东海带鱼摄食习性、饵料基础及与渔场的关系   总被引：9，自引：1，他引：9  

陈亚瞿  朱启琴 《水产学报》1984,8(2):135-145

本文对东海主要渔场中带鱼Trichiurus lepturus Linnaeus的摄食习性、饵料浮游生物的群落结构及数量分布等进行了阐述和分析，并对其与渔场间的关系进行了探讨。研究结果表明，东海带鱼是一种以磷虾等甲壳动物和小型鱼类等为主食，并兼食头足类、毛颚动物等的杂食性鱼类。研究结果还阐明浮游动物生物量及磷虾等的数量分布同东海带鱼渔场的位置变化和鱼群移动的关系密切，其中冬、春季浙江南部近海渔场；夏、秋季长江口及海礁、舟山等渔场，其关系尤为明显。  相似文献   

南沙群岛重点岛礁潟湖微型浮游动物的群落结构与摄食     

赵常升  刘永  肖雅元  谢志超  王学锋  李纯厚 《水产学报》2022,46(6):973-983

潟湖是岛礁生物多样性演变的重要环境场,在岛礁水生态系统的物质循环和能量流动中发挥重要作用,而微型浮游动物的生态功能研究是解析南沙群岛岛礁水域潟湖生态系统初级生产力组成、流向、能量流动效率的重要研究内容之一。实验通过对南沙群岛重点岛礁渚碧礁、美济礁与永暑礁潟湖表层水域中微型浮游动物与生态环境调查,研究了其群落结构及其与环境因子的关系,并通过稀释培养实验研究了微型浮游动物的摄食压力。结果显示,调查水域共发现微型浮游动物20种,总丰度的范围为320～1 460个/L,以无壳纤毛虫丰度最高。无壳纤毛虫在渚碧礁潟湖西部水域（ZB-1）丰度最高,砂壳纤毛虫峰值则出现在永暑礁潟湖中部水域（YS-3）,桡足类幼体丰度最大值出现在美济礁潟湖北部水域（MJ-2）。聚类分析结果显示,3个岛礁潟湖中部区域的微型浮游动物群落相似度较高,溶解氧是影响群落结构的最重要因素,特别是对MJ-3站位影响最为突出。摄食实验结果显示,3个岛礁潟湖水域浮游植物生长率为0.22～1.36 d^-1;微型浮游动物摄食率范围为0.22～0.60 d^-1,微型浮游动物每天约摄食浮游植物现存量的...  相似文献   

中国对虾养成期间虾池水体和底质中细菌含量的变化   总被引：34，自引：2，他引：34  

高尚德  陈旭仁  吴以平 《水产学报》1994,18(2):138-142

中国对虾养成期间虾池水体和底质中细菌含量的变化高尚德，陈旭仁，吴以平（青岛海洋大学，２６６００３）（青岛教育学院，２６６００１）关键词养虾池，细菌数量，变化ＶＡＲＩＡＴＩＯＮＯＦＴＯＴＡＬＢＡＣＴＥＲＩＡＮＵＭＢＥＲＩＮＳＨＲＩＭＰＰＯＮＤＷＡＴＥＲ...  相似文献   

珠江斑鳠年龄和生长的研究↑（*）   总被引：4，自引：0，他引：4  

陈焜慈  邬国民  李恒颂  李大疆  邓国成  黎镇芳  胡隐昌 《中国水产科学》1999,6(4)

观察珠江斑鳠的胸鳍和鳃盖骨,研究其年龄特征、渔获物年龄组成和体长、体重组成,并对其体长与鳃盖骨长、体长与体重的关系,以及生长规律进行了分析。其年轮形成时间为１２ 月～翌年３ 月;体长与鳃盖骨长的关系式为Ｌ＝ ３４ ．７６ Ｒ＋ ０ ．４５３ ３ ,体长与体重的关系式为 Ｗ＝ ０ ．０３２ Ｌ３ ．１８７ ２ 。生长Ｖｏｎ Ｂｅｒｔａｌａｎｆｆｙ方程分别为Ｌｔ ＝ １５６ ．７５〔１ － ｅ－ ０ ．０８９（ｔ－ ０ ．０１６ ８）〕和Ｗｔ ＝ ３１ １９３ ．１７〔１ － ｅ－ ０ ．０８９（ ｔ－ ０ ．０１６ ８）〕３ ．１８７ ２ 。还讨论了年轮形成原因和生长特性,并对合理利用自然资源和生产养殖提出建议。  相似文献   

