UV-B辐射增强对芦苇叶绿素荧光参数的影响

叶绿素荧光是光合作用的探针,可反映光合机构内一系列重要的调节过程.本文在露天条件下研究了不同UV-B辐照强度(对照:168μW·cm~2,低强度:210μW·cm~2,高强度:252μW·cm~2)对芦苇色素含量及叶绿素荧光参数的影响,探讨了芦苇光合生理对UV-B辐射的响应机制.结果表明:与自然光照相比,UV-B辐射增强对芦苇叶片表观造成一定的损伤,且随辐射梯度增大,损伤加剧.与自然光照相比,低辐射初期可促进芦苇叶片叶绿素a、叶绿素b、总叶绿素及类胡萝卜素含量增大,但随辐射时间延长抑制作用显现;高辐射下,芦苇叶绿素a、叶绿素b、总叶绿素及类胡萝卜素含量均显著降低.与自然光照相比,低辐射前期,叶绿素荧光参数无显著变化,随辐照时间延长,Fo、NPQ增高,Fm、Fv/Fm与Fv/Fo显著降低,ΦPSII值、q P降低.高辐射可显著增大Fo、NPQ,显著降低Fm、Fv/Fm、Fv/Fo、ΦPSII,降低q P.试验结束时,处理组NPQ均低于对照,且随辐射梯度增大,下降幅度加剧.UV-B辐射对PSII的破坏作用随辐射强度增大而增大.     

Decomposition dynamic of higher plant pigments by HPLC analysis

IntroductionHigh performanceliquidchromatographic (HPLC )systemsweredevelopedforhigherplantpigmentsinthelate1970’sandearly 1980’s .Subsequently ,morecomplexHPLCsystemsweredevelopedforchlorophyllsandcarotenoidsfrommicroalgaeandnaturalphytoplanktonpopulations(Gieskes,1991;Hodgson ,1997;Bris,1998) .Bothreversedphaseandnormalphasesystemswereused .TheHPLCtechniquewasusedmorerecentlyforplantpigmentanalysis,andithasledtoasignificantincreaseinseparationandinthenumberofpigmentsthatcanbeidentifi…     

Managing Invasive Aquatic Plants in a Changing System: Strategic Consideration of Ecosystem Services

Abstract:  Climate change is projected to increase stress for many coastal plant communities. Along large portions of the North American coast, habitat degradation from anthropogenic changes to the environment already threaten the community structure of tidal marshes and submerged aquatic grass beds. The potential loss of ecological services historically provided by these communities has been a long-standing rationale for aggressive control of invading plants such as Phragmites australis and Hydrilla verticillata . Increasing evidence of ecological services provided by invasive species such as P. australis and H. verticillata suggest that, in the face of increasing stress, it may be prudent to take a more pragmatic approach regarding the effect of these species on coastal ecosystems. The notable resilience of these species to control efforts and their competitive success and comparative vigor in stressed systems and capacity to provide at least some beneficial services combine to suggest some invasive species may have a useful role in managed coastal ecosystems.     

芦苇抑藻化感物质的分离及其抑制蛋白核小球藻效果研究

采用乙醇提取、溶剂萃取法从芦苇中分离出2组能抑制蛋白核小球藻生长的化感物质. 该2组化感物质对蛋白核小球藻的半效应浓度(EC₅₀)分别为0.68mg/L和2.65mg/L. 将前者用碱性氧化铝层析柱分离得到一组抑藻活性更强的化感物质和一组能够促进蛋白核小球藻生长的化感物质: 前者对蛋白核小球藻的EC₅₀为0.50mg/L, 是目前报道的抑藻能力最强的化感物质; 后者在浓度为0.63mg/L时能显著促进蛋白核小球藻的生长. 芦苇化感物质可以用来控制淡水中有害藻类.     

微波消解-火焰原子吸收光谱法测定芦苇笋中的镉

采用密闭微波消解-火焰原子吸收光谱法对洞庭湖区芦苇笋中的镉进行了测定.结果表明,密闭微波消解是一种非常有效的植物样品前处理方法,对国家标准物质灌木枝叶的测定结果与推荐值吻合,表明该方法准确可靠.     

