Seaweed floristic studies along tsunami affected Indian coasts: A litmus test scenario after 26th December 2004     

Vaibhav A Mantri 《Journal of Earth System Science》2006,115(3):371-378

On 26th December 2004, the world witnessed the devastating power of tsunami, affecting many countries, bordering the Indian Ocean region. This has caused significant changes in the shallow and intertidal regions of the Indian coast, especially the Andaman and Nicobar Islands, Tamil Nadu, Kerala and Pondicherry. The baseline data on biomass availability and distribution of benthic intertidal seaweed species were collected immediately after this catastrophic event by spot surveying 11 selected localities of the above-mentioned regions. In all, 45 species belonging to 31 genera were recorded during the present survey, the maximum number of seaweed species were recorded at Thirumullavarum, Kerala with the minimum at Car Nicobar, Andaman and Nicobar Islands. A very different trend was observed in the case of biomass availability at some locations which was due to the influence of habitat suitability over the tsunami damage. The details of this study have been provided in the present communication  相似文献   

沿海表层沉积物中重金属的有效结合态   总被引：13，自引：0，他引：13       下载免费PDF全文

翁焕新  沈忠悦  陈建裕  张兴茂  钟国林 《地质科学》2002,37(2):243-252

以浙江沿海表层沉积物为研究对象,系统地研究了重金属有效结合态与沉积环境、矿物组成和人为排放等环境因素之间的相互关系.结果表明:沿海表层沉积物中重金属的积累数量,呈现出潮汐河口沉积物>沿海沉积物>强潮汐河口沉积物的趋势,这反映了不同沉积类型对重金属富集作用的差异;重金属的有效结合态,总体上以铁锰氧化物结合态>碳酸盐结合态>硫化物及有机结合态>可交换态的顺序存在,但是不同的重金属或同种重金属在不同的采点,主要有效结合态的比例存在明显的差异,这不仅与重金属的地球化学性质、沉积环境和沉积物中的粘土矿物组成有关,更受到重金属污染物的人为排放量的影响.  相似文献   

Closterium cornu Ehrenb. ex Ralfs var. lundellii (Lagerh.) Willi Krieg. 1935 (Desmidiaceae) — eine Taxon-Revision     

Marliese Müller   《Limnologica》2002,32(1)

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Fish zonation in a Mediterranean stream: Effects of human disturbances   总被引：7，自引：0，他引：7  

Anna Vila-Gispert  Emili García-Berthou  Ramon Moreno-Amich 《Aquatic Sciences - Research Across Boundaries》2002,64(2):163-170

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滇西北亚高山针叶林、硬叶栎类林的树种多样性   总被引：2，自引：0，他引：2  

于洋  曹敏  刘文胜 《山地学报》2003,21(5):568-575

在滇西北香格里拉地区,以长苞冷杉(Abiesgeorgei)林、丽江云杉(Picealikiangensis)林作为亚高山针叶林的代表,以川滇高山栎(Quercusaquifolioides)林作为硬叶栎类林的代表,分别选择了6块样地,采用Shannon-Wiener多样性指数(H)、Simpson多样性指数的倒数(D')、Pielou均匀度指数(JH、JD)分别测定其树种多样性,并进行了比较研究。结果表明,三个森林类型的Shannon Wiener指数、Simpson指数的倒数、物种丰富度的顺序均为:长苞冷杉林>川滇高山栎林>丽江云杉林;而前两类森林的Pielou均匀度指数差异不大,但都高于丽江云杉林的均匀度指数值。滇西北的川滇高山栎具有很强的萌生能力。人工种植的亚高山针叶林的树种多样性较原始林低,需要较长时间的恢复过程。亚高山针叶林的存在极大地丰富了云南省的树种多样性,使云南植被的垂直地带性得到了充分体现。  相似文献   

The colonization of periphytic diatom species on artificial substrates in the Ashar canal, Basrah, Iraq   总被引：1，自引：0，他引：1  

H.A. Hameed 《Limnologica》2003,33(1):54-61

Studies have been conducted between March 1993 and March 1994 in the Ashar canal, a backwater of the Shatt al-Arab River, Iraq. Using artificial substrates, the colonization and development of seventy-five diatom species belonging to twenty genera could be revealed. Taxa apportionment varied seasonally as well as within each season. A few species have been found during all experiments. These are Amphora ovalis, Bacillaria paradoxa, Cocconeis placentula var. euglypta, Cyclotella meneghiniana, Cymbella ventricosa, Navicula tripunctata var. schizonemoides, Rhoicosphenia curvata, and Synedra ulna. The occurrence of B. paradoxa in Experiment 1 (March-April 1993) and Experiment 4 (end of January to beginning of March 1994) was higher than 50%. Similarity of species increased towards the end of each season, and the communities from experiments 1 and 4 were more similar than others. The experiments also suggest that week 4 represents the equilibrium phase while week 6 reflects the increase in biological interactions. The results could also indicate the sequence of primary colonizers and the community development towards the equilibrium.  相似文献   

