EAGER-NEON: Earthworm Diversity at Multiple Scales: What can Genetics Tell us about the Distribution of these Important Soil Organisms?

拟议的研究将开发和应用方法（DNA元条形码）来检查和比较大陆范围内蚯蚓多样性的测量。这些蚯蚓多样性的比较研究提供了一个独特的机会来评估几个主要的环境问题，如土壤生态系统服务和生物多样性丧失和物种入侵的存在和后果。地球上大约四分之一的已知物种生活在土壤中，但由于采样、提取和识别土壤生物需要大量的劳动，这些生物多样性中的大部分都被隐藏起来了。DNA元条形码是一种针对细胞外DNA的技术，即来自土壤中裂解或降解细胞的DNA。因此，它提供了识别在采样时土壤中物理上不存在的物种的机会。NEON数据的大陆覆盖范围和存档的土壤样本提供了一个独特的机会来研究蚯蚓物种丰富度在不同空间尺度上的模式。该研究的第一阶段将为NEON收集和存档的土壤样本制定专门的方案。在史密森尼环境研究中心（SERC）收集的土壤和蚯蚓将用于这一阶段。主要目标是确定测序所需的最小土壤量。pi还将在三个不同的SERC栖息地内采样土壤，代表三种不同的蚯蚓群落。不同的物种在一年中的不同时间活跃，因此他们将在2016年春季和夏季进行采样。他们计划采用模拟NEON网络目前使用的采样的复合样本。下一阶段将从NEON存档的土壤样本中提取DNA并进行测序。然后，物种多样性数据将与同样由NEON收集的环境数据相关联。环境数据包括：当地气候条件、凋落叶的数量和质量、土壤性质，特别是pH值、有机质含量和质地。如果可以获得，土壤微生物多样性数据也将被用作评估和解释蚯蚓物种丰富度模式的元数据。pi将发表论文，重点介绍新方法和蚯蚓生物多样性的遗传分析结果。科学上的新物种和/或重要的新记录也将在单独的论文中描述。

The proposed research will develop and apply methods (DNA metabarcoding) to examine and compare measures of earthworm diversity on a continental scale. These comparative studies of earthworm diversity provide a unique opportunity to evaluate several major environmental issues, such as soil ecosystem services and the existence and consequences of biodiversity loss and species invasion. About one fourth of all known species on Earth resides in the soil, but most of this biodiversity is hidden due to the amount of labor needed to sample, extract and identify soil organisms. DNA metabarcoding is a technique that targets extracellular DNA, that is DNA from lysed or degraded cells in the soil. Thus, it provides the opportunity to identify species that are not physically present in the soil at the time of sampling. The continental scale coverage of NEON data and archived soil samples provides a unique opportunity to examine patterns of earthworm species richness at different spatial scales.The first phase of the study will establish protocols tailored to soil samples collected and archived by NEON. Soils and earthworms collected at the Smithsonian Environmental Research Center (SERC) will be used for this phase. The main goal is to establish the minimum amount of soil needed for sequencing. The PIs will also sample soil within three different SERC habitats representing three distinct earthworm communities. Different species are active at different times of the year, thus they will conduct sampling both in spring and summer 2016. They plan to take composite samples mimicking the sampling that is currently used by the NEON network. In the next stage DNA from soil samples from the NEON archive will be extracted and sequenced. The species diversity data will then be correlated with environmental data, also collected by NEON. The environmental data includes: local climatic conditions, the amount and quality of leaf litter, and soil properties, particularly pH, organic matter content and texture. If available, data on soil microbe diversity will also be used as metadata to evaluate and interpret species richness patterns for earthworms. The PIs will publish papers focusing on the new methods, and on the results of the genetic analyses of earthworm biological diversity. Species new to science and/or significant new records will also be described in separate papers.