水生昆虫通量的动态变化对河岸结网型蜘蛛分布的影响

译文

　　从溪流中大量羽化的水生昆虫的流动可以为河岸织网蜘蛛提供大量的能源补贴。然而，尽管水生昆虫羽化的时间非常临时性，但这种水生昆虫动态对蜘蛛分布的影响却知之甚少。为了检验这一关系，在5月至7月期间，利用温室类型的覆盖物对日本北部落叶林源头溪流中的水生昆虫数量进行了实验控制。

　　在自然条件下，水生昆虫丰度在5-7月份急剧下降，陆生昆虫丰度在5-7月份显著增加。实验中，水生昆虫通量的减少在5月和6月都降低了水平圆网蜘蛛（肖蛸科）的密度，但在水生昆虫稀少的7月没有降低，表明水生昆虫通量对蜘蛛分布的影响有时间限制。

　　相反，在整个研究期间，垂直圆网蜘蛛(园蛛科)和片状网蜘蛛(皿蛛科)的密度都没有受到影响。这些反应在不同月份或蜘蛛类群之间是不同的，可能归因于蜘蛛对水生猎物捕食的专门化程度和它们对水生昆虫流动的反应能力。实验结果直接证明了水生昆虫数量的时间动态变化和蜘蛛的特征是决定河岸结网蜘蛛分布型的主要因素。

原文

The flux of emerging aquatic insects from streams can provide a significant energy subsidy to riparian web-building spiders. However, despite the high temporality of aquatic insect emergence, the effects of such aquatic insect dynamics on spider distribution are poorly understood. To examine the relationship, the aquatic insect flux from a headwater stream in a northern Japanese deciduous forest was experimentally manipulated by using a greenhouse-type covering, during May to July. 

Under natural conditions, the aquatic and terrestrial insect abundances dramatically decreased and increased from May through July, respectively. The experimental reduction of aquatic insect flux depressed the density of horizontal orb weavers (Tetragnathidae) in both May and June, but not in July when aquatic insects were scarce, indicating a temporal limitation on spider distribution by aquatic insect flux. 

In contrast, the densities of both vertical orb weavers (Araneidae) and sheet weavers (Linyphiidae) were unaffected by the manipulation throughout the study period. These various responses, differing among months or spider guilds, may be attributed to the degree of specialization for aquatic prey in the spiders and their mobility in response to aquatic insect flux. The experimental results provided direct evidence that the temporal dynamics of aquatic insect flux, as well as spider characteristics, were primary factors determining the distributional patterns of riparian web-building spiders.

flux 这个单词在文中语境下翻译比较困难。最开始准备翻译成数量，随后保留默认翻译 通量，感觉就是单位时间内羽化昆虫的数量，在文中。

flux

　常用词汇　英 [flʌks] 　 　 美 [flʌks] 　 　

• n. 流量；变迁；助熔剂

• vt. 使熔化；使泻；涨

• vi. 熔化

参考文献

Kato, C., Iwata, T., Nakano, S., Kishi, D., 2003. Dynamics of aquatic insect flux affects distribution of riparian web‐building spiders. Oikos 103, 113-120.