Pre- and Post-Construction Assessment of Nutrient Concentrations at Shallow Water Habitat Restoration Sites on the Lower Missouri River

Loss of shallow water habitat (SWH) is hypothesized as a factor contributing to the decline of native Missouri River fishes, including the endangered pallid sturgeon. As a result, the restoration of SWH is a high priority in this large river system. Restoration activities often include constructing side channel chutes;however, limited information exists on the potential negative, unintended effects of chute construction activities on water quality. This study was designed to better understand the possible effects of chute construction, both initially and as chute development continues, on Missouri River nutrient concentrations. Our first objective was to determine if the addition of sediment from proposed chute locations to river water samples (i.e., elutriate samples) increased nutrient concentrations relative to water-only river samples collected just upstream of the proposed chute locations or river water samples collected from eight long-term water quality monitoring stations. Our second objective was to determine if nutrient concentrations of river samples monitored during 2009 and 2010 increased after water passed through previously-constructed chutes. Nutrient concentrations of elutriate samples were not significantly higher than river water samples collected just upstream of the proposed chute locations;the same was true for Missouri River water samples collected from seven of eight long-term water quality monitoring stations. Furthermore, monitoring of nutrient concentrations collected from water samples at the outlet of previously-constructed chutes were not significantly higher than water samples collected at the upstream inlet of these chutes. Our results suggest that individual SWH chute construction projects designed to restore some of the natural form and function of the Missouri River are unlikely to significantly increase Missouri Rivernutrient concentrations initially or as these chutes continue to develop.

Integrated assessment of river health based on water quality, aquatic life and physical habitat

The health conditions of Liao River were assessed using 25 sampling sites in April 2005, with water quality index, biotic index and physical habitat quality index. Based on the method of cluster analysis （CA） for water quality indices, it revealed that heavily polluted sites of Liao River are located at estuary and mainstream. The aquatic species surveyed were attached algae and benthic invertebrates. The result showed that the diversity and biomass of attached algae and benthic index of biotic integrity （B-IBI） were degrading as the chemical and physical quality of water bodies deteriorating. Physiochemical parameters, BODs, CODcr, TN, TP, NH3-N, DO, petroleum hydrocarbon and conductivity, were statistically analyzed with principal component analysis and correlation analysis. The statistical results were incorporated into the integrated assessing water quality index, combining fecal coliform count, attached algae diversity, B-IBI and physical habitat quality score. A comprehensive integrated assessing system of fiver ecological health was established. Based on the systimetic assessment, the assessed sites are categorized into 9 ＂healthy＂ and ＂sub-healthy＂ sites and 8 ＂sub-sick＂ and ＂sick＂ sites.

Habitat suitability of Scapharca subcrenata (Lischke) inthe shallow water of the Xiaoheishan Island

The habitat suitability index(HSI) model was used to identify potential sites for sustainable restoration of ark shell, Scapharca subcrenata(Lischke), in the shallow water of Xiaoheishan Island, using a geographic information system framework. The seven input variables of the HSI model were sediment composition, water temperature, salinity, dissolved oxygen, water depth, p H, and ammonia. A non-linear suitability function for each variable factor was used to transform the value into a normalized quality index ranging from 0(nonsuitability) to 1(best suitability). In present study, the analysis of habitat suitability was conducted for four seasons respectively. The majority of the study area has a high HSI value(>0.6) year round, which implies a strong suitability for restoration, with the optimal habitat located on the eastern side of the island.Correspondence analysis indicated that water temperature was the main factor causing seasonal variation,while sediment composition and water depth were the two major reasons for the differences in sites. The results of this work could provide support for restoration decision making through identification of potential sites for sustainable establishment of S. subcrenata.

