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1.
神农架大九湖泥炭地是华中地区少有的亚高山泥炭藓湿地,是研究长江中游气候变化及其生态效应的理想区域.本文通过大九湖一根泥炭岩芯的年代学、元素及摇蚊亚化石记录,结合区域古气候资料,探讨大九湖泥炭地地表干湿变化历史及生物响应过程.结果表明,近400年来大九湖泥炭地古水文和摇蚊种群变化经历了3个主要阶段：1820s之前研究区内气候偏冷湿,尤其是1720s-1820s年间,冷湿的环境有利于泥炭中碳的大量积累,较高的地表有效湿度使得摇蚊大量生长,同时湖泊相摇蚊属种丰富度及含量均较高;1820s-1940s年间,区域内夏季降水量显著降低,同时伴随明显的区域增温过程,泥炭地地表有效湿度过低不利于水生生物生长,摇蚊种群生物量极低;1940s （尤其1970s）后,摇蚊种群丰度逐渐回升,但湖泊相摇蚊丰度较1820s以前明显降低,半陆生摇蚊属种丰度有所增加,说明尽管该时期泥炭地表湿度有所增加,但较1820s前仍较低,暖湿气候下泥炭分解也较为明显.本研究探索性地分析了气候变化背景下泥炭地摇蚊种群对泥炭地湿度变化的响应过程,这不仅为摇蚊亚化石在气候变化研究中的应用开拓了新的领域,同时也为全面、精准地理解泥炭地演化及区域环境变化过程提供了新线索. 相似文献
2.
升金湖是长江中下游地区典型的浅水通江湖泊,是东亚-澳大利西亚候鸟迁徙路线上水鸟重要的越冬地. 2017年11月-2018年3月,以该湖泊越冬鸭属(Anas)鸟类为研究对象,对其在芦苇湿地、芡实塘、退耕还湿和水生植被恢复湿地4种湿地生境中的群落结构、行为特征及其环境影响因素进行了研究. 结果表明,升金湖分布有10种越冬鸭属鸟类,斑嘴鸭(Anas poecilorhyncha)、绿翅鸭(A. crecca)和绿头鸭(A. platyrhynchos)为该属鸟类群落的优势种. 鸭属鸟类群落在越冬前期种类和数量最多,在整个越冬期,鸭属鸟类在芦苇湿地中种数、数量、密度和多样性指数最高. 在水生植物盖度高、人为活动弱的芦苇湿地,鸭类的主要行为是休息;在食物资源丰富、人为活动强的芡实塘和退耕还湿湿地,其主要行为是觅食和警戒. 鸭属鸟类群落种数、数量、密度和多样性指数与湿地的面积、水域面积、水生植物盖度呈正相关,与干扰度和水深呈负相关. 觅食时间与气温和沉水植物的盖度呈正相关,与水深和干扰度呈负相关,警戒时间与干扰度呈正相关,与挺水植物的盖度呈负相关. 各种恢复类型的湿地生境成为越冬鸭属鸟类的重要栖息地,因此恢复多种湿地栖息地对于越冬水鸟的保护具有重要意义. 相似文献
3.
山东某新建水库浮游藻类的群落结构特征及其环境驱动因子 总被引：2，自引：1，他引：1
基于山东某新建水库中2014年4月-2017年12月的浮游藻类和水质监测结果,研究了藻类群落结构特征,采用非度量多维尺度分析了各年份不同季节藻类群落结构的相似性,利用冗余分析探究了藻类群落结构和环境因子的关系.结果表明：尖针杆藻（Synedra acus）、湖泊伪鱼腥藻（Pseudanabaena limnetica）和小球藻（Chlorella vulgaris）为此水库的主要优势藻种.水库藻类群落结构的季节演替不稳定,冬、春季多以硅藻和绿藻占优势,不同年份夏、秋季藻类结构差异较大,蓝藻和硅藻在夏、秋季存在一定的竞争优势.该水库于2013年底开始启用,由于水体环境的波动,藻类群落结构有所变化,整体上是由蓝藻-绿藻-硅藻向硅藻-绿藻-蓝藻变化.水库浮游藻类生长主要受到氮盐和高锰酸盐指数影响,但不同年份的主要环境影响因子存在一定差异. 相似文献
4.
