共查询到20条相似文献,搜索用时 109 毫秒
1.
立柱无土栽培研究初报 总被引:6,自引:1,他引:6
立柱无土栽培研究初报龚颂福,李止正(中国科学院上海植物生理研究所上海200032)关键词立柱无土栽培;蔬菜;花卉STUDIESONTHESOILLESSCULTURESONVERTICALCOLUMNS¥GongSongfuandLiZhisheng... 相似文献
2.
红豆杉培养细胞紫杉醇的分离及鉴定 总被引:2,自引:0,他引:2
红豆杉培养细胞紫杉醇的分离及鉴定甘烦远,郑光植,彭丽萍,沈月毛(中国科学院昆明植物研究所昆明650204)关键词红豆杉;紫杉醇;细胞培养;分离鉴定ISOLATIONANDIDENTIFICATIONOFTAXOLFROMCULTUREDCELLSOF... 相似文献
3.
SO2和O3动态胁迫烟草致病的暴露试验 总被引:1,自引:0,他引:1
SO_2和O_3动态胁迫烟草致病的暴露试验陈锦云,兰志斌,苏珍山,曾军,王阳青(福建龙岩地区烟科所龙岩364000)关键词S)_2和O_3;烟草;气候斑点病,动态胁迫暴露THEDYNAMICSTRESSEXPOSURETESTONTOBACCOBLADE... 相似文献
4.
叶面喷施磁处理复合肥对新红星(Starkrimson)苹果树营养元素的影响程文林,杨佩芳,刘和,陈晓春,高美英(山西农业大学大谷030801)关键词磁处理复合肥,根外追肥,新红星苹果树,营养元素EFFECTOFMAGNETIZEDCOMPOUNDFE... 相似文献
5.
毛细管气相色谱—负离子化学电离源质谱法测定空气颗粒物中的硝基?… 总被引:1,自引:0,他引:1
本文用毛细管气相色谱-负离子化学电离源质谱法(GC-NICIMS)测定了空气颗粒物中的硝基多环芳烃(NO2-PAH),通过与标准的保留时间和质谱图的比较,确定了空气颗粒物中含有四种NO2-PAH,它们是29-硝基芴,9-硝基蒽,1-硝基芘和2-硝基萤蒽。用同一样品进行了毛细管气相色谱正离子电子轰击源质谱分析,并与GC-NICIMS进行比较 相似文献
6.
在一定自然光照条件下,采用动态烟雾箱,模拟NO_2—空气、NO_2—SO_2—空气、NO_2—水稻—空气和NO_2—SO_2—水稻—空气4种体系中的光化学反应。得出不同起始浓度NO_4在上述各体系中起光化学反应时生成的O-3稳态浓度。研究发现,在NO_2—SO_2—空气体系中O_3稳态浓度比在NO_2—空气体系中平均增加7%,比NO_2—水稻体系中平均增加14%。 相似文献
7.
PACS的结构特征及絮凝性能研究 总被引:11,自引:0,他引:11
制备了碱化度及Al^3+/SO^2-4摩尔比不同的系列PACS,分别进行常压(干燥温度105℃)及真空干燥(真空度为-0.098MPa、干燥温度65℃)制备固体产品。用红外光谱及X-射线衍射谱研究了碱化度、Al^3+/SO^2-4摩尔比、干燥温度对PACS的结构影响,比较了干燥温度不同对PACS固体样品的溶解度及絮凝效果的影响,借助于显微电泳测定技术研究不同碱化度及不同Al^3+/SO^2-4摩尔 相似文献
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9.
H2O2对抗旱性不同玉米品种愈伤组织抗氧化系统的影响 总被引:1,自引:0,他引:1
李玲 《应用与环境生物学报》1999,5(4):347-351
两个玉米品种愈伤组织经10-4molL-1、10-3molL-1和10-2molL-1H2O2处理3h后,电解质泄漏率加大;H2O2和MDA含量增加;AsA和CAR含量的减少.10-4molL-1的H2O2处理对愈伤组织产生的氧化伤害较小.抗旱性较强品种PAN6043愈伤组织的抗氧化酶(SOD、POD、AP和GR)活性高于抗旱性较弱品种SC701,AsA和CAR含量的下降程度低于SC701.PAN6043愈伤组织具有较强的抗H2O2能力,与含高活力抗氧化系统密切相关 相似文献
10.
NOx分解还原催化研究进展 总被引:1,自引:0,他引:1
介绍和评价了NO_x分解还原的3类催化剂:贵金属催化剂、氧化物催化剂、金属离子置换的分子筛。在NO_x的碳氢化合物选择性催化还原反应(HC-SCR反应)中,同样有3类催化剂,即金属氧化物、贵金属和分子筛。由于Cu-ZSM-5是目前最有希望投入实际使用的一种,故本文重点介绍了它对NO_x的HC-SCR反应的催化机理,以及温度、O_2含量、Cu~(2+)的置换度、不同种类HC及HC含量等各种因素对Cu-ZSM-5的影响,并对其工作台试验进行了评价,指出了其存在的问题及当前的研究热点。 相似文献
11.
A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity. 相似文献
12.
Sebastian Theis Jonathan L.W. Ruppert Karling N. Roberts Charles K. Minns Marten Koops Mark S. Poesch 《Conservation biology》2020,34(1):41-53
Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes. 相似文献
13.
