广州流溪河与生态修复塘底栖动物群落结构特征及生态健康评估

发布时间：2018-07-28 18:17

【摘要】：流溪河位于广州市从化区西北部,作为广州市重要的饮用水源保护地,其水质状况对广州市饮用水水源安全有着至关重要的作用。因此,对流溪河水环境状况进行长期监测和健康评估,是维护广州市民生活健康的基本保障,也是保护河流水生生物的重要途径。作为河流生态系统的关键生物要素,底栖动物(Zoobenthos)的物种组成和群落结构与水环境因子有着紧密联系,且因其寿命较长,迁移能力弱,反应敏感等特点,近年来应用底栖动物评价水环境健康成为生态学研究的热点。流溪河属于典型的亚热带气候区,流域内生物的分布和生态系统具有很强的地域特征,此外,受城市快速发展的影响,流域内自然环境受人为干扰的程度日趋严重。鉴于此,本研究对流溪河水质和底栖动物的群落结构进行野外监测,从时空尺度上对流域内水环境因子与底栖动物群落结构组成间的内在联系进行深入分析,并通过构建底栖动物完整性指数(B-IBI)体系,对流溪河生态系统健康状况进行综合评价。此外,以示范工程区生态修复塘为研究对象,从底栖动物群落演变的角度探讨沉水植物的修复效果。本研究一方面丰富了我国华南地区大中型河流底栖动物基础数据,同时为以底栖动物为核心的河流生物评价方法提供了模式参考。本论文研究的主要结果和结论如下:(1)于2016年平水期(4月)、丰水期(7月)和枯水期(10月)对流溪河14个河段水质状况进行调查,从上游源头至下游广州河段水体质量逐渐变差(DO 3.28-8.95 mg/L、EC 40.8-327.7μs/cm、TN 0.11-6.46 mg/L、NH4+-N 0.04-5.29 mg/L、TP 0.01-3.06 mg/L、CODMn 1.0-5.6 mg/L、BOD5 0.6-4.9 mg/L)。结果表明,流溪河上游源头受外来干扰程度低,水质为I-II类水标准,且支流水质优于干流;至下游河段,生活污水排放和工业污染增加,水质降为IV-V类水标准,且干流水质优于支流。(2)底栖动物调查共发现144种,隶属于4门8纲22目52科134属,流域内底栖动物平均密度和生物量分别为217.35 ind./m2和20.38 g/m2。上游物种数量最高,以仙女虫属和四节蜉属为代表的敏感类群为主,至下游地区物种数量逐渐减少,以水丝蚓为代表的耐污类群占优。各位点间底栖动物生物量和密度差异显示,支流位点底栖动物多于干流;多样性指数差异显示,上游物种数量较下游丰富。底栖动物各指标与环境参数间相关性分析发现:4月底栖动物密度与DO呈负相关,与CODMn呈正相关;7月底栖动物密度与BOD5呈显著正相关(P0.05);10月底栖动物密度与EC呈显著正相关。结果表明,不同时期影响底栖动物分布的环境因子存在差异,总体上,上游至下游,随DO含量降低、EC和营养盐含量升高,底栖动物多样性受到显著负面影响。(3)按摄食方式和对象进行分类,流溪河现有刮食者19种、撕食者10种、直接收集者64种、滤食收集者10种、捕食者41种。各摄食类群的总平均密度在5-2098 ind./m2,以直接收集者居多,撕食者最少。总平均生物量在为0.05-228.28 g/m2,以刮食者居多,撕食者最少。空间尺度上,功能摄食类群整体数量的下降主要受撕食者和滤食收集者减少的影响,至下游河段污染加重,仅存以寡毛类(水丝蚓)为主的耐污性直接收集者。5种功能摄食类群在支流均有发现,而干流仅有4种,说明缺失的撕食者是反映干流水质和生境退化的重要指示类群。从上游至下游,底栖动物功能摄食类群的物种组成、多样性、密度生生物量指标均有明显降低,说明目前流溪河生态系统受水体质量下降和沿岸带生境退化影响严重。(4)流溪河B-IBI评价体系5个核心指标构成,包括生物量,敏感类群个体%,EPT、摇蚊和耐污类群分类单元。制定的健康标准为:B-IBI值3.24为健康;3.24-2.43为亚健康;2.43-1.62为一般;1.62-0.81为差;0.81-0为极差。流域内健康位点数占14.3%,亚健康占50.0%,一般占21.4%。EPT分类单元数和敏感类群个体%对上游河段B-IBI值贡献最高,反映健康状况良好,而耐污类群单元数对下游河段B-IBI值贡献最高,反映健康状况恶化。B-IBI值与溶解氧浓度呈极显著正相关(P0.01),与总氮、氨氮、总磷浓度和电导率值呈显著(P0.05)负相关。评价结果表明,作为一条典型城市河流,目前流溪河中下游地区受人为干扰和水体污染影响严重,生态健康状况恶化,尤其是下游干、支流河段的底栖动物群落衰退严重。对照不同地理区域的应用结果发现,B-IBI体系在热带亚热带地区也有较好的适用性。(5)对沉水植物修复的生态塘进行底栖动物恢复监测,修复过程中共发现底栖动物11种,隶属于3门4纲6目9科10属。沉水植物种植前,底栖动物仅有耐污类群4种,修复半年后,可采集到中等耐污种群11种。相关性分析结果显示,NH4+-N、TP、CODcr和Chl.a对底栖动物群落结构影响显著,说明随塘内水质的提升,底栖动物群落多样性指标也随之增加。总体上,经沉水植物修复后,底栖动物的物种数量、生物量及物种多样性较修复前均有明显增加,并与沉水植物生物量的变化呈显著正相关(P0.05),说明沉水植物种植明显改善了示范工程区内的水质和生物状况。
[Abstract]:Liu Xi River is located in the northwest of Conghua District of Guangzhou city. As an important source of drinking water protection in Guangzhou City, its water quality has a vital role in the safety of drinking water source in Guangzhou. Therefore, the long-term monitoring and health assessment of the river water environment in the convective river is the basic guarantee for the maintenance of the health of the citizens of Guangzhou and the protection of the river. As an important way of aquatic organisms, as the key biological element of the river ecosystem, the species composition and community structure of the benthic animal (Zoobenthos) are closely related to water environmental factors, and because of their long life, weak migration ability and sensitivity to reaction, the assessment of water environment health by benthic animals in recent years has become an ecological study. Liu Xi River is a typical subtropical climate zone, and the distribution and ecosystem in the basin have strong regional characteristics. In