From the ground up: holistic management and grassroots rural adaptation to bovine spongiform encephalopathy across western Canada

Bovine spongiform encephalopathy (BSE) has been documented in 28 countries and adversely affected farmers and rural communities around the world. Our study examines the impacts of and adaptive responses of producers to BSE in western Canada. Moreover, it explores the role that holistic management (HM), and its combined focus on environmental, social, and economic sustainability, might play in mitigating the effects of BSE. One survey was sent to 835 HM producers and another to 9,740 producers across Manitoba, Saskatchewan, and Alberta. The disease, and concomitant climate change and low commodity prices, had devastating impacts on both groups. Yet, HM producers were much more optimistic about their ability to adapt to BSE and the future of agriculture than their non-HM counterparts. Social networks, namely HM clubs and the larger HM community, enabled these producers to mitigate the impacts of BSE. Agronomic responses, especially those associated with rotational grazing and increases in on-farm biodiversity were also important. That HM has been such an effective adaptive response to BSE indicates the importance of this and other grassroots responses to rural crises, whether they be associated with zoonotic diseases or indeed environmental change as a whole.     

Sulfur cycle in the typical meadow Calamagrostis angustifolia wetland ecosystem in the Sanjiang Plain, Northeast China

The sulfur cycle and its compartmental distribution within an atmosphere-plant-soil system was studied using a compartment model in the typical meadow Calamagrostis angustifolia wetland in the Sanjiang Plain Northeast China. The results showed that in the typical meadow C. angustifolia wetland ecosystem, soil was the main storage compartment and current hinge of sulfur in which 98.4% sulfur was accumulated, while only 1.6% sulfur was accumulated in the plant compartment. In the plant subsystem, roots and litters were the main storage compartment of sulfur and they remained 83.5% of the total plant sulfur. The calculations of sulfur turnover through the compartments of the typical meadow C. angustifolia wetland ecosystem demonstrated that the above-ground component took up 0.99 gS/m2 from the root, of which 0.16 gS/m2 was translocated to the roots and 0.83 gS/m2 to the litter. The roots took in 1.05 gS/m2 from the soil, subsequent translocation back to the soil accounted for 1.31 gS/m2, while there was 1.84 gS/m2 in the litter and the net transfer of sulfur to the soil was more than 0.44 gS/(m2·a). The emission of H2S from the typical meadow C. angustifolia wetland ecosystem to the atmosphere was 1.83 mgS/(m2·a), while carbonyl sulfide (COS) was absorbed by the typical meadow C. angustifolia wetland ecosystem from the atmosphere at the rate of 1.76 mgS/(m2·a). The input of sulfur by the rainfall to the ecosystem was 4.85 mgS/m2 during the growing season. The difference between input and output was 4.78 mgS/m2, which indicated that sulfur was accumulated in the ecosystem and may cause wetland acidify in the future.     

惠阳城区降雨径流重金属污染特征研究：Ⅱ.重金属污染负荷估算

用0.5 mol/L HCI提取出来的重金属含量可以代表地表堆积物中能被降雨径流浸出的重金属污染物,模拟一次典型降雨在不同功能区所造成的降雨径流污染特征.结果表明,一次典型降雨径流中的重金属产生量:ρ(Pb)为0.143 mg/L,ρ(Zn)为0.206 mg/L,ρ(Cu)为0.087 mg/L,L,ρ(Cr)为0.040 mg/L.Pb的污染负荷总量达68.77 kg,Zn的污染负荷总量为88.50 kg,Cu的污染负荷总量为41.77 kg,Cr的污染负荷总量为20.37 kg.交通区产生的重金属负荷占总负荷的比例:Pb为78%,Zn为58%,Cu为76%,Cr为47%.降雨径流所致的重金属污染负荷已接近甚至超出了当地重点污染点源的重金属污染负荷.降雨径流将会对淡水河产生短期污染.     

胶州湾东岸典型河口区COD浓度响应系数分布探讨

利用胶州湾海域成熟的COD平流-扩散输运模型,对胶州湾东岸典型河(海泊河、李村河和娄山河)口区COD响应系数进行了系统的计算和分析.结果为:海泊河、李村河和娄山河口区沿河道主流向,离岸方向海水COD的响应系数在潮周期内随着潮波变化而变化,不同空间点出现最大值的时间不同,变化的幅度范围也不同,李村河和海泊河口区海水COD响应系数变化幅度明显,娄山河口区变化微小;三个河口区COD响应系数随离开河口距离的增大呈幂函数形式下降,水体活跃大小次序为:海泊河口>李村河口>娄山河口;胶州湾中部海水COD对海泊河、李村河和娄山河口的响应系数基本上没有明显差异.     