Diversity and Adaptations of Immature Diptera in Semiaquatic Habitats at Shorelines of Hypersaline Lakes in the Crimea,with a Brief Review of Diptera in Mineralized Bodies of Water

The order Diptera(Insecta)is one of animal groups most successful in the colonization of mineralized shallow aquatic and semiaquatic environments.At the same time,the taxonomic composition of Diptera,their role in

Water Quality Assessment of Dachangshan ArtificialHabitat Development Demonstration Area

[Objective] The paper was to evaluate the water quality environment in Dachangshan artificial habitat development demonstration area.[Method] From 2013 to 2015, an environmental survey was conducted for eight voyages in Dachangshan artificial habitat development demonstration area of Changhai County, Dalian City, and 20 hydrochemical indexes including salinity, pH, and COD were monitored. The water quality of thesea area was analyzed by principal component analysis and single factor index method. [Result] Except for that the control area of the August 2014voyage belonged to IIclass sea water standard, the water quality in other stations of all voyages conformed toIclass sea water standard. Totally 20water quality indicators were synthesized into six principal components using principal component analysis, which explained 79.165% of the results;the principal component score was ranged from -1.536 to 3.706; the score in August 2014 was the highest, and the evaluation results were basicallyconsistent with the results of single factor index analysis. [Conclusion] The overall water quality is good in Dachangshan artificial habitat development demonstration area.

The water level simulation for crane habitat optimization in Xianghai Nature Reserve

The probability of crane living in reedy wetlands can reach 100%, at the same time, the area of reed, the water level and adjacent water area are main factors which control the crane's habitat selection. We all know that all these factors are spatially heterogeneous. For the Xianghai wetland safety and to protect the Xianghai wetland habitat of crane, this paper has mainly identified a solution to these problems. The wetland information is extracted from the TM images, which reflect the whole wetland landscape and are very important for both quantitative analysis of remote sensing observation of the earth system and positioning analysis in GIS database that is automatically extracted from DEM. The DEM for Xianghai characteristics of topography is created. On the basis of the GRID SUBMODULE, applying the GIS spatial overlay analysis, the relationship between the water level and the reed area below the water level and the rating distribution maps of reed area above water level is established. When the water level reaches the altitude of 165 m, the reed area, 981.2 ha is maximum, i.e., the water level of 165 m is the optimal.

养殖池塘丝状藻发生关键因子调查

以水绵和刚毛藻为代表的丝状藻广泛存在于各种自然水体和养殖水体,其过度生长对水体环境和养殖动物构成威胁。为探究丝状藻发生的关键因子,实验通过走访调查,筛选了5组环境相同且隶属同一家养殖户的有丝状藻池塘和无丝状藻池塘,重点对水质、底泥生物可利用性氮磷含量及丝状藻繁殖体进行了检测分析。结果显示,5组有丝状藻塘、无丝状藻塘整体水体氮磷水平无显著差异,而有4组无丝状藻塘叶绿素a含量显著高于有丝状藻塘。5组有丝状藻塘底泥平均生物可利用性氮含量为(15.72±3.60)mg/kg,而无丝状藻塘底泥平均生物可利用性氮为(13.22±1.97)mg/kg,较前者低2.50 mg/kg。5组有丝状藻塘底泥平均生物可利用性磷含量为(72.26±10.57)mg/kg,无丝状藻塘底泥平均生物可利用性磷含量为(50.33±12.62)mg/kg,较前者低21.93 mg/kg。底泥生物可利用性氮磷比在5组中均小于0.5,而无丝状藻塘平均较有丝状藻塘高26.32%。低氮磷比会抑制浮游藻类的繁殖,而丝状藻则对低氮及低氮磷比环境具有较强的适应能力。因此,在养殖开始时,底泥低氮及低氮磷比的条件使得浮游藻类在与丝状藻的初期生态位竞争中处于劣势,即使检测到的浮游藻类OTUs数量高于丝状藻繁殖体,也不能使其在上述条件下成为优势种。另外,对丝状藻繁殖体的检测发现,其广泛存在于有丝状藻塘、无丝状藻塘及水源的水体和底泥中,即使清塘、晒塘依然检测到繁殖体的存在,但清塘、晒塘能够减少丝状藻繁殖体的数量。研究表明,单独依靠生石灰或漂白粉清塘并不能完全杜绝丝状藻的发生,但可以作为一个辅助防控措施,而通过调控养殖系统的生物可利用氮含量及氮磷比左右种间生态位竞争则是一个值得深入研究的、有前景的丝状藻防控方向。本实验结果对养殖池塘的丝状藻防控研究和生产实践具有重要的参考价值。

