LTER-LIFE

LTER-LIFE is a Dutch scientific infrastructure for shared, integrated ecological research, working towards digital twins of ecosystems.¹ It was founded in August 2023 with a ten-year grant from NWO, the Dutch Research Council.^1,7 The grant (184.036.014) comes from NWO's Large-Scale Research Infrastructures programme.⁷ It starts with two of the most extensive and best-studied ecosystems in the Netherlands, one aquatic and one on land: the Wadden Sea and the Veluwe.¹

The work is done by researchers and software developers at NIOO-KNAW, NIOZ, the University of Amsterdam, Wageningen University and RIVM, supported by teams at LifeWatch VLIC, Wageningen Research, the Netherlands eScience Center and DANS-KNAW.² Marcel Visser of NIOO-KNAW chairs the steering board, and Geerten Hengeveld of NIOO-KNAW is executive manager; each site has a community coordinator.² It builds on three national infrastructures. LTER-NL runs long-term ecosystem monitoring at two sites and is part of LTER-Europe. NemNet runs national monitoring of soil, water and air. LifeWatch develops virtual laboratories.²

It works in three ways: bringing together the researchers who study different parts of the same ecosystem, a portal to find data, models and tools for those communities (including old datasets), and a virtual research environment where they can be reused and connected.¹ Inside that environment, a virtual lab gathers the data, models and analysis tools for one ecosystem, and a twin is assembled in the lab, updated with measurements from the real place, and used for experiments and scenarios on the computer.³ The models can be process-based, written from how the system works, or data-driven, from statistics or machine learning; both are to be made findable, accessible, interoperable and reusable (FAIR).³ LTER-LIFE is to be an open-source infrastructure: users can run its assets on their own machines or in the cloud through its partner SURF, and workflows and data used in projects get a persistent identifier and are stored by DANS-KNAW and SURF.³ The lab environment it uses is NaaVRE, which it is developing further for building twins.⁴

LTER-LIFE is building its services step by step, and several can already be tried, some at an early stage.⁴

• NatureDataCube, geodata for Dutch nature areas through one API (below).⁴
• NaaVRE, the virtual lab environment.⁴
• The LTER Data Registry, to register and find ecological data collected on the Veluwe and IJsselmeer LTSER platforms (long-term research sites).⁴
• The Waddenregister, Datahuis Wadden's search engine for Wadden Sea data and metadata.⁴
• A prototype twin that calculates the primary productivity of the Wadden Sea, the growth of its algae, at chosen moments, built to learn what a full twin would need.⁴
• A metadata template for data used in ecosystem twins, a checklist (FAIR+SET) that suggests how to share a dataset better, and a hands-on guide to FAIR ecological data.⁴

Its code is on GitHub. It includes a NaaVRE virtual lab for a forest landscape model of the Veluwe, setups of 3D GETM-BFM models of the Dutch Wadden Sea, a browser viewer that compares coastal-sea model output with observations, and a metadata harvester that uses large language models.⁶

NatureDataCube, made by Wageningen Environmental Research as an initiative of LTER-LIFE, serves geodata for Dutch nature areas through a STAC API (STAC is an open standard for catalogues of maps and satellite images, readable by QGIS, ArcGIS Pro and Python tools).⁵

Its collections are:⁵

• vegetation index (NDVI) and colour images from Sentinel-2
• terrain and object heights from AHN, the national elevation survey
• the boundaries of 34 Dutch long-term research sites and about 264,000 nature management parcels
• ammonia, nitrogen oxide and total nitrogen deposition from RIVM, which are modelled, not measured
• land use from LGN and the Dutch soil map, both at 5 m

Weather and groundwater are in development.⁵ A free token is needed, and the data are under CC BY-NC-SA, free for non-commercial use.⁵ An R package and a Shiny interface for it are on GitHub.⁶

The group's view of what a twin of an ecosystem is, and how to build one, is set out in Digital twins as a tool for ecosystem research, whose authors all belong to LTER-LIFE.⁷ For someone modelling a place in the Netherlands, NatureDataCube is a ready source of site-level data. Outside the Netherlands, the FAIR checklist and the hands-on guide to FAIR ecological data apply to any ecological dataset.⁴