Redistribution of habitats between the Sand lizard (Lacerta agilis) and the Common lizard (Zootoca vivipara) in the southern taiga subzone. Reaction to temperature rise or result of processes not related to climate change?

Main observations were made in a sample plot (by 10 km2) during 1999–2023. In 1999 about 40% of the sample plot was arable lands. In 2000–2003 the ploughing had been stopped. In sandy patches, former arables began to be replaced by heathlands with xerophytic grass and sparse sprouts of pine. In 1999–2005 Z. vivipara inhabited the outer edges of floodplain forest with high density; L. agilis distribution was restricted to small patch (about 25 ha) of drained peatland located 4 km away from floodplain forest. Since 2006 L. agilis began to inhabit arising heathlands, and by 2019 its population has reached high density there. Z. vivipara was pushed out of the forest edges into the floodplain. In 2000–2023, the duration of period with favorable for lizards activity temperature conditions was for 15–17 days longer than in 1978–1999. There is a desire to suggest that spatial redistribution of lizards is dependent on temperature conditions. However, comparison of lizard’s distribution in sample plot with the same in adjacent areas, where agricultural lands were absent and heathlands were widely represented, indicates that main factors of lizard’s habitat redistribution are a decrease of anthropogenic pressure, natural succession of vegetation communities and interspecific competition in the lizards. Climate change could be the cause of increase in the growth rate of population on newly settled areas, but it not be a trigger of a spread.