Bioclimate change across the protected area network of Finland

Juha Aalto; Ilari Lehtonen; Pentti Pirinen; Kaisu Aapala; Risto K Heikkinen

doi:10.1016/j.scitotenv.2023.164782

Bioclimate change across the protected area network of Finland

Sci Total Environ. 2023 Oct 1:893:164782. doi: 10.1016/j.scitotenv.2023.164782. Epub 2023 Jun 14.

Authors

Juha Aalto¹, Ilari Lehtonen², Pentti Pirinen², Kaisu Aapala³, Risto K Heikkinen³

Affiliations

¹ Finnish Meteorological Institute, P.O. Box 503, FI-00101 Helsinki, Finland; Department of Geosciences and Geography, University of Helsinki, P.O. Box 64, Gustaf Hällströmin katu 2a, 00014 Helsinki, Finland. Electronic address: juha.aalto@fmi.fi.
² Finnish Meteorological Institute, P.O. Box 503, FI-00101 Helsinki, Finland.
³ Nature Solutions Unit, Finnish Environment Institute, Latokartanonkaari 11, FI-00790 Helsinki, Finland.

PMID: 37321502
DOI: 10.1016/j.scitotenv.2023.164782

Abstract

Protected areas (PAs) are crucial in conserving biodiversity under climate change. In boreal regions, trends of biologically relevant climate variables (i.e., bioclimate) in PAs have remained unquantified. We investigated the changes and variability of 11 key bioclimatic variables across Finland during the period 1961-2020 based on gridded climatology. Our results suggest significant changes in annual mean and growing season temperatures over the entire study area, whereas, e.g., annual precipitation sum and April-September water balance have increased especially in the central and northern parts of Finland. We found substantial variation in bioclimatic changes over the 631 studied PAs; in the northern boreal zone (NB) the number of snow-covered days has decreased on average by 5.9 days between 1961-1990 and 1991-2020, while in the southern boreal zone (SB) the corresponding decrease has been 16.1 days. The number of frost days in spring with absent snow cover has decreased in the NB (on average -0.9 days) while increasing in the SB (0.5 days), reflecting the changing exposure of biota to frost. The observed increases in accumulation of heat in the SB and more frequent rain-on-snow events in the NB can affect drought tolerance and winter survival of species, respectively. Principal component analysis suggested that the main dimensions of bioclimate change in PAs vary across vegetation zones; for example, in the SB the changes are related to annual and growing season temperatures, whereas in the middle boreal zone the changes are linked to altered moisture and snow conditions. Our results highlight the substantial spatial variation in bioclimatic trends and climate vulnerability across the PAs and vegetation zones. These findings provide a basis for the understanding of the multifaceted changes the boreal PA network is facing and help to develop and direct conservation and management.

Keywords: Biodiversity conservation; Climate change; Climate vulnerability; Gridded data; Northern Europe; Protected area.

MeSH terms

Biodiversity*
Climate Change*
Finland
Seasons
Snow