addition, influenced by the rapid development of the city, the natural environment in the basin is increasingly disturbed by human disturbance. In view of this, the community structure of the convection stream and benthic animals is studied in the field. The internal relationship between water environmental factors and the structure of benthic animal community in the basin was analyzed from time and space, and the ecological health status of the convective river ecosystem was evaluated comprehensively by the construction of the benthic animal integrity index (B-IBI) system. This study enriches the basic data of benthic Zoobenthos in large and medium rivers in Southern China and provides a model reference for the river biological evaluation method with benthic animals as the core. The main results and conclusions of this paper are as follows: (1) in 2016 (April) The water quality of the 14 river sections of the river river in the flood season (July) and the low water period (October) was investigated. The water quality of the 14 reaches of the Guangzhou river was gradually changed from the upstream source to the lower reaches (EC 40.8-327.7 mg/L, EC 40.8-327.7 s/cm, TN 0.11-6.46 mg/L, NH4+-N 0.04-5.29 mg/L). The water quality of the upstream source of the river is low, the water quality is I-II water standard, and the water quality of the tributaries is better than the main stream. To the lower reaches, the sewage discharge and the industrial pollution are increased, the water quality is reduced to the IV-V water standard, and the water quality is superior to the tributaries. (2) 144 species of benthic animals were found, belonging to 134 genera, 52 families, 4 doors, 8 classes, 22 orders, and benthic animals. The average density and biomass of 217.35 ind./m2 and 20.38 g/m2. were the highest in the upper reaches of the upstream species. The number of species represented by the genus Andromeda and four is the dominant species, and the number of species decreased gradually in the lower reaches, and the pollution resistant groups represented by the water worms were dominant. The diversity index difference showed that the number of upstream species was more abundant than the downstream. The correlation analysis between the indexes of benthos and the environmental parameters showed that the density of benthic animals in April was negatively correlated with DO, and was positively correlated with CODMn; the density of Zoobenthos in July was positively correlated with BOD5 (P0.05), and the density of benthic animals in October showed a significant difference with EC. The results showed that the environmental factors affecting the distribution of benthic animals in different periods were different, and on the whole, the upstream to downstream, with the decrease of DO content, the increase of EC and nutrient content, the diversity of benthic animals were negatively affected. (3) there were 19 species of scrapers and 10 tearing predators in the stream stream. There are 64 species of collector, 10 species of filter collector and 41 predator. The total average density of each feeding group is 5-2098 ind./m2, the most of the direct collector and the tearing person are the least. The total average biomass is 0.05-228.28 g/m2, the most of