偏远的亚高山湿地受人为活动直接干扰较小,是追踪气候变化和大气沉降双重影响下湿地生态系统演化的理想研究地.本研究以位于巫山的葱坪湿地为研究对象,基于一根50 cm沉积岩芯的210Pb和137Cs测年、摇蚊亚化石和元素序列,探讨该湿地近200年来环境演化历史.结果表明,摇蚊种群由1910年之前的Chironomus anthracinus-type、Limnophyes sp.、Cladotanytarsus mancus-type 1变为1910-1925年的C.mancus-type 1、C.anthracinus-type、Procladius sp.和Endochironomus impar-type的优势组合,这些优势种均指示浅水环境.此后,耐营养种E.impar-type、Polypedilum nubeculosum-type和C.anthracinus-type逐渐成为优势种.冗余分析表明,总磷、总碳和钙是解释摇蚊组合变化的显著环境因子.20世纪30年代以前摇蚊种群可能与进入湿地的径流量小、水位较低相关,而20世纪中叶以来摇蚊组合变化指示大气沉降增长背景下湿地营养富集过程.在大气沉降和气候变化的双重影响下,耐营养属种增加和生物多样性降低表明葱坪湿地生态环境正发生退化. 相似文献
5.
2019年春、秋两季,对江西省76个湖泊的底栖动物进行了调查,在分析其群落结构和多样性的基础上,探讨了多样性与环境因子间的关系,旨在确定影响大型底栖无脊椎动物多样性的重要环境因子,以期为江西省湖泊的精准化管理提供科学依据和技术支持。两次调查共检出140个分类单元,以水生昆虫和软体动物为主,摇蚊类物种数占水生昆虫物种数的53.62%。富营养指示种(长足摇蚊属一种和摇蚊属一种)为春、秋两季的优势分类单元,湖沼典型种(长足摇蚊属一种、摇蚊属一种、石田螺属一种、苏氏尾鳃蚓和霍甫水丝蚓)的丰度变化导致了群落结构的季节变化。大型底栖无脊椎动物α多样性水平较低,基于PLSR和PLS-SEM的分析结果表明,影响大型底栖无脊椎动物多样性指标的环境因子既与藻类种群动态密切相关,也与水质状态有关。大型底栖无脊椎动物多样性与藻类种群状态存在稳定的联系,不受季节因素的影响,过高的藻类丰度不利于大型底栖无脊椎动物多样性的提高,而较好的水质状况有利于大型底栖无脊椎动物多样性的提高。为保护江西省湖泊大型底栖无脊椎动物资源,应在具有渔业养殖功能的湖泊和城镇湖泊中进行水生植物的修复工作,使藻型湖泊向草型湖泊方向演化;对一... 相似文献
6.
沉水植物附植生物群落生态学研究进展 总被引：6，自引：4，他引：2
在高等水生植物表面经常附着生长着藻类、真菌和细菌等,这些有机群体组成附植生物群落,在大中型浅水湖泊中普遍存在.附植生物群落具有特定的物种组成和空间结构,并随季节推移和沉水植物生长表现出一定的动态变化特征.附植生物群落与宿主植物及周围水体环境联系密切,不仅能够表征水体营养盐、光照、温度等环境因子特征,与沉水植物、食草动物、浮游植物等水生生物类群也存在不同的相互作用.水生生态系统中,附植生物群落参与水体营养物质转化,在草-藻型湖泊生态系统的相互转化过程中起重要作用;其较高的初级生产力作为水生动物重要的食物来源,增加了食物网的多样性;同时,附植生物群落因其独特的生理生态特征正逐渐被应用于水质净化和水环境质量监测.本文在综述近年来附植生物群落研究进展的基础上,分析了附植生物群落的组成结构和动态变化特征,阐述了附植生物群落在水生生态系统中的功能,可为湖泊富营养化治理,尤其是沉水植被的生态修复和管理提供科学依据. 相似文献
7.
