Structural patterns of beech and silver fir suggest stability and resilience of the virgin forest Sinca in the Southern Carpathians, Romania

摘要: Abstract The structural patterns and dynamics of a primeval silver fir ( Abies alba ) – European beech Fagus sylvatica forest in the Southern Carpathians (Romania) were assessed to gain deeper insight into species interactions mechanisms coexistence, study influence composition on structure. At 21 sample plots, each covering 0.123 ha within an area 240 ha, all living dead trees ⩾6 cm dbh (diameter at breast height) mapped measured. Regeneration was four sub-plots per plot. Additionally, 1-ha permanent plot established 2003 re-measured 2013 obtain information stand dynamics. Point pattern analyses conducted spatial tree-to-tree interactions. overall distributions tended indicate sustainable population structures. share varying from 24.8% 95% (average 58%) basal did not parameters such as or volume, nor distribution growing stock different canopy layers. We found dominate lowest classes plots that strongly dominated by top layer vice versa, locally indicating alternation. regeneration density lower than beech, although browsing ungulates negligible. In contrast its among trees, contributed two-thirds deadwood volume. 10-year changes structure mortality rate very small, suggesting absence recent intermediate severe disturbances. layers agreed with disturbance regime stochastic small-scale events. Although similar, indicated higher intraspecific competition shade tolerance particularly later stages development. Both could be important factors for coexistence two species. conclude fir–beech Sinca shows under present small scale high stability resilience. Temporal only lead fluctuations do threaten long-term fir. Forest managers may vary forests without substantially influencing productivity.