the shavers and the tearing is the least. On the space scale, the decrease of the whole number of functional feeding groups is mainly by the rip and filter. The influence of the food collector was reduced and the pollution of the lower reaches was aggravated. Only the.5 functional groups were found in the tributaries with only the oligohairs (water silk worms). There were only 4 main streams in the main stream, indicating that the missing tearing is an important indicator of the water quality and habitat degradation. The species composition, diversity, and density of biomass were significantly reduced, indicating that the current river ecosystem was affected seriously by the decline of water quality and the degradation of coastal habitat. (4) the 5 core indexes of the B-IBI evaluation system in the stream River, including biomass, EPT, chironomid and pollution resistant groups The health standards are as follows: B-IBI value 3.24 is healthy; 3.24-2.43 is subhealth; 2.43-1.62 is general; 1.62-0.81 is poor; 0.81-0 is the worst. The number of health points in the basin is 14.3%, the sub health accounts for 50%. Generally, the number of 21.4%.EPT taxa and the sensitive group individual% contribute the highest to the B-IBI value of the upstream river, which reflects healthy condition and tolerance. The number of contaminated group units has the highest contribution to the B-IBI value of the lower reaches, reflecting a significant positive correlation between the.B-IBI value of the health deterioration and the concentration of dissolved oxygen (P0.01), which is negatively correlated with the total nitrogen, ammonia nitrogen, total phosphorus concentration and electrical conductivity value (P0.05). The evaluation results show that, as a typical urban river, the middle and lower reaches of the fluvial river are disturbed by human interference. The ecological health condition worsened, especially the downstream dry, and the benthic Zoobenthos Community declined seriously in the branch river section. The application results from different geographical regions found that the B-IBI system had good applicability in the tropical and subtropical regions. (5) the restoration of benthic animals for the restoration of submerged plants and the restoration of benthic animals There are 11 species of benthic animals, belonging to 3 families, 4 classes, 6 orders, 9 families and 10 genera. Before the submerged plants are planted, there are only 4 species of benthic animals. After half a year, 11 species can be collected. The results of correlation analysis show that NH4+-N, TP, CODcr and Chl.a have significant influence on the community structure of benthic animals, indicating the improvement of water quality in the pond. On the whole, the number, biomass and species diversity of benthic animals were significantly increased after the restoration of submerged plants, and there was a significant positive correlation with the changes in the biomass of submerged plants (P0.05), indicating that the water quality of the plant has obviously improved the water quality in the demonstration project area. And biological condition.
【学位授予单位】：暨南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X826;Q958.8

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