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641.
不同栽培基质对石山珍稀濒危植物苗期生长的影响 总被引:6,自引:0,他引:6
对 6种石山珍稀濒危植物在石灰岩土壤和酸性红壤上的苗期生长状况及体内化学元素含量进行了对比研究 ,结果表明 :(1 )每种植物在 2种土壤上的物候学特征基本一致 ;(2 )小花异裂菊和青檀在石灰岩土壤上生长量比酸性土壤上高 ,海南椴在酸性土壤上生长量比石灰岩土壤上高 ;(3 ) 6种植物体内Ca、B 2种化学元素的含量是石灰岩土上比酸性土上高 ;除小花异裂菊外 ,Al在其它 5种植物中的含量都是酸性土上高于石灰岩土上 ,小花异裂菊则是石灰岩土上高于酸性土上 ;(4 )K、Zn、B的生物吸收系数是石灰岩土高于酸性土 ,而N、P、Ca、Mg、Fe、Al、Mn则是酸性土高于石灰岩土。 相似文献
642.
This study was to investigate the activities and contents of 137Cs in the profiles of selected arable and forest soils in Taiwan and various solid-phase species of 85Sr and 137Cs in selected arable soils in Taiwan. The gamma (γ) ray spectra of the collected soil samples and some of the soils amended
with 85Sr and 137Cs were measured. The data indicate that the arable soils from Sanhsing series, Sanhsing Township and Chuangwei series, Chuangwei
Township, Ilan County, and from Tunglochuan series, Pinglin Township, Taipei County shows significantly higher radioactivity
of 137Cs (ND − 11.0 ± 0.2 Bq kg−1). Furthermore, the radioactivity of 137Cs in the mountain soils (1.24 ± 0.07 − 42 ± 1 Bq kg−1) from Yuanyang Lake Nature Preserve among Ilan, Taoyuan, and Hsinchu Counties is the highest among the investigated mountain
forest soils. This may be mainly attributed to the fact that Ilan County is located in the northeastern part of Taiwan and
faces the northeastern and northern seasonal winds with lots of precipitation annually from mid-autumn through mid-spring
next year and is receiving greater amount of fallouts yearly. Due to longer reaction period (≥3 y) of 137Cs with soil components, 137Cs was mainly in the forms bound to oxides and to organic matter in the soil amended with 137Cs and in the soil contaminated with 137Cs. On the contrary, due to shorter reaction period (<60 d) of 85Sr with soil components, 85Sr was mainly in exchangeable form and partially in the forms bound to carbonates and oxides in the soils amended with 85Sr. 相似文献
643.
In urban cities, the environmental services are the responsibility of the public sector, where piped water supply is the norm
for urban household. Likewise, in Beirut City (capital of Lebanon) official water authorities are the main supplier of domestic
water through a network of piping system that leaks in many areas. Beirut City and its suburbs are overpopulated since it
is the residence of 1/3 of the Lebanese citizens. Thus, Beirut suffers deficiency in meeting its water demand. Water rationing,
as a remedial action, is firmly established since four decades by the Lebanese Water Authorities. Consumers resorted then
to private wells to supplement their domestic water needs. Consequently, household water quality is influenced by external
factors relating to well water characteristics and internal factors depending on the types of the pipes of the distribution
network and cross connections to sewer pipes. These factors could result in chemical and microbial contamination of drinking
water. The objective of this study is to investigate domestic water quality variation in Beirut City emerging form the aforementioned
factors. The presented work encircles a typical case study of Beirut City (Ras Beirut). Results showed deterioration pattern
in domestic water quality. The predicted metal species and scales within the water pipes of distribution network depended
on water pH, hardness, sulfate, chloride, and iron. The corrosion of iron pipes mainly depended on Mg hardness. 相似文献
644.
Evaluating the impacts of point source discharges on fish species in estuarine environments can be challenging because of
a paucity of resident species. We evaluated the biology of rock gunnel (Pholis gunnellus) at three relatively uncontaminated sites in the Bay of Fundy, along the Atlantic coast of Canada. Rock gunnel are seasonally
resident (April to November) in tide pools, but little was known about their life history in Atlantic Canada or their potential
for use for monitoring environmental quality. Fish were collected between April and November, and ranged from 2.46 g--15.2~g
in weight and 97 mm-170 mm in length, with a maximum age of 7 years. Both males and females were similar in size, and both
reached sexual maturity at a size of 5.5 g. Organ weights and condition indices of fish were stable from spring when they
returned from offshore (April to May) until late summer (August to September), but fall fish (October to November) had slightly
larger gonads, livers and condition indices. Rock gunnel may be a useful indicator to provide insight into local impacts of
point sources over a short time period. However, they do not provide adequate information on reproductive development and
performance since they are not exposed to onshore contaminants during the periods of gonadal development that have most commonly
found to be sensitive to anthropogenic stressors. 相似文献
645.
