Fungal and bacterial growth variation due to drought and nitrogen addition experimental treatments. Loma Ridge Experimental Project. 2010-2012

Terrestrial ecosystem models assume that microbial communities respond instantaneously, or are immediately resilient, to environmental change. Here we tested this assumption by quantifying the resilience of a leaf litter community to changes in precipitation or nitrogen availability. By manipulating composition within a global change experiment, we decoupled the legacies of abiotic parameters versus that of the microbial community itself. After one rainy season, more variation in fungal composition could be explained by the original microbial inoculum than the litterbag environment (18% versus 5.5% of total variation). This compositional legacy persisted for 3 years, when 6% of the variability in fungal composition was still explained by the microbial origin. In contrast, bacterial composition was generally more resilient than fungal composition. Microbial functioning (measured as decomposition rate) was not immediately resilient to the global change manipulations; decomposition depended on both the contemporary environment and rainfall the year prior. Finally, using metagenomic sequencing, we showed that changes in precipitation, but not nitrogen availability, altered the potential for bacterial carbohydrate degradation, suggesting why the functional consequences of the two experiments may have differed. Predictions of how terrestrial ecosystem processes respond to environmental change may thus be improved by considering the legacies of microbial communities. This data package includes ten csv files (five data files and their corresponding data dictionaries) and one file-level metadata excel file. Data files contains information about which plots were exposed to treatments related to drought and nitrogen, information about litter bags reciprocal transplants manipulation for water input and nitrogen, detail information about water addition, precipitation records, and litter variables collected. Data dictionary files include detail explanation for each column in the data files. The file-level metadata file describes each file mentioned above. All the analyses were done using the R software.

陆地生态系统模型普遍假设，微生物群落对环境变化的响应是瞬时的，或具备即时恢复力。本研究通过量化叶凋落物群落对降水或氮素有效性变化的恢复力，对这一假设展开验证。研究依托全球变化实验中的群落操控手段，将非生物参数的遗留效应与微生物群落自身的遗留效应进行了解耦。经过一个雨季之后，相较于凋落袋（litterbag）环境仅能解释总变异的5.5%，初始微生物接种源可解释更多的真菌群落组成变异（解释率达18%）。这种群落组成的遗留效应持续了3年，直至实验末期仍有6%的真菌群落组成变异可由微生物接种源的起源所解释。相比之下，细菌群落组成的恢复力普遍高于真菌群落。以分解速率为衡量指标的微生物功能，并未对全球变化操控表现出即时恢复力；分解过程同时取决于当前环境与前一年的降水状况。最后，本研究通过宏基因组测序（metagenomic sequencing）发现，降水变化而非氮素有效性改变了细菌的碳水化合物降解潜力，这一结果解释了两项实验所产生的功能效应存在差异的原因。因此，在预测陆地生态系统过程对环境变化的响应时，纳入微生物群落的遗留效应可有效提升预测精度。本数据包包含10个CSV文件（5个数据文件及其对应的数据字典）与1个文件级元数据Excel文件。数据文件涵盖如下信息：各样地接受干旱与氮素相关处理的情况、用于调控水分输入与氮素水平的凋落袋互易移植操控实验的相关记录、水分添加的详细参数、降水观测数据以及采集的凋落物相关变量。数据字典文件用于详细说明数据文件中每一列的具体含义。文件级元数据文件则对上述所有文件进行整体描述。本研究的所有分析均通过R软件完成。