Some criteria of regeneration density in young beech populations

Some criteria of density in beech saplings were studied in various forest associations (mainly Galio odoratiFagetum typicum) growing in the submontane region near Zurich (Swiss Central Plateau). The sample plots were established in regeneration gaps resulting from Swiss irregular shelter wood system (Femelschlag). Five sample plots, each 2x2m in 3 transects (a total of 15 plots in each gap, x 10 gaps), were laid out from the center to the edge of the gap and under the old growth stand in the upper, middle and lower parts of the gap. Three collective criteria (i) number of saplings (Nm-2), (ii) mean distance of saplings and (iii) crown competition factor and one individual criterion (growth space) were investigated within the sample plots. Results showed that the density of beech saplings was not homogenous. The number of saplings (Nm-2) had wide amplitude, which varied between 2.5 and 54.8 and the mean distance of saplings varied between 14.5 and 68.0 cm. The crown competition factor varied between 1 (100%) and 5 (500%) indicating five times of overlapping in crown space of saplings, while the growth space of the studied beech saplings varied between 1.2 and 12.0

Canopy gaps characteristics and structural dynamics in a natural unmanaged oriental beech (Fagus orientalis Lipsky) stand in the north of Iran

Canopy gaps are one of the most important structural features of forest ecosystems, and studying them can have useful results and implications for forest management. The aim of this study was to investigate the characteristics and regeneration within canopy gaps in an intact beech stand in Shastkalateh experimental forest of Hyrcanian region, north of Iran. All canopy gaps and related forest parameters were measured within a permanent plot of 16 ha. Then, for each canopy gap, two parameters were measured—the length (L) as the longest distance within the gap, and the width (W) as the largest distance perpendicular to the length. Considering the composition of the forest, the dominant tree species was oriental beech with 36.3% of the stem number and 56.6% of the stand volume. Totally, 54 canopy gaps were identified which covered about 5% of the forest area. An average of 4.32 gaps.ha-1 existed in the permanent plot and gap sizes varied from 48.3 to 622.7 m^2. Over three-quarters (77.7%) of canopy gaps were smaller than ≤200 m^2 and also over half of the gaps (53%) were formed by a single tree-fall event. The beech made up 52% of gap makers and 23.4% of gap fillers and also had the second largest proportion on standing deadwood of gap maker in the study area, while velvet maple was the most frequent gap filler in approximately 30% of the gaps. Despite the high frequency of small gaps 100 m^2, their proportion of the overall gap area reached only 25%, suggesting the important role of intermediate and large gaps in the gap dynamics. Considering the recent occurring disturbances in the Hyrcanian forests, the study analyzed the main characteristics of disturbance regime with the emphasis on the role of wind and longevity of trees. In general, findings of this study showed that creating small and average gaps in intact beech forests could be based on natural disturbance regimes, and suitable conditions provides for successful regeneration of beech forests in close to nature silviculture

Influence of gap size and development stages on the silvicultural characteristics of oriental beech (Fagus orientalis Lipsky) regeneration

We studied 11 gaps covered with beech saplings (< 1.30 m tall) in a reserve compartment (compartment 139, district one, Langa forest, watershed 36: Kazemrood) of the Caspian beech forest in N Iran. Two transects, each 2 m wide, were laid along the longest (N-S) and shortest (E-W) axis of each gap. Five micro sample plots, each 4 m2, were established: one at the center, and one at each corner. Qualitative and quantitative characteristics of saplings with a diameter at breast height less than 7.5 cm were examined in the micro sample plots. Analysis of variance (ANOVA) and Kruskal-Wallis test were performed using SPSS software for quantitative characteristics, and chi-square test for qualitative characteristics. Results indicated that medium-sized (200-500 m2) gaps promote the growth of oriental beech saplings of desirable silvicultural forms during decay and initial stages