Results 71 to 80 of about 20,824 (277)
Distribution, scale, and drivers of mass mortality events in Europe's freshwater bivalves
Abstract Mass mortality events (MMEs) are decimating populations and compromising key ecosystem functions around the globe. One taxon particularly vulnerable to MMEs is freshwater bivalve mollusks. This group has important ecosystem engineering capacities and includes highly threatened and highly invasive taxa.
Daniel A. Cossey +39 more
wiley +1 more source
中华按蚊孳生广泛,种群数量大,是我国重要传疟媒介。深入研究其种群动力学,无论对流行病学或者媒介防制都有重要意义。有关中华按蚊的种群动力学研究,国内目前仅限于实验种群的观察(曲传智,1981,苏寿(氵氏)等,1982)。对现场自然种群的观察,尚未见报道。本文通过现场观察中华按蚊各龄期幼虫存活率的结果,作为研究中华按蚊自然种群动力学的一个组成部分,比较各龄期幼虫的变动情况,分析种群增殖与死亡的相互关系,反映自然界中华按蚊种群变动,为寻找更有效的防制提供依据。
潘实清
doaj
The foraminiferal taxa in surface sediment and its environmental implication in Sansha Bay [PDF]
有孔虫对所生存的环境变化较敏感。对于不同的水深、温度、盐度、pH、沉积速率等环境因子的变化,有孔虫群落特征会发生相应变化。故有孔虫群落特征能较好地反映海洋环境变化。由于季节的变化,夏季和冬季所对应的环境因子条件不同,其有孔虫群落特征也会发生相应变化。本论文根据福建三沙湾的夏冬季24个站位表层沉积物样品,进行有孔虫鉴定和沉积物粒度分析。在广泛收集前人资料及室内分析的基础上,结合表层沉积物中七种重金属含量平面分布特征,通过研究分析有孔虫种群的空间分布及其与环境因子间相互关系 ...
龚凌
core
How much biotic nativeness matters across human demographic groups
Abstract Many central concepts of conservation biology—such as nativeness—are structured by ecological and social factors. However, the social consequences of using these concepts to make conservation decisions remain inadequately understood. Some researchers argue that nativeness, rather than acting as an objective proxy for important ecological ...
Harold N. Eyster, Rachelle K. Gould
wiley +1 more source
4.连接各个种群 生境的变化往往造成种群的破碎化,形成岛屿化的小种群。许多生态学家建议维护或建立小种群间的景观连接带,降低种群破碎化的影响。保护生物学方面的最新文献支持了在种群中心地带建立“走廊带”这一理论。走廊带是动物从一个生境斑块到另一个生境斑块进行日常性的、季节性的扩散性移动的旅行通道,从理论上讲,走廊带有利于种群间个体相互交流,大大减少因近交和偶然发生自然灾害引起绝灭的可能。
高中信, 刘元
doaj
曹扬环浜是一条环形封闭水道,水质低于地表水V类标准,水体处于严重超富营养化水平,全浜暴发蓝藻水华现象。在采用截污、造流、生态恢复等生态工程措施综合治理后,随着健康水生态系统的建立,河浜水质逐步变好(由劣V类改善为接近Ⅲ类标准),水体透明见底,沉水植物覆盖率达70%~90%,水体一直维持“清水草型稳态”。重点介绍了河道治理中采用的生态修复措施及其作用,并从截污、营养盐、水生生物等方面分析了各项工程措施对抑制藻类生长、水质改善的影响 ...
方涛,王春树,陈洪达,李敦海,刘永定
core
Differences in characteristics between naturalized threatened plants and other threatened plants
Abstract Many non‐native plant species introduced by humans have become naturalized. At the same time many species are threatened in their native range. However, the number of plant species threatened in their native range that are naturalized elsewhere remains unknown.
Weihan Zhao +10 more
wiley +1 more source
对东白山(Dongbaishan,DBS)1 hm2森林样地内胸径≥1 cm的木本植物进行统计,初步分析了样地的区系成分、物种组成、群落结构和α多样性.结果表明:样地内共计木本植物48种,隶属23科36属,总计5 493株,以常绿树种为主,共25种,占总优势度的98.18%,重要值的95.22%,总个体数的96.65% ;群落内有明显的优势种、偶见种和部分稀有种,木荷(Schima superba)和马尾松(Pinus massoniana)占显著优势;偶见种和稀有种分别占总物种数的35.42%和20 ...
WANGYunquan(王云泉) +7 more
doaj +1 more source
The impacts of coastal defense structures on rocky intertidal community in Yangtze River Delta [PDF]
长江三角洲是长江、黄河以及在此区域的其他河流的活动形成的冲积平原。末次冰期(LastGlacialMaximum,LGM)以后的一万年以来,长江三角洲在海陆交互作用的影响下逐渐扩展。位于长江三角洲地带的近900km的江苏沿岸海岸线除约40km的基岩海岸以外,均为不适宜岩相潮间带生物大量聚集的淤泥质平原海岸。近年来随着中国沿海经济的飞速发展,对土地需求的不断增加,越来越多的沿岸防护建筑正在被修建,成为我国沿岸的“海上长城”。这些沿岸防护建筑显著改变了江苏沿岸的滩涂景观,可能对潮间带群落造成严重影响 ...
黄雄伟
core
Representation of obligate groundwater‐dwelling copepod diversity in European protected areas
Abstract Groundwaters sustain diverse surface ecosystems and are populated by metazoan species, mostly invertebrates, that provide fundamental ecological functions and are often of prominent conservation value due to narrow endemism and high phylogenetic rarity.
Francesco Cerasoli +7 more
wiley +1 more source