近百年来长江中下游地区的浅水湖泊经历了气候变化及日益增强的人类扰动,造成了普遍的湖泊富营养化、水动力条件和水生生态系统的状态转变,水体的生态服务功能明显退化.枝角类作为一种重要的水生生物,敏感地响应于湖泊及其流域的环境变化,但目前对亚热带湖泊中的枝角类亚化石的环境指示意义,与其它古生态指标如硅藻、摇蚊等对环境变化的响应差异尚未明确.因此,本文以浅水湖泊太白湖为研究对象,结合流域历史资料和监测数据,基于沉积岩芯中枝角类群落过去百年来的期演化序列,重建了近百年来太白湖的历史环境演变过程及机制.对比硅藻及摇蚊的群落演化特征,探讨了多门类古生态指标对环境变化的响应差异.本文重点讨论了枝角类对湖泊鱼类产量指示意义及利用枝角类亚化石来重建历史环境的应用前景及不足. 相似文献
8.
水体和沉积物是湖泊生态系统中迥异但又紧密相连的两类生境,栖息在这两类生境中的细菌在维持生态系统平衡和驱动元素循环中起着关键性作用。为了探究湖泊水体和沉积物细菌群落的分布格局,本文对太湖四个湖区水体和沉积物中细菌群落进行调查,基于高通量测序技术和统计分析手段,分析这两类生境中的细菌群落组成和多样性水平、分布特征及其驱动因素。结果表明:放线菌门(Actinobacteria)、变形菌门(Proteobacteria)和蓝细菌门(Cyanobacteria)是水体细菌群落中最主要的细菌门,而沉积物中Proteobacteria占据优势地位。在两类生境中,太湖西部区域细菌群落丰富度和独特性(LCBD)相对较高,各区域群落结构表现出显著性差异。对水体而言,电导率、pH值、PC1(重金属组成)和沉积物孔隙度是驱动细菌丰富度的重要因子,PC1、水温及pH值是影响细菌群落LCBD的重要因子,而细菌网络复杂性随pH值的增加而增加,且在高pH环境中占主导地位;对沉积物而言,其丰富度和LCBD的重要影响因子均是沉积物中总磷和锂,细菌网络复杂性随金属元素施加的环境压力增大而降低,但随总磷、磷酸盐和铵态氮浓度的... 相似文献
9.
为了探讨泥炭藓共生细菌和泥炭表层沉积物细菌群落的垂向变化以及它们在湿地生态系统中的作用,对大九湖泥炭湿地泥炭藓植株的不同部位和下伏泥炭沉积物进行了分层采样.利用克隆文库和荧光定量PCR技术对样品中的细菌进行了定性和定量分析.结果表明,尽管细菌的16S rRNA基因拷贝数在同一个数量级(108个拷贝/克样品),并以变形菌和酸杆菌占优势,但细菌群落组成由泥炭藓上部至下部再到泥炭沉积物不同深度存在显著的空间变化.泥炭藓上部以蓝细菌(Cyanobacteria)和a变形菌门(alpha-Proteobacteria)为主,中部则以酸杆菌门(Acidobateria)为主,泥炭藓下部和最表层泥炭以?变形菌门和酸杆菌门为主,地表以下的泥炭样品以酸杆菌门占优势.细菌组成的这种空间分布规律与细菌的生态功能密切相关.泥炭藓上部的蓝细菌通过光合作用与泥炭藓共生.酸杆菌门的细菌一方面能适应泥炭湿地低pH的环境条件,另一方面还在泥炭藓植株的降解及泥炭的形成中发挥重要作用,并可能参与泥炭湿地酸性条件的形成.在泥炭藓不同部位均发现了甲基胞囊菌科(Methylocystaceae)的克隆,暗示甲烷氧化不仅局限于泥炭藓死亡的透明细胞中,而是在泥炭藓的整个植株中均可能存在着活跃的甲烷氧化过程.这一工作对深刻理解和定量研究泥炭地的微生物地球化学过程,特别是甲烷通量以及甲烷循环具有重要意义. 相似文献
10.
