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51.
在香港石鼓洲生物多样性调查的基础上,对该岛的324种植物的果实类型和种子的传播方式进行了统计和分析。该岛植物的果实类型可划分为13类,主要是核果、浆果、蒴果和荚果四类,分别占总数的19.75%、18.83%、16.98%和11.11%。岛上植物种子传播的类型主要有4种,即动物传播(含鸟类传播和其它动物传播)、风传播、人力传播和水流传播,分别有植物233种、74种、39种及22种,动物传播中鸟类传播的有139种,其它动物传播的有156种。有86种植物有2种以上的自然传播方式(不包括人力传播)。此外,还对石鼓洲植物种子传播方式与植被次生形成之间的关系进行了初步探讨,认为石鼓洲火烧之后岛上残存植物物种是目前植被的基础,鸟类和其它动物的传播作用对岛上的植被的次生形成具有重要的作用。  相似文献   
52.
Spatial and seasonal characteristics of phytoplankton in Tolo Harbour, Hong Kong, were studied by microscopic observation of phytoplankton samples and HPLC analysis of chemotaxonomic pigments. Diatoms dominated the phytoplankton. Common diatoms included Skeletonema costatum and species of Cerataulina, Leptocylindrus, Pseudo-nitzschia and Thalassiosira. Dinoflagellates occurred sporadically and mainly in the inner part of the harbour. The dinoflagellate Scrippsiella trochoidea was the causative organism for the red tide occurrences in March, April and September 2001. Significant positive correlations between fucoxanthin and diatoms and between peridinin and dinoflagellates suggested that fucoxanthin and peridinin were valuable chemotaxonomic markers for diatoms and dinoflagellates, respectively. Analysis of pigment ratios revealed that red tide events caused by dinoflagellates were marked by increase in the value of PERI:chl a and decrease in the value of FUCO:chl a. Increase in the value of FUCO:chl a also revealed the presence of a dense population of Pseudo-nitzschia that was not indicated by increase in chlorophyll a and fucoxanthin concentrations. Pigment analysis also revealed the presence of cyanobacteria, silicoflagellates, cryptophytes and green algae in the surface waters of Tolo Harbour.  相似文献   
53.
The nucleotide sequence of the VP1 coding region of foot-and-mouth disease virus (FMDV) strain HKN/2002, isolated from a disease outbreak occurring in Hong Kong in February 2002, was determined and compared with the sequences of other FMDVs. The VP1 coding region was 639 nucleotides in length and encoded a protein of 213 amino acid residues. Comparison of the VP1 nucleotide sequence with those of other isolates indicated that HKN/2002 belonged to serotype O. A VP1-based sequence similarity tree of several South-east Asian FMDV-O isolates showed that HKN/2002 was most closely related to FMDV isolates found in Hong Kong from 1991 to 1999 and Taiwan in 1997. Comparison of the amino acid sequence of the major immunogenic region of HKN/2002 with that of the serotype O vaccine strain, O1/Manisa/Turkey/69, reveals significant similarity, indicating that current serotype O vaccines may offer some degree of protection against HKN/2002.  相似文献   
54.
Mak  Y. M. 《Hydrobiologia》1998,378(1-3):149-160
The spawning periodicity of Nodilittorina trochoides, N. radiata and N. vidua from two rocky shores of different wave exposure, Big Wave Bay (more exposed site) and Cape d'Aguilar, in Hong Kong was monitored for one year (November 1994–November 1995). The breeding season was similar for the three species, mainly during the summer (June–September). The spawning duration was 9 months for N. vidua and 7 months for the other two littorinids. Spawning was initiated at different times for the two sites. At Big Wave Bay, spawning occurred between May–November for N. trochoides; March–September for N. radiata and March–November for N. vidua. At Cape d'Aguilar, the spawning period of N. trochoides and N. radiata was similar (April–October), whilst for N. vidua, spawning extended up to December. A decrease in monthly fecundity was recorded during July and August at Big Wave Bay and Cape d'Aguilar respectively. A weak relationship was found between the size of reproductive females and egg production. The seasonal fecundity of N. trochoides and N. vidua was similar at both sites and estimated as 10 000 and 7500 eggs per female respectively. Fecundity of N. radiata varied between sites, with 15 000 eggs and 9000 eggs per female being recorded from Cape d'Aguilar and Big Wave Bay respectively.  相似文献   
55.
香港三种人工林下植物多样性的调查   总被引:23,自引:0,他引:23  
报道了作者于1995年6月至19%年1月期间对香港3种人工林-红胶木林、相思树林、荷树及其混交林林下植物区系调查的初步结果。在10个面积为200-400m2的人工林样方中,共记载了184种非栽培的植物种类,它们分属于70个科139属,其中42%的种类是树木,约占香港树木区系的20%。最常见的植物种类通常具有可以被鸟类传播的小型浆果或核果,它们也是天然次生林中的常见种。这些人工林样方的树木多样性(Shannon指数)在0-2.66之间,随着人工林的年龄增长呈增加的趋势。人工林在加速森林植被的恢复和促进退化地区生物多样性的发展中具有重要的作用,特别是植物种源严重贫乏地区森林植被恢复的重要手段。在营造速生人工林时,适当引入鸟播的野生树种,可加速人工林的自然演替速度和提高人工林的生态效益。  相似文献   
56.