密云水库上游(北京段)流域水生态健康评价

密云水库是北京市重要饮用水水源地,开展流域水生态健康评价并分析影响水生态健康的关键因素,对于密云水库上游(北京段)流域水生态保护具有重要意义。基于密云水库上游20个小流域生境结构、水质和水生生物数据,结合密云水库上游(北京段)流域生态现状,构建了涵盖生境结构、水质和水生生物的评价指标体系,运用基于熵权法的综合健康指数法对流域水生态健康状况进行综合评价,结果表明:密云水库上游(北京段)流域水生态健康状况总体为亚健康,其中小流域健康、亚健康、一般等级占比分别为10%、65%、25%;密云水库上游(北京段)流域水生态健康状况具有较强的空间异质性,健康等级较高的地区主要分布在白马关河、琉璃河、汤河中游、天河上游,健康等级相对较低的地区主要分布在潮河、白河中下游、汤河下游、清水河、安达木河上游;面源污染、植被覆盖度低、水土流失等是影响密云水库上游(北京段)流域水生态健康的关键因素。

安吉小鲵栖息地浮游植物群落结构特征及水生态评价

为研究安吉小鲵栖息地水体浮游植物群落结构和时空变化特征,2022年3—12月对浙江龙王山安吉小鲵栖息地水环境进行采样,测定浮游植物种类数及数量,并对水体理化性质进行分析。结果表明:安吉小鲵栖息地共鉴定出浮游植物8门72属116种,年平均密度为2.62×10^(6)cells/L,年平均生物量为4.25mg/L,年平均叶绿素a浓度为21.72μg/L。Shannon-weiner和Pielou多样性指数分别为0.09~3.63和0.02~0.93。综合3个水体评价指标,安吉小鲵栖息地水体处于中营养状态,其中两个繁殖坑S4和S8向轻度富营养化转变。水体营养状况具有一定的季节特征,夏季营养水平显著高于其他季节。本研究首次报道了安吉小鲵栖息地浮游植物群落结构及其变化,建议今后密切监测栖息地水生生态变化,必要时开展安吉小鲵栖息地生态保护措施。

基于AHP-模糊综合评价法的渭河河流健康评价

河流健康评估为河流可持续发展提供了依据,渭河作为黄河的一级支流,其生态健康对于黄河高质量发展具有重要意义。为全面评价渭河流域的健康状况,选取物理栖息地状况、水质状况及水生生物状况3个准则、11个指标,建立渭河生态健康评价标准,采用层次分析法(AHP)确定权重,结合最大隶属度原则对渭河流域进行多级模糊评价。结果表明,25个点位中有8个处于健康水平,13个处于亚健康水平,4个处于不健康水平,渭河综合健康评价结果为亚健康。渭河源头、宝鸡至西安段河流生态健康状况较好,天水至宝鸡段及下游河段生态健康较差,不健康的点主要集中在下游,表现出显著的空间差异。物理栖息地、水质及水生生物的评价结果分别为亚健康、健康、亚健康,物理栖息地与水生生物状况是影响河流生态系统健康的关键,主要受人为活动以及自然环境的影响。针对特定河段需要采取相应措施恢复生态健康。