2013年6月-2015年6月,对安徽颍州西湖省级湿地自然保护区内农田区、河流湿地和湖泊湿地3种典型生境的鸟类进行调查,共记录到鸟类123种,属于14目33科69属.按照季节和生境的不同对鸟类多样性进行分析,结果表明:颍州西湖湿地保护区秋季鸟类的物种数和密度显著高于其他季节,而夏季拥有最高的物种多样性指数和均匀度指数;在颍州西湖湿地保护区3种典型生境中,湖泊湿地的鸟类物种数显著多于河流湿地和农田区,同时,湖泊湿地和农田区鸟类密度、物种多样性指数、均匀度指数显著高于河流湿地,而河流湿地拥有最高的优势度指数.就科属水平上的多样性而言,该保护区鸟类群落科属间多样性为0.76.颍州西湖湿地是鸻鹬类和雁鸭类等迁徙鸟类的重要中途停歇地和越冬地. 相似文献
11.
M. van Hardenbroek O. Heiri M. F. Wilhelm A. F. Lotter 《Aquatic Sciences - Research Across Boundaries》2011,73(2):247-259
The distribution of benthic invertebrates and their subfossil remains was examined within the basin of De Waay, a dimictic,
eutrophic lake in the Netherlands. We focused on Chironomidae, but also report the abundances of 11 invertebrate groups that
potentially produce chitinous remains that are preserved in the fossil record, although their remains could only be identified
at a coarser taxonomic resolution. Most living invertebrates sampled in different seasons were constrained to the littoral
zone, with the exception of a few taxa (Ceratopogonidae, Chaoborus flavicans, and Chironomus) that are adapted to low oxygen conditions in the seasonally anoxic profundal zone. In contrast, assemblages of invertebrate
remains in lake surface sediments were similar in the entire lake basin, suggesting that considerable numbers of invertebrate
remains are transported and redeposited off-shore in Lake De Waay, due to its steep bathymetry. These results indicate that
a single sediment sample obtained from the centre of this lake contains subfossil invertebrate remains originating from the
entire lake basin. In Lake De Waay, the majority of taxa found in the living assemblages were identified as remains in lake
surface sediments, at least for the Chironomidae that could be identified at a similar taxonomic level in living and subfossil
assemblages. Of the total 44 chironomid taxa found in Lake De Waay, 35 taxa occurred in the living assemblages and 34 taxa
occurred in the subfossil assemblages. Thirty chironomid taxa occurred both as living and subfossil specimens, and on average
these 30 taxa represent 94% of the specimens encountered in a sediment sample. Five rare chironomid taxa present as living
larvae were not detected in the subfossil assemblages. Conversely, eight rare and four common chironomid taxa were found in
subfossil remains, but not in living assemblages. Our results indicate that subfossil assemblages in surface sediment samples
provide spatially integrated and representative samples of the living assemblage. However, a combined approach examining both
the living benthic invertebrate fauna and invertebrate remains in lake surface sediments will potentially give a more complete
and detailed overview of benthic invertebrates in a lake ecosystem than an approach based exclusively on one of these groups. 相似文献
12.
《Limnologica》2021
Chironomid taxa in the diets of six co-occurring gobiids (Caucasian dwarf goby Knipowitschia caucasica; monkey goby, Neogobius fluviatilis; racer goby, Babka gymnotrachelus; round goby, Neogobius melanostomus; bighead goby, Ponticola kessleri; and western tubenose goby, Proterorhinus semilunaris) were investigated in a freshwater habitat in Ukraine. Overall, 32 chironomid morphotypes were identified, among which the most abundant were Polypedilum convictum, Cricotopus sylvestris, Glyptotendipes spp., and Endochironomus albipennis. The racer and monkey gobies were characterized by the highest diversity of chironomid morphotypes in their diets, while the bighead goby by the lowest diversity. Highest similarities of chironomid assemblages in gut contents were observed among the monkey, racer, and round gobies as well as between the bighead and tubenose gobies, while the lowest similarity was observed between the monkey goby and Caucasian dwarf, tubenose, and bighead gobies. Mean sizes of chironomids in the gut contents of different gobiids varied; Caucasian dwarf and tubenose gobies consumed significantly smaller chironomids. Diversity of chironomid taxa in the diets of gobies depended on the type of each fishes’ habitat. Tubenose and bighead gobies preyed mainly on phytophilous chironomids; the monkey and round gobies preferred bottom-dwelling, burrowing chironomids; while Caucasian dwarf and racer gobies consumed both phytophilous and bottom-dwelling, burrowing taxa. 相似文献
13.