南极中山站近岸海冰生态学研究Ⅲ.冰藻优势种的季节变化及其与冰下浮游植物的关系          下载免费PDF全文

何剑锋  陈波 《极地研究》1997,9(3):22-31

自１９９２年４月１２日至１２月３０日对中山站以西内拉峡湾海冰和冰下水柱中藻类优势种组成和丰度进行了测定。４月份和１１月中旬至１２月中旬冰柱和水柱（０～５０ｍ）藻类丰度高达１０８～１０９ｃｅｌｓ／ｍ２。冰藻的普遍或季节性优势种主要包括Ａｍｐｈｉｐｒｏｒａｋｊｅｌｍａｎｉ、Ｂｅｒｋｅｌｅｙａｒｕｔｉｌａｎｓ、Ｎａｖｉｃｕｌａｇｌａｃｉｅｉ、Ｎｉｔｚｓｃｈｉａｂａｒｋｌｅｙｉ、Ｎ．ｃｙｌｉｎｄｒｕｓ、Ｎ．ｌｅｃｏｉｎｔｅｉ和Ｎｉｔｚｓｃｈｉａｓｐ．。由于藻类结合入冰后自身的演替，春－夏季海冰剖面中所记录的优势种组成并不能准确反映冰底优势种的季节演替过程。从冰底和水表藻种组成的对比表明，两者仅在春末冰底冰藻水华期间具有较强的相似性。秋、春季冰底冰藻水华的形成以现场生长为主，夏初冰藻释放入水后对冰下浮游植物的播种作用不明显。  相似文献   

Amelioration of soil fertility by woody perennials in cropping fields: evaluation of three tree species in the semi-arid zone of Nigeria     

I. A. Jaiyeoba 《Journal of Arid Environments》1996,33(4):473-482

Soil was sampled from cropping fields in radial patterns from beneathAcacia albida, Parkia bigloboza(Jacq.) Benth. andEucalyptus camaldulensisDehnh. near Zaria, Nigeria. Results of analysis show a significant coarsening of soil texture and a decrease in organic matter and cation exchange capacity with increasing distance from all three tree species at a depth of 0–15 cm. Concentrations of nitrogen and some exchangeable cations decreased significantly with increasing distance from beneath acacia and parkia, and soil pH decreased with increasing distance from eucalyptus. The implication of the results for land management are discussed in relation to increasing productivity and soil use sustainability.  相似文献   

Methodical approach to distribution of epilithic and drifting algae communities in a French subalpine river: Inferences on water quality assessment   总被引：2，自引：0，他引：2  

Thierry Rolland  Stéphanie Fayolle  Arlette Cazaubon  Stéphane Pagnetti 《Aquatic Sciences - Research Across Boundaries》1997,59(1):57-73

In a sub-alpine river, the Asse, with an unpredictable discharge regime, chlorophyll, density and taxonomic diversity of both drifting and periphytic communities were studied from a methodical approach. The investigations based on stamping two close cross-sections to know their spatial distributions in a heterogeneous bed substrate showed a heterogeneous pattern of colonization mainly influenced by hydrological variables as the current velocity, the size of the substrata (gravel-pebble-boulder). For the drifting algae, mainly composed with benthic species temporarily unhooked to the substrata, the heterogeneity of the distribution was reduced in fast flow which induced a mixing of the whole mass of water. For the periphyton, some results indicated that the greatest diversity and the highest chlorophyll concentration were found on pebble substratum where the current velocity was moderate. These results have also shown that the classical methods used to day for investigations were inadequate for most Mediterranean rivers. It was really difficult to estimate the water quality from classical index created for use in regular large plain rivers.  相似文献   

Comparative study of activation energies of conductance and desiccation rates of some marine algae     

David G. Rands  Joseph S. Davis 《Aquatic Sciences - Research Across Boundaries》1997,59(3):275-281

Measurements of the activation energy of electrical conductance and desiccation rates on subtidal marine algae from Florida were compared to similar data from the Bay of Fundy, Nova Scotia, on intertidal marine algae frequently subjected to long periods of exposure to air. We have developed a method for calculating the reaction rate constant of desiccation of fully hydrated marine algae. Values of activation energies and desiccation rate constants are consistent with the requirements for survival of these algae under widely different environmental conditions.  相似文献