我国南方不同类型草地生产力及对气候变化的响应

为进一步明晰南方不同类型草地的碳源汇关系,预测未来气候情景下可能的碳循环特征,利用本地参数化的BIOME-BGC模型对2001~2010年低山丘陵草原化草甸、典型草山草坡和典型山地草甸样地净初级生产力(NPP)与净生态系统生产力(NEP)进行了模拟估算。不同类型草地的NPP和NEP 10年间变化趋势不同,低山丘陵草原化草甸、典型草山草坡和典型山地草甸的NPP平均值分别为357.17、232.4和191.96gC/(m2·a);NEP的平均值分别为3.25、21.28和81.96gC/(m2·a)。3种类型草地NPP与温度之间存在显著的正相关关系,NEP与温度之间存在着显著的负相关关系;本模型模拟的NPP和NEP与年平均降水量之间相关性不明显。未来气候情景C1P-1T1下(CO2浓度倍增,年均温增加2℃,降水减少10%),低山丘陵草原化草甸样地NPP增加26.93%,NEP增加160%;典型草山草坡样地NPP增加62.20%,NEP增加153%;典型山地草甸样地NPP增加135%,NEP增加206%。3种南方草地类型在未来气候情景下都将有一定的碳汇增长潜力,其中以典型山地草甸的碳汇潜力最为明显,与降水量相比受温度变化的影响相对较大。     

Growth promotion and disease prevention effects of streptomyces on Amorphophallus konjac K. Koch ex N.E.Br北大核心CSCD

This study aimed to evaluate the disease antagonism and seed growth promotion effects of streptomyces on Amorphophallus konjac by agar block and axenic fermentation extract experiments. Pot experiments were taken to assess relative biocontrol effiency and effect of streptomyce preparation M (mixture of S. carnosus and S. pactum in solid-state fermentation with 1:1 ratio) on biomass, photosynthetic rate, yield and corm quality of A. konjac K. Koch ex N.E.Br. Results showed that: 1 Streptomyces Act12 had obvious antagonistic activity against six soft rot pathogens, and the diameter of growth inhibition zones ranged from 19.4 to 31.6 mm. Fermentation filtrate of streptomyces exhibited growth-promoting activity on melon seed germination and seedling growth. 2 Streptomyce-derived viable preparations had biocontrol effect on A. konjac regarding soft rot-disease prevention. In the pot experiment, individual inoculation of preparations achieved 65.0% relative biocontrol effect on A. konjac during the harvest stage. After 10 and 20 days of inoculation combined with Pectobacterium chrysanthemi (a bacterial pathogen), the relative biocontrol effiency of streptomyces were 100.0% and 58.4%, respectively. 3 Streptomyces showed obvious growth-promoting effect on growth and yield of A. konjac. In the pot experiment, combined inoculation of streptomyces and Pectobacterium chrysanthemi significantly increased the petiole diameter by 11.1%, net photosynthetic rate by 111.7%, fresh weight of corm by 54.8%, fresh weight of rhizome by 304.2%, and the number of rhizomes by 200.0%, compared with individual inoculation of Pectobacterium chrysanthemi. 4 Individual inoculation with streptomyces improved corm quality of A. konjac. The contents of glucomannan, starch and cellulose significantly increased by 14.0%, 8.1% and 27.7%, respectively compared with control (P < 0.05) . This study indicates that streptomyces promotes the growth of A. konjac, enhances the yield and the content of glucomannan, and at the same time helps disease prevention of A. konjac.     

COVID-19管控前后不同污染阶段PM2.5中二次无机离子变化特征

为探讨新冠肺炎疫情(COVID-19)管控前后不同污染阶段PM_2.5中二次无机离子变化特征,使用高分辨率(1 h)在线仪器对2019年12月15日至2020年2月15日郑州冬季气象、污染气体浓度和PM_2.5中水溶性离子水平进行在线监测,分析此次COVID-19管控前后霾过程的成因、大气污染物的日变化特征和在霾不同阶段下大气污染物的分布特征.结果表明,郑州主要受到高压脊控制,天气形势稳定,有利于大气污染物累积,二次无机气溶胶(SNA,包括SO₄^2-、NO^-₃和NH⁺₄)是水溶性离子的主要组分,占比高达90%以上,COVID-19期间居家隔离措施对霾不同阶段下大气污染物的分布特征产生不同的影响,COVID-19期间PM_2.5在干净、发生和消散阶段的浓度比COVID-19前有所提高,但是发展阶段明显降低,居家隔离明显使PM_2.5高值降低了;NO₂、SO<...     