Directly comparable data on the environmental and socio-economic impacts of alien species informs the effective prioritisation of their management. We used two frameworks, the Environmental Impact Classification for Alien Taxa (EICAT) and Socio-Economic Impact Classification for Alien Taxa (SEICAT), to create a unified dataset on the severity and type of impacts caused by alien leporids (rabbits and hares). Literature was reviewed to collate impact data, which was categorised following EICAT and SEICAT guidelines. We aimed to use these data to identify: (1) alien leporid species with severe impacts, (2) their impact mechanisms, (3) the native species and local communities vulnerable to impacts and (4) knowledge gaps. Native species from a range of taxonomic groups were affected by environmental impacts which tended to be more damaging than socio-economic impacts. Indirect environmental impacts were particularly damaging and underreported. No impact data were found for several alien leporid species.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01642-7. 相似文献
646.
兰州市大气污染对绿化树种叶绿素含量的影响 总被引:1,自引:1,他引:0
为了筛选出兰州市大气污染的抗性树种和敏感监测树种,对树种的叶绿素a、叶绿素b含量进行了测定,运用spss11.5软件分析。研究发现:同一绿化树种在不同功能区的叶绿素含量不同,存在极显著性的差异。随着功能区污染程度的加深,绿化树种的叶绿素含量(ωa、ωb、ωa+ωb)呈现减小的趋势,但叶绿素ωa/ωb值却呈现增大的趋势。绿化树种抗污染能力为:杨树小叶黄杨椿树国槐圆柏,兰州市主要功能区的污染程度为:兰炼厂区兰化厂区橡胶厂西关西站交大兴隆山。 相似文献
647.
648.
Liu CW Huang YK Hsueh YM Lin KH Jang CS Huang LP 《Environmental monitoring and assessment》2008,138(1-3):181-190
This study investigated total arsenic (As) and As species contents of oysters (Crassostrea gigas) in different production areas, seasons and sea locations on the southwestern coast of Taiwan. Analytical results indicate
that contents of total As, arsenite, arsenate, dimethylarsinic acid, monomethylarsonic acid and arsenobetaine in oysters are
9.90 ± 3.68, 0.091 ± 0.104, 0.033 ± 0.038, 0.529 ± 0.284, 0.037 ± 0.046 and 3.94 ± 1.33 mg/g (dry wt), respectively. A ratio
of inorganic As concentrations to total As concentrations is 1.26%. Total As contents of oysters cultured in the outer sea
are statistically significantly lower than those of oysters cultured in the inner sea. The total As contents of oysters is
the highest in Putai, where the blackfoot disease prevails. The low As contents in oysters is attributed to the low temperature
in winter, which slows the metabolism of oysters. A maximum value is 33.37 μg/g (dry) in Putai in spring, because a considerable
amount of aquacultural waste water with high As contents is discharged into adjacent drainage channels and rivers there during
that season. 相似文献
649.
The magnetic properties of tree leaves along with their ecological, economical and aesthetic importance can be used to control
road derived respirable particulates. Isothermal remanent magnetization (IRM300 mT) of three different tree leaves viz. Mango (Mangifera indica), Sisso (Dalbergia sisso) and Banyan (Ficus benghalensis) were determined and IRM300 mT normalized for the leaf area. The normalized 2-D magnetization of leaves as shown by results is dominantly controlled
by leaf morphology and traffic density. F. benghalensis (Banyan) leaf has highest 2-D magnetization and D. sisso (Sisso) leaf having least 2-D magnetization suggesting greater ability of F. benghalensis (Banyan) tree leaves to reduce magnetic particulates. The particle size of the magnetic grains falls in the category of PM2.5,
a particle size hazardous to human health due to its capacity to be inhaled deeply into the lungs. 相似文献
650.
长江常熟江段近岸小型鱼类群落结构及多样性探析 总被引:2,自引:0,他引:2
2009年3月~2010年2月,利用密目插网对长江常熟江段小型鱼类进行了连续监测,首次对该江段的小型鱼类群落组成、优势种组成及生物多样性进行了剖析。结果表明:该江段共有小型鱼类24种,隶属于5目7科,其中鲤形目最多。根据〖WTBX〗IRI〖WTBZ〗指数分析,贝氏〖FK(W1。1〗〖PS餐鱼1.eps〗〖FK)〗、刀鲚、窄体舌鳎、蛇鮈和光泽黄颡鱼为优势种,共占总数量的83.44%,占总重量的8202%;贝氏〖FK(W1。1〗〖PS餐鱼1.eps〗〖FK)〗和窄体舌鳎在各个季节中均为优势种,刀鲚在春、夏、秋3季为优势种。基于渔获数量的分析结果显示,常熟江段各月多样性特征值范围为:Shannon Wiener指数(H’) 118~176, Margalef指数(R)087 ~207,Pielou指数(J’)048~083,McNaughton指数(Dn) 057~086。Margalef指数和McNaughton指数春季最高,冬季最低;Shannon Wiener指数和Pielou指数冬季最高,夏季最低。最后探讨了影响该江段小型鱼类群落结构的各种因素,提出了合理开发和保护小型渔业资源的建议 相似文献