水文情势与盐分变化对湿地植被的影响研究综述

湿地植被是湿地生态系统的重要组成部分。水文情势与盐分变化直接影响到湿地植被的分布与演替。目前,全球气候变化和人类活动导致的水文情势改变与盐分聚集已造成大面积的湿地退化和盐渍化,已严重威胁全球淡水湿地生态系统的稳定和健康。系统总结了水文情势与盐分变化单一环境变量及其交互作用对湿地植物生理生态、物种多样性、群落结构与演替和植被动态等诸多方面的影响研究进展,并探讨了湿地水文动态-盐分变化-植被响应的综合模型研究现状,认为发展湿地综合模型预测未来水文情势与盐分变化情景下湿地演变,是应对气候变化湿地水盐管理和生态保护的重要工具,最后指出今后亟需加强的研究方向。     

Response of wetland plant communities to inundation within floodplain landscapes

Summary Many floodplain wetlands in south‐eastern Australia have become isolated from the main river channel as a consequence of reduced high flows and associated flood events following river regulation. In the Central Murray region of south‐eastern Australia, many temporary wetlands would have received water once every five years or so, with large floods maintaining floodplain connectivity every decade, under natural conditions. Now, the River Murray is highly regulated and many of these wetland areas have not been flooded for periods of up to 30 years. Consequently, these wetlands are becoming degraded and the biodiversity of the area is in decline. From 2001–2003, 21 Black Box depression wetlands in the Central Murray region were each watered once. Plant communities in each wetland were monitored for changes in abundance (assessed as percentage cover) before and during the wetting and drying phases. Wetlands were watered during spring or early summer with the length of inundation ranging from 6 to 19 weeks. After watering, the percentage cover of native plant taxa and native plant functional groups in most wetlands increased. In general, there was a decrease in the percentage number of terrestrial plants present and an increase in the percentage cover of aquatic plants. Introduced species were a minor component. Although these wetlands are all located in the Central Murray region, individual wetlands developed plant communities that contained taxa specific to individual wetlands despite initial similarities. These results indicate that wetland plant biodiversity within the landscape can be promoted and maintained by ensuring there is a diversity of wetlands with varying flood regimes within the landscape.     

Comparing the diversity and composition of waterbird functional traits between natural,restored, and artificial wetlands

1. The restoration of degraded areas and the creation of artificial ecosystems have partially compensated for the continuing loss of natural wetlands. However, the success of these wetlands in terms of the capacity of supporting biodiversity and ecosystem functions is unclear. Research is needed to improve our understanding of the value of restored and constructed wetlands for functional diversity of freshwater fauna.
2. We compared natural, restored, and artificially created wetlands present within the Doñana Natural Space, Spain and valued as important for waterbirds. We evaluated if these wetlands are equivalent in terms of waterbird functional trait diversity and composition, during both the wintering and breeding seasons. We modelled functional diversity measures and functional group species richness describing species diet, body mass, and foraging techniques with generalised linear mixed models in 20 wetlands monitored between 2006 and 2011. We used three different statistical approaches to evaluate the robustness of our results.
3. Artificial wetlands constructed for conservation failed to reach the functional diversity of natural and restored wetlands. Unexpectedly, artificial ponds constructed for fish production performed better, and even exceeded natural wetlands for functional richness during winter. Fish ponds stood out as having a unique functional composition, connected with increase in richness of opportunistic gulls and decrease of species sensitive to high salinity. Overall, the functional structure of breeding communities was more affected by wetland type than wintering communities.
4. Our findings suggest that compensating the loss of natural wetlands with restored and artificial wetlands results in systems with altered waterbird-supported functions, such as seed dispersal or nutrient cycling. Protection of natural Mediterranean wetlands is vital to maintain the original diversity and composition of waterbird functional traits. Furthermore, restoration must be prioritised over the creation of artificial wetlands, which, even when intended for conservation, may not provide an adequate replacement.

     

江苏沿江地区出口产品仓储昆虫群落结构数量特征研究

对江苏沿江地区出口产品仓储昆虫进行调查,分析了5种出口产品仓储昆虫群落的优势种.利用群落物种的丰富度、生态优势度、多样性和均匀度等群落特征指数,研究了5种类型出口产品仓储昆虫群落结构的数量特征,并分析了它们的相似性.通过系统聚类分析将5种群落分为4类,草柳藤制品和羽绒制品仓储昆虫群落同属一类,其它3种产品仓储昆虫群落各属一类.除木制品群落结构相对合理外,其它群落结构都不合理,皮毛制品群落结构尤其不合理.     

