Seed germination and early field performance of Quercus robur and Pinus sylvestris seedlings under soil compaction conditions

Forest operation processes by heavy equipment induces severe soil stresses that may influence natural stand regeneration. However, there is a lack of information about relation between forest machine passes and tree regeneration and growth. The aim of the study was to determine the effects of soil compaction on seed germination and on the early growth and development of seedlings belonging to two of the most spread species in Europe, Quercus robur and Pinus sylvestris. The study was carried out in a field plot located in Italian Northern Apennine, where the soil developed on Lower Miocene-Oligocene sandstone and was classified as Dystric Cambisol. Three different compaction levels (control and slightly compacted and compacted by logging operations) were considered. In 3 randomized blocks, 375 seeds for each species were sowed in February-March 2017. Data on germination and seedlings height were collected about every 10 days during the first vegetative season. The morphological attributes of seedlings' shoot and root system were assessed by five destructive analyses during and at the end of the first vegetative season, in order to evaluate the soil compaction influence on biomass, dimensions and architecture. Data processing was focused to compare undisturbed condition with the different compaction level in order to highlight the potential constraint effect over the whole first vegetative season since germination. The poster presents the preliminary results including data collected in early summer 2017.