Stand structure, tree density as well as tree spatial pattern define natural dynamics and competition process. They are therefore parameters used to define any silvicultural management type. This work aims to report first data resulting from a silvicultural experiment in beech forests. The objective of the trial is testing the structure manipulation in terms of diversity and the reduction of inter-tree competition of different thinning approaches. Alternative thinning methods have been applied in two independent experimental sites located in the pre-Alps and southern Apennines, in Italy. Specific goals were to: (i) verify the impact early after thinning implementation on forest structure through a set of diversity and competition metrics resulting from a literature review; (ii) the sensitivity of tested indexes to detect effectively thinning manipulation. Main results show the low sensitivity of stand structure indexes and the ability of competition metrics to detect thinning outcome.

Biodiversity restoration is pivotal to enhance natural ecological processes in riparian ecosystems, affected by intensive human impact. Improving the riparian area functionality through new plantations is an effective Nature-based Solution. Poplar plantations have great potential for preventing soil erosion and providing habitats, but their impact on biodiversity has been little studied. Aims of this study were to: (1) investigate the effect of different poplar woodland management on vascular species diversity; (2) define the main drivers of vascular plant species richness, community composition, invasiveness and functional strategies. In three sites (Po river, Italy), an integrated survey protocol was applied to assess vascular species diversity, stand structure and soil properties. For each site, three stands with different management (cultivated, semi-natural and natural) were surveyed. Differences among all stand structural parameters and the management types were found. Tree diameter did not change between natural and seminatural stands but mean quadratic diameter of seminatural stands (28.1 cm) was similar to cultivated ones (26.8 cm). While cultivated stands showed the highest species richness (mean 28 species), semi-natural stands showed the highest number of native species (82 %) and an efficient soil N cycle (microbial N limitation, MNL < 0). The total Ca and MNL in soil resulted the main drivers of species diversity in the studied poplar stands. Semi-natural stands highlighted the best trade-off amongst vascular plant species diversity, invasiveness and soil process. The used integrated approach was effective and extendable to ecological and functional assessment of poplar riparian forests under different management gradients. © 2025 The Authors

Holm oak (Quercus ilex L.) is one of the most diffuse and economically important forest species in Sardinia, where it holds about 40% of holm oak cover in Italy. The forest type has also acquired a high ecological, recreational and landscape value over the last decades. Most of holm oak stands originated from overgrown coppice forests partly undergoing conversion into high forest. This study was set up in 1994 to analyse, as a function of site-index, the effects of conversion thinning on productivity, biodiversity, structural dynamics and canopy characteristics in an holm oak forest located in southern Sardinia. Two experimental permanent plots, differing in site index, stand structure and tree density, were established. The surveys were carried out in 1994-95 and 2010-11. The analysis included growth pattern, dynamics of stand structure and estimation of forest canopy attributes as leaf area index and canopy transmittance. Results pointed out the simplified stand structure, the poor biodiversity, the low LAI and high transmittance values 9 years after thinning implementation. These characteristics were more pronounced in the less productive area, characterised by substantial canopy gaps. 25 years after thinning implementation, both stands showed significant increase in the number of trees, strengthening of the clustered structure and high canopy recovery. Conversely, no significant changes in biodiversity and vertical structure were observed. Overall results contributed to a positive evaluation of the conversion practice based on periodical thinnings, even if the excessive reduction of tree density, mainly in the lower site-index area, did not allow yet the fully achievement of canopy recovery.