FATE‐HD: a spatially and temporally explicit integrated model for predicting vegetation structure and diversity at regional scale

During the last decade, despite strenuous efforts to develop new models and compare different approaches, few conclusions have been drawn on their ability to provide robust biodiversity projections in an environmental change context. The recurring suggestions are that models should explicitly (i) include spatiotemporal dynamics; (ii) consider multiple species in interactions and (iii) account for the processes shaping biodiversity distribution. This article presents a biodiversity model (FATE‐HD) that meets this challenge at regional scale by combining phenomenological and process‐based approaches and using well‐defined plant functional groups. FATE‐HD has been tested and validated in a French National Park, demonstrating its ability to simulate vegetation dynamics, structure and diversity in response to disturbances and climate change. The analysis demonstrated the importance of considering biotic interactions, spatio‐temporal dynamics and disturbances in addition to abiotic drivers to simulate vegetation dynamics. The distribution of pioneer trees was particularly improved, as were all undergrowth functional groups.     

人工和天然湿地芦苇根际土壤细菌群落结构多样性的比较

为认识人工湿地运行初期根际土壤细菌群落的结构多样性,本研究采用聚合酶链式反应-变性梯度凝胶电泳（PCR-DGGE）的方法,比较了嘉兴石臼漾人工构筑生态湿地和白洋淀天然湿地府河河口区域芦苇根际土壤的细菌群落结构多样性。研究结果显示,嘉兴石臼漾湿地在运行初期（1~1.5年）,根际土壤细菌的物种丰富度已与白洋淀湿地相近,但香农指数和均匀度指数均显著低于白洋淀湿地;随着污染物浓度的降低,土壤细菌群落基因型多样性指数增大。     

Managed flooding can augment the benefits of natural flooding for native wetland vegetation

Managed flooding is increasingly being used to maintain and restore the ecological values of floodplain wetlands. However, evidence for its effectiveness is sometimes inconsistent and water available for environmental purposes often limited. We experimentally inundated a floodplain wetland (or “billabong”) in late spring by pumping water from its adjacent creek, aiming to promote the native wetland flora and suppress terrestrial exotics. Vegetation was surveyed before (spring) and after (late summer) the managed flood in the experimental billabong and in three control billabongs. Floodplain water levels were continuously monitored. Wet conditions caused two of the control billabongs to also flood, but to a lesser extent than the experimental billabong. We therefore assessed vegetation changes relative to flooding duration. With increasing flooding duration, the cover of wetland vegetation (amphibious and aquatic species) increased and the cover of terrestrial and exotic vegetation decreased, with these effects largest in the deliberately flooded billabong. Flooding durations greater than 20 days generally resulted in increased cover of wetland plants and restricted the growth of terrestrial plants. Reinstatement of more appropriate flooding regimes can thus promote native wetland plants, while suppressing terrestrial exotic species. Our study also provides evidence for the use of modest water allocations to augment the benefits of natural flooding in the maintenance and restoration of native wetland plant communities.     

崇明东滩湿地植被演替过程中生物量与氮含量的时空变化

研究了长江口东滩潮滩植物群落各演替阶段优势种的生物量与氮含量的季节变化以及演替过程中的空间变化格局。结果表明,潮滩植被生物量在生长季内随时间呈增长趋势,氮含量则在植被生长初期最大,生长末期最小。在演替过程中,植被总体生物量变化趋势为:演替中期>演替后期>演替早期。植物单位氮含量的变化是:地下部分氮含量随演替呈降低趋势,地上部分氮含量从演替中期开始随演替呈增长趋势。每1 hm2湿地植被氮含量平均值变化趋势为:演替晚期>演替中期>演替早期。根据计算,崇明东滩鸟类自然保护区内芦苇地上部分蓄积的氮含量为227.5 t,互花米草地上部分蓄积的氮含量45.9 t,海三棱草体内蓄积的氮含量为68.2 t。     

