同植被层的变化各有其特征。     

汉江水生植物多样性研究

对汉江沿途 1 3个地区的所在江段进行了水生植物种类组成、分布、生物多样性调查。结果表明 ,在汉江共有水生植物 2 6科 3 6属 5 4种 ;物种α多样性在丹江口最高 ,H、D和R指数由上游汉中江段至下游汉口段表现出上升—下降—上升的三折线及四折线变化趋势 ;β多样性在水深梯度及距离梯度上表现为 β下 >β上 >β中 ,说明下游江段的生境异质性程度高 ;γ多样性是γ上 >γ中 >γ下 ,对各个江段而言以中游老河口江段γ多样性最大为 2 9种 ,丹江口和襄樊江段次之 ,汉口段最小。中游地区水生环境和生态因子更适合于水生植物的生长 ,而下游人类活动导致水环境趋于恶化限制了水生植物的生长和分布     

岷江上游干旱河谷植物群落分布的环境与空间因素分析

为了探讨土壤环境因子对植物群落物种数量、结构格局的影响 ,通过对岷江上游干旱河谷灌丛植被的大量群落学调查 ,采用了群落中 9个土壤特征指标 ,利用去势典范对应分析 (DCCA)排序方法 ,分析了不同群落类型中不同层次的物种数量结构的空间格局 ;定量分离了土壤、空间及其交互作用等因素对不同层次群落格局总体变异的影响。结果表明 :以水分为主导的多种环境因子耦合梯度决定着植物群落结构格局。环境因子对群落的影响程度在不同层次有差异 ,在灌木层中 ,单纯环境因子对植被格局的解释占 2 8.0 2 % ,环境 -空间耦合因子占 8.90 % ,空间因子独立占 10 .69% ,其他因子占 52 .3 9% ;而在草本层中 ,单纯环境因子对植被格局的解释占 2 0 .64% ,而环境 -空间耦合因子仅占 0 .83 % ,空间因子独立占 5.10 % ,其他因子占 73 .43 % ,草本的可解释性远远低于灌木。但无论是灌木层还是草本层 ,在诸多因子中 ,土壤水分始终在影响群落物种数量结构的空间格局分布中起着主导作用     

排序法在植物群落与环境关系研究中的应用述评

自然环境对植物的影响主要表现在气候、水文、土壤及地形方面。大尺度上,气候类型明显影响植物的带状分布与物种空间格局;中小尺度上,土壤、水文、地形以及三者的交互作用影响植物生长必需的环境与资源条件,并对植物群落物种多样性起决定性作用。多元数量分析是研究植物群落生态关系的重要方法,在揭示植物群落与环境关系方面起到关键作用。排序法作为数量分析的重要手段,经常在植物生态学研究中扮演重要角色,尤其是在植物群落分布以及群落结构方面的应用已形成一种趋势。主要从植物群落分布以及群落结构的角度综述了当今排序法的应用,分析了面临的主要问题,并提出了未来可能发展方向,以期为今后排序方法的选择应用提供参考。     

Distribution patterns and changes of aquatic plant communities in Napahai Wetland in northwestern Yunnan Plateau,China

Using GPS technology and community research methods for plant communities,we investigated the distribution patterns of aquatic plant communities in the high plateaus of the Napahai Wetlands,Yunnan,China,as well as the species changes of plant communities compared with that of 24 years ago since 2005.We found that the types and numbers of aquatic plant communities have changed.Some pollution-tolerant,nutrient-loving plant communities such as Scirpus tabernaemontani,Zizania caduciflora,Myriophyllum spicatum,and Azolla imbricata flourished,while the primary aquatic plant com-munities were reduced or even disappeared.The number of aquatic plant communities were increased from nine to 12 with the addition of two new emergent plant com-munities and one new floating-leaved plant community.The increase in emergent plant communities was signifi-cant.From east to west and from south to north,various types of plant communities were continuously distributed,including floating-leaved plant communities,emergent plant communities and submerged plant communities.The composition of the communities became more com-plicated and the number of accompanying species increased,while the percentage ratio of dominant plant species declined.In 2005,the coverage of emergent plant communities was the largest (528.42 hm2) followed by submerged plant communities (362.50 hm2) and the float-ing-leaf plant communities was the smallest (70.23 hm2).The variations in the distribution of aquatic plant com-munities in the Napahai Wetlands reflect the natural responses to the change of the wetland ecological envir-onment.This study indicates that human disturbances have led to an inward movement of the wetland shoreline,a decrease in water quality and a reduction in wetland habitat.     

Does richness of emergent plants affect CO2 and CH4 emissions in experimental wetlands?

