We investigated how compositional differences in riparian leaf litter derived from burned and undisturbed forests influenced leaf breakdown and macroinvertebrate communities using experimental mixed‐species leaf packs in boreal headwater streams. Leaf pack mixtures simulating leaf litter from dominant riparian woody‐stem species in burned and undisturbed riparian zones were incubated in two references and two fire‐disturbed streams for 5 weeks prior to measuring temperature‐corrected breakdown rates and macroinvertebrate community composition, richness, and functional metrics associated with decomposers such as shredder abundance and % shredders. Leaf litter breakdown rates were higher and had greater variability in streams bordered by reference riparian forests than in streams where riparian forests had been burned during a wildfire. Streams bordered by fire disturbance showed significant effects of litter mixture on decomposition rates, observed as significantly higher decomposition rates of a fire‐simulated leaf mixture compared to all other mixtures. Variation among sites was higher than variation among litter mixtures, especially for macroinvertebrate community composition. In general, fire‐simulated leaf mixtures had greater shredder abundances and proportions, but lower overall macroinvertebrate abundance; however, the shredder abundance trend was not consistent across all leaf mixtures at each stream. These results show that disturbance‐driven riparian forest condition and resulting composition of leaf subsidies to streams can influence aquatic invertebrate community composition and their function as decomposers. Therefore, if one of the primary goals of modern forest management is to emulate natural disturbance patterns, boreal forest managers should adapt silvicultural practices to promote leaf litter input that would arise post‐fire, thereby supporting stream invertebrate communities and their function.

中文翻译：

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使用混合物种叶包评估野火对北方溪流中叶分解和大型无脊椎动物群落的影响

我们使用北方源头溪流中的实验性混合物种叶包研究了来自烧毁和未受干扰森林的河岸落叶的组成差异如何影响叶片分解和大型无脊椎动物群落。在测量温度校正的分解率和大型无脊椎动物群落组成、丰富度和功能之前，在两个参考和两个受火干扰的溪流中，模拟来自主要河岸木茎物种在燃烧和未受干扰的河岸区的枯枝落叶的叶包混合物与分解器相关的指标，例如粉碎机丰度和粉碎机百分比。与河岸森林在野火中被烧毁的溪流相比，与参考河岸森林接壤的溪流中的落叶分解率更高，并且变异性更大。以火灾干扰为边界的溪流显示枯枝落叶混合物对分解速率的显着影响，观察到与所有其他混合物相比，火灾模拟叶子混合物的分解速率显着更高。地点之间的变化高于垃圾混合物之间的变化，尤其是大型无脊椎动物群落组成。一般来说，模拟火灾的叶子混合物具有更高的粉碎机丰度和比例，但总体大型无脊椎动物丰度较低；然而，每条河流的所有叶子混合物的粉碎机丰度趋势并不一致。这些结果表明干扰驱动的河岸森林条件和由此产生的对溪流的叶子补贴组成会影响水生无脊椎动物群落组成及其作为分解者的功能。所以，