洞庭湖地区生境水生态空间结构和功能的时空分异

【目的】为延缓洞庭湖地区生境质量持续下降和生态服务功能继续减弱,从结构、功能和质量的角度提出生境水生态空间可持续发展研究框架,以期为生态空间保护和水安全保障提供理论依据。【方法】基于土地利用和社会统计数据,借助ArcGIS分析手段,对洞庭湖地区2010、2015和2020年3个年份的生境水生态空间的结构、功能及质量状况进行监测,并提出管控框架和关键举措。【结果】1)洞庭湖地区生境水生态空间总体规模在7300 km^(2)以上,其中水体区域所占比例最大,其次是临岸陆生区,而水陆交错区所占比重最小,研究期间生境水生态空间面积存在小幅减少;岳阳市的生境水生态空间总体规模较大,临澧县的生境水生态空间规模较小。2)洞庭湖地区生境水生态空间的综合功能约为0.4000,研究期间有一定提升;各单元中,沅江市生境水生态空间综合功能价值最高,津市市生境水生态空间综合功能价值则相对最低。3)生境质量在空间分布上呈现出明显的空间分异,以洞庭湖及沿岸河流、东部与南部山地丘陵区为高生境质量集中分布区,而在地形平坦、人口经济活动较密集的城镇地区的生境质量较低。【结论】应从生境水生态空间的结构要素出发,科学规划生境水生态空间功能分区,并与“三区三线”划定相结合,在此基础上推动多尺度多层级生境水生态空间可持续发展关键举措的实施。

长江安庆段长江江豚分布特征及其影响因子探究

研究于2021年秋季至2023年夏季在长江安庆段(安庆市程营村-凤凰码头)开展了2个周年共8次目视考察,从种群数量、集群规模、迁移规律、栖息地偏好四个方面探讨了该水域长江江豚(Neophocaena asiaeorientalis asiaeorientalis)的分布特征及影响因子。研究期间共观测到长江江豚555群次、1000头次,最大单次评估结果为192头;其中2023年观测到长江江豚336群次、603头次,较2022年分别上升53.4%和51.9%。研究期间长江江豚最大集群规模为8头,平均集群规模为1.8头/群。考察发现长江安庆段长江江豚总体呈连续分布,但存在明显的热点区域,其中张家州北汊、上三号洲、下三号洲洲尾及清洁洲洲头水域为长江江豚的重要栖息地,四个栖息地内观测头次分别占总头次的19.3%、4.9%、12.6%和10.8%。禁捕后长江江豚在河口汇流区活跃的月份增加并有从八里江安徽段向下游扩散分布的趋势,但码头、崩岸区对其栖息地范围的拓展仍存在一定影响,华阳河口以下江段仍只有清洁洲洲头水域为长江江豚的重要栖息地。因此研究认为在十年禁渔及鄱阳湖极端枯水频发的背景下,长江安庆段的长江江豚数量有明显上升趋势,同时长江江豚对各重要栖息地斑块之间迁移通道的利用情况逐渐好转,分布更具连续性。研究建议,应在长江江豚可能的聚集觅食区及迁移通道保持自然岸线占比,加大岸线整治力度,加强人类活动管控;根据极枯水位下鄱阳湖长江江豚迁移入江的时序特征,制定湖口-华阳河口水域的应急管理预案。

湿地公园水稻田冬季水鸟分布及其栖息地特征

稻田是我国人工湿地的重要组成部分。为探究冬季稻田管理模式对湿地水鸟多样性保护及栖息生境改善的重要意义,2017年12月至2018年2月及2018年11月,采用样带法对天福国家湿地公园冬季休耕蓄水区和传统稻田的水鸟种群进行调查,对比水鸟种群及栖息地特征。结果表明:1)冬季休耕蓄水区记录4目7科25种水鸟,鸻鹬类占36%,鹭类占28%,雁鸭类占24%;传统稻田湿地共3目5科10种,其中鸻鹬类和鹭类分别占30%,无雁鸭类水鸟。2)冬季蓄水区水鸟多样性及物种丰富度较高,水鸟优势种群数量明显增多,Shannon-Wiener多样性指数(1.64)高于传统稻田(1.50),水鸟均匀度指数(0.84)低于传统稻田(1.37),相似性系数为0.51。3)冬季休耕蓄水区的水面面积、水位、食物、植被覆盖度是影响水鸟种数增多的重要因子,营巢地、停歇点也是影响冬季水鸟栖息的因素。因此,冬季稻田休耕蓄水管理的实施能够对生物多样性保护与提升发挥积极作用。

