Changes in Species Composition in Alder Swamp Forest Following Forest Dieback

摘要: It is generally hypothesized that forest dieback a characteristic of alder swamp forests (alder carrs, Alnion glutinosae alliance). Different internal and external factors may trigger this process, including human disturbance, changes in river discharge, unusually severe prolonged flooding, terminal age an even-aged (ca. 100–150 years) others. Although type cause major environmental conditions, the influence change on floristic composition has not been well recognized. The study aimed to detect any possible variation following dieback. Vegetation plots affected by were resurveyed 20 years after previous study. PERMANOVA was used test significance compositional nonmetric multidimensional scaling (NMDS) with passively fitted means Ellenberg’s Indicator Values interpret its ecological meaning. In addition, different structural diversity indices compared, species richness, percentage cover vegetation layers, Shannon Simpson evenness. Finally, we analyzed frequency vascular plant using Chi square tests. We recorded clear significant This most related gradient moisture, followed gradients light temperature. analysis individual showed hummocks declined, while hollows increased. Moreover, current communities are dominated some hydrophytes ago. Forest resulted profound hydrological regime. observed consistent model cyclic succession as proposed for swamps. conclude natural dynamics have be taken into consideration interpreting results re-survey studies.