红树林生态系统及功能研究综述

概述红树林的分布及品种、生长环境、生理生态特点,以及其生态、社会、经济意义;展望红树林的研究方向。     

Do postlarval amphidromous fishes transport marine‐derived nutrients and pollutants to Caribbean streams?

Diadromous fishes are known biotransport vectors that can move nutrients, energy and contaminants in an upstream direction in lotic ecosystems. This function has been demonstrated repeatedly in anadromous salmonids, but the role of other diadromous species, especially tropical taxa, as biotransport vectors is less studied. Amphidromous fish species exhibit potential to act as upstream vectors of nutrients and contaminants in their postlarval and juvenile stages, but this role is largely unknown because of limited understanding of larval growth habitats. Moreover, because some species are harvested in artisanal fisheries as postlarvae, and postlarvae are consumed by riverine and estuarine predators, heavy contaminant loads may present a human or wildlife health concern. This research incorporates stable isotope and contaminant analyses to infer larval habitats and contaminant accumulation of amphidromous fishes on the Caribbean island of Puerto Rico. The isotopic signatures of postlarval amphidromous fishes indicated marine basal sources and food web components, rather than those from riverine habitats. Additionally, postlarvae did not contain concentrations of anthropogenic pollutants that would be of ecological or human health concern. These findings are the first and strongest evidence that amphidromous fish postlarvae function as biotransport vectors of marine nutrients into and up river ecosystems without posing a health threat to the receiving food web or human consumers.     

何仙姑森林公园天然林保护探究

通过天然林保护工程的实施,建成比较完善的森林生态环境建设体系和保障体系,使现有天然林资源得到保护和恢复。以何仙姑森林公园天然林为研究对象,探究天然林保护的现状以及存在的问题,以便更好的保护天然林。     

森林生态系统涡度相关法碳通量长时间连续性缺失数据插补方法的比较

针对森林通量观测站涡度相关法碳通量观测普遍存在的长时间连续性数据缺失情景，为探究不同数据插补方法的有效性，以华北低丘山地栓皮栎人工混交林生态系统为例，以经EddyPro处理和质量控制的2017年3月1日-11月30日0.5h尺度净生态系统碳交换（NEE）数据为基准数据集，随机生成含有连续1、3、7、15和31d数据缺失的5类数据缺失集，重复10次，使用固定窗口平均昼夜变化法（MDV）、可变窗口平均昼夜变化法（MDC）、查表法（LUT）、非线性回归法（NLR）、边际分布采样法（MDS）、人工神经网络法（ANN）对缺失数据集进行插补，并将插补数据与实际观测数据进行对比，通过分析统计参数来评估不同方法的插补精度和稳定性，以评估不同方法的适用范围。结果表明：日间，当连续缺失少于15d时，ANN方法插补数据与实测数据间的R2（决定系数）相对较高，NLR方法的R2较低；LUT方法插补数据与实测数据间的相对均方根误差（RRMSE）较低，NLR方法的RRMSE较高。当缺失达到连续15d时，除NLR方法的R2显著较低（P＜0.05）外，其它方法间R2差异不显著；LUT方法的RRMSE显著（P＜0.05）较低，其它方法间RRMSE差异不显著。当缺失达到连续31d时，除NLR方法R2显著较低（P＜0.05）外，各方法间R2和RRMSE无显著差异；MDV方法的平均绝对误差（MAE）出现较多异常值，各方法间的MAE开始出现分化的趋势。随着缺失片段长度的增加，除MDV方法外，各方法的R2呈下降趋势，连续1d缺失与连续31d缺失情景下插补所得NEE与实测NEE的R2差异显著（P＜0.05）；MDV和MDS方法的RRMSE呈增大趋势，连续1d缺失与连续31d缺失情景下的RRMSE差异显著（P＜0.05），其它方法的RRMSE差异相对不显著。夜间，在各缺失情景下，ANN方法的R2较高，LUT方法的R2较低，二者之间差异显著（P＜0.05）；LUT方法的RRMSE最高，与其它方法存在显著差异（P＜0.05）。在连续缺失大于31d的情景下，各方法的RRMSE差异均不显著。除LUT方法MAE显著（P＜0.05）较高外，其它方法的MAE无明显差异。随着缺失片段长度的增加，MDC、MDS和ANN方法插补数据的R2呈下降趋势，MDV和LUT的R2始终无显著差异；各方法的RRMSE差异无显著变化。在对典型晴天0.5h尺度上NEE日变化趋势的还原方面，MDC方法性能相对较优。综上，NLR方法适用于气象数据完备、NEE数据连续缺失少于7d的情景；MDV或MDC方法适用于气象数据不可用或缺失严重、NEE数据连续缺失少于15d的情景；LUT和MDS方法则适用于气象数据缺失较少、NEE数据连续缺失少于15d的情景；ANN方法适用性相对较广，可用于气象数据缺失较少、NEE数据连续缺失长达31d的情景。     

In‐stream structure alters density‐dependent fish effects in stream ecosystems

The independent effects of in‐stream structure (ISS) and fish foraging on stream properties have been well documented, but few studies have explored the interactive effects of ISS and fishes on streams. Herein, we tested the independent and interactive effects of ISS and a generalist fish (Blacktail shiner, Cyprinella venusta) on suspended organic matter (SOM), benthic algae, invertebrate density and fish growth using experimental mesocosms. We found that Blacktail shiner foraging affected all of the ecosystem properties; however, in some cases, the fish effects differed between mesocosms with and without ISS. Specifically, mesocosms with ISS provided greater surface area for invertebrate colonisation and enhanced food resources for Blacktail shiner. As a result, benthic foraging by Blacktail shiner was reduced in these mesocosms. The reduced benthic foraging in turn enhanced benthic algae and benthic invertebrates via a bottom‐up, nutrient excretion pathway. The ISS‐dependent effects of fish on these stream properties, however, were only evident at low and intermediate fish densities (1 and 2 fish·m^?2 respectively). This was likely because at the highest fish density (4 fish·m^?2) intense fish foraging overrode any mediating effects of ISS. Furthermore, fish growth decreased with fish density because of intraspecific competition, but this negative effect on growth was reduced in mesocosms with ISS because of the increased forage base. However, the positive effect on fish growth was weak and only marginally significant. Our data suggest that fish‐mediated effects on streams are context dependent, changing with microhabitat availability (e.g. ISS) and density of the fish population.     