苏干湖湿地植被覆盖度时空变化格局

植被覆盖度是反映群落外貌特征和影响植被生态系统稳定性的重要因子,其时空异质性演化规律研究有助于认识湿地群落的结构功能及其环境响应机制。采用湿地群落学调查和遥感技术相结合的方法,分析了苏干湖内陆盐沼湿地近30年植被覆盖度的时空变化及其影响因素。结果表明:像元二分模型在内陆盐沼湿地植被覆盖度研究方面具有较高的模拟精度;苏干湖湿地的植被覆盖度在1987—2017年间总体呈上升趋势,年际增幅为0.162%/5a,与气温和降水呈正相关关系;在空间上植被覆盖度与地下水位埋深呈正相关,与土壤全盐量呈负相关,但不同等级植被覆盖度与地下水位埋深、土壤全盐量间的相关性各有差异。苏干湖湿地植被覆盖度受地下水位埋深、土壤全盐量空间异质性的影响,呈现出斑块状镶嵌分布。     

洪河国家级自然保护区最小生态需水量与补水分析

湿地生态水文及其水资源优化配置已成为湿地研究中的重大科学问题之一.该研究基于湿地最小生态水位,以湿地静态补水与动态补水的定量方法,对洪河国家级自然保护区湿地最小生态需水量进行估算.研究结果表明:洪河湿地最小生态水位为51.5 m,静态需水量1863×104 m3,动态补水方案为1级补水量867.4×104 ～ 1518.0×104 m3/月,2级补水量693.9×104 ～ 1214.4×104 m3/月,3级补水量520.4×104 ～ 910.8×104 m3/月,4级补水量173.5×104 ～ 303.6×104 m3/月,5级补水量0.0×104 m3/月.研究确定的最小生态水位具有一定科学性,湿地生态水位提高30cm,能够为该区湿地植被群落的水生演替提供适宜生境.该研究结果可为其他湿地自然保护区的科学、有效管理提供理论依据.     

鄱阳湖典型湿地土壤微生物活性对季节性水位变化的响应

为探究湿地土壤微生物对季节性水位变化的响应关系,以鄱阳湖湿地土壤为研究对象,在2014年3、6、10及2015年1月4个季节采集了3个不同高程样带的土壤样品,对土壤微生物基础呼吸、生物量及胞外酶等活性进行了测定。研究结果表明:(1)季节性水位变化不仅显著改变了土壤有机碳、溶解性有机碳、有效磷等含量,也使得微生物量碳和4种水解酶β-葡萄糖苷酶、β-木糖苷酶、N-乙酰氨基葡萄糖苷酶、磷酸酶活性表现出夏冬季较高、秋季最低的动态变化,而2种氧化酶酚氧化酶和过氧化氢酶的表现正好相反。(2)水位高程和地上植被类型同样对土壤微生物产生了显著影响,表现为南荻样带有较高营养元素含量和微生物活性。(3)一些土壤理化指标(含水量、铵态氮、有机碳、有效磷等)与微生物活性(微生物量、基础呼吸、酶活)显著相关;季节水位变化对微生物活性的影响大于高程差异。研究结果表明水位波动对湿地土壤微生物活性产生了重要影响,鄱阳湖水文节律的改变将影响到湿地土壤的正常生态功能。     

三环泡湿地浮游动物功能群季节变化及其影响因子

为了研究寒区湿地浮游动物功能群的季节变化以及水环境等因素的影响,对淡水浮游动物进行了功能群划分,以北方寒冷地区沼泽型湿地三环泡国家级自然保护区为例,于2014年春季(5月)、夏季(7月)和秋季(9月)对三环泡国家级自然保护区15个采样点进行了浮游动物采样,系统分析了浮游动物功能群的组成特征。结果表明:三环泡国家级自然保护区浮游动物功能群共划分为7个功能群,春季以功能群RF占优势,为83.82%;夏季以功能群RC、PF、RF和LCC占优势,分别为34.15%,19.58%,18.49%和10.54%;秋季以功能群RC和RF占优势,分别为71.94%和17.86%。浮游动物功能群季节变化表现为RF→RC+PF+RF+LCC→RC+RF的特点,表明春季功能群RF对浮游植物起到了很好的滤食作用,夏季和秋季功能群RC对功能群PF和RF捕食压力较大。通过Pearson相关分析和RDA多元统计分析表明,种间竞争、氯离子(Cl-)、总氮(TN)、总无机碳(IC)和生物耗氧量(BOD5)是影响三环泡国家级自然保护区浮游动物功能群的主要影响因素,除功能群RF外,其它功能群同氯离子(Cl-)、总氮(TN)和总无机碳(IC)显著正相关,同生物耗氧量(BOD5)显著负相关,SCF、MCF、MCC和LCC由于食物竞争和捕食之间的关系表现出极显著的相关性,同为捕食关系的RC和RF、PF则没有表现出明显的相关性。种间竞争、浮游植物上行效应和营养盐是影响寒区沼泽型湿地浮游动物功能群季节变化和生物量的主要因素。     

