To decipher the <30% of unexplained variation in leaf litter decomposition, a process important for nutrient cycling yet vulnerable to rising CO2 levels, numerous hypotheses have been proposed. The home-field advantage (HFA) hypothesis states that leaf litter decomposes more rapidly beneath canopies of tree species from which the leaves originate (home environment), than beneath other tree species. Most HFA studies typically involve reciprocal litter transplants between habitat types (i.e. forest vs. grassland) or successional stages (i.e. early vs. late). The mixed and often conflicting results pertaining to this hypothesis, mostly assessed at the landscape-level, merit a finer scale analysis of decomposition variability, i.e. at the tree species level. Despite homogenous litter build up close to any given tree individual in a mixed forest, along with evidence of varying decomposition rates under different tree species, we still lack basic understanding of forest floor decomposition dynamics at the tree species level, strongly driven by host selection by fungi as well as arthropod detritivores. To address these gaps, we first determined differences in decomposition rates between leaves of three dominant forest tree species. We then compared decomposition rates between leaf litter placed beneath the canopies of source species vs. non-source species in a mixed-tree natural, temperate rainforest, accounting for the activity of both fungi (microbiota) and arthropod detritivores (both meso- and macrofauna). We found that leaf-litter decomposition rates can differ significantly depending on the source-tree species. Despite this, we found no effect of overhead tree species on decomposition rates of leaf litter, irrespective whether under source species or non-source species. Only one species' leaf litter showed differences in arthropod diversity between leaf litter placed beneath source tree species vs. non-source species, with higher arthropod diversity in leaf litter placed beneath source trees. Also, arthropods here contributed significantly more than fungi to overall decomposition. However, bacteria (not measured here) may also have decomposed litter greatly, with litter loss not solely due to our focal groups. We conclude that, in a single, diverse forest, perhaps due to differences in litter fall rate and nutrient content of leaf litter, only some plant species might reveal small-scale patterns for detritivore diversity, with yet unknown effects overall decomposition. As such, landscape-level studies on decomposition should incorporate and account for the effects of tree species-level decomposition variability.

为了破译<< 30％的未解释的凋落物分解的变化，这一过程对养分循环很重要，但易受CO2水平升高的影响，已经提出了许多假设。主场优势（HFA）假设指出，落叶比其他树种分解更快（在其叶子起源的树种）下分解（家庭环境）。大多数HFA研究通常涉及在生境类型（即森林与草地）或演替阶段（即早期与晚期）之间进行相互的垫料移植。与该假设有关的混杂且常常矛盾的结果（主要是在景观级别进行评估），值得对分解变异性（即在树种级别）进行更精细的规模分析。尽管杂草丛生的杂物堆积在混交林中靠近任何给定树木的地方，除了在不同树种下分解速率变化的证据外，我们仍然缺乏对树种一级林地分解动力学的基本了解，这在很大程度上取决于真菌和节肢动物对寄主的选择。为了解决这些差距，我们首先确定了三种优势林木树种叶片之间的分解速率差异。然后，我们比较了混合树天然温带雨林中位于源物种冠层之下和非源物种冠层之下的凋落物之间的分解率，从而说明了真菌（微生物群）和节肢动物（中生和大型动物）的活动）。我们发现，枯叶凋落物的分解速率可能会根据源树的种类而显着不同。尽管如此，我们发现高架树种对叶片凋落物的分解速率没有影响，无论是源树种还是非源树种。只有一种物种的凋落物显示出放置在源树物种之下的叶子凋落物与非起源物种之间的节肢动物多样性不同，而放置在起源树之下的叶子凋落物中的节肢动物多样性更高。此外，节肢动物对真菌的总体分解作用远胜于真菌。但是，细菌（此处未测量）也可能已大大分解了凋落物，凋落物的损失不仅是由于我们的焦点人群造成的。我们得出的结论是，在一个单一的，多样化的森林中，也许是由于凋落物下降率和凋落物养分含量的差异所致，只有一些植物物种可能会显示出小规模的有害生物多样性模式，总体分解效果未知。因此，景观层次的分解研究应纳入并考虑树木物种层次分解变异性的影响。