浙北山区典型小流域农村面源污染现状调查与治理对策

山区小流域与平原河网小流域在地形地貌上具有显著不同的特点,它们在面源污染的发生规律上必然也不尽相同。笔者以西山村为例,就太湖地区浙北山区小流域农村面源污染物氮、磷排放规律进行调查,提出治理相关对策。调查结果表明：西山村总氮、总磷污染排放总量分别高达3604.99 t/a和609.17 t/a。该流域的4大污染源对TN的贡献率依次为：雷竹林-茶园种植业（47.59%）>养殖业（24.41%）>生活污水（19.94%）>水稻种植业（8.06%）;对TP的贡献率分别为：雷竹林-茶园种植业（49.59%）>养殖业（24.13%）>水稻种植业（20.90%）>生活污水（5.38%）。该流域面源污染控制重心应放在雷竹林-茶园种植业和养殖业污染上,特别是雷竹林-茶园种植业这类高效益种植业上。笔者认为,进行河道修复,结合人工湿地净化,并充分利用当地稻田种植区以及生态沟渠对氮、磷污染物进行消纳,将其进行技术整合在山区小流域具有良好的运用前景。     

人工湿地处理农业径流研究

为了处理农业径流的污染,本研究采用水平潜流人工湿地对农业径流进行处理试验,以减轻河流污染。结果表明,进水流量2.5m3/d运行条件下,水平潜流人工湿地有较好的处理效果。潜流人工湿地CODcr、TN、NH4+-N、TP的平均去除率均分别达到49.65%,51.37 %,56.24% 和59.12%;潜流人工湿地系统的出水CODcr、TN、NH4+-N、TP平均含量分别达到Ⅱ类水质的含量,Ⅴ类水质的含量, ,Ⅱ类水质的含和Ⅳ类水质的含量。通过对人工湿地处理系统影响因素分析表明：进水流量的控制非常关键,适宜的进水流量处理效果最佳。     

A general model of temporary aquatic habitat use: Water phenology as a life history filter

Temporary aquatic habitats are not widely appreciated fish habitat. However, fish navigate the transient waters of intertidal zones, floodplains, intermittent and ephemeral streams, lake margins, seasonally frozen lakes and streams, and anthropogenic aquatic habitats across the globe to access important resources. The selective pressures imposed by water impermanence (i.e., freezing, drying, tidal fluctuations), however, operate similarly across taxa and ecosystems. These similarities are formalized into a conceptual model relating habitat use to surface water phenology. Whereas all necessary life history functions (spawning, foraging, refuge, and dispersal) can be accomplished in temporary habitats, the timing, duration, and predictability of water act as a “life history filter” to which habitats can be used and for what purpose. Habitats wet from minutes to months may all be important—albeit in different ways, for different species. If life history needs co‐occur with accessibility, temporary habitats can contribute substantially to individual fitness, overall production and important metapopulation processes. This heuristic is intended to promote research, recognition and conservation of these frequently overlooked habitats that can be disproportionately important relative to their size or brevity of existence. There is a pressing need to quantify how use of temporary aquatic habitats translates to individual fitness benefits, population size and temporal stability, and ecosystem‐level consequences. Temporary aquatic habitats are being impacted at an alarming rate by anthropogenic activities altering their existence, phenology, and connectivity. It is timely that scientists, managers and policymakers consider the role these habitats play in global fish production.     

Episodic recruitment of young Prochilodus lineatus (Valenciennes, 1836) (Characiformes: Prochilodontidae) during high discharge in a floodplain lake of the River Paraná, Argentina

Prochilodus lineatus (Val.) is one of the main target species of South American freshwater fisheries. The following null hypotheses regarding juvenile recruitment of P. lineatus were tested: (a) recruitment is not determined by variations in larval abundance and (b) recruitment is not determined by variations in discharge. For this purpose, variations in abundance of larvae in main channel drift and monthly captures of juveniles in a floodplain lake of the River Paraná were examined weekly between 2009 and 2016. Mean annual abundances of larval densities and CPUE of juveniles were correlated with a set of hydrometric variables. A positive correlation was found between the abundance of juveniles with high and persistent flood pulses. By contrast, larval abundance was not correlated with juvenile abundance. Pronounced contrast was found in the recruitment of P. lineatus between years of high and low discharge, which supports the hypothesis that floods are the main determining factor for recruitment of this species.     

国内外湿地研究进展和展望

主要分析了国内外湿地的概念和分类、形成和发育、湿地评价和健康评价、恢复和重建、生物地球化学过程、模型研究、人工湿地、全球变暖及湿地生态系统关系等方面研究进展,据此提出展望。     

Multiple predator effects and native prey responses to two non‐native Everglades cichlids

Abstract – Non‐native predators may have negative impacts on native communities, and these effects may be dependent on interactions among multiple non‐native predators. Sequential invasions by predators can enhance risk for native prey. Prey have a limited ability to respond to multiple threats since appropriate responses may conflict, and interactions with recent invaders may be novel. We examined predator–prey interactions among two non‐native predators, a recent invader, the African jewelfish, and the longer‐established Mayan cichlid, and a native Florida Everglades prey assemblage. Using field enclosures and laboratory aquaria, we compared predatory effects and antipredator responses across five prey taxa. Total predation rates were higher for Mayan cichlids, which also targeted more prey types. The cichlid invaders had similar microhabitat use, but varied in foraging styles, with African jewelfish being more active. The three prey species that experienced predation were those that overlapped in habitat use with predators. Flagfish were consumed by both predators, while riverine grass shrimp and bluefin killifish were eaten only by Mayan cichlids. In mixed predator treatments, we saw no evidence of emergent effects, since interactions between the two cichlid predators were low. Prey responded to predator threats by altering activity but not vertical distribution. Results suggest that prey vulnerability is affected by activity and habitat domain overlap with predators and may be lower to newly invading predators, perhaps due to novelty in the interaction.     

