Effect of climate variability on Quercus rubra phenotype and spread in Lithuanian forests

This study investigates the effect of climate variability on the phenotype, leaf litter decomposition intensity and seedling spread of alien red oak (Quercus rubra L.). Twenty-eight red oak forest stands located in Lithuania were evaluated. Indirect climate change indicators such as continentality were used in the analysis. Simulation of climate warming was achieved using an agro sheet cover. According to the results, the morphological traits of red oak stems in the maritime regions (warmer winters) do not differ significantly from those of red oaks stems in the continental areas of Lithuania (colder winters, more frequent spring frosts). Red oak leaf litter under an agro sheet cover (warmer conditions) decomposes at almost the same intensity as without the cover (natural conditions). The red oak seedlings spread 100 m or more irrespective of continentality. These results showed indirectly that climate change will not affect red oak stem quality or microorganism activity in the process of leaf litter decomposition. Red oak will thus remain as an invasive species, threatening composition change in native forests.