影响合肥市河流水质的生境多样性关键因素研究

针对当下城市河流修复缺乏物理空间生境研究的知识缺口,面向生态文明建设与国土空间生态修复的国家战略需求,从提升生态系统服务综合效能的角度出发,通过学科交叉,定量揭示影响城市河流水质的生境多样性关键因素。以合肥市南淝河、塘西河作为实证研究案例,通过水质实验与天空地生境信息采集获取样本数据,依据水质评价与URS生境多样性评价体系的研究方法,揭示水质与生境多样性之间的相关性,发现了同时对水质与生境多样性产生影响的关键因素。产生正向显著影响的指标分别为河岸自然化形态比例、河道生境类型数量、滨水带种植宽度、河岸乔木连续性指数、水生植被平均覆盖度、主导水生植物类型、水生植物长势、河岸植被特征指数;产生负向显著影响的指标为河岸带植被相关特征、河岸表层植被平均高度、固定河床材料比例、护岸存在比例、河岸材质指数、主导护岸材质类型、护岸材质指数、入河排污口数量。这些关键因素可作为城市河流生态修复重点关注的生境指标,为基于生境多样性恢复的城市河流生态修复提供一定的理论依据与技术支撑。

三峡水库消落带生境特征与植被恢复模式

[目的]三峡水库蓄水运行后消落带生境破碎斑块化加剧,极端生境胁迫严重损害植被的结构和功能。厘清三峡水库消落带生境状况,提出适宜性植被恢复对策,重建河流受损廊道综合生态功能,对构建区域生态安全格局和保障长江流域水资源安全具有重要意义。[方法]针对三峡水库消落带植被退化与生态功能受损的突出问题,系统解析了消落带生境特征及其对植被生长的影响,围绕水库河岸受损廊道生态修复重大需求,探讨面向消落带微生境构建与植被格局功能优化的三峡水库消落带植被恢复模式。[结果]三峡水库消落带生境状况受水库运行形成的独特水位节律、出露期植被生长季气候条件、土壤侵蚀与泥沙沉积过程、土壤环境等多生境因子协同影响,呈现高度空间异质性特征。水位变动形成的淹没时长、出露时令、淹水强度是影响植株繁衍、生长的首要因素;土壤侵蚀、泥沙掩埋、土壤水养条件等影响植被生长状况。[结论]三峡水库消落带植被恢复需综合考虑水位节律、立地条件与物种形态-功能性状,选育优质抗逆物种,注重土壤基质保育,突出植被格局的分区优化配置。重建消落带综合生态功能,为水库消落带生态治理提供理论支撑和科学依据。

氨氮胁迫下鲢幼鱼下行洄游通道质量研究

为定量揭示氨氮浓度对鱼类栖息地质量的影响,以淮河干流鲁台子至窑河闸段为研究区域,选择典型土著洄游鱼类鲢作为目标物种,耦合研究区域内平面二维水动力水质模型构建了含有氨氮指标的鲢幼鱼下行洄游通道栖息地模型。假定入流边界氨氮浓度满足地表水Ⅲ类水质标准(1.0 mg·L^(-1)),选取栖息地面积、栖息地斑块数和栖息地连通性指数三个景观生态学特征指标,定量评估了高、中、低三组代表性流量下氨氮对鲢幼鱼下行洄游通道质量的影响。结果表明:与不考虑氨氮指标情况下的洄游通道质量相比,(1)鲢幼鱼下行洄游通道适宜生境面积分别下降1.6%、6.7%和3.4%,氨氮对洄游通道适宜生境面积的影响较小。(2)鲢幼鱼下行洄游通道斑块数分别增加4.5%、28.7%和3.6%,在原本具有较高破碎度的情况下氨氮影响最大,二者存在一定程度的正相关和协同效应。(3)鲢幼鱼下洄游通道连通性分别降低54.3%、34.6%和24.8%,连通性下降幅度与入流边界流量成反比。研究结果可为鱼类栖息地指标体系构建和基于水质需求的生态流量调度提供依据。