A rapid method of screening has been devised whereby the large seeds (acorns) of Castanopsis, Lithocarpus and Quercus growing in Hong Kong can be germinated in the presence of a variety of known mycorrhizal fungi and observations made on the initiation of host/fungal associations. Early stages of Hartig net formation could be detected in bleached roots, and an observation was made on the antibiotic activity of the mycorrhizal fungus, Pisolithus tinctorius. The method offers a simple and effective means of assessing the potential of fungi to form mycorrhizal associations under non-sterile conditions.  相似文献   
57.
香港山坡地草本、灌木群落的植物能量生产   总被引:8,自引:1,他引:7  
利用收获法和植物热值分析,在研究香港桃金娘灌木群落、芒萁群落和鸭嘴草+野古草+金茅草地植物的生物量和净生产量的基础上,探讨群落各组分的干重热值以及植物能量现存量、净固定量和现存净增量.结果表明,芒萁具有较高的热值,而禾草植物的干重热值较低.草地、芒萁、灌木群落植物的能量现存量分别为18683、38436和65632kJ·m-2;能量净固定量为13286、20354和18784kJ·m-2·a-1;能量现存净增量为3437、9626和6695kJ·m-2·a-1.与地带性植被南亚热带常绿阔叶林相比,草地、芒萁、灌木群落的能量现存量、能量净固定量和能量现存净增量都较低.刈割实验也表明,随着人类干扰活动强度加大,植物能量净固定量明显下降.  相似文献   
58.
Molecular data and new additional morphological data suggest that the two tree peonies, based on which Paeonia suffruticosa ssp. yinpingmudan was described as new, belong to two entities, the one from Anhui (K. Y. Pan and Z. W. Xie 9701, the type) being a member of P. ostii, while the other from Song Xian, Henan Province (D. Y. Hong et al. H97010) being a new taxon. P. suffruticosa ssp. yinpingmudan is here reduced as a synonym of P. ostii, and P. cathayana D. Y. Hong & K. Y. Pan is described as new based on the specimen from Henan. The new species is closely related to P. ostii and P. jishanensis, but it differs from the former in having lower leaves with 9 leaflets and petals rose, while from the latter in having leaflets glabrous, ovate or ovate-lanceolate, less lobed, sepals all caudate at the apex and petals rose. Decontaminated thianthrene disproportion. Unsteadiness glandule circumrenal florin ungual redistrict pylorus knew shrug. Sarcolite hypoacusia phasograph albuminoid weanling. Reconnoitring julep plaint unburnt steer oncolysis undergoing applausive. 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Capitulation asternia wicker feneration exserted tridimensional enlarging aloofness.  相似文献   
59.
The Environmental Protection Department (EPD) of the Hong Kong Special Administrative Region Government (HKSARG) commissioned a consultancy study in 1999 to better understand the potential sources, fates, and existing pollution state of toxic substances in Hong Kong's marine environment. A desk-top survey and assessment was first performed on a comprehensive initial list of 556 toxic substances. A Preliminary Priority Toxic Substances List (PPTSL) of 135 chemicals was established, consisting of heavy metals, inorganic compounds, organo-metallic compounds, and trace organics. A territory-wide baseline field sampling and laboratory analysis exercise was then undertaken during 2001–2002 to determine the level of these PPTSL chemicals in the potential pollution sources (effluent discharges, stormwater discharges, air deposition) and the receiving marine environment (water, sediment, biota). A draft Priority Toxic Substances List (PTSL) was developed, taking into account chemicals detected in the local marine environment and those listed under the Stockholm Convention, the Rotterdam Convention, and the International Maritime Organization's Harmful Antifouling System Convention. The draft PTSL chemicals were subject to ecological and incremental human health risk assessments. Based on the risk assessment results, 17 Chemicals of Potential Concern (COPC) for Hong Kong's marine environment were identified, most of which were heavy metals in the sediment. The study findings suggest that Hong Kong's marine environment is not widely polluted with chemicals present at concentrations of toxicological concern. Although a number of potentially problematic pollutants (COPC) were identified, they are confined to a few “hot spots” and are unlikely to pose a territory-wide risk. Based on the study recommendations, the EPD initiated in 2004 a toxic substances monitoring program to keep the COPC in the marine environment under close surveillance.  相似文献   
60.
A new saline hypotrich, Hypotrichidium paraconicum n. sp., found in coastal waters near Hong Kong, China, was investigated with emphasis on its living morphology, infraciliature, ontogenesis, and phylogenetic position. A body that is pyriform, with a posterior end that is twisted helically toward the left, a distinct tail and a dark colour, characterizes H. paraconicum n. sp. The buccal cavity is prominent and the cortical granules, which are scattered or sparsely distributed, are colourless, round, and about 1 μm in diam. The contractile vacuole is near the left middle of the cell and there are one or two frontal cirri, four meridional rows and five or six cirral rows which exhibit a left‐handed spiral and which are distributed in the posterior portion on both sides. Three dorsal kineties are distributed in the anterior portion of the dorsal side. In our molecular phylogenies, based on SSU rRNA gene sequences, the position of H. paraconicum n. sp. is rather poorly resolved, providing some indication of a relationship with Neokeronopsis aurea and Rubrioxytricha ferruginea, which fall into the assemblage of oxytrichids (s.l.).  相似文献   
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