Spatial patterns in recent forest growth trends across the Czech Republic

The radial growth of trees significantly contributes to climate change mitigation by sequestering carbon into woody biomass. Radial growth trends observed in European temperate forests during the recent period of climate warming vary between growth acceleration due to longer growing seasons and growth declines due to amplified drought stress. Assessing the spatial variation of growth trends is challenging due to the point relevance of available empirical data including forest inventories and tree-ring width chronologies. Here, we used a database of tree-ring width chronologies from 596 sites and spatial models to describe the growth trends of five tree species across the Czech Republic between 1990 and 2018. The resulting map highlights multiple sources of variation in growth trends including differences between species and prominent spatial gradients along elevation, latitude, and longitude. The knowledge of spatially explicit growth trends is essential for the adaptation of the forestry sector to ongoing climate change. Differences among species, regions, and over time shape current growth trends of European temperate forests.Abies alba shows mostly positive growth trends. By contrast, Fagus sylvatica and Picea abies currently decline across most of their species ranges.Growth trends shift from negative to positive with increasing elevation for species covering a broad elevation range.The growth trends of some species follow latitudinal (Abies alba) or longitudinal (Quercus spp.) gradients.The growth trends tend to be more negative in the recent period 2005-2018 compared to the 1990-2005 baseline for most species and regions.