Genome-wide analysis of the putative AP2/ERF family genes in Vitis vinifera     

Jing Zhuang  Ri-He Peng  Zong-Ming Cheng  Jian Zhang  Bin Cai  Zhen Zhang  Feng Gao  Bo Zhu  Xiao-Yan Fu  Xiao-Feng Jin  Jian-Min Chen  Yu-Shan Qiao  Ai-Sheng Xiong  Quan-Hong Yao 《Scientia Horticulturae》2009,123(1):73-81

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Response of snails and slugs to fragmentation of lowland forests in NW Germany     

Heike Kappes  Kurt Jordaens  Frederik Hendrickx  Jean-Pierre Maelfait  Luc Lens  Thierry Backeljau 《Landscape Ecology》2009,24(5):685-697

Habitat fragmentation is a major cause for species loss, but its effect on invertebrates with low active dispersal power, like terrestrial gastropods, has rarely been studied. Such species can not cross a hostile habitat matrix, for which the predictions of island theory, such as positive relations between species richness and patch size, should apply. In order to test this prediction, we studied gastropod species diversity by assessing gastropod assemblage characteristics from 35 sites in 19 fragments of deciduous old-growth forests in the Lower Rhine Embayment, Germany. Assemblages differed between larger (≥700 ha) and smaller forests (<400 ha), those of large forests held a higher percentage of forest species. Although α-diversity was similar between the two forest size classes, small forests often comprised matrix species, resulting in a higher β-diversity. Edge effects on the species richness of matrix species were noticeable up to 250 m into the forest. Hierarchical partitioning revealed that distance to disturbances (external edge, internal edges like roads) explained most assemblage variables, whereas forest size and woodland cover within a 1 km radius from the sites explained only a few assemblage variables. Densities of two forest-associated species, Discus rotundatus and Arion fuscus, decreased with forest size. Yet, forest size was positively correlated with richness of typical forest species and densities of Limax cinereoniger. The latter species seems to need forests of >1,000 ha, i.e., well above the size of most fragments. In conclusion, the prediction is valid only for forest species. The response to fragmentation is species specific and seems to depend on habitat specialization and macroclimatic conditions. Jean-Pierre Maelfait: Deceased.  相似文献   

Comparing fire spread algorithms using equivalence testing and neutral landscape models     

Brian R. Miranda  Brian R. Sturtevant  Jian Yang  Eric J. Gustafson 《Landscape Ecology》2009,24(5):587-598

We demonstrate a method to evaluate the degree to which a meta-model approximates spatial disturbance processes represented by a more detailed model across a range of landscape conditions, using neutral landscapes and equivalence testing. We illustrate this approach by comparing burn patterns produced by a relatively simple fire spread algorithm with those generated by a more detailed fire behavior model from which the simpler algorithm was derived. Equivalence testing allows objective comparisons of the output of simple and complex models, to determine if the results are significantly similar. Neutral landscape models represent a range of landscape conditions that the model may encounter, allowing evaluation of the sensitivity and behavior of the model to different landscape compositions and configurations. We first tested the model for universal applicability, then narrowed the testing to assess the practical domain of applicability. As a whole, the calibrated simple model passed the test for significant equivalence using the 25% threshold. When applied to a range of landscape conditions different from the calibration scenarios, the model failed the tests for equivalence. Although our particular model failed the tests, the neutral landscape models were helpful in determining an appropriate domain of applicability and in assessing the model sensitivity to landscape changes. Equivalence testing provides an effective method for model comparison, and coupled with neutral landscapes, our approach provides an objective way to assess the domain of applicability of a spatial model.  相似文献   

Graph theory in action: evaluating planned highway tracks based on connectivity measures     

Vera Vasas  Tibor Magura  Ferenc Jordán  Béla Tóthmérész 《Landscape Ecology》2009,24(5):581-586