合肥市典型臭氧污染特征及成因分析

综合利用环境空气质量常规监测、挥发性有机物(VOCs)在线监测,以及后向轨迹聚类分析、权重潜在源区分析和正交矩阵因子分解法等多种监测分析方法,基于合肥市经历的一次典型臭氧(O₃)污染过程(2020年9月1—10日),系统分析了合肥市O₃污染的典型特征及成因。结果显示,此次污染过程的O₃小时平均浓度高达96 μg/m³,且O₃浓度波动较大,在9月6日13:00达到了224 μg/m³,呈现出快速生成、快速消耗的污染特征,并在夜间呈现出非典型的二次峰值过程。污染期间,合肥市基本处于VOCs控制区,芳香烃对O₃生成潜势的贡献最大(45.2%),其次是烷烃(31.8%)和烯烃(21.5%);污染阶段的VOCs主要来自机动车排放源(44.1%)、燃烧源(21.3%)、工业源(15.3%)、溶剂使用源(12.4%)和天然源(6.9%),累积阶段和污染阶段均受机动车尾气排放和溶剂使用的影响较大。此外,台风外围下沉气流和高温、低湿、低风速等气象条件是引发此次O₃污染过程的主要外因,而合肥市周边的高污染区域则是此次O₃污染过程的潜在外部源区。     

面向疫情危机的城市公共卫生系统韧性

为有效应对城市公共卫生危机,公共卫生系统韧性至关重要。以武汉新冠肺炎(COVID-19)疫情防控成功经验为例,运用扎根理论分析政府、社区、医疗机构、媒体、非政府组织在COVID-19疫情防控中的观念与行为,解析出反映系统韧性特征的疾病监测体系、防疫资源管理、合作治理能力等10个主范畴及对应的52个子范畴,由此将系统韧性细分为功能韧性、过程韧性和整体韧性。运用解释结构模型(ISM)构建提升公共卫生系统韧性的层次结构模型,揭示多元社会主体通过前述韧性要素集合:社会防疫基础、防疫科技与文化、疫情风险综合治理的层级递进应急准备,实现城市公共卫生系统韧性提升目标。     

The scope and severity of white-nose syndrome on hibernating bats in North America

Assessing the scope and severity of threats is necessary for evaluating impacts on populations to inform conservation planning. Quantitative threat assessment often requires monitoring programs that provide reliable data over relevant spatial and temporal scales, yet such programs can be difficult to justify until there is an apparent stressor. Leveraging efforts of wildlife management agencies to record winter counts of hibernating bats, we collated data for 5 species from over 200 sites across 27 U.S. states and 2 Canadian provinces from 1995 to 2018 to determine the impact of white-nose syndrome (WNS), a deadly disease of hibernating bats. We estimated declines of winter counts of bat colonies at sites where the invasive fungus that causes WNS (Pseudogymnoascus destructans) had been detected to assess the threat impact of WNS. Three species undergoing species status assessment by the U.S. Fish and Wildlife Service (Myotis septentrionalis, Myotis lucifugus, and Perimyotis subflavus) declined by more than 90%, which warrants classifying the severity of the WNS threat as extreme based on criteria used by NatureServe. The scope of the WNS threat as defined by NatureServe criteria was large (36% of Myotis lucifugus range) to pervasive (79% of Myotis septentrionalis range) for these species. Declines for 2 other species (Myotis sodalis and Eptesicus fuscus) were less severe but still qualified as moderate to serious based on NatureServe criteria. Data-sharing across jurisdictions provided a comprehensive evaluation of scope and severity of the threat of WNS and indicated regional differences that can inform response efforts at international, national, and state or provincial jurisdictions. We assessed the threat impact of an emerging infectious disease by uniting monitoring efforts across jurisdictional boundaries and demonstrated the importance of coordinated monitoring programs, such as the North American Bat Monitoring Program (NABat), for data-driven conservation assessments and planning.