LIFEPLAN: A worldwide biodiversity sampling design

Metadata When collecting spatiotemporal data, it is essential to keep track of where and when each sam- ple was collected. At a minimum, each sample must be associated with information on the date and time of sample start and end, and the sampling location. We give each sample a unique identifier, which is a six-character code. A “sample” is either: a bottle containing a Malaise sample; a vial containing a cyclone sample; a bag containing a soil sample; or, for image and audio data, the contents of a memory card. For image and audio data, the uniquely identified memory cards are reused week after week and a sample is defined as one batch of data collected between memory card changes, so the unique identifier of an image or audio sample consisted of the six-character code of the memory card combined with the date on which the sample is collected. We also give unique six-character codes to the sampling equipment. All equipment and samples are labelled with durable stickers that contain the unique identifier both as a human readable code and a scannable QR code. When placing or collecting a sample, we use the LIFEPLAN mobile application [44] to scan the QR code of the equipment and the QR code of the sample. In the case of soil samples, we scanned only the sample code as there is no fixed equipment. This scanning creates an Activ- ity, which is a row in a metadata table (Table 1). Table 1. Metadata fields recorded for each activity. Field Description DarwinCore term Activity ID Running number N/A

Activity type Selected by user: Placement (start of sample) / Collection (end of sample) dwc:eventType Activity UUID Universally Unique IDentifier, e.g. 62185720-d7b4-4417-9385-d0bd072be2f8 dwc:eventMeasurementID Equipment type Selected by user: Cyclone sampler / Malaise trap / camera trap / audio recorder / blank for soil samples dwc:measurementMethod Date and time From mobile phone local date and time converted to UTC dwc:eventDate GPS latitude From mobile phone location data, in decimal degrees dwc:decimalLatitude GPS longitude From mobile phone location data, in decimal degrees dwc:decimalLongitude Equipment code E.g. ET5J3G. Scanned from the QR code on the equipment. N/A Sample code E.g. GDL2EM. Scanned from the QR code on the container or memory card. dwc:materialSampleID Site ID Running number unique to a Site. Entered by the application from the database based on the equipment code, which is associated with a particular Site. dwc:locationID Team ID Running number unique to a Team. A Team is in charge of both a natural and urban Site in the Global design. Entered by the application from the database based on the Equipment code, which is associated with a particular Site, which is associated with a Team. N/A User ID Entered by the application from the database. All users are logged in with a personal username and password. dwc: measurementDeterminedBy Equipment condition Selected by the user from a drop-down menu. N/A Sample condition Selected by the user from a drop-down menu. dwc:measurementRemarks Notes Open text field. dwc:eventRemarks

Created at Date and time that the Activity was created. N/A Updated at Date and time that the Activity was last edited. N/A Deleted at Date and time that the Activity was deleted. All deletions are soft deletions, where the Activity remains in the database but is marked deleted. N/A Link Link to audio or image data: here users can paste a share link which gives access to the actual audio or image data stored in a cloud. After the data have been transferred to LIFEPLAN, the link becomes a link to the LIFEPLAN data repository. N/A Processing status For image and audio data, this field indicates whether or not the data have been transferred to LIFEPLAN. N/A https://doi.org/10.1371/journal.pone.0313353.t001 PLOS ONE LIFEPLAN: A worldwide biodiversity sampling design PLOS ONE | https://doi.org/10.1371/journal.pone.0313353 December 31, 2024 9 / 15