Abstract One of the factors regulating the functioning of detrital food webs can be a supplementary input of carbon and nutrients from aboveground. The intensity of the “arthropod rain”, i.e., various invertebrates falling from the tree crowns in temperate forests, remains unquantified, although the importance of this phenomenon for the functioning of aquatic ecosystems is relatively well documented. The study was carried out in two forest stands during the whole growing season. Arthropods falling from tree crowns were sampled using custom-made traps that separated dead and living animals. In addition to the arthropod rain, the amounts of plant litter and arthropod frass collected by the traps were measured. The intensity of the arthropod rain fluctuated with time but remained relatively constant from May to October, averaging 19 mg dry weight m−2 day-1. The taxonomic composition of the arthropod rain was diverse and included more than 60 families. Collembolans and mites were the most abundant animals, whereas Diptera, Coleoptera, and Hemiptera, including aphids, were the most important groups in terms of biomass. Some of these animals can be easy prey for soil predators. Moreover, approx. 28% of the total arthropod rain is formed by dead animals and exuviae; this fraction can be readily consumed by soil decomposers. The arthropod rain can be a non-negligible energy channel subsidizing detrital food webs, although its functional significance requires further investigation.

中文翻译：

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温带森林中的节肢动物雨：强度和成分

摘要 调节碎屑食物网功能的因素之一可以是来自地上的碳和营养物质的补充输入。“节肢动物雨”的强度，即温带森林中从树冠上掉下来的各种无脊椎动物，仍然没有量化，尽管这种现象对水生生态系统功能的重要性有相对充分的记载。该研究在整个生长季节期间在两个林分中进行。从树冠上掉下来的节肢动物使用定制的陷阱进行采样，将死的和活的动物分开。除了节肢动物雨外，还测量了陷阱收集的植物凋落物和节肢动物粪便的量。节肢动物降雨强度随时间波动，但在 5 月至 10 月保持相对稳定，平均 19 mg 干重 m−2 day-1。节肢动物雨的分类组成多种多样，包括 60 多个科。跳虫和螨类是最丰富的动物，而双翅目、鞘翅目和半翅目，包括蚜虫，是生物量最重要的类群。其中一些动物很容易成为土壤捕食者的猎物。此外，约。28% 的节肢动物雨是由死亡的动物和蜕皮形成的；这部分很容易被土壤分解者消耗掉。节肢动物雨可以是一种不可忽视的能量通道，可以补贴碎屑食物网，尽管其功能意义需要进一步研究。和半翅目，包括蚜虫，是生物量方面最重要的类群。其中一些动物很容易成为土壤捕食者的猎物。此外，约。28% 的节肢动物雨是由死亡的动物和蜕皮形成的；这部分很容易被土壤分解者消耗掉。节肢动物雨可以是一种不可忽视的能量通道，可以补贴碎屑食物网，尽管其功能意义需要进一步研究。和半翅目，包括蚜虫，是生物量方面最重要的类群。其中一些动物很容易成为土壤捕食者的猎物。此外，约。28% 的节肢动物雨是由死亡的动物和蜕皮形成的；这部分很容易被土壤分解者消耗掉。节肢动物雨可以是一种不可忽视的能量通道，可以补贴碎屑食物网，尽管其功能意义需要进一步研究。