文章摘要
费鸿年,何宝全,陈国铭.南海北部大陆架底栖鱼群聚的多样度以及优势种区域和季节变化[J].水产学报,1981,5(1):1~20
南海北部大陆架底栖鱼群聚的多样度以及优势种区域和季节变化
THE REGIONAL AND SEASUNAL VARIATIDNS OF DIVERSITY AND DDMINANT SPECIES OF DEMERSAL FISH COMMUNITIES IN CUNTINENTAL SHELF OF NURTHERN NAN HAI
  
DOI:
中文关键词: 
英文关键词: 
基金项目:
作者单位
费鸿年 南海水产研究所 
何宝全 南海水产研究所 
陈国铭 南海水产研究所 
摘要点击次数: 1388
全文下载次数: 1006
中文摘要:
      本文提出了关于南海北部大陆架底栖鱼类群聚若干属性的区域性和季节性变化研究概略。采集鱼类是在1964年3月到1965年2月由3艘研究船在137,667平方公里范围内人为地划成8小区共计51采集点进行的。在每一点拖2小时,每一样品当作一个鱼类群聚。本研究仅使用3月、6月、10月和12月代表春、夏、秋、冬四季的资料。 种类多样度是鱼类群聚的一个重要属性,在几种计算方法中,本文应用了修改过的Shannon-Weaver公式,并用生物量代替了个体数的算法。一般这样算出的指数值略高于用个体数算出的结果。本研究算出H″ 的变化幅度为1.40到4.40,与国外发表的近海底拖网鱼类多样度指数相比是最高的。作了多样度等值线群分布图,四个月份有差异,但还不能作出明显关系的判断。H″ 与温度、水深有相关。 另作了3种与多样度有关连的参数计算:(1)种类数(H);(2)最大多样度(Hmax);(3)种类均匀度(J)。(1)、(2)两种参数变化有伴随关系,均匀度有类似于多样度变化的倾向。 优势种的组成是群聚的第一种基本属性。我们把优势种概念与信息量相结合作了详细解释,根据这一新概念,我们把一个种类在样品渔获量中占20—60%的作为优势种,在8小区和4个月中共见到有优势种47种,频度变化很复杂,用英文字母来代表优势种作了用代码的优势种频度分布模式图,可以直观地看出一些表面的现象。但不仅优势种与多样度数值关系还没有找到, 优势种种群变动本身问题也还需要进一步连续研究和积累资料。
英文摘要:
      In present paper, an outline is given of results of investigation concerning regionaland seasonal changes of some criterin of bottom fish communities in the continenta shelf of northern Nan--Hai. Fish collection was made by three research vessels duringMarch 1964 through Febraury 1965. Fifty-one sampling sites were assigned within 8arbitrarysub--areas of the shelf, which cover an area of 137,667 Km2. Towing time oftrawlnet around each site was 2 hours, Every sample of fish was considered as a fishcommunity, of which only the data of March, June, September and December weretreated as representatives of spring, summer, fall and winter respectively. Species diversity is the principal criterion of fish community and there are severalmodels for computing the index of diversity. The modified Shannon--Weaver formulawas employed in the present paper. For eliminating the bias arosing from the discre-pancy of weight of individuals in samples, we used biomass units instead of numbers.Thus, the actual formula we used was H" = -∑ from (wt/w )log2(wt/w)where wt is the biomass of i-th species in sample, w the biomass of sample. The resultsof implementation of biomass units suggest that this modified computing method mightbe convenient for practical purpose, but the values obtained in terms of biomass tendedto be slightly higher then those in terms of numbers. In the range of the indexes of diversity overall sites within the studied periord,the lowest was 1. 41 occurred at a site of V sub-area in September and the highest was4. 40 at a site of IV sub-area in June. In comparing with the published values of H" ofcoastal bottom-trawled fishes, our figures may be ranged as the highest one. An isopleth diagram of H" was drawn, it was found that the distribution patternof isopleth families in different seasons was distinct each other, but no explicit relation-ship could be ruled out, as the data were still insufficient. The relations of H" withshelf-depth and temperature were also investigated and it seems some possible correla-tions could be found. In conjunction with species diversity, 3 other parameters were calculated:number of species contained in community (S); (2) maximum of species diversity(H_(max)); (3) evenness of Species (J). The Pattern of variations was apparent in theindexes calculated. The variation of H_(max) followed the pattern of S, while the evennessof species (J) shows close association with the trend of species diversity (H"). The component of dominant species is a second fundamental critirion of fishcommuncties and we proposed to formulate a concept of dominant species in con-nection with imformation theory, its interpretation being given in detail. Thus, anyspecies of fish comprised 20--60% of catches in one specified sample is defined as adominant species (D. S.); 24 D. S. were observed in 8 sub-areas and 4 months, andtheir frequencies of occurrence in each sub--area and month showed a wide range. Acode diagram is drawn to demonstrate the regional and seasonal distribution of frequen- cy of D. S., so that the transmission and replacemeat of D. S. between areas or seasonscan be found intuitively. But the situation is very complex, therefore the possiblerelationship between species diversity and dominant species still remains unknown, andthe problem of dynamic of dominant species population itself needs further consecutivestudy and data accumulation.
HTML   查看全文   下载PDF阅读器
关闭

手机扫一扫看