Hg、Cd污染对2种外生菌根真菌氮素营养吸收的影响

以从中国西南林区分离获得的外生菌根真菌彩色豆马勃(Pisolithus tinctorius 715,简称Pt715)、松乳菇(Lactarius delicious.ex Gray-1(简称Ld-1)、Lactarius delicious.exPink-2(简称Ld-2)、Lactarius delicious.ex White-3(简称Ld-3))为供试菌种,研究Hg、Cd对其吸收氮素的影响,从而筛选出在营养吸收上具有重金属耐受性的菌株。结果表明,重金属对外生菌根真菌吸收氮素营养的影响因重金属元素种类、真菌种类和氮素形态不同而异,Hg、Cd基本不会抑制供试菌种对有机态氮的吸收,而对NH+4-N、NO-3-N的吸收有不同程度的抑制或促进作用,但无明显的规律可循;Ld-1菌株具有一定的耐Hg性,在培养液中加入不同浓度的Hg后,Ld-1菌株对3种氮源的吸收均未受到明显抑制,相反在高Hg浓度下还促进了对NH+4-N、NO-3-N的吸收。Ld-1菌株有可能在Hg的胁迫下诱导合成了新的特异性蛋白,Hg与特异性蛋白结合从而缓解了其污染胁迫。     

Recognize fish as food in policy discourse and development funding

The international development community is off-track from meeting targets for alleviating global malnutrition. Meanwhile, there is growing consensus across scientific disciplines that fish plays a crucial role in food and nutrition security. However, this ‘fish as food’ perspective has yet to translate into policy and development funding priorities. We argue that the traditional framing of fish as a natural resource emphasizes economic development and biodiversity conservation objectives, whereas situating fish within a food systems perspective can lead to innovative policies and investments that promote nutrition-sensitive and socially equitable capture fisheries and aquaculture. This paper highlights four pillars of research needs and policy directions toward this end. Ultimately, recognizing and working to enhance the role of fish in alleviating hunger and malnutrition can provide an additional long-term development incentive, beyond revenue generation and biodiversity conservation, for governments, international development organizations, and society more broadly to invest in the sustainability of capture fisheries and aquaculture.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01451-4) contains supplementary material, which is available to authorized users.     

峡谷型水源水库的氮、磷季节变化及其来源分析

石砭峪水库总氮(TN)和总磷(TP)的质量浓度均值分别为2.67 mg.L-1和0.04 mg.L-1,其在丰水期最大,平水期次之,枯水期最小;水库富营养化严重,叶绿素a含量和藻细胞密度分别高达50 mg.m-3和10 000×104cells.L-1.水库TN的年输入和输出负荷分别为203.1 t和181.3 t,而TP的年输入和输出负荷分别为4.2 t和4.1 t;外源输入水库的TN和TP负荷均占各自总输入负荷的90%以上;就全年而言,水库沉积物表现为蓄积作用,TN和TP年净积累量分别约为20.2 t和0.8 t;内源污染控制是水库污染控制的关键.     

武汉月湖近代沉积物中的硅藻组合与环境关系研究

采集武汉月湖2处近代沉积物,分析了沉积硅藻组合与其环境关系,共发现24属83种硅藻。结果表明：2个柱状沉积物中硅藻优势属为小环藻属、直链藻属、舟形藻属、Cyclostephanos属。Z-1钻孔共有20属61种硅藻,Z-2钻孔共有24属68种硅藻。Z-1钻孔优势种为梅尼小环藻（Cyclotella meneghiniana）、颗粒直链藻（Aulacoseira granulata）、Navicula porifera、Cyclostephanos tholifomis。Z-2钻孔优势种为梅尼小环藻、颗粒直链藻、舟形藻（Navicula sp.）、Cyclostephanos invisitatus。就硅藻密度分布而言,总趋势上层最多,平均7.14×10^5～58.65×10^5 ind.g-1,中层其次,平均0.08×10^5～13.98×10^5 ind.g-1,下层最少,平均0.24×10^5～0.64×10^5 ind.g-1。硅藻种数最少的样品出现在沉积物中层,梅尼小环藻、颗粒直链藻、舟形藻、Navicula porifera、Cyclostephanos tholifomis、Cyclostephanos invisitatus的组合可以指示湖泊水体环境出现富营养化。通过探讨分析影响硅藻分布的环境因素,为恢复月湖近代水环境演化过程提供了依据。     

