NemEu: European database on nematode communities at genus or family level

Abstract

This repository hosts the NemEu database, a harmonized collection of spatially explicit nematode community data from approximately 1,500 locations across Europe, spanning 1975–2020. The dataset contains genus- and family-level nematode counts, enabling analyses of nematode biogeography at the taxon level. This taxonomic resolution also enables the calculation of ecologically meaningful derivatives, including diversity metrics, nematode-based indices of soil food-web functioning, and community-weighted means for traits such as body mass.<br>The NemEu database was assembled by gathering existing nematode community data from researchers across Europe. A composite database like this contains considerable variability. Data contributors were therefore asked to submit additional metadata providing relevant context for each observation, including geographic coordinates, land use, sampling depth, and time of sampling. This metadata was harmonized to facilitate its use in accounting for part of the variability inherent to the dataset. The metadata includes categorical variables that can be used to select groups of interest or subset the data, as well as coded variables (0/1) that can be used to identify and remove potential outlier data points, such as polluted sites or rhizosphere samples.<br>An accompanying data paper has been published that extensively describes the data collection and harmonization procedures, provides an overview of the included data, and offers usage notes on best practices and key considerations when working with the data. The scripts in this repository contain the code used to calculate the statistics and generate the figures presented in the data paper.