广东省草皮种植场和城市草坪红火蚁发生为害程度调查

[背景]在防控红火蚁的工作中,有效控制该虫传播途径、降低传播风险是预防的关键。随草皮调运传播是红火蚁扩散的重要方式之一。[方法]采用活蚁巢密度、诱集比率、诱集工蚁数量、发生率等多个指标,调查评价了广东省主要草皮种植地区广州石基、广州增城、深圳南山、惠州博罗等草皮种植场和城市绿化草坪红火蚁发生程度。[结果]广东省草皮种植场红火蚁发生普遍,携带该虫扩散传播的风险极大。不同地区草皮种植场红火蚁发生程度存在明显差异。惠州博罗草场红火蚁发生程度最重,活蚁巢密度、诱集比率、诱集工蚁数量和发生率分别为0．0085个·m^-2、56．75％、16．80头·个^-1和83．60％;深圳南山发生程度最轻,各项指标分别为0．0011个·m^-2、9．62％、0．92头·个^-1和24．50％。城市绿化草坪红火蚁发生较为普遍。调查的3个城市中惠州发生程度最重,活蚁巢密度、诱集比率、诱集工蚁数量和发生率等均最高,分别为0．0149个·m2、10．46％、14．30头·个-1和62．86％。不同品种草坪草红火蚁发生程度不同,以假俭草最高,以上4个指标分别为0．0140个·100m^-2、6．85％、5．57头·个^-1和51．43％。城区类型不同红火蚁发生程度不同,老城区红火蚁发生较轻,新城区较重,发生点常在移植草坪、绿化苗木区域。[结论与意义[广东省主要草皮种植区和城市草坪红火蚁发生均较为普遍,运输携带该虫传播的风险极大,研究结果可为加强草皮检疫、防止携带红火蚁传播提供依据。     

草坪地灰翅夜蛾的发生与防治药剂筛选

灰翅夜蛾Spodoptera mauritia是危害草坪的重要害虫。药剂测定试验表明,抑太保,氯氰菊酯,灭多威等药剂对灰翅夜蛾有较高毒力。对3龄初幼虫的LC50为0.4895-2.3672mg/L。4龄以上害虫耐药性显著增强。     

结缕草(Zoysia japonica)在镉(Cd)污染农田上开发与应用的研究

为了对Cd污染农田实施农业生态整治及安全高效利用,将Cd污染土壤作为一种特殊的资源,在Cd污染农田建植绿化草坪繁育基地是近年提出的新方法。Cd污染地各种草坪草富集Cd含量的结果表明,结缕草是对污染地中Cd的摄取富集量最低的草坪品种,进行异地栽植,不会造成二次污染,并改变了土壤层中Cd的浓度构成。通过采用草坪生产模式,消除食物链中Cd的危害,为重金属污染地的生物修复和开发利用探索新的途径。     

High white-tailed deer densities benefit graminoids and contribute to biotic homogenization of forest ground-layer vegetation

Biotic homogenization, with its emphasis on invasions, extinctions, and convergence in taxonomic similarity, provides an important framework for investigating changes in biodiversity across scales. Through their selective foraging, large populations of white-tailed deer are altering population sizes, driving extirpations, and facilitating invasions of plants throughout the eastern United States. I hypothesize that deer can drive biotic homogenization in forest understory communities by shifting species composition to one dominated by grasses, sedges, and ferns (all wind-pollinated plants). I report the effects of 16 years of deer exclusion in a hemlock-northern hardwood stand in N Wisconsin using a block design. Species composition showed greater convergence in control plots than exclosure plots, indicating deer can drive biotic homogenization at the stand level. Total percent cover is nearly 4 times greater in exclosure plots. Percent cover by woody plants, broadleaf herbs, and ferns is 150, 63, and 20 times greater in exclosure plots, respectively, while cover by sedges and grasses is 3.8 and 2.2 times greater in control plots. Cover by species with showy, insect-pollinated flowers is 79 times greater in exclosures. Graminoid-dominated control plots represent a novel state not observed fifty years ago, and could reflect the emergence of a grazing lawn. The increase in graminoids at this study area and throughout the region could under some global change scenarios be an early stage of conversion from forest to savanna or wood pasture.     