The natural carbon storage function of peatland ecosystems can be severely affected by the abandonment of peat extraction, influencing peatland drainage, leading to large and persistent sources of atmospheric CO2. Moreover, these cutover peatlands have a low and variable water table position and high tension at the surface, creating harsh ecohydrological conditions for vegetation re‐establishment, particularly peat forming Sphagnum moss. Standard restoration techniques aim to restore the peatland to a carbon accumulating system through various water management techniques to improve hydrological conditions and by reintroducing Sphagnum at the surface. However, restoring the hydrology of peatlands can be expensive due to the cost of implementing the various restoration techniques. This study examines a peat extraction‐restoration technique where the acrotelm is preserved and replaced directly on the cutover peat surface. An experimental peatland adopting this acrotelm transplant technique had both a high water table and peat moisture conditions providing sufficient water at the surface for Sphagnum moss. Average water table conditions were higher at the experimental site (?8·4 ± 4·2 cm) compared to an adjacent natural site (?12·7 ± 6·0 cm) suggesting adequate moisture conditions at the restored surface. However, the experimental site experienced high variability in volumetric moisture content (VMC) in the capitula zone (upper 2 cm) where large diurnal changes in VMC (～30%) were observed, suggesting possible disturbance to the peat matrix structure during the extraction‐restoration process. However, soil–water retention analysis and physical peat properties (porosity and bulk density) suggest that no significant differences existed between the natural and experimental sites. Any structural changes within the peat matrix were therefore minimal. Moreover, low soil‐water tensions were maintained well above the laboratory measured critical Sphagnum threshold of 33% (?100 mb) VMC, further indicating favourable conditions for Sphagnum moss survival and growth. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
14.
To investigate vertical changes of bacterial communities from living plants to the associated sediments and bacterial biogeochemical roles in peatland ecosystem,samples of different part of individual Sphagnum palustre and the different layers of the underlying sediments were collected from Dajiuhu Peatland in central China.All samples were subject to 16S rRNA gene clone libraries and quantitative PCR analysis.Even though bacteria vary in abundance at the same order of magnitude in all samples,they show great profile difference in composition from the top part of S.palustre to the low layer of the sediments.Cyanobacteria and alpha-Proteobacteria dominate at the top part whereas Acidobacteria at the middle part of S.palustre.Alpha-Proteobacteria and Acidobacteria are the dominant phyla at the bottom part of S.palustre and in the surface peat sediment.In contrast,bacterial communities in the subsurface sediments are dominated by Acidobacteria.These profile distributions of different bacterial communities are closely related to their ecological functions in the peatland ecosystem.Specifically,most Cyanobacteria were observed at the top green part of S.palustre,a horizon where the active photosynthesis of the moss occurs,which infers their endosymbiosis.In contrast,Acidobacteria,dominant in the subsurface sediments,are able to decompose the specific compounds on the cell wall of Sphagnum moss and thus might play an important role in the formation of the peatland,including the acidic condition.Methane oxidizing process might have been underestimated in Sphagnum peatland due to the identification of Methylocystaceae in all parts of the moss investigated here.The vertical difference in bacterial composition and bacterial ecological functions presented here sheds light on the understanding of biogeochemical processes,in particular the CH4 flux,in peat ecosystems. 相似文献
15.
