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南海大鹏湾夜光藻种群生态及其赤潮成因分析   总被引:19,自引:3,他引:16       下载免费PDF全文
分析了1990年3月--1992年6月南海大鹏湾夜光藻种妲民环境因子之间的动态关系。研究发现,夜光藻的生存水温的高限可达28.6℃左右,但其最适不温范围为20-22℃而适温范围可扩到16-25℃。所以,每年夏季高温季节,大鹏湾的夜光藻因无法忍受高温(30℃)而自然死亡,秋季再由外洋海流将其营养细胞带回。夜光藻的最适盐度应在29-33之间,但盐度线般与夜光藻的咱群变动没有明显的相关关系,不过暴雨或梅  相似文献
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绥芬河大麻哈鱼类种群生态的初步研究   总被引:1,自引:0,他引:1       下载免费PDF全文
3种大麻哈鱼的洄游期、种群组成、数量变动等进行了调查研究。结果认为:溯河期依每年河流生态条件而有变化;驼背大麻哈鱼为单一龄组型,马苏大麻哈鱼为双龄组型,大麻哈鱼为多龄组型;其主要产卵场分布于绥芬河中、上游河区,我国河区种群数量较多。  相似文献
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We studied the population ecology of the snail Melampus bidentatus in relation to patch composition and landscape structure across several salt marsh systems in Connecticut, USA. These marshes have changed significantly over the past 40–50 years including loss of total area, increased areas of short Spartina alterniflora, and decreased areas and fragmentation of Spartina patens. These changes are consistent with tidal inundation patterns that indicate frequent flooding of high marsh areas. Melampus bidentatus densities were highly variable, both among different salt marsh systems and locations within specific marshes, but were generally similar among short Sp. alterniflora and Sp. patens patches within locations. Densities were lowest where the marsh was regularly inundated at high tide and only remnant Sp. patens patches remained. Almost no snails were found in bare patches. Areas that had large Sp. patens patches adjacent to short Sp. alterniflora supported the highest M. bidentatus densities. Population size‐structure varied significantly among patch types, with higher proportions of large individuals in short Sp. alterniflora and hummocked Sp. patens patches than in large and remnant Sp. patens patches. This was likely due to size‐selective predation and/or higher snail growth rates due to better food resource conditions in short Sp. alterniflora patches. Egg mass densities and the number of eggs per egg mass were highest in short Sp. alterniflora. Our results indicate that M. bidentatus is resilient to the level and patterns of salt marsh change evident at our study sites. Indeed, snail densities were significantly higher than reported in other field studies, suggesting that increased patch areas of short Sp. alterniflora and associated environmental conditions at our study sites may provide more favorable habitats than previously when marshes were dominated by extensive Sp. patens meadows. However, there may be threshold conditions that could overwhelm the ability of M. bidentatus to maintain itself within salt marsh systems where changes in hydrology, sedimentation and other factors lead to increased numbers of bare patches and ponds and loss of short Sp. alterniflora and Sp. patens. Studies of the responses of resident and transient fauna to salt marsh change are critically needed in order to better understand the implications for salt marsh ecosystem dynamics and services.  相似文献
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近35年来,多家高校、科研机构和政府管理部门在大亚湾潮下带和潮间带进行了软体动物群落生态、种群生态和污染生态研究,揭示了不同生境软体动物的物种数、栖息密度和生物量的时空变化,为渔业生产和生态评估提供了基础资料。但早期有关文献难觅、信息不畅,导致软体动物分类存在同物异名和异物同名现象,一些中文学名和拉丁文学名张冠李戴,历史数据之间缺乏可比性等。作者提出了几点研究展望:(1)加强软体动物分类基础研究和科普宣传;(2)建立软体动物群落生态大数据式研究规则;(3)建立软体动物数据库;(4)人工智能及其他新技术和新方法的引入。本文可为科技工作者制订较完善的研究计划以及获得更精准的研究结果提供参考,可为政府部门提供决策依据。  相似文献
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