As temperatures drop and the daylight period shortens towards the end of the year, the supply of food for animals also decreases. In late autumn, for many animals, the preparations for overwintering begins, either in the form of hibernation or as a journey to warmer areas. Insects are no exception to this: The number of insects observed decreases from end of summer to winter. While it hums and buzzes in summer, most insects overwinter under leaves or underground. The signal for individual insect species to prepare for overwintering varies greatly with geography and species. We define an insect season as the yearly active period of flying insects. In Denmark, the insect season runs from around mid-March until mid-October. This means the FaunaPhotonics Danish Biodiversity Project 2022 has now come to an end.
For the past couple of months, we have seen a clear decrease in the number of flying insects detected by the sensor (Figure 1). Notice that while at an earlier point in the season the indices were further apart, the differences in the biodiversity indices become less at the end of the season: The data from the sites converge together, and all show a clear trend toward a lower index (Figure 1). Our team of biologists, agronomists, and data experts are currently examining the data collected from the 2022 season in detail. We would like to give a sneak peek into the findings and share an exciting insight into a result that we did not expect. During the measured insect season, the highest average biodiversity was measured in salt marsh areas (marked yellow in Figure 2). Salt marshes are areas of coastal grassland. The second-highest biodiversity was measured in forests (marked dark green in Figure 2). On the other hand, the lowest diversity was, as expected, measured in urban areas (marked grey in Figure 2).
Figure 1: The biodiversity indices of the individual locations where we set up a sensor for our FaunaPhotonics Danish Biodiversity Project 2022.
Figure 2: The average biodiversity indices measured in the habitats where we set up sensors for our FaunaPhotonics Danish Biodiversity Project 2022.
It is important that we find out – based on data – which biodiversity-promoting actions are best for insects. And if, for example, the planting of trees could increase the insect biodiversity of previously farmed grasslands. The user-friendly data in our customer portal can show the impact that regeneration efforts and biodiversity initiatives have. The sensor works faster and is more cost-effective than any other monitoring of insect activity and biodiversity before. You can help compare initiatives that increase biodiversity and ultimately prove which initiatives are most effective at increasing biodiversity in an area. Make sure you get a sensor for the next insect season and track the biodiversity in your area too. If you want to do something to promote healthier biodiversity already this year, help animals to overwinter. This can be as simple as leaving old, dead wood and leaves on the ground, instead of cleaning it up. In many ways, when it comes to biodiversity – doing less is doing more. If you want to do a bit extra, consider building an insect hotel. They are easily installed and provide different insects with a safe place to get through the winter.