Stanger G 《Environmental geochemistry and health》2005,27(4):359-368
An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common
origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further
concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain.
Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and
Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily
redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and
authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above
palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern
Asia. 相似文献
14.
Lucy E. Rose Geoffrey W. Heard Yung En Chee Brendan A. Wintle 《Conservation biology》2016,30(2):350-361
How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty. 相似文献
15.
K.H. Roucoux I.T. Lawson T.R. Baker D. Del Castillo Torres F.C. Draper O. Lähteenoja M.P. Gilmore E.N. Honorio Coronado T.J. Kelly E.T.A. Mitchard C.F. Vriesendorp 《Conservation biology》2017,31(6):1283-1292
Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza‐Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land‐use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon‐dense (domed pole forest) areas. New carbon‐based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development. 相似文献
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17.
Biogeographic theory predicts that rare species occur more often in larger, less‐isolated habitat patches and suggests that patch size and connectivity are positive predictors of patch quality for conservation. However, in areas substantially modified by humans, rare species may be relegated to the most isolated patches. We used data from plant surveys of 81 meadow patches in the Georgia Basin of Canada and the United States to show that presence of threatened and endangered plants was positively predicted for patches that were isolated on small islands surrounded by ocean and for patches that were isolated by surrounding forest. Neither patch size nor connectivity were positive predictors of rare species occurrence. Thus, in our study area, human influence, presumably due to disturbance or introduction of competitive non‐native species, appears to have overwhelmed classical predictors of rare species distribution, such that greater patch isolation appeared to favor presence of rare species. We suggest conservation planners consider the potential advantages of protecting geographically isolated patches in human‐modified landscapes because such patches may represent the only habitats in which rare species are likely to persist. Influencia Humana y Predictores Biogeográficos Clásicos de la Ocurrencia de Especies Raras 相似文献
18.
The macro-algae communities observed in the south lake of Tunis are characterized by the predominance of nitrophilous algae
which are in the order of biomass importance:Ulva, Cladophora andEnteromorpha. We have noted seasonal changes of alga distribution. The wind appears to be one of the most important factors influencing
this distribution. The total biomass reaches a maximum in the spring. Rapid decomposition of the biomass leads to a severe
ecological imbalance, resulting in crises of anoxia and fish death.
A restoration project has already started. It aims at removal of contaminated muds and the introduction of a new circulation
system.
The main objectives of this work were to collect information on the distribution and biomass of the phytobenthic communities
as a first step in the constitution of a database for further comparison. 相似文献
19.
International Union for Conservation of Nature (IUCN) Red List assessments rely on published data and expert inputs, and biases can be introduced where underlying definitions and concepts are ambiguous. Consideration of climate change threat is no exception, and recently numerous approaches to assessing the threat of climate change to species have been developed. We explored IUCN Red List assessments of amphibians and birds to determine whether species listed as threatened by climate change display distinct patterns in terms of habitat occupied and additional nonclimatic threats faced. We compared IUCN Red List data with a published data set of species’ biological and ecological traits believed to infer high vulnerability to climate change and determined whether distributions of climate change‐threatened species on the IUCN Red List concur with those of climate change‐threatened species identified with the trait‐based approach and whether species possessing these traits are more likely to have climate change listed as a threat on the IUCN Red List. Species in some ecosystems (e.g., grassland, shrubland) and subject to particular threats (e.g., invasive species) were more likely to have climate change as a listed threat. Geographical patterns of climate change‐threatened amphibians and birds on the IUCN Red List were incongruent with patterns of global species richness and patterns identified using trait‐based approaches. Certain traits were linked to increases or decreases in the likelihood of a species being threatened by climate change. Broad temperature tolerance of a species was consistently related to an increased likelihood of climate change threat, indicating counterintuitive relationships in IUCN assessments. To improve the robustness of species assessments of the vulnerability or extinction risk associated with climate change, we suggest IUCN adopt a more cohesive approach whereby specific traits highlighted by our results are considered in Red List assessments. To achieve this and to strengthen the climate change‐vulnerability assessments approach, it is necessary to identify and implement logical avenues for further research into traits that make species vulnerable to climate change (including population‐level threats). 相似文献
20.
Parasitic wasps orient to green leaf volatiles 总被引:12,自引:0,他引:12
Summary Undamaged plants emit low levels of green leaf volatiles (GLVs), while caterpillar-damaged and artificially damaged plants emit relatively higher levels of certain GLVs. Female braconid parasitoids,Microplitis croceipes, oriented to both damaged plants and to individual GLVs in no-choice tests in a wind tunnel, but seldom oriented to undamaged plants. Female ichneumonid parasitoids,Netelia heroica, also oriented to individual GLVs in a wind tunnel. Males of both wasp species failed to orient to the GLVs. These data show that leaf-feeding caterpillars can cause the release of GLVs, and that parasitic wasps can respond to these odors by flying upwind (chemoanemotactic response), which brings the wasps to their caterpillar hosts. This supports the hypothesis that plants communicate with members of the third trophic level,i.e., plants under herbivore attack emit chemical signals that guide natural enemies of herbivores to sites of plant damage. In this interaction, the GLVs serve as tritrophic plant-to-parasitoid synomones. That parasitoids from two different wasp families oriented to GLVs suggests that the response may be widespread among the Hymenoptera.Mention of a commercial or proprietary product does not constitute an endorsement by the U.S. Department of Agriculture 相似文献