黄河三角洲湿地蒸散量与典型植被的生态需水量

蒸散量（ET）是黄河三角洲湿地水资源的主要消耗项,包括植被蒸腾、水面蒸发以及裸土蒸发等。植被生态需水是为了保证植被生态系统能够健康维持并确保其生态服务功能得到正常发挥而必须消耗的一部分水量。准确地估算湿地蒸散量、研究植被生态需水量对于保护湿地生态环境是十分必要的。应用MODIS的地表反射率、地表温度数据与常规气象数据以及土地利用/覆盖图,利用蒸散量的遥感估算模型SEBS模型估算了晴天条件下的黄河三角洲湿地日蒸散量,采用HANTS算法插补了非晴天条件下的日蒸散量,从而得到2001～2005年的该湿地年蒸散量的时间序列,并对蒸散量进行验证和分析。结合该地区典型植被生态需水量与植被蒸散耗水量,估算了2001～2005年的生态补水量。结果表明：与实测值相比,遥感估算月蒸散量的均方差RMSD为16.4mm,平均绝对百分比误差MAPD是11.9%,两者基本一致。黄河三角洲湿地的蒸散量在空间分布上以水体及周围地区、滨海滩涂、黄河故道以及黄河两岸沼泽湿地等的蒸散量较高,居民地蒸散量较低。蒸散量的年际变化不大,季节变化呈单峰型,以5、6、7月份蒸散量最大,月蒸散量在110～120mm之间。2001～2005年期间,每年至少有40%面积的芦苇沼泽和60%面积的芦苇草甸水分供应不足,植被的正常生长受到影响,尤其2002年较为严重,2004年以后情况有所改善。2002年芦苇的生态补水量最大,在9.9×10^7～3.19×108m^3之间,而2004年的生态补水量最小,在3.0×10^7～2.39×108m^3之间。     

耕作方式对玉-豆轮作地表节肢动物多样性及其营养结构的影响

为阐明长期不同耕作方式对轮作种植模式黑土农田地表节肢动物多样性及其营养结构的影响,2015年5月至9月间,利用陷阱法对连续13年玉米大豆轮作模式的定位试验站三种耕作方式(免耕、垄作、秋翻)的地表节肢动物群落进行了调查。共捕获动物1002只,隶属于3纲11目29科37个类群,凹唇蚁、玉米毛蚁和直角通缘步甲为优势类群。免耕(NT,no tillage)有利于增加蜘蛛类群密度,垄作(RT,ridge tillage)和秋翻(MP,mould board plough)显著增加了玉米毛蚁密度。耕作方式仅对群落密度有显著影响显著影响(P0.05),而大豆不同生育阶段显著或极显著的影响地表节肢动物群落组成特征(P0.05; P0.001)。长期玉米大豆轮作种植的地表节肢动物群落营养功能群在不同耕作方式中所占比例不同,保护性耕作方式(NT、RT)更有利于捕食性和植食性动物的生存和繁殖,常规耕作(MP)则是杂食性动物占据优势,明显呈现对不稳定环境的适应。大豆不同生育期,各功能群的个体数与类群数的动态变化不尽一致,不具有明显的规律性。研究结果表明,免耕轮作对维持地表节肢动物群落内部物种间的关系及其营养结构有着较为重要的作用,保护性耕作和轮作种植模式相结合可维持农田生态系统平衡。     

水位梯度对三江平原典型湿地植物根茎萌发及生长的影响

通过水位控制模拟试验,研究了水位梯度对三江平原典型湿地植物——小叶章和毛苔草根茎萌发及生长的影响.结果表明:2种植物对水位的适应策略各异,小叶章种群密度、平均高度和最大高度都在0cm水位条件下出现极大值,而毛苔草种群平均高度和最大高度随水位上升而升高,种群密度则随水位上升而下降.在萌发初期,一定时间的无淹水环境促进2种湿地植物的根茎萌发,而淹水抑制其萌发;在生长期,过度的淹水限制了小叶章的生长,而毛苔草则水分越多生长越旺盛;干旱缺水限制植物生长,可能会引起植物生活史的改变.     