《Limnologica》2020
Fish may affect macrobenthic communities through trophic interactions and modification of habitat conditions. We compared the density, diversity and taxonomic composition of larval chironomids under low vs high fish impact, created by stocking semi-natural ponds with either young/small common carp Cyprinus carpio at low biomass densities or with high biomass densities of older/large common carp, supplemented by other cyprinids and predatory fish species.Over the study season, May–August, total chironomid abundance was considerably lower in ponds with high fish biomass than in low fish biomass ponds. In July–August larval densities declined significantly, irrespective of the fish status of the ponds. The composition of larval communities diverged between ponds with different fish status. Chironomus riparius and C. plumosus accounted for most of the observed dissimilarity. C. plumosus densities were not affected by the fish status of the pond, constituting on average >38 % of chironomid specimens in both types of ponds. C. riparius was abundant in ponds with low fish biomass (on average 30 %), but rare in ponds with high fish biomass (4 %). Other common taxa were Glyptotendipes pallens (15 % and 13 %, respectively) and Procladius sp. (14 % in ponds with low fish impact). Canonical correspondence analysis showed that fish biomass was more important in determining chironomid community composition than environmental variables indicative of pond eutrophication (total N, P, chlorophyll a and conductivity).Despite adverse effects on total abundance, chironomid diversity was higher under apparently stronger trophic pressure by fish. Fish may have relieved some chironomid species from invertebrate predation and competition with dominant Chironomus larvae. Other important drivers of chironomid assemblage and diversity patterns may include species-specific feeding modes and prey size selectivity of fish, the ability of chironomid larvae to attain size- and depth-refuge from small fish but not larger fish, and differential vulnerability of free-living and tube-dwelling larvae relative to ontogenetic niche shifts of fish. 相似文献
16.
The importance of characterizing the ecohydrological interactions in natural, damaged/drained, and restored bogs is underscored by the importance of peatlands to global climate change and the growing need for peatland restoration. An understudied aspect of peatland ecohydrology is how shallow lateral flow impacts local hydrological conditions and water balance, which are critical for peatland restoration success. A novel method is presented using microcosms installed in the field to understand the dynamics of shallow lateral flow. Analysis of the difference in water table fluctuation inside and outside the microcosm experimental areas allowed the water balance to be constrained and the calculation of lateral flow and evapotranspiration. As an initial demonstration of this method, a series of four microcosm experiments were set up in locations with differing ecological quality and land management histories, on a raised bog complex in the midlands of Ireland. The timing and magnitude of the lateral flow differed considerably between locations with differing ecological conditions, indicating that shallow lateral flow is an important determining factor in the ecohydrological trajectory of a recovering bog system. For locations where Sphagnum spp. moss layer was present, a slow continuous net lateral input of water from the upstream catchment area supported the water table during drought periods, which was not observed in locations lacking Sphagnum. Consistent with other studies, evapotranspiration was greater in locations with a Spaghnum moss layer than in locations with a surface of peat soil. 相似文献
17.
In the present study the initial succession of the aquatic macroinvertebrate communities of a newly created shallow lake in a wetland area was monitored during 15 months. Three different types of macroinvertebrate samples (multihabitat, associated to the Phragmites australis stands and associated to the sediment) were collected monthly from May 2004 to July 2005. Additional samples were collected in the reed stand in 2007, when the reed belt had become much taller and thicker. Colonization of the lake was fast, and the colonization sequence was mainly related to the dispersal abilities of the taxa. Habitat-specific changes in the assemblage's structure and composition were registered. The communities associated to the sediment showed a decrease in overall biomass, density and species richness along time. The density of the gastropod Physella acuta and the chironomid species Dicrotendipes pallidicornis, Polypedilum nubifer and Tanytarsus horni decreased significantly, after Chara stands declined; while the chironomid Chironomus riparius became dominant. The epiphytic macroinvertebrate communities associated with the reed stands followed a seasonal pattern, with a warm-period community dominated by the chironomid species Ablabesmyia monilis and Psectrocladius sordidellus-group, and a cold-period community dominated by the chironomid species Cricotopus ornatus and D. pallidicornis. 相似文献