Changes in species and functional composition in the herb layer of sub-Mediterranean Ostrya carpinifolia abandoned coppices

In recent decades, the traditional management of woods has ceased in several parts of the Apennine ridge, with the result that some woods have not undergone forestry for 40–70 years. The research aim was to assess the variation of species and functional composition in the herb layer of Ostrya carpinifolia woods (central Italy), after cessation of the usual management (coppice-with-standards). Using a space-for-time substitution, we compared stands at the end of the usual rotation cycle (20–25 years) with stands not subjected to silvicultural treatments for about 40–45 years and collected environmental and structural data. The main drivers of the herb layer modification, assessed using Ellenberg indicator values analysis and redundancy analysis (RDA), were primarily related to time since the last coppicing and wood structure. Results of indicator species analyses (ISAs) and Wilcoxon rank sum tests indicated that in abandoned coppices, the regenerative processes proceed through the spread of late-successional species, while the light filtering through canopy fosters species usually considered of fringe habitats. The functional strategies revealed by ISA and RDA underlined still stressful conditions in stands at the end of the usual coppicing rotation cycle, which might be thought as a legacy of the post-logging condition, and processes of recovery/maturation of the forest systems in abandoned woods leading to a better spatial and temporal niche partitioning. The preferential distribution of species usually growing in the Apennine beech woods supports the hypothesis that the studied O. carpinifolia woods are secondary forest ecosystems originating from the degradation of mixed beech woods.