人工湿地植物对观赏水中氮磷去除的贡献

研究了处理观赏用轻度富营养化水的人工湿地中植物的生长特性和氮磷去除作用。研究发现 ,所选用的 2 1种植物中 ,有17种植物在人工湿地中生长良好 ,稳定生长 10 5 d以后 ,其平均总生物量在 15 5～ 1317g/ m2之间 ,除了鸭跖草的地上地下生物量比 (A/ U)为 2 0 .5外 ,其余都在 1.18～ 4 .2 9之间。植株地上部 N和 P的浓度分别在 10 .99～ 34.74 mg/ g和 0 .5 9～ 3.81mg/ g之间 ;地下部 N和 P浓度分别在 6 .2 0～ 2 9.5 0 mg/ g及 0 .72～ 3.83mg/ g之间。大部分植物地上部 N和 P的浓度大于地下部 (p<0 .0 5 )。植物的 N、P积累量分别在 2 .10～ 2 4 .4 8g/ m2 和 0 .2 3～ 1.95 g/ m2 之间。在处理轻度富营养化水的人工湿地中 ,植物吸收对氮磷的去除起着主要作用——贡献率分别为 4 6 .8%和 5 1.0 %。植物的氮磷积累量与浓度及生物量之间均存在显著相关 ,所以可以直接以生物量为指标选择人工湿地植物。同时考虑净化和景观效果 ,可为处理城镇轻度富营养化水的人工湿地的植物选择提供参考     

南四湖沉水植物物种多样性和功能多样性对水深梯度的响应

从物种多样性和功能多样性探讨沉水植物群落对水深的响应可深刻揭示水深对群落构建的影响机制。以南四湖不同水深沉水植物群落为研究对象,对比分析了群落的9个加权功能性状（株高、茎分支数、茎节数、茎直径、根长、根围直径、生物量分配比、比叶面积、植物体磷含量）、5个物种多样性指数（Berger-Parker生态优势度指数、Margalef丰富度指数、Simpson多样性指数、Shannon-Wiener多样性指数和Pielou均匀度指数）和5个功能多样性指数（功能丰富度FRic指数、功能均匀度FEve指数、功能离散度FDiv指数、功能分散度FDis指数和二次熵Rao指数）以及物种多样性和功能多样性关系对水深的响应规律。研究结果表明：（1）水深可显著改变群落株高、根长、根围直径、比叶面积、生物量分配比和植物体磷含量6个加权功能性状;群落茎分支数、茎节数和茎直径3个加权功能性状对水深变化无显著响应;（2）水深可显著影响群落物种多样性和功能多样性,中等水深处沉水植物群落具有较高的Margalef丰富度指数、Shannon-Wiener多样性指数、Berger-Parker生态优势度指数、Pielou均匀度指数以及功能丰富度FRic指数、功能均匀度FEve指数、功能离散度FDis指数、二次熵Rao指数;（3）水深可改变5个物种多样性指数与功能丰富度FRic指数、功能均匀度FEve指数、功能离散度FDiv指数3个功能多样性指数间的相关关系,但对5个物种多样性指数与功能离散度FDis指数、二次熵Rao指数2个功能多样性指数间的相关关系无显著影响。研究结论为：群落不同测度的物种多样性和功能多样性指数及其相关关系对水深变化的响应迥异,在探讨水深对沉水植物群落构建的影响机制时应从多个方面综合考量。     

Predicting interactions between wetland vegetation and the soil-water and surface-water environment using diversity, abundance and attribute values

This study investigated the response of freshwater wetland vegetation to hydrological driving factors by assessing collective vegetation variables, traits of dominant plant populations and hydrological and hydrochemical variables, repeat-sampled within wetland sites across Scotland and northern England. Sampling was conducted at 55 permanent sample stations located along 11 independent transects. Eco-hydrological interactions were investigated using a regression-based modelling approach. Facets of the water-table dynamic (e.g., level of drawdown, level of fluctuation), along with vegetation abundance (e.g., biomass, stem density) and diversity (e.g., species richness) values, were used to build predictive models. Of the models predicting vegetation characteristics, the greatest predictive power was R ² = 0.67 (p < 0.001) for a model predicting stem density (m⁻²). Conversely, vegetation variables proved useful for predicting characteristics of the water-table environment. In this instance, the greatest predictive power was R ² = 0.79 (p < 0.001) for a model predicting minimum water table level (i.e. maximum level of drawdown). The models were tested using data collected during 2000 from repeat sites and independent sites. This approach might be successfully applied for the purposes of integrated eco-hydrological management and monitoring of freshwater wetland vegetation.