1. Wood ants, species of the subgenus Formica s. str., are one of the most important groups of insects in forest ecosystems due to their high abundance and activity.
2. We assessed the foraging pressure of Formica polyctena and Formica rufa, two dominant wood ant species in the Białowieża Forest. In addition, we compared coniferous and mixed stands in these respects.
3. In mixed stands F. polyctena visited more trees per plot than F. rufa. F. polyctena might forage a larger area due to higher population sizes, which further confirms higher foraging pressure of F. polyctena in comparison with F. rufa.
4. In our study area, host trees of the ant–aphid mutualism were larger in diameter than nonhost trees. The ants also preferred trees situated closer to their nests. In both mixed and coniferous stands, the most visited tree species was Norway spruce. Thus, we can conclude that Norway spruce seems to be preferred by the ant. The decline of living spruce in the Białowieża Forest may endanger their food source and impact the vitality of ant colonies.

中文翻译：

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在混合温带森林中，木蚂蚁更喜欢针叶树而不是阔叶树

1. 木蚁，福米卡亚属的物种。str. 是森林生态系统中最重要的昆虫类群之一，因为它们的丰度和活动性很高。
2. 我们评估的觅食压力福米卡polyctena和红林蚁，在比亚沃维耶扎原始森林两个主要的木蚂蚁。此外，我们在这些方面比较了针叶林和混交林。
3. 在混合林分中，F. polyctena比F. rufa每块地访问的树木更多。由于种群规模较大，F. polyctena可能觅食更大的区域，这进一步证实了F. polyctena与F. rufa相比具有更高的觅食压力。
4. 在我们的研究区域，蚂蚁-蚜虫共生的寄主树的直径比非寄主树大。蚂蚁也更喜欢靠近巢穴的树木。在混交林和针叶林中，访问量最大的树种是挪威云杉。因此，我们可以得出结论，蚂蚁似乎更喜欢挪威云杉。Białowieża 森林中活云杉的减少可能会危及它们的食物来源并影响蚁群的活力。