翦股颖和高羊茅对铜、铅吸收及耐受性

测定了高羊茅和翦股颖两种草坪植物在Cu、Pb污染下发芽率、叶绿素、净光合速率和SOD的变化,以及两种草对Cu、Pb的吸收.结果表明, 重金属污染对高羊茅种子的萌发产生显著影响.高浓度Pb污染以及Pb、Cu复合污染对高羊茅的叶绿素影响很大,Cu单独污染对高羊茅叶绿素的抑制作用较小.翦股颖的叶绿素变化不显著.在3个Pb处理及350 mg·kg^-1 Cu处理下,翦股颖的SOD活性均高于对照,而只有在700 mg·kg^-1Pb 和350 mg·kg^-1 Cu+1 100 mg·kg^-1 Pb处理下高羊茅的SOD活性才升高.高羊茅的净光合速率受Cu污染影响较小,而受Pb污染影响较大.在Cu、Pb单独污染条件下,翦股颖净光合速率均呈下降趋势.从生理角度来看,翦股颖对Cu、Pb污染的耐受性强于高羊茅,而高羊茅对Cu污染的耐受性强于Pb.高羊茅Cu吸收量大,但Cu吸收量不随污染浓度升高而升高.翦股颖对土壤Pb的吸收能力较强, 且Pb吸收量随污染浓度的增加而增加.翦股颖和高羊茅可分别用于Pb和Cu污染土壤的治理.     

鲁西北草坪植食性昆虫的种类组成及危害现状

普查了鲁西北地区草坪植食性昆虫的种类 ,共发现草坪植食性昆虫及其它有害动物 5 5种 ,其中成灾种类 2 0多种 ,例如危害禾本科草坪的草地螟、赤须盲蝽、麦牧野螟、灰飞虱和叶蝉类、危害白三叶草的烟蓟马、甜菜白带野螟、豆卷叶螟和多种盲蝽象以及在两类草坪上均造成严重危害的大青叶蝉、黄地老虎和蛴螬类等 ,首次报道了小蓑蛾和梨冠网蝽可对三叶草造成危害。研究了草坪害虫的分布特点及主要害虫的消长规律 ,发现不同区域、不同栽培环境害虫种类组成不同 ;同一区域在不同年份、不同季节优势种群不同。并针对草坪害虫的时空分布提出了几点治理对策     

Polycation inhibition of exocytosis from sea urchin egg cortex

Summary The Ca²⁺-stimulated release of vesicle contents from cortical fragments prepared from sea urchin eggs is an in vitro model for exocytosis. Cortical fragments have been isolated either in suspension (cell surface complex, CSC preparation), or attached to polycation-coated surfaces (cortical lawn, CL preparation). CL, but not CSC, have been reported to undergo a rapid aging process whereby they fail to respond to micromolar free Ca²⁺. Since, in principle, the only difference between the two preparations is the use of polycations in the CL preparation, polycations were suspected of being inhibitory. This hypothesis was tested by evaluating the effects of polycation-containing buffers on the Ca²⁺ threshold, rate, and extent of exocytosis in CL prepared from the eggs ofStrongylocentrotus purpuratus. A sensitive microphotometric assay, based on light scattering by the individual cortical vesicles in the CL, was used to quantitate the exocytotic response. Buffers containing polylysine were found to be potent inhibitors of cortical exocytosis. The Ca²⁺ threshold of CL that had been treated for 15 min at room temperature with 50 g/ml of polylysine was more than three orders of magnitude greater than that of freshly prepared CL. The other polycations tested (protamine, spermine and neomycin) were also found to be inhibitory, but to a lesser degree than polylysine. Two lines of evidence suggested that the polycations used in the preparation of CL are responsible for the rapid aging phenomenon: (i) CSC fragments that had been affixed to polylysine-coated coverslips were shown to aquire aging characteristics similar to the CL preparations; control CSC that had been maintained in suspension did not. (ii) Radiolabeled poly-l-lysine was shown to dissociate from coated coverslips and redistribute onto CL.     

