Effects of a herbicide-insecticide mixture in freshwater microcosms: risk assessment and ecological effect chain

Effects of chronic application of a mixture of the herbicide atrazine and the insecticide lindane were studied in indoor freshwater plankton-dominated microcosms. The macroinvertebrate community was seriously affected at all but the lowest treatment levels, the zooplankton community at the three highest treatment levels, with crustaceans, caddisflies and dipterans being the most sensitive groups. Increased abundance of the phytoplankton taxa Cyclotella sp. was found at the highest treatment level. Threshold levels for lindane, both at population and community level, corresponded well with those reported in the literature. Atrazine produced fewer effects than expected, probably due to decreased grazer stress on the algae as a result of the lindane application. The safety factors set by the Uniform Principles for individual compounds were also found to ensure protection against chronic exposure to a mixture of a herbicide and insecticide at community level, though not always at the population level.     

Evaluation of the community multiscale air quality (CMAQ) model version 4.5: Sensitivities impacting model performance; Part II—particulate matter

This paper is Part II in a pair of papers that examines the results of the Community Multiscale Air Quality (CMAQ) model version 4.5 (v4.5) and discusses the potential explanations for the model performance characteristics seen. The focus of this paper is on fine particulate matter (PM_2.5) and its chemical composition. Improvements made to the dry deposition velocity and cloud treatment in CMAQ v4.5 addressing compensating errors in 36-km simulations improved particulate sulfate (SO₄²⁻) predictions. Large overpredictions of particulate nitrate (NO₃⁻) and ammonium (NH₄⁺) in the fall are likely due to a gross overestimation of seasonal ammonia (NH₃) emissions. Carbonaceous aerosol concentrations are substantially underpredicted during the late spring and summer months, most likely due, in part, to a lack of some secondary organic aerosol (SOA) formation pathways in the model. Comparisons of CMAQ PM_2.5 predictions with observed PM_2.5 mass show mixed seasonal performance. Spring and summer show the best overall performance, while performance in the winter and fall is relatively poor, with significant overpredictions of total PM_2.5 mass in those seasons. The model biases in PM_2.5 mass cannot be explained by summing the model biases for the major inorganic ions plus carbon. Errors in the prediction of other unspeciated PM_2.5 (PM_Other) are largely to blame for the errors in total PM_2.5 mass predictions, and efforts are underway to identify the cause of these errors.     

长江口大洋山近岸水域浮游植物群落及其与环境因子的关系

2012年对上海大洋山近岸水域浮游植物的群落结构和物种多样性的周年动态进行了逐月的研究。结果表明:浮游植物共有141种,隶属6门62属。以硅藻为主,共43属110种,占物种总种类的78.01%。该水域浮游植物的年平均细胞密度为(37.86±39.79)×104cell/L。中肋骨条藻(Skeletonema costatum)和具槽帕拉藻(Paralia sulcata)为第一和第二优势种,细长列海链藻(Thalassiosira leptopus)、肋缝菱形藻(Nitzschia frustulum)和梅尼小环藻(Cyclotella meneghiniana)为该水域常见种。从水质参数和物种多样性指数综合评价:大洋山近岸水域水质总体属于轻中污染。冗余分析(RDA)表明对大洋山近岸水域浮游植物影响较大的是悬浮物浓度、盐度、水温和溶解氧。     

Isolated Ficus trees deliver dual conservation and development benefits in a rural landscape

Many of the world’s rural populations are dependent on the local provision of economically and medicinally important plant resources. However, increasing land-use intensity is depleting these resources, reducing human welfare, and thereby constraining development. Here we investigate a low cost strategy to manage the availability of valuable plant resources, facilitated by the use of isolated Ficus trees as restoration nuclei. We surveyed the plants growing under 207 isolated trees in Assam, India, and categorized them according to their local human-uses. We found that Ficus trees were associated with double the density of important high-grade timber, firewood, human food, livestock fodder, and medicinal plants compared to non-Ficus trees. Management practices were also important in determining the density of valuable plants, with grazing pressure and land-use intensity significantly affecting densities in most categories. Community management practices that conserve isolated Ficus trees, and restrict livestock grazing and high-intensity land-use in their vicinity, can promote plant growth and the provision of important local resources.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-015-0645-9) contains supplementary material, which is available to authorized users.     

Community gardening and social cohesion: different designs,different motivations

Community gardens vary in several ways: they are cultivated by different kinds of communities in various locations, entail individual or communal plots and the extent of active participation (e.g. gardening) differs. In this paper, we study seven community gardens with varying organisational designs and objectives, and investigate the extent to which these influence the enhancement of social cohesion. We also take into account to what extent differences in motivation among community gardeners matter. Despite these differences in motivation, however, we find that in all of the cases studied, people talk to and get to know others, and mutual help is widespread. We, therefore, conclude that community gardens contribute to the development of social cohesion – even if people are not particularly driven by social motivations. Moreover, while participants who are motivated by the social aspects of gardening naturally show a higher level of appreciation for them, these social aspects also bring added value for those participants who are motivated primarily by growing vegetables.     

