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采用野外定点试验方法,分析除草剂乙草胺、2,4滴丁酯、噻吩磺隆对农田中小型土壤动物群落结构的影响。结果表明,3次取样共获得中小型土壤动物2 748只,隶属于2门,4纲,10目,其中占优势的类群有甲螨亚目、中气门亚目,分别占总个体数量的51.16%和26.82%,常见类群包括前气门亚目、弹尾目、膜翅目和鞘翅目,占总个体数量的20.27%,稀有类群占总个体数量的1.75%。喷施除草剂使中小型土壤动物个体数量明显减少,尤其是使优势类群个体数量减少最大,使群落多样性指数和均匀度指数增高,优势度指数降低,但没有使土壤动物类群数发生明显变化;3种除草剂影响下的土壤动物个体数量、类群数量、群落特征指数没有很大的差异,在不同层次的表现也没有明显的规律性。  相似文献   
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【Objective】 Soil fauna is an important component of terrestrial ecosystem, therefore, the studying of the relationship between soil fauna and amendments will help reveal the mechanism of amendments to soil fauna.【Method】During 2016-2019, the characteristics of the soil fauna community in the soil surface layer (0-20 cm) of wheat and maize rotation area with different amendments were investigated. There were four treatments, including no amendment (CK), organic amendment 15 t·hm-2 (YJ), inorganic amendment 2.25 t·hm-2 (WJ) and organic amendment 15 t·hm-2+inorganic amendment 2.25 t·hm-2 (YW). 【Result】During the study period, 4 351 soil fauna belonging to 8 classes, 20 orders, 41 families, and 44 classes were collected, of which 28 families were macrofauna, and the dominant groups were Asilidae and Myrmicinae, accounting for 62.9% of the total captured soil macrofauna. In another, 14 families soil meso-and micro-fauna were collected, and the dominant groups were Acarid and Oribatida, accounting for 93.0% of the total captured soil meso- and micro-fauna. Soil fauna mainly belonged to saprozoic and omnivores. The data indicated that the total number and taxa of soil fauna collected during the experiment was the highest under WJ, and the lowest under YJ. The number of Scutigerellidae, Sejidae and Japygidae decreased and their richness index decreased, while the mites increased, and the dominance index was high under amendments comparing with CK. There were significant differences in individual number and diversity index of small and medium animal communities among different years (P<0.05), and the number of individuals showed a gradually increasing trend; but the Jaccard index (q) of soil fauna was less than 0.50 among all treatments, and the similarity of macrofauna community was lower than that of meso- and micro- community. The ecological niche widths of meso- and micro- soil fauna, such as Acarid, Oribatida, and Onychiuridae, were higher than those of macrofauna, such as Myrmicinae. However, the niche overlap index was higher than 0.97, indicating that the application of amendments increased the common resources of soil fauna. The NMDS analysis showed that the soil animal community in wheat season 2018 was significantly different from that in other years, whereas, in maize season of 2016, 2018, and 2019, there were different. The results of RDA indicated that soil TN and AK were significantly correlated with Acarid, Oribatida, Onychiuridae, Enicocephalidae, Carabidaein wheat season (P<0.05); the soil organic matter and pH were main factors influencing Acarid, Enicocephalidae, Sciaridae, and Asilidae in maize season (P<0.05). The PRC analysis showed that the relative abundance of Uropodidae peaked in October 2017, and that of Asilidae and Myrmicinae peaked in October 2016 under YJ. The relative abundance of Onychiuridae, Acarid, and Oribatida reached a peak in October 2016 under the combined application of organic and inorganic amendments, and that of Phlaeothripidae and Enicocephalidae appeared in 2019 and peaked in October 2019, demonstrating the incongruity of soil fauna groups to the amendments. 【Conclusion】The variation of soil fauna community and diversity in different years were much more profound than amendments, and the amendments modified soil fauna community and diversity mainly by changing soil pH, SOM, and TN in a fluvo-aquic sandy soil.  相似文献   
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2014年5月21—23日和27日在南沙群岛中部海域开展灯光罩网作业的同时,开展诱集前后中小型浮游动物群落变化的初步实验,研究浮游动物群落对灯光反应的敏感性,灯光对群落产生了较为明显的生态学效应。诱集前后共出现浮游动物178种,隶属16个类群。诱集后种类数增加,种类组成的更替率为41%。各类群中,除枝角类外其余15个类群在诱集前后出现的种类均发生变化;除原生动物在诱集后种类数下降外,其他类群的种类数均呈增加的趋势。浮游动物绝大部分类群对灯光诱集较为敏感,趋光性有正有负。诱集前后浮游动物优势种组成发生一定的变化,更替率为50%。诱集前优势种以桡足类为主,而诱集后有尾类的优势地位明显增强。诱集后浮游动物优势种优势度和出现频率均呈明显降低的趋势。南沙群岛海域中小型浮游动物优势种诱集前后均呈聚集分布,各优势种对灯光反应敏感,不同种类对灯光的适应性有所差异。住囊虫等大部分种类对灯光的适应性较强,诱集后聚集强度明显增加;而驼背大眼水蚤和活泼大眼剑水蚤诱集后聚集强度明显下降。桡足类幼虫和小纺锤水蚤等诱集后,聚集强度明显上升,之后又大幅下降。浮游动物生物量和栖息密度在诱集后总体呈明显的增加趋势,以诱集初期增幅最大,之后数量虽有所降低,但仍高于诱集前。灯光可使浮游动物物种丰富度和多样性水平明显提高,但尚未改变浮游动物的群落结构。浮游动物对人造光反应的种间和类群间差异,是由生物自身的生理特征和不同的摄食策略决定的。诱集后游泳生物摄食强度提高,导致了诱集后期浮游动物数量下降。  相似文献   
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