基于栅格尺度下喀斯特专性植物海南凤仙花生境水资源脆弱性时空分异变化

频繁的干湿交替导致热带雨林喀斯特地貌的水分脉动特征显著,地带性本底环境呈现强烈的脆弱性和异质性。研究喀斯特植物生境的水资源脆弱性特征,有助于理解当地植物对热带喀斯特生境的适应机制,为植物的生态恢复和种质资源保护提供理论依据。以海南岛喀斯特专性植物海南凤仙花(Impatiens hainanensis)生境的自然环境栅格数据为基础,运用RS和GIS技术构建水资源脆弱性评价指标体系,结合综合指数法分析海南凤仙花生境的水资源脆弱性时空分异特征。研究结果表明,2003—2018年,海南凤仙花生境的水资源脆弱性以自然脆弱性为主,自然脆弱性波动与降水等自然因素密切相关。极度脆弱和重度脆弱区面积比例较大;中度脆弱和轻度脆弱区面积比例较小。基于综合指数法的海南凤仙花生境水资源脆弱性在0.6612—0.7532之间,基于GIS与RS的水资源脆弱性在0.6624—1之间,海南凤仙花生境处于水资源脆弱性的高值区。受干湿季热带雨林喀斯特地貌水分特征的影响,海南凤仙花生境水资源脆弱性时空变异性较强,区域分异程度明显,可利用其水分特征变化对海南凤仙花生境进行水土流失的及时阻控,保护海南凤仙花的生态环境和种质资源。

大亚湾近岸浅海马尾藻遥感信息提取

马尾藻对健康的沿海生态系统具有重要作用。遥感监测多针对开阔海域的漂浮马尾藻,对浅海底栖型马尾藻研究较少;技术方法大多基于经验模型,依赖大量实测数据。本文基于水体辐射传输过程,建立马尾藻遥感信息提取模型。大亚湾3个试验结果表明:①马尾藻丰度分布情况与野外调查数据基本吻合;②大亚湾的马尾藻在水域开阔程度高、水体交换条件良好、受一定风浪影响、水深小于1.6 m的环境条件下,长势更好,丰度更高;③水深、海浪作用是影响马尾藻生长分布的重要环境因子。本文方法对马尾藻资源的保护和海岸带生物多样性建设具有积极意义。

乡镇尺度上1980—2020年广东省生态系统服务分析

分析生态系统服务的影响因子是管理生态系统并提出规划建议的基础。本研究基于InVEST模型量化广东省乡镇尺度的4种生态系统服务。结果表明,广东省各生态系统组成呈“三增两减”变化趋势,不同用地生态系统占比不同;可根据区域需求通过改变用地占比改变生态系统服务占比,进而优化区域生态系统服务。

南宁市南湖水质改善与水生态修复策略研究

城市湖泊是生态系统的重要组成部分,由于受人类活动干扰及外源、内源污染物输入等影响,其水生态系统退化,水环境质量恶化。通过对典型城市湖泊——南宁市南湖进行溢流口强化处理与生态净化、污水口设施改造、补水口水质优化、底泥清淤疏浚及水生态系统构建等,使湖区水质提升至地表水Ⅳ类标准,水体透明度提高到1.80m以上。水生态系统构建是南湖水质改善与水生态修复的核心,通过湖底生境营造,沉水植物群落构建,浮游动物、底栖动物及鱼类投放等,使“藻型”浑水态湖泊生态系统转变为以沉水植物为主的“草型”清水态湖泊生态系统,恢复了水生态系统完整性,水体营养状态由中度富营养转变为中营养,这对国内其他城市湖泊水质改善与水生态修复具有重要借鉴意义。