## 4 Discussion  
In some studies, the diversity was improved by using Scots pine as an important element for disturbed stands under the climatic and site conditions. Besides this, as in our research, Scots pine creates specific conditions for hardwood species (oak, beech, etc. ), which form populations with homogenous structures. The effects of harmful abiotic factors, analyzed individually or in covariance, correlated with poor environmental characteristics definitive of degraded lands from the Curvature Subcarbathians, creating an imbalance in the resistance-equilibrium relationship. Furthermore, these aspects were observed in past experiments by specialists in ecological reconstruction and degraded land afforestation domains, in which the effects of exogenous factors (wind, snow) were proven after a successive inventory at an interval of 5 or 10 years, based on the evolution of the pine stand structure [32]. As trees advance in age, the ratio between crown diameter (Dc) and base diameter (DBH) decreases, especially when silvicultural interventions are of a weak intensity. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & & & & EP3-RP9\_Pin vs. EP1-RP9\_Pin & & & & & & \\ \hline \multirow{2}{*}{Vulnerability} & Mean—Group 1 & Mean–Group 2 & \multirow{2}{*}{\(t\)-value} & \multirow{2}{*}{df} & \multirow{2}{*}{\(p\)} & Std.Dev.—Group 1 & Std.Dev.—Group 2 & F-ratio—Variances & \(p\)-Variances \\ \hline I \(<\) 0.80 & 0.67 & 0.73 & \(-\)**3.45** & 79 & **0.00 \({}^{*}\)** & 0.09 & 0.05 & **2.51** & **0.00 \({}^{*}\)** \\ \hline
0.80 \(<\) I \(<\) 1.00 & 0.87 & 0.88 & \(-\)0.65 & 60 & 0.51 & 0.05 & 0.05 & 1.00 & 0.95 \\ \hline I \(>\) 1.00 & 1.11 & 1.12 & \(-\)0.18 & 21 & 0.85 & 0.07 & 0.13 & 3.23 & 0.26 \\ \hline \multicolumn{8}{c}{EP3-RP9\_Pin vs. EP1-RP5\_Pin} \\ \hline \multirow{2}{*}{Vulnerability} & Mean—Group 1 & Mean–Group 2 & \multirow{2}{*}{\(t\)-value} & \multirow{2}{*}{df} & \multirow{2}{*}{\(p\)} & Std.Dev.—Group 1 & Std.Dev.—Group 2 & F-ratio—Variances & \(p\)-Variances \\ \hline I \(<\) 0.80 & 0.67 & 0.68 & \(-\)0.29 & 50 & 0.76 & 0.09 & 0.09 & 1.01 & 0.93 \\ \hline
0.80 \(<\) I \(<\) 1.00 & 0.87 & 0.88 & \(-\)0.65 & 55 & 0.51 & 0.05 & 0.07 & 1.58 & 0.27 \\ \hline
1 \(>\) 1.00 & 1.11 & 1.16 & \(-\)0.98 & 27 & 0.33 & 0.07 & 0.11 & 2.33 & 0.42 \\ \hline \multicolumn{8}{c}{EP3-RP10\_Pi vs. EP1-RP9\_Pi} \\ \hline \multirow{2}{*}{Vulnerability} & Mean—Group 1 & Mean–Group 2 & \multirow{2}{*}{\(t\)-value} & \multirow{2}{*}{df} & \multirow{2}{*}{\(p\)} & Std.Dev.—Group 1 & Std.Dev.—Group 2 & F-ratio—Variances & \(p\)-Variances \\ \hline I \(<\) 0.80 & 0.73 & 0.68 & 1.47 & 32 & 0.15 & 0.02 & 0.07 & 6.86 & 0.02 \\ \hline
0.80 \(<\) I \(<\) 1.00 & 0.89 & 0.87 & 1.10 & 31 & 0.27 & 0.05 & 0.03 & 2.40 & 0.33 \\ \hline \multicolumn{8}{c}{EP3-RP10\_Pi vs. EP1-RP5\_Pi} \\ \hline \multirow{2}{*}{Vulnerability} & Mean—Group 1 & Mean–Group 2 & \multirow{2}{*}{\(t\)-value} & \multirow{2}{*}{df} & \multirow{2}{*}{\(p\)} & Std.Dev.—Group 1 & Std.Dev.—Group 2 & F-ratio—Variances & \(p\)-Variances \\ \hline I \(<\) 0.80 & 0.68 & 0.73 & \(-\)1.39 & 32 & 0.17 & 0.07 & 0.06 & 1.36 & 0.74 \\ \hline
0.80 \(<\) I \(<\) 1.00 & 0.87 & 0.91 & \(-\)1.91 & 37 & 0.06 & 0.03 & 0.04 & 1.87 & 0.49 \\ \hline \hlineThe average tree crown diameter (Dc), determined as the average between crown lengths in two directions (N-S and E-W) on the horizontal plane and the crown relative length (Lc%) on the vertical plane, is considered an important biometric characteristic in expressing stand structure. Generally speaking, the variability of crown diameter is more stable around large diameters of trees from the superior level and situated in superior positional Kraft classes (I, II). Trees framed here have a major advantage in regard to crown development on the horizontal plane. The research conducted by [33; 34] analyzed the wind effect on tree stalks as being dominated by the effect of emitted vibrations as well as by changes that appear in the structure and diversity evolution.