Construction Simplicity and Cost as Selection Criteria Between Two Types of Constructed Wetlands Treating Highway Runoff

Two free water surface (FWS) and two subsurface flow (SSF) pilot-size wetlands were constructed for the evaluation of their performance in treating highway runoff (HRO) in the heart of the Mediterranean region, the island of Crete, at the southernmost point of Greece. Detailed recordings of the resources involved during the construction allowed a thorough calculation of the cost of the systems and the requirements in materials, man-hours, and equipment. The two identical FWS systems had a surface area of 33 m² each, while the two identical SSF covered 32 m² each. One FWS and one SSF, named FWS12 and SSF12, respectively, were designed with a hydraulic retention time (HRT) of 12 h, with each one capable of treating a maximum HRO of 12.6 m³/day. The other couple, named FWS24 and SSF24, respectively, was designed with an HRT of 24 h, with each receiving a maximum HRO of 6.3 m³/days. An influent storage tank was required to hold the runoff during the common storm events and control the flow rate (and the hydraulic retention time) into the wetlands. This construction represented 25% of the total construction cost, while 5% was spent on the influent automated (and sun-powered) control and distribution system, from the storage tank to the wetlands. The respective total cost allocated to the two SSF systems (€14,676) was approximately 10% higher than that of the FWS (€13,596), mainly due to the three different-sized gravel layers used in the SSF substrate compared to the topsoil used in the FWS, which tripled the cost and placement time. The Total Annual Economic Cost (TAEC) was €1799/year and €1847/year for the FWS and SSF pair, respectively. TAEC was also used to compare the economic efficiency of the systems per cubic meter of HRO treated and kilograms of COD and TSS removed from the wetlands during their first operational year. Based on these estimations, FWS12 recorded the lowest TAEC_COD and TAEC_TSS values (€89.09/kg and €43.69/kg, respectively) compared to the other three systems, presenting a more economically favorable option.     

黄河三角洲芦苇湿地土壤有机碳储量沿盐分梯度的变化特征

以黄河三角洲芦苇湿地为研究对象,于2019年6月自海向陆沿盐分梯度采集土壤和植物样品,研究了不同盐度条件下芦苇湿地土壤有机碳含量和储量的空间分布特征及其与土壤属性和植物地下生物量的关系.结果 表明,黄河三角洲芦苇湿地100 cm深土壤有机碳储量为4.46～7.65 kg·m-2,平均值为6.24 kg· m-2.表层浓...     

黄河三角洲不同生境下芦苇磷的累积和分配过程

为阐明不同生境对黄河三角洲滨海湿地芦苇磷(P)的累积和分配过程的影响,于2016年5-11月,选取新生芦苇湿地和退耕芦苇湿地为研究对象,测定了芦苇植物体各器官与枯落物的生物量和P含量.结果 表明:①新生湿地和退耕湿地内芦苇各器官生物量均呈现先增加后减少的变化特征,枯落物生物量符合指数型增加模型,退耕湿地内的芦苇生物量高...     

生物质粒径对负载MgO生物炭吸附水体中磷的影响

为研究生物质粒径对负载MgO芦苇生物炭（MBC）去除水体中磷的速率和能力的影响,以0~0.5、1~2和6~8 mm这3种不同粒径的芦苇颗粒为原料、MgCl₂为改性剂制备MBC,用傅里叶变换红外光谱仪（FTIR）、X射线衍射仪（XRD）和扫描电子显微镜（SEM）等对MBC表征,开展MBC吸附溶液中磷酸盐（PO₄^3--P）动力学和等温线实验以及实验数据模型拟合.结果表明,MBC对溶液中PO₄^3--P的吸附速率随生物质粒径增大而增大,0~0.5、1~2和6~8 mm芦苇颗粒制备的MBC对PO₄^3--P的吸附量在2 h内分别达到平衡吸附量的15.4%、25.8%和80.8%,而生物质粒径对MBC的PO₄^3--P最大吸附量（249.0~254.7 mg·g^-1）无明显影响.6~8 mm芦苇颗粒制备的MBC保留了较完整的芦苇细胞壁结构,且含有丰富的微孔和中孔,形成多层次、规则的、连通性好的孔隙结构.0~0.5 mm和1~2 mm芦苇颗粒制备的MBC孔隙结构较差,孔隙连通性受损,影响了磷酸根离子在MBC内部的扩散速率,限制了对磷的吸附速率.因此,以人工湿地收割的废弃植物芦苇为原料制备MBC用于去除水体中磷时,将芦苇破碎至6~8 mm即可,过度破碎会破坏MBC的孔隙结构,减小MBC对磷的去除速率.