Measuring environmental value for Natural Lawn and Garden Care practices

Background, Aims and Scope   Measuring Environmental Value for Natural Lawn and Garden Care Practices provides a life cycle assessment and impacts valuation methodology to quantify environmental (public health and ecological) and water conservation benefits from natural lawn and garden care practices in Seattle. Seattle Public Utilities (SPU) initiated this study as part of a triple-bottom-line analysis of its Natural Lawn and Garden Care program. Methods  The study uses life cycle assessment (LCA) methods, including the Carnegie-Mellon Economic Input-Output Life Cycle Assessment (EIOLCA) tool publicly available on the Internet, to inventory pollutant generation from a synthetic nutrients and pesticide approach to lawn and garden care compared against a natural/organic care approach. The study applies US Environmental Protection Agency’s TRACI (Tool for the Reduction and Assessment of Chemical and other environmental Impacts) climate change, acidification, eutrophication, and human health-criteria air pollutant stressor factors, along with the Lawrence Berkeley National Laboratory’s CalTOX risk assessment model’s human and ecosystem toxicity potentials to roll up the numerous pollutant quantities into six environmental impact categories (global warming potential, human respiratory disease potential, human toxicity potential, ecological toxicity potential, acidification potential and eutrophication potential). The study develops cost valuation estimates for each impact category to produce a dollar estimate of the environmental cost of the two archetypical lawn and garden care methods. Results  Lawns and gardens account for 25% of Seattle’s land area, so lawn and garden care methods potentially have substantial impacts on the city’s land-and water-based ecosystems. LCA methods provide an informative methodology for comparing environmental impacts from lawn and garden care practices. These methods reveal the importance of more natural lawn and garden care practices. They also show that resource extraction and manufacturing impacts of pesticides and synthetic fertilizers dominate their on site use impacts in the case of global warming, but that the reverse holds for human and ecological toxicity, and eutrophication. In addition, releases of particulates, SO_x and NO_x associated with gasoline-powered lawn mowing are nearly an order of magnitude larger than releases of these pollutants as a result of the production of pesticides and fertilizers. Discussion  The study proceeds by using available data and research to build a desktop model that characterizes and contrasts two archetypical lawn and garden care practices: (1) Petroleum-based fertilizers and pesticides, a gasoline-powered lawn mower, and substantial irrigation to maintain a traditional weed-free, always-green lawn and garden, versus (2) A backyard compost system to provide lawn and garden nutrients, supplemented moderately by purchased non-synthetic soil amendments, an electricity-powered mower, no pesticides, and drought tolerant lawn and garden species having little need for irrigation. Conclusions  The study concludes that each household converting from synthetic to natural practices produces nearly $75 in annual ongoing public health, ecological, water conservation and hazardous waste management benefits — between $16 and $21 of environmental benefits from reduced use of synthetic fertilizers and pesticides, $8 of environmental benefits for switching from gas to electricity for lawn mowing, $42 in cost savings due to reduced irrigation, and $5 or $6 from lower hazardous waste management costs. There also is a potential one time avoidance of $31 in construction costs resulting from reduced need for storm water detention and diversion capacity. Recommendations and Perspectives  This study’s estimates of environmental value would benefit from comprehensive information on direct exposure to active ingredients in insecticides during their application. Estimates of impacts are based only on volatilization and runoff of active ingredients after application. Furthermore, the study would benefit from estimates of carbon sequestration in soils promoted by natural lawn and garden care techniques, and on the upstream pollutant releases from production of synthetic versus organic fertilizers. All three of these data gaps suggest that the estimated $75 per single family residence for environmental value is probably a lower bound on benefits from natural lawn and garden care versus more traditional pesticide-and-synthetic-fertilizer-based approaches. ESS-Submission Editor: Mary Ann Curran (curran.maryann@epa.gov)     

林下广场、无林广场和草坪的温湿度及人体舒适度

园林绿地是缓解城市热岛效应的有效途径,绿地在降温增湿方面发挥着重要作用。选择北京市万芳亭公园林下广场、无林广场和草坪作为研究对象,对三者调节城市小气候的效应进行了定量化研究。每天8:00～18:00,每2h一次分别对林下广场、无林广场和草坪的温度、相对湿度进行同步测定,连续测定7d。结果表明:在一天中的高温时段(12:00～16:00),林下广场的温度最低、相对湿度最高;在傍晚(18:00)草坪的温度最低、相对湿度最高。与无林广场相比,林下广场的降温幅度为0.3～3.3℃,平均值为1.9℃;增湿幅度为1.1%～5.9%,平均值为4.1%。林下广场的日最高温度值是最低的,可大大缩短高温持续时间,最多可缩短8h。在一天中的任何时刻,林下广场和无林广场的温度、相对湿度差异均达到了极显著水平(Duncan’s多重比较,p<0.01)。林下广场调节城市小气候的功能最佳,人体舒适度最好,是夏季人们户外活动的较佳选择。     

上海地区新入侵草坪害虫早熟禾拟茎草螟的鉴定及危害

在上海发现一种取食观赏草坪矮生百慕大Cynodon dactylon的草螟科新害虫。为了明确这一新害虫的分类地位、 寄主及危害状况, 本研究在形态鉴定的基础上, 结合线粒体细胞色素氧化酶亚基Ⅰ （COI/cox1）的测序和比对方法, 对其分类地位进行了核实; 并调查了其在上海地区草坪草上的发生及危害现状。形态鉴定结果表明, 这一新害虫为原产于北美的早熟禾拟茎草螟Parapediasia teterrella, 是中国新记录属种。序列比对显示, 目标样本656 bp的cox1序列与NCBI中已提交的P. teterrellus的4个COI条形码序列覆盖率为100%, 同源性达100%, 表明分子遗传数据支持形态鉴定结果。调查发现, 早熟禾拟茎草螟寄主主要为矮生百慕大, 已在上海多个区县形成危害, 局部地区危害严重, 种群密度最高的区域达740头/m²。早熟禾拟茎草螟是中国新发现的入侵害虫, 已明确其在上海地区能定殖、 扩散, 并形成经济危害, 其入侵将威胁我国草坪产业和园林绿化的健康发展, 需引起足够重视。