I have worked on the causes of change in European and Canadian forests, including climate change, insect outbreaks and human disturbances. Tools that I apply to understand forests include Species Distribution Models, demographic models, forest landscape models, and metapopulation/ metacommunity models. A related interest is how species interactions can affect dynamics, and I have studied how food webs could explain Pleistocene mammal extinctions, and developed new mechanisms for how hyperparasitoids could alter parasitoid densities and thus contribute to large-scale insect outbreaks.
In my previous postdoc at SLU Artdatabanken, I studied wood-decay fungi, and developed a metacommunity model where species influence the colonization and extinction of other species in the community (through competition, facilitation).
Underprediction of extirpation and colonisation following climate and land-use change using species distribution models. Auffret, A, Nenzén, H, Polaina, E. 2024. Diversity and Distributions (e13834).
Oil sands restoration with warm‐adapted trees improves outcomes under moderate but not severe warming scenarios. 2023. H Nenzén, Y Boulanger, E Campbell, D Price, C Mallon, A Petty, D Stralberg. Ecosphere 14 (12), e4721
H Nenzén, D Price, D Cyr, Y Boulanger, A Taylor, E Campbell. 2020. Projected climate change effects on Alberta’s boreal forests imply future challenges for oil sands reclamation. Restoration Ecology, 28: 39-50
Nenzén, HK, V Martel, D Gravel. Can hyperparasitoids cause large‐scale outbreaks of insect herbivores? 2018. Oikos, 127: 1344–1354
Nenzén, HK, P Peres-Neto, D Gravel. 2017. More than Moran: Coupling statistical and simulation models to understand how dispersal and climate variation drive insect outbreak dynamics. Special issue of Canadian Journal of Forest Research,48: 255-264
Nenzén, HK, MB Araújo. 2011. Choice of threshold alters projections of species range shifts under climate change. Ecological Modelling, 222: 3346-3354.