Plant litter decomposition is a key process for carbon dynamics and nutrient cycling in terrestrial ecosystems. The interaction between litter properties, climatic conditions and soil attributes, influences the activity of microorganisms responsible for litter mineralization. So far, studies using standardized litters to investigate the response of bacterial and fungal communities under different environmental conditions are scarce, especially along wide geographic ranges.

We used a standardized protocol to investigate the diversity of bacteria and fungi in plant litter with the aim of: (i) comparing the microbial communities of native and exotic litters with the community of local soil along a European transect from northern Finland to southern Italy, (ii) defining whether and to what extent, litter types with different traits represent selective substrates for microbial communities, (iii) disentangling the abiotic drivers of microbial diversity, and (iv) correlating the microbial diversity and species co-occurrences patterns with litter mass loss.

We buried native litter and three exotic standardized litters (Deschampsia cespitosa, rooibos tea and green tea) at 12 European study sites. We determined litter mass loss after 94 days. We used an automated molecular DNA-based fingerprinting (ARISA) to profile the bacterial and fungal communities of each litter type and soil (180 samples in total).

Microbial communities in native and exotic litters differed from local soil assemblages. Green tea and D. cespitosa litter represented more selective substrates compared to native litter and rooibos. Soil moisture and soil temperature were the major drivers of microbial community structure at larger scales, though with varying patterns according to litter type. Soil attributes (i.e. moisture and C/N ratios) better explained the differences in microbial abundances than litter type. Green tea degraded faster than all other litter types and accounted for the largest number of positive co-occurrences among microbial taxa. Litter mass loss was positively correlated with fungal evenness and with the percentage of positive co-occurrences between fungi.

Our findings suggest that the microbial community at larger scales reflects the complex interplay between litter type and soil attributes, with the latter exerting a major influence. Mass loss patterns are in part determined by inter- and intra-kingdom interactions and fungal diversity.

植物凋落物分解是陆地生态系统中碳动力学和养分循环的关键过程。垫料特性，气候条件和土壤属性之间的相互作用会影响负责垫料矿化的微生物的活动。迄今为止，在不同环境条件下使用标准化垫料调查细菌和真菌群落反应的研究很少，尤其是在广泛的地理范围内。

我们使用标准化协议来调查植物凋落物中细菌和真菌的多样性，目的是：（i）比较原生和外来凋落物的微生物群落与从芬兰北部到意大利南部的欧洲样带的当地土壤群落， （ii）定义不同性状的凋落物类型是否以及在何种程度上代表微生物群落的选择性底物；（iii）区分微生物多样性的非生物驱动因素；（iv）将微生物多样性和物种共生模式与凋落物质量相关联失利。

我们在12个欧洲研究地点掩埋了本地垃圾和3种异国标准化垃圾（地香，茶和绿茶）。我们确定了94天后的垫料质量损失。我们使用了基于自动分子DNA的指纹图谱（ARISA）来分析每种垃圾类型和土壤的细菌和真菌群落（总共180个样品）。

本地和外来垃圾中的微生物群落不同于当地的土壤群落。与天然垃圾和如意宝相比，绿茶和D. cepitosa垃圾代表了更多的选择性底物。土壤水分和土壤温度是更大范围内微生物群落结构的主要驱动力，尽管随垫料类型的不同而变化。与垃圾类型相比，土壤属性（即水分和碳氮比）可以更好地说明微生物丰度的差异。绿茶的降解速度快于所有其他垃圾类型，并且在微生物分类中阳性共存的数量最多。凋落物质量损失与真菌均匀度以及真菌之间阳性共存百分比呈正相关。

我们的研究结果表明，较大范围内的微生物群落反映了凋落物类型与土壤属性之间的复杂相互作用，而后者则起着重要的作用。质量损失的模式部分取决于王国之间和王国之间的相互作用以及真菌多样性。