Adaptive Capacity of Fishing Communities at Marine Protected Areas: A Case Study from the Colombian Pacific

Departing from a theoretical methodology, we estimate empirically an index of adaptive capacity (IAC) of a fishing community to the establishment of marine protected areas (MPAs). We carried out household surveys, designed to obtain information for indicators and sub-indicators, and calculated the IAC. Moreover, we performed a sensitivity analysis to check for robustness of the results. Our findings show that, despite being located between two MPAs, the fishing community of Bazán in the Colombian Pacific is highly vulnerable and that the socioeconomic dimension of the IAC constitutes the most binding dimension for building adaptive capacity. Bazán is characterized by extreme poverty, high dependence on resources, and lack of basic public infrastructure. Notwithstanding, social capital and local awareness about ecological conditions may act as enhancers of adaptive capacity. The establishment of MPAs should consider the development of strategies to confer adaptive capacity to local communities highly dependent on resource extraction.     

Volatile organic compounds at swine facilities: A critical review

Volatile organic compounds (VOCs) are regulated aerial pollutants that have environmental and health concerns. Swine operations produce and emit a complex mixture of VOCs with a wide range of molecular weights and a variety of physicochemical properties. Significant progress has been made in this area since the first experiment on VOCs at a swine facility in the early 1960s. A total of 47 research institutions in 15 North American, European, and Asian countries contributed to an increasing number of scientific publications. Nearly half of the research papers were published by U.S. institutions.Investigated major VOC sources included air inside swine barns, in headspaces of manure storages and composts, in open atmosphere above swine wastewater, and surrounding swine farms. They also included liquid swine manure and wastewater, and dusts inside and outside swine barns. Most of the sample analyses have been focusing on identification of VOC compounds and their relationship with odors. More than 500 VOCs have been identified. About 60% and 10% of the studies contributed to the quantification of VOC concentrations and emissions, respectively. The largest numbers of VOC compounds with reported concentrations in a single experimental study were 82 in air, 36 in manure, and 34 in dust samples.The relatively abundant VOC compounds that were quantified in at least two independent studies included acetic acid, butanoic acid (butyric acid), dimethyl disulfide, dimethyl sulfide, iso-valeric, p-cresol, propionic acid, skatole, trimethyl amine, and valeric acid in air. They included acetic acid, p-cresol, iso-butyric acid, butyric acid, indole, phenol, propionic acid, iso-valeric acid, and skatole in manure. In dust samples, they were acetic acid, propionic acid, butyric acid, valeric acid, p-cresol, hexanal, and decanal. Swine facility VOCs were preferentially bound to smaller-size dusts.Identification and quantification of VOCs were restricted by using instruments based on gas Chromatography (GC) and liquid chromatography (LC) with different detectors most of which require time-consuming procedures to obtain results. Various methodologies and technologies in sampling, sample preparation, and sample analysis have been used. Only four publications reported using GC based analyzers and PTR-MS (proton-transfer-reaction mass spectrometry) that allowed continuous VOC measurement. Because of this, the majority of experimental studies were only performed on limited numbers of air, manure, or dust samples. Many aerial VOCs had concentrations that were too low to be identified by the GC peaks.Although VOCs emitted from swine facilities have environmental concerns, only a few studies investigated VOC emission rates, which ranged from 3.0 to 176.5 mg d⁻¹ kg⁻¹ pig at swine finishing barns and from 2.3 to 45.2 g d⁻¹ m⁻² at manure storages. Similar to the other pollutants, spatial and temporal variations of aerial VOC concentrations and emissions existed and were significantly affected by manure management systems, barn structural designs, and ventilation rates.Scientific research in this area has been mainly driven by odor nuisance, instead of environment or health concerns. Compared with other aerial pollutants in animal agriculture, the current scientific knowledge about VOCs at swine facilities is still very limited and far from sufficient to develop reliable emission factors.     

Building community resilience in a context of climate change: The role of social capital

Social capital is considered important for resilience across social levels, including communities, yet insights are scattered across disciplines. This meta-synthesis of 187 studies examines conceptual and empirical understandings of how social capital relates to resilience, identifying implications for community resilience and climate change practice. Different conceptualisations are highlighted, yet also limited focus on underlying dimensions of social capital and proactive types of resilience for engaging with the complex climate change challenge. Empirical insights show that structural and socio-cultural aspects of social capital, multiple other factors and formal actors are all important for shaping the role of social capital for guiding resilience outcomes. Thus, finding ways to work with these different elements is important. Greater attention on how and why outcomes emerge, interactions between factors, approaches of formal actors and different socio-cultural dimensions will advance understandings about how to nurture social capital for resilience in the context of climate change.     

无机碳对浮游藻类生长和群落结构的影响

采用水族箱生态模拟方法,利用碳酸钠和碳酸氢钠作为碱度调节剂设置不同碱度水平,研究了氮磷营养相对充足的试验水体中藻类各相关指标对无机碳的响应,并对试验过程中所测得的理化指标和生物指标进行统计分析.研究表明:富营养水体无机碳含量与藻类叶绿素水平存在着正相关关系;适当增加水体中的无机碳浓度能够改变蓝、绿藻门种类比例;当碱度水平达到一定程度时,铜绿微囊藻可以逐渐成为优势种,并从体系中上升,演替成为水华.     

淮河流域淮安段着生藻类群落结构特征分析

于2021年5月对淮安境内淮河主要干支流8个点位的水质状况和着生藻类群落结构采样调查,应用3种多样性指数模型评价区域水生态健康状况,并探究影响着生藻类多样性的因素。结果表明：采样期间淮河流域淮安市域共检出着生藻类3门23科32属（种）,由硅藻门、蓝藻门和绿藻门组成,硅藻门占绝对优势;多样性指数计算结果显示,流域水生态状况良好,整体表现为清洁-轻污型水体,淮河上游水质稍差于其他水域;结合水质监测数据与卫星遥感影像分析,认为生境状况是影响着生藻类群落分布的主要因素。