Category: NordBorn publications

A recent paper from the Machine Vision for Natural History research group at NTNU University Museum, including several NordBorN members, reports on global trends in flowering phenology, an indicator of the impact of anthropogenic climate change. A machine learning model was used to examine more than 8 million images of herbarium specimens from around the world and spanning two centuries. High diversity in temporal trends in flowering seasonality was found across different ecoregions, with greater variability at low latitudes than at high latitudes. This likely reflects the effects of a combination of shifts in temperature and precipitation seasonality, together with lower photoperiodic constraints to flowering. The study demonstrates the utility of machine learning approaches in large-scale analysis of museum collections and underscores both the importance of natural history collections in assessing long-term trends and the need for digitization efforts to make such specimens available to researchers across the world.

Future work is planned to link global flowering phenology patterns with local climate data, and to examine borealization by combining analysis of historical museum collections with data from field studies. You can read the paper here.

Reference: Williamson, D.R., Prestø, T., Westergaard, K.B., Trascau, B.M., Vange, V., Hassel, K., Koch, W. and Speed, J.D., Long‐term trends in global flowering phenology. New Phytologist. https://doi.org/10.1111/nph.70139

---

Image: Herbarium specimen of Leucanthemum maximum from the NTNU collection which was IDed by one of the co-authors

NordBorN researchers have estimated and mapped historic biomass densities of large herbivores and carnivores across Norway. The current high densities of wild ungulates, especially moose and roe deer, contrast with historically high densities of livestock. Carnivores show a low level of recovery from near absence in the mid 20^th century. However, densities are far below where they were in the 19^th century.

These findings have implications for borealization: Previous studies have shown that herbivory can prevent the spread of boreal species into the tundra, yet it is clear that the trophic interactions involving large herbivores and carnivores are highly dynamic in both time and space.

Reference: Speed, J.D.M, Sobocinski, A., Kolstad, A. L., Linnell, J. D., Solberg, E. J., Mattisson, J., & Austrheim, G. (2025). The trophic distribution of biomass in ecosystems with co-occurring wildlife and livestock. Scientific Reports, 15(1), 1474. https://www.nature.com/articles/s41598-025-85469-2

---

Photo: Lynx (Erik F. Brandsborg, CC BY-SA)

This paper published by NordBorN researchers in Frontiers in Environmental Science as part of the research topic Climate Change Impacts on Arctic Ecosystems and Associated Climate Feedbacks highlights the role of biota in feedback loops from tundra ecosystems to the atmosphere.

Ecosystem modelling has greatly improved or understanding of ongoing and future changes in the Arctic, but beyond vegetation and to some extent microbes, most ecosystem models still do not consider the influence of biotic components on feedback loops between biosphere and atmosphere. This article provides an overview of the influence of three key ecosystem compartments (vegetation, decomposers and herbivores) on three key feedback loops between tundra and atmosphere
(carbon dynamics, albedo and permafrost thaw). Including these dynamics
into ecosystem models will likely improve the magnitude, accuracy and credibility of model projections.

Reference: Schmidt, N.M., Barrio, I.C., Kristensen, J.A., López-Blanco, E. and Van Beest, F.M., 2024. Highlighting the role of biota in feedback loops from tundra ecosystems to the atmosphere. Frontiers in Environmental Science, 12, p.1491604. https://doi.org/10.3389/fenvs.2024.1491604

---

Photo: diagram of feedback loops mediated by biota from tundra ecosystems to the atmosphere (credit: Niels Martin Schmidt)