组合湿地系统对养殖尾水的净化效果

利用组合湿地系统对湖区池塘养殖尾水进行净化,以实现水体循环再利用,减少对周围水环境的污染。组合湿地系统由3个莲藕净化塘、1个生态沟渠和1个人工湿地组成,面积分别为2.1 hm2、1.47 hm2和0.52 hm2,其中净化塘莲藕的覆盖度分别为0%、30%、60%。沿程采样测定水化学指标。结果显示,组合系统能够有效降低养殖尾水中的总氮(TN)、总磷(TP)、氨氮(NH4+-N)和化学耗氧量(COD)等指标。TN、TP由初始值1.3 mg/L、0.76 mg/L降到0.4 mg/L、0.09 mg/L,去除率分别为41.5%、77.5%;NH4+-N、COD由初始值0.27 mg/L、42 mg/L降到0.06 mg/L、27 mg/L,去除率分别为77.7%、35%。研究表明,该组合湿地系统能有效净化养殖尾水,实现水体循环再利用,可有效缓解南四湖的入湖污染负荷。     

复合池塘循环水养殖系统生态足迹分析

生态足迹模型已广泛应用于可持续发展的评估中。将生物塘、人工湿地、生态沟渠等生态工程系统与传统养殖塘有机结合而构建形成的复合池塘循环水养殖系统,作为一种新养殖模式,它具有循环微流水养殖、种养结合、水陆交互作用的特点。本文运用生态足迹方法对这一新养殖模式进行了定量分析。结果表明:就单位利润生态足迹量而言,复合池塘循环水养殖模式为2.92 ghm2/万元,而传统池塘养殖模式为4.91ghm2/万元,复合模式具有更高的生态经济综合效益,更符合可持续发展要求。     

Coastal wetland vegetation features and digital Change Detection Mapping based on remotely sensed imagery: El-Burullus Lake,Egypt

El-Burullus Lake is one of the four Egyptian Ramsar sites that constitute internationally important wetlands as they contain a rich biodiversity and have a large number of water bird species. But the valuable resources in El-Burullus Lake and its surrounding area have faced various threats to wetlands over recent decades. This study was carried out to evaluate the dynamics of land cover change using three change scenes of recent and past satellite data from 1990 to 2019. The study utilized ArcGIS10.7, ERDAS Imagine 14, Landsat TM (1990, 1999, and 2010), Landsat OLI-TIRS (2019) to analyze the land-use/land-cover (LULC) of El-Burullus wetland. Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) were employed to assess the change scenario of the area. Results indicated that vegetated land has increased significantly with a concomitant shrinkage in the water body and open soil during the study period. Approximately 53 km² (7.0%) of water body and 8.7 km² (1.3%) of open soil were lost, while vegetation areas expanded to approximately 29.9 km² (7.4%). Factors that underpin the observed changes in the area are; reclamation projects and fish-farms which are creating the danger of drying up of the southern coastal parts of the lake, as well as spreading of reed beds (mainly: Phragmites australis) that covers about 20% of El-Burullus lake which led to dry up the lake parts. Therefore, the study suggests the need for urgent attention on conservation of remaining wetland resources for sustainable utilization for the next generation.     

几种挺水植物净化生活污水总氮和总磷效果的研究

研究了石菖蒲、灯心草和蝴蝶花3种不同植被系统、基质为河砂的潜流型人工湿地净化生活污水总氮和总磷的效果,并同无植被系统、相同基质的潜流型人工湿地净化效果进行了比较,结果表明:在较低浓度范围里无植被的人工湿地和3种有植被的人工湿地对污水中总氮有较好的去除作用,随着污水中总氮浓度的增加,虽然无植被的人工湿地和有植被的人工湿地去除总氮的效果均有下降的趋势,但有植被的人工湿地仍然能维持较高的总氮去除水平,无植被的人工湿地总氮去除效果则下降较快。在有植被的人工湿地中,以石菖蒲植被人工湿地氮素净化能力最强,其次为灯心草和蝴蝶花,这与植被自身吸收同化污水中氮素水平以及植物根系微生物作用有关。对于污水中总磷的去除,本研究中由于污水中磷素浓度较低,无植被和有植被的人工湿地对污水中磷素均有很好的去除作用,没有明显差异,但不同的植物体中磷素仍有明显的吸收同化富集现象,其中石菖蒲吸收同化磷素能力最强,其次为蝴蝶花和灯心草,植被在人工湿地系统中对于污水中总氮和总磷的去除起着重要的作用。