A Permanent Research Platform for Ecological Studies in Intact Temperate Mountainous Forests from Slătioara UNESCO Site and Its Surroundings, Romania

Abstract

This paper describes a permanent research platform (PRP) designed and implemented in “Codrul secular Slătioara” and its surroundings (2205.85 ha), having also the role of introductory paper for future research articles based on data collected from this platform. “Codrul secular Slătioara” is known as one of the largest temperate mountainous intact forests of Europe and, in 2017, it was included in UNESCO World Heritage List, as part of the “Ancient and Primeval Beech Forests of the Carpathians and Other Regions of Europe”. Moreover, the PRP overlaps other three scientific reserves, the share of strictly protected forests exceeding 70%. This platform has a multiple role, being developed for research, conservation and educational activities. The PRP was designed for an ecological analysis of the intact forest ecosystems. It contains 193 circular sample plots, each of them of 500 m2, and it is structured on two levels. The first level contains 58 sample plots corresponding to a square grid of 500 × 500 m, stretching over the entire forested area, and the second level contains 135 plots, placed according to a square grid of 100 × 100 m, covering 136 ha within the core area of the UNESCO site. We measured the characteristics of 8296 living trees, 1743 standing dead trees, 1900 dead wood trunks, 3214 saplings, and the abundance–dominance indices of flora species. Thus, we identified 14 tree species, 17 shrub species, and 248 other cormophyte species forming the herbaceous layer. In terms of volume, the main tree species are Norway spruce, silver fir and European beech. The tallest species are Norway spruce (56 m) and silver fir (51 m). The average volume of living trees is 659 m3·ha−1, with a maximum of 1441 m3·ha−1. The mean total dead wood volume is about 158 m3·ha−1, with sample plots where the total dead wood volume exceeds 600 m3·ha−1. After presenting the results of preliminary data processing, the paper describes the main research topics to be further considered, based on the PRP, and the foresights related to the PRP’s monitoring and development.

Aboveground Biomass of Living Trees Depends on Topographic Conditions and Tree Diversity in Temperate Montane Forests from the Slătioara-Rarău Area (Romania)

“…In order to compare the distribution of variables among the inventoried SPs, a principal component analysis (PCA) was used as an exploratory data analysis, considering the number of tree species, stem density, species diversity (D), tree size heterogeneity (G), modified Lorenz curve asymmetry, aboveground biomass, elevation, aspect and slope as variables and the 193 plots as observations. The PCA was applied for two different situations: (i) considering all SPs; (ii) considering only the first level of PRP [59]. The FactoMineR package (version 2.3) [79] of R (version 3.6.2) was used.…”

“…The climate is continental-temperate, with mean annual temperatures between 3.8 • C at high elevations and 5.9 • C at low elevations, and mean annual rainfall between 700 and 810 mm. Duduman et al [59] provide a detailed description of the study area, in terms of biodiversity and topography. The landscape is characterized by mixed temperate forests with coniferous trees and European beech at low and middle elevations, and by pure Norway spruce stands at high elevations, where they alternate with pasture lands.…”

“…Data were collected in 2015 from 193 sample plots, 500 m 2 each (horizontal area), within a permanent research platform (PRP) covering the 1724.57 ha of forests and structured on two levels: the first level of PRP covers the entire area and corresponds to a square grid of 500 × 500 m; the second level of PRP was set up for the core area, according to a square grid of 100 × 100 m (see Figure 3 in [59]). All (living or dead) standing trees with diameter at breast height (dbh) larger than 5 cm were inventoried within every sample plot (SP) but, for this study, only the data regarding the 8296 living standing trees were analyzed.…”

“…All the 135 SPs from second level PRP, installed in the core area of the Slătioara UNESCO site were assigned to N2000 habitat types, most of them (88) as Dacian Beech forests (Symphyto-Fagion) (91V0), 35 SPs correspond to Luzulo-Fagetum beech forests (9110) and 12 to Acidophilous Picea forests of the montane to alpine levels (Vaccinio-Piceetea) (9410). If considering only the first level of PRP [59], 30 SPs correspond to 9410, 13 SP to 91V0 and 15 SP are NN.…”

“…Given the rare opportunity to study these interactions in natural forests located on sites with a wide range of topographical conditions, knowing that they are not fully understood and that Romania has 8% of Europe's intact forests [8], we intend to exploit the existence of a permanent research platform (PRP) within the Slătioara UNESCO site and its surroundings [59] and to expand the research methodology to a wider network of intact forest sites. Through this analysis, we aim to highlight interaction patterns between aboveground biomass, biodiversity and topographical factors, and patterns transcending the micro-site context.…”