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Distribution patterns and changes of aquatic plant communities in Napahai Wetland in northwestern Yunnan Plateau, China

Using GPS technology and community research methods for plant communities, we investigated the distribution patterns of aquatic plant communities in the high plateaus of the Napahai Wetlands, Yunnan, China, as well as the species changes of plant communities compared with that of 24 years ago since 2005. We found that the types and numbers of aquatic plant communities have changed. Some pollution-tolerant, nutrient-loving plant communities such as Scirpus tabernaemontani, Zizania caduciflora, Myriophyllum spicatum, and Azolla imbricata flourished, while the primary aquatic plant communities were reduced or even disappeared. The number of aquatic plant communities were increased from nine to 12 with the addition of two new emergent plant communities and one new floating-leaved plant community. The increase in emergent plant communities was significant. From east to west and from south to north, various types of plant communities were continuously distributed, including floating-leaved plant communities, emergent plant communities and submerged plant communities. The composition of the communities became more complicated and the number of accompanying species increased, while the percentage ratio of dominant plant species declined. In 2005, the coverage of emergent plant communities was the largest (528.42 hm²) followed by submerged plant communities (362.50 hm²) and the floating-leaf plant communities was the smallest (70.23 hm²). The variations in the distribution of aquatic plant communities in the Napahai Wetlands reflect the natural responses to the change of the wetland ecological environment. This study indicates that human disturbances have led to an inward movement of the wetland shoreline, a decrease in water quality and a reduction in wetland habitat. __________ Translated from Acta Ecologica Sinica, 2006, 26(11): 3624–3630 [译自: 生态学报]     

Plant community,primary productivity,and environmental conditions following wetland re-establishment in the Sacramento-San Joaquin Delta,California

Wetland restoration can mitigate aerobic decomposition of subsided organic soils, as well as re-establish conditions favorable for carbon storage. Rates of carbon storage result from the balance of inputs and losses, both of which are affected by wetland hydrology. We followed the effect of water depth (25 and 55 cm) on the plant community, primary production, and changes in two re-established wetlands in the Sacramento San-Joaquin River Delta, California for 9 years after flooding to determine how relatively small differences in water depth affect carbon storage rates over time. To estimate annual carbon inputs, plant species cover, standing above- and below-ground plant biomass, and annual biomass turnover rates were measured, and allometric biomass models for Schoenoplectus (Scirpus) acutus and Typha spp., the emergent marsh dominants, were developed. As the wetlands developed, environmental factors, including water temperature, depth, and pH were measured. Emergent marsh vegetation colonized the shallow wetland more rapidly than the deeper wetland. This is important to potential carbon storage because emergent marsh vegetation is more productive, and less labile, than submerged and floating vegetation. Primary production of emergent marsh vegetation ranged from 1.3 to 3.2 kg of carbon per square meter annually; and, mid-season standing live biomass represented about half of the annual primary production. Changes in species composition occurred in both submerged and emergent plant communities as the wetlands matured. Water depth, temperature, and pH were lower in areas with emergent marsh vegetation compared to submerged vegetation, all of which, in turn, can affect carbon cycling and storage rates.     

白洋淀水生植被初步调查

通过野外实地调查对白洋淀水生植被的物种组成、群落类型、分布格局及物种生物量进行了初步研究.结果表明：白洋淀湿地共有水生植物39种,隶属于21科32属,其中挺水植物16种,沉水植物14种,浮叶根生植物6种,漂浮植物3种.与20世纪90年代初相比,水生植物共减少了9种,群落类型也由原来的16种变为现在的13种,大面积轮叶黑藻、大茨藻等优势群落消失,物种分布格局也发生了巨大变化.群落生物量较1980年大幅下降.人工养殖、污染物随意排放和水位的变化可能是造成白洋淀湿地退化、水生植被格局发生巨大变化的主要原因.     

Shifts in aquatic macrophyte abundance and community composition in cottage developed lakes of the Canadian Shield

In this study, we examined how the biomass and species composition of aquatic plant communities relates to cottage development of Canadian Shield lakes. Within the North Kawartha Region of Ontario, we sampled the macrophyte communities at two water depths (0.5 m and 1.5 m) in lakes (n = 12) having a range of cottage densities (0-23 cottages km⁻¹ of shoreline). Across all lakes, 39 species were found, with individual lake richness ranging from six to ten. Macrophyte biomass decreased with increasing cottage density, irrespective of depth (ANCOVA dev’t*depth p = 0.925). In contrast, only the shallower depth showed a relationship between cottage development and richness and diversity; highly developed lakes had three or fewer species and diversities less than 1.5. There was also a shift in structural plant type from floating leaf and emergent on undeveloped lakes to submersed and submersed low-lying on developed lakes. Ordination analysis demonstrated that cottage development (and to a lesser extent, lake area) was strongly correlated (p = 0.05) with community species composition in southern Ontario lakes. Our results thus demonstrate that the management of cottage development should minimize the loss of biomass and species richness of aquatic plants given the likely negative effects of these alterations on other taxa in littoral zones and foodwebs in lake ecosystems.