Dendroclimatological comparison of native Pinus sylvestris and invasive Pinus strobus in different habitats in the Czech Republic.

Many species of the genus Pinus are important forestry trees that escape from plantations and invade natural and seminatural habitats. This study compares the native Pinus sylvestris with an invasive alien P. strobus in the Czech Republic in terms of their radial growth response to climate. Pinus strobus invades sandstone regions, while in areas with another bedrock and soil type it regenerates only sparsely. The research was conducted in six areas differing in abiotic characteristics and the degree of P. strobus regeneration. The effect of climate on the diameter growth was studied using moving and evolutionary correlation and response function analyses. Climatic factors affect radial growth of both species; some reactions are species-specific, others are the same for both species but differ in their intensity. Pinus sylvestris responded positively to high February/March temperatures, P. strobus negatively to high temperatures and low precipitation in the previous September in all study sites. Both species responded to summer rainfall in warm and dry areas, but the response of P. strobus was stronger than that of P. sylvestris. In sandstone areas, both species responded to specific microsite conditions. The study did not find a clear link between dendroclimatological response of P. strobus and its invasive behaviour in sandstone areas of the Czech Republic.