Environmental and economic impact assessment of alien and invasive fish species in Europe using the generic impact scoring system

Invasions by alien species are one of the major threats to the native environment. There are multifold attempts to counter alien species, but limited resources for mitigation or eradication programmes makes prioritisation indispensable. We used the generic impact scoring system to assess the impact of alien fish species in Europe. It prioritises species, but also offers the possibility to compare the impact of alien invasive species between different taxonomic groups. For alien fish in Europe, we compiled a list of 40 established species. By literature research, we assessed the environmental impact (through herbivory, predation, competition, disease transmission, hybridisation and ecosystem alteration) and economic impact (on agriculture, animal production, forestry, human infrastructure, human health and human social life) of each species. The goldfish/gibel complex Carassius auratus/C. gibelio scored the highest impact points, followed by the grass carp Ctenopharyngodon idella and the topmouth gudgeon Pseudorasbora parva. According to our analyses, alien fish species have the strongest impact on the environment through predation, followed by competition with native species. Besides negatively affecting animal production (mainly in aquaculture), alien fish have no pronounced economic impact. At the species level, C. auratus/C. gibelio show similar impact scores to the worst alien mammals in Europe. This study indicates that the generic impact scoring system is useful to investigate the impact of alien fish, also allowing cross‐taxa comparisons. Our results are therefore of major relevance for stakeholders and decision‐makers involved in management and eradication of alien fish species.     

浅析城市森林的发展之路

随着人们日常生活水平的不断提高,城市化建设的进程也在不断地加剧,怎样才能有效地维持生存环境的可持续发展,已经成了摆在所有设计师面前的一道难题,就城市森林的发展之路,进行阐述和分析。     

The social and economic value of cultural ecosystem services provided by urban forests in North America: A review and suggestions for future research

With the majority of the world’s human population now living in cities, urban forests provide an increasingly important range of ecosystem services, from improved air quality and climate change adaptation to better public health outcomes and increased tourism revenues. The importance of these ecosystem services in urban environments, and the central role that cities play in the lives of people around the world, have motivated various attempts to quantify the value of ecosystem services provided by urban forests. This paper reviews existing research in the fields of urban forestry, economics, sociology, and health on the value of urban ecosystem services, with a focus on cultural services, a category of ecosystem services that is of key importance to human well-being but that has suffered from a lack of empirical research. The review identified 38 studies that examined the value of mixed vegetation, 31 studies that examined the value of trees, and 43 studies that examined the value of green spaces. Psychological health is the most-studied ecosystem service category, with most research in this area focusing on the services of mixed vegetation. Social health, community economic development, and tourism are the least-studied, with most research in these areas focusing on mixed vegetation and trees. Multiple metrics were used to quantify the value of urban greenery within each ecosystem service category but only 11 metrics were assigned a monetary value. Gaps in the literature that present strong opportunities for future research include: the value of urban forests for improving social health, equitable access to ecosystem services, the impact of urban forests on community economic development, and economic valuation and green exposure metrics. We hope that this review stimulates future research in the areas highlighted and that municipalities consider including evaluations of a broad range of ecosystem services during land use planning and budgeting processes.     

从建筑文化的构成分析中国古典园林的形成发展

该研究套用了文化生态系统的结构模式，用人类活动、建筑环境、建筑文化分别替换了文化生态系统中的人类社会、外部环境、文化，从而组建了建筑文化的结构模式，它是依托于文化生态系统结构模式存在的。该模式中，建筑工程技术位于建筑文化结构的最外层，设计方法及著述位于中间层，价值观位于最内层。将这一结构模式应用于分析中国古典园林的形成发展过程，按照朝代更替的时间跨度，从社会意识、文化心理和审美风尚的角度分析中国古典园林从苑囿到山水园，从城市宅园到江南私家园林的变更过程，指出园林发展过程是从外部形态到实用功能的改变，这一改变是由当时的社会思想意识、价值观念通过一定的设计方法指导实现的。     

江西省丰城市药湖湿地生态服务功能评价研究

根据药湖国家湿地公园长期、连续观测数据及多年科研成果,运用能值分析法,从湿地物质产品功能、涵养水源功能、固碳释氧功能、调节气候功能、保护环境功能、生物多样性保护功能、人文功能等七个方面估算了江西省药湖国家湿地公园湿地生态服务功能总价值,结果表明,2014年药湖国家湿地公园湿地生态服务功能总能值3.85×1020sej·a-1,能值货币总价值为353474768元·a-1,平均每公顷价值为138076元·a-1。药湖国家湿地公园湿地生态服务功能价值量大小顺序为:物质产品保护环境涵养水源生物多样性人文功能调节气候固碳释氧。研究结果表明,药湖湿地公园湿地物质产品功能、保护环境功能、涵养水源功能三个功能所占的比重较大,说明药湖动植物资源非常丰富,在保护当地生态环境、涵养水源等方面发挥巨大作用。