Climate variables governing the growth of Tilia cordata (Malvaceae s. l. / Tiliaceae s. str.) in forest biotope in Kyiv

The green belt of Kyiv includes several rare forest biotopes ringing the city and experiencing numerous disturbances and stressors derived from both urbanization processes and climate changes. The arboreal species perform multiple ecological function and influence overall forested ecosystems vulnerability to natural or anthropogenic factors. We have developed the radial growth chronology of Tilia cordata, a common native species in Ukraine, to investigate its climate sensitivity in an urban forest in Kyiv. We assessed relationships between the radial growth of seven trees and hydrothermal variables derived from daily data sets aggregated in intervals from 14 to 180 days instead of the conventional monthly resolution. The studied trees demonstrated a weak intercorrelation, but high subsample signal strength allowed us to perform further analysis. The overall analyses spanned common for all studied trees chronologies period 1977–2015 shows that precipitation governed the growth of Tilia cordata in Kyiv's forest, and the influence was significant in the interval between December of the resting period and May in the growing season. Temperatures averaged for March–May of the prior growth period had a weaker but significant negative impact on Tilia cordata growth. The co-inertia analysis shows that despite low intercorrelation between trees chronologies, individual growth patterns highly correlated with growth-to-climate relationships patterns suggesting that precipitations synchronized trees growth even in various microsites conditions of the studied forest. The age of the oldest studied trees, which had a mean growth rate of 0.95 mm per year, reached 300 years.