Structural Features of Old Growth Forest from South Eastern Carpathians, Romania

Background and Purpose: Romania’s forests are of globally significant value due to their natural characteristics, as similar forests in some other parts of the world have been lost forever. These types of forests, so-called "virgin" and "quasi-virgin (old growth)" forests, are also identified in the Buzau Mountains, which are part of the Eastern Carpathians in Romania (Curvature Region). Materials and Methods: To study and understand the structure and dynamics of primeval forest, four permanent one-hectare research plots were installed in the Penteleu Mountains, part of the Buzau Mountains. All trees with a diameter at breast height (DBH) greater than 80 mm were measured and their main dendrometric characteristics (DBH, height and social position) registered. The forest structure was analysed by fitting different theoretical distribution functions (beta, gamma, gamma 3P, gamma 3P mixt, loglogistic 3p, lognormal 3P and Weibull 3p). The structural homogeneity of the permanent research plots was tested using the Camino index (H) and Gini index (G). Results: For the smaller DBH categories, Norway spruce was relatively shorter in height, but with increasing DBH, the heights of Norway spruce exceeded those of European beech. Stand volume varied between 615 and 1133 m3 per hectare. The area of maximum stability where we encountered the lowest tree height variability was recorded between the 60 cm and 100 cm diameter categories. The Lorenz curve and the Gini index indicated that the studied stands have high structural biodiversity. Conclusions: The results showed that the studied forests have an optimal structural diversity, assuring them a higher stability and multifunctionality. Thus, these forests are models for managed forests

Importance of Dead Wood in Virgin Forest Ecosystem Functioning in Southern Carpathians

Dead wood (DW) is an important component of sustainable forest management and climate change mitigation. Three research plots (each with an area of 1 ha), located in virgin forests in the Southern Carpathians (Semenic P20, Retezat–Zănoaga, and Făgăraș–Șinca), were installed in order to study the synergies between DW and climate change mitigation effects. Data on the dendrometric characteristics of standing and lying DW, the species, and the degree of decay were recorded. The aboveground biomass (AGB) and carbon stock (CS) of the DW were also determined. The DW volume was between 48 m3·ha−1 and 148 m3·ha−1, with the total volume (dead and alive) ranging between 725 m3·ha−1 and 966 m3·ha−1. The DW volume distribution shows a decreasing trend, with the most suitable theoretical distributions for describing this being the lognormal, the 2P Weibull, and the 2P-Gamma. The AGB ranged between 17 t·ha−1 and 30 t·ha−1 and showed a decreasing trend according to altitude. The CS was between 8 t·ha−1 and 14.33 t·ha−1. A slow decomposition rate for the hardwood was identified by analyzing the relationship between the surface and volume of the DW. This highlighted the capacity of DW to store carbon for a long period of time