The study was performed in a degraded ecosystem by grazing from North-Est of Romania. The aim of the study was to determine main characteristics of primary succession in a pioneer stage initiated on a weathered land by intensive grazing and to identify vegetation classes and potential successional directions. Primary succession analysis was performed by non-systematic inventory in rectangular experimental plots of 25 m2, by identifying woody species presence, biometric measurements (diameter, number of individuals/bushes, number of stems and heights). The analysis of composition indicated the presence of 17 woody species, which were further grouped in classes of vegetation (Corylus-Carpinus, Cornus-Crataegus, Crataegus-Corylus, Populus- Carpinus, names according to two first dominant species). The classes were distinguished as associations between the main pioneer species (Corylus avellana L., Crataegus monogyna Jacq., Cornus sanguinea L., Populus tremula L.). Variability of diameters and heights indicating homogeneous distribution of structure. Grazing had a very important role in the installation and increase of species diversity (zoochor vector), as the most instaled species has a zoochor type dissemination. The possible directions of succession (beech forests or beech and hornbeam forests) were also discussed.

The paper presents the results of a naturalness assessments, and also of the first inventory in two newly established forest reserves (Voievodeasa and Loben) from North of Romanian Eastern Carpathians. The evaluation of naturalness used the historical data concerning the wood extraction, as were recorded in the forest management plans. In selected stands of higher local naturalness was further conducted an inventory, following the methodology recommended by COST E4 and based on a systematic grid with circular plots of 500 m2 . Expected, the results showed that extraction impacted the structural characteristics of stands, esspecially the standing/downing trees volume. The comparison of structural data resulted from inventory (density and volume of both alive and dead standing trees and coarse woody debris) with local references - “virgin“ forests located about 40 km apart of the forest reserves under study - suggested a degree of correspondence between 20-40%. The same data, compared with published information available from mixed forest of beech-fir-spruce accross temperate zone of Europe confirmed the departure of selected stands from the references of naturalness and their distinct grouping, compared with other forest reserves.

Fără Rezumat

The paper analyses, from structural and compositional aspects, the diversity of vascular flora from natural mixed forests with coniferous and beech. Six experimental plots were installed in mixed forest stands with coniferous and beech from Slătioara natural reserve, and the vascular flora was studied on three different layers: trees, seedlings and herbaceous layer. For each layer the species diversity was assessed through Shannon index, and additionally, for trees’ layer, the structural diversity was quantified with respect to the basal area, using the Gini index. It was observed that among the experimental plots, the Gini index ranges between 0.65 and 0.83, corresponding to the uneven-sized balanced structures, and Shannon index computed for species diversity ranges between 0.66 and 1.22 for trees layer, between 0.71 and 1.38 for seedling and between 1.12 and 2.38 for herbaceous layer. The structural diversity of trees layer assessed through the Gini index do not influences directly the species diversity of seedling and herbaceous layers. Nevertheless, when Gini index is higher than 0.48, only shadow tolerant species (ex. Silver fir) might form pure seedling patches. Additionally, regarding the trees layer, pure patches are formed only by beech (92%) or silver fir (8%), and the pure silver fir patches are characterized by low structural diversity (Gini index ranges between 0.27 and 0.32). Also, it was found that beyond certain thresholds of Gini index, the increase of structural diversity is associated with a decrease in the spread of variation of species diversity for all the analyzed layers, and the identified thresholds of Gini index are: 0.6 for trees layer, respectively 0.7 for seedling and herbaceous layers