Maintaining connectivity among local populations in a fragmented landscape is crucial for the survival of many species. For isolated habitat patches, stochastic fluctuations and reduced gene flow can lead to high risk of extinction. The connectivity of the landscape is especially crucial for the carabid species living in the fragmented forests of the Bereg plain (NE Hungary and W Ukraine) because a highway will be constructed through the plain. Our purpose is to (1) evaluate the impacts of three possible highway tracks, (2) suggest a solution that is realistic with less impact on connectivity than other plans and (3) discuss how to decrease the disadvantageous effects of each track. Our results, based on a network analysis of landscape graph of patches and ecological corridors, indicate that the intended highway could have deleterious consequences on forest-living carabids. Relatively simple actions, like the establishment of stepping stones, could compensate for the loss of habitat connectivity and promote the survival of carabids, or minor modifications in one possible track could diminish its adverse effects. While many other studies would be needed for a comprehensive assessment of the biotic impact of the highway, we provide an example on the usefulness of network analysis for land use management. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

The concept of habitat specificity revisited     

Rune Halvorsen  Anette Edvardsen 《Landscape Ecology》2009,24(7):851-861

Habitat specificity indices reflect richness (α) and/or distinctiveness (β) components of diversity. The latter may be defined by α and γ (landscape) diversity in two alternative ways: multiplicatively () and additively (). We demonstrate that the original habitat specificity concept of Wagner and Edwards (Landscape Ecol 16:121–131, 2001) consists of three independent components: core habitat specificity (uniqueness of the species composition), patch area and patch species richness. We describe habitat specificity as a family of indices that may include either area or richness components, or none or both, and open for use of different types of mean in calculation of core habitat specificity. Core habitat specificity is a beta diversity measure: the effective number of completely distinct communities in the landscape. Habitat specificity weighted by species number is a gamma diversity measure: the effective number of species that a patch contributes to landscape richness. We compared 12 habitat specificity indices by theoretical reasoning and by use of field data (vascular plant species in SE Norwegian agricultural landscapes). Habitat specificity indices are strongly influenced by weights for patch area and patch species richness, and the relative contribution of rare vs. common species (type of mean). The relevance of properties emphasized by each habitat specificity index for evaluation of patches in a biodiversity context is discussed. Core habitat specificity is emphasized as an ecologically interpretable measure that specifically addresses patch uniqueness while habitat specificity weighted by species number combines species richness and species composition in ways relevant for conservation biological assessment. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

Upscaling as ecological information transfer: a simple framework with application to Arctic ecosystem carbon exchange     

Paul C. Stoy  Mathew Williams  Mathias Disney  Ana Prieto-Blanco  Brian Huntley  Robert Baxter  Philip Lewis 《Landscape Ecology》2009,24(7):971-986

Transferring ecological information across scale often involves spatial aggregation, which alters information content and may bias estimates if the scaling process is nonlinear. Here, a potential solution, the preservation of the information content of fine-scale measurements, is highlighted using modeled net ecosystem exchange (NEE) of an Arctic tundra landscape as an example. The variance of aggregated normalized difference vegetation index (NDVI), measured from an airborne platform, decreased linearly with log(scale), resulting in a linear relationship between log(scale) and the scale-wise modeled NEE estimate. Preserving three units of information, the mean, variance and skewness of fine-scale NDVI observations, resulted in upscaled NEE estimates that deviated less than 4% from the fine-scale estimate. Preserving only the mean and variance resulted in nearly 23% NEE bias, and preserving only the mean resulted in larger error and a change in sign from CO₂ sink to source. Compressing NDVI maps by 70–75% using wavelet thresholding with the Haar and Coiflet basis functions resulted in 13% NEE bias across the study domain. Applying unique scale-dependent transfer functions between NDVI and leaf area index (LAI) decreased, but did not remove, bias in modeled flux in a smaller expanse using handheld NDVI observations. Quantifying the parameters of statistical distributions to preserve ecological information reduces bias when upscaling and makes possible spatial data assimilation to further reduce errors in estimates of ecological processes across scale.  相似文献