National insect monitoring in Norway

The Norwegian Institute for Nature Research (https://www.nina.no) conducts a general monitoring of terrestrial insects in Norway since 2020, on behalf of the Norwegian Environmental Agency (https://www.miljodirektoratet.no/). As of 2024, the monitoring program covers semi-natural land across all five major areas of Norway ; "Sørlandet" (south-west), "Vestlandet" (west), "Østlandet" (south-east), "Trøndelag" (middle), and "Nord-Norge" (northern). In addition, we monitor the forests in "Østlandet". Expanded coverage of forest ecosystems may occur in the future. The monitoring is based on passive sampling through malaisetraps with addition of windowtraps in forests. Identification of insects is mainly done through metabarcoding after a soft lysis of the material. Caution should be excercised when interpreting occurrences of single species, as the metabarcoding and bioinformatics may contain errors. Three possible errors to be aware of: 1) false positives of some species not present in the sample, 2) wrong asssignment of DNA-sequence to species name, 3) false negatives of species present in the sample. The bioinformatics is occationally updated for the entire dataset on the entire dataset, with more and more DNA-sequencies being assigned to a species name, and some species assignments being corrected, as the reference libraries continue to improve. This was last done after the 2024 season, and we are currently at version 2.0 of our internal bioinformatics database NorInvert. In this export, we filter out the taxonomic identifications that has been flagged as uncertain in our internal quality assessment. The sample design is expressed through a series of hierarchical event levels, that should be unpacked before analysis. We also collect a range of environmental data at the sampling sites. These are collected in the dynamicalProperties column as a JSON-string, at the hierarchical level they are related to. An R-script for unpacking the data into a more usable format is (will be) available at https://github.com/NINAnor/national_insect_monitoring Brief explanation of the hierarchical structure of the dataset:

1. The occurrence table can be joined to the event table through the parentEvent, which joins to an
2. identification event. This level exists because any sample may have gone through several identification events, possibly with differing methods. The identification events joins through its parentEvent with
3. a sampling_trap event, which designates a single trap in a single sampling event at a location. Sampling_trap events are joined through their parentEvent to a
4. locality sampling event, which is a single sampling period in a locality. Sampling events can have 1 or more traps (sampling trap events). Finally, the locality sampling events can be joined through their parentEvent to a
5. year locality event, which designates the sampling of insects in a single locality in a year. Relevant metadata or collected explanatory data is attached to each level, with the dynamicProperties column collecting the datatypes that the Darwin Event Core doesn't presently cater to. This is the second version of this dataset. This version does not contain the records with taxonomy matches that has been flagged as uncertain, according to our bioinformatics pipeline (Identification confidence LOW, MEDIUM). The full data set can be sent on request.