城市湖泊富营养化的影响探讨——以金山湖为实例

以金山湖为研究对象,建立了金山湖二维水流水质耦合模型,利用有限差分法离解方程,模拟了金山湖在东风作用下的流场,在此基础上模拟了水温、营养盐（总磷、总氮）、流速与浮游藻类生长的关系以及湖水水质变化趋势。     

香溪河库湾浮游植物调查及多样性研究

为了分析新生水库库湾藻类组成及演替规律,2010年对三峡水库香溪河库湾进行了跟踪监测,对监测结果用9种多样性指数进行多样性评价,用综合营养状态指数进行水质评价,并将9种评价指数分别与综合营养状态指数进行拟合分析,得出最适于评价香溪河水体污染程度的评价指数。结果表明春季优势藻种为硅藻、夏季为绿藻和蓝藻、秋季为硅藻和绿藻,冬季为甲藻。XX06秋季与冬季富营养化程度为贫营养级,春季与秋季主要为轻-中度富营养级。Menhinick index与综合营养状态指数的拟合度最大,最能反映水污染程度变化趋势。     

The biogeochemical cycles of phosphorus: A review of local and global consequences of the atmospheric input

P‐input from the atmosphere is, in many oligotrophic ecosystems, substantial for the biomass production; in some regions biomass formation may depend fully or partially on the phosphorus input from the atmosphere. As a consequence, phosphorus must be considered as an element participating in cycles involving the atmosphere, like sulfur and nitrogen. Dust and aerosols containing phosphorus are transported worldwide, linking even distant regions. Human activities enhance the amounts of P distributed. Since the concentrations of P in the atmospheric dry and wet input are usually very low, special care in sampling and analysis is a prerequisite to obtain reproducible data. Some values in the literature may be questionable.     

Flooding: what is the impact on pregnancy and child health?

Floods are the most common type of natural disaster in both developed and developing countries and have led to extensive morbidity and mortality throughout the world. Worldwide, over the past 30 years, flooding has claimed the lives of more than 200,000 people and affected more than 2.8 billion others. The impact of flooding on health varies among populations and depends primarily on vulnerability and the kind of event experienced. It severely disrupts livelihoods and has a significant impact on the health of pregnant women and children. In addition, it may exacerbate a range of negative psychological and physiological child and reproductive health outcomes. Awareness‐raising, education, and the issuing of warnings appear to be key initiatives to mitigate or prevent flood morbidity and mortality, especially among people living in low‐ and middle‐income countries. Agencies responding to emergencies also need to be more cognisant of the dangers, specifically those engaged in healthcare, nutrition, and water safety programmes.     

风浪对太湖水体中胶体态营养盐和浮游植物的影响

为了解不同风浪条件下太湖水中胶体态营养盐和浮游植物含量的特征, 选择不同风速情况进行现场观测和采样, 用切向流超滤法获取胶体, 测定胶体态有机碳、氮、磷及其他形态营养盐含量. 同时收集浮游植物样品, 测定其密度和生物量. 结果表明, 在风速小于4m/s时胶体氮(CN)和胶体磷(CP)含量随风速变大而升高, 而在风速大于4 m/s时其含量不再升高, 甚至略有降低; 叶绿素a(Chl-a)、浮游植物密度、蓝藻密度和蓝藻生物量均在风速小于4m/s时随风速增大而升高, 在风速大于4 m/s时随风速增大而降低, 说明小风浪有利于蓝藻生长或漂浮, 而大风浪对其生长或漂浮不利. CN和CP含量与浮游藻类含量呈显著正相关, 表明在藻类生长旺盛的夏季, 太湖水中胶体氮、磷的主要来源为藻类产物.     

Soil Erosion: A Food and Environmental Threat

Soil erosion is one of the most serious environmental and public health problems facing human society. Humans obtain more than 99.7% of their food (calories) from the land and less than 0.3% from the oceans and other aquatic ecosystems. Each year about 10 million ha of cropland are lost due to soil erosion, thus reducing the cropland available for food production. The loss of cropland is a serious problem because the World Health Organization reports that more than 3.7 billion people are malnourished in the world. Overall soil is being lost from land areas 10 to 40 times faster than the rate of soil renewal imperiling future human food security and environmental quality.