## 3 Results  
### Characteristics of the Amount of Sap Obtained from Individual Trees  
#### 3.1.1 Daily Efficiency of Sap Leak  
Trees growing in the mixed coniferous forest site were characterized by an average daily birch sap leakage from 3.05 dm\({}^{3}\)/24 h (MED2) to 11.50 dm\({}^{3}\)/24 h (MED1) (Table 1). The lowest recorded amount of sap was 0.00 dm\({}^{3}\)/24 h for trees MED 2 and TCK1, which resulted from the later date of the start of leakage by these trees. The most considerable daily amount of sap obtained from one tree at this site was 19.2 dm\({}^{3}\)/24 h and was observed in the group of medium trees (MED1). The variability of the amount of sap obtained on individual days expressed as a standard deviation ranged from 1.80 dm\({}^{3}\)/24 h (THN2) to 5.80 dm\({}^{3}\)/24 h (MED1). The coefficient of variation of daily sap yield was very high and shows values ranging