Sustainability of some forest species' associations established on degraded lands from the Transylvania plain, in the context of climate change

Abstract

This research was carried out based on a wide range of knowledge and research results reported due to previous studies on afforestation of degraded lands and forest species associations, in the southwestern part of the Transylvanian Plain. The existing knowledge made it possible to deepen and analyze different forest management practices, such as forest stand improvement, restoration of degraded lands through afforestation in the context of climate change. Therefore, the main objective of this research was to restore a degraded land in the south-western part of Transylvania. To achieve this goal, different forest plant communities were proposed, established and monitored over 9 years. During the research period, the development of forest plant communities was monitored in a fixed area in Viișoara, in order to determine the influence of soil type and plant community composition on the survival rate of the plants. For this purpose, the survival rates after 3, 5, 7 and 9 years after planting were calculated in relation to forest biometric data such as tree height and crown diameter. The results show that both soil type and forest plant community composition influenced the development of the species. The highest survival rates (96-99.5%) were recorded in Pinus sylvestris, Acer campestre, Hippophaë rhamnoides and Crataegus monogyna preluvosol, erodisol and luvosol. Among the 12 forest species tested, Tilia cordata, Quercus petraea and Acer campestre had the highest biometric values in terms of plant height, which ranged from 357.33 cm (Acer campestre) to 412.42 cm (Tilia cordata) along the diameter of the trunk, which varied from 6.27 cm (Quercus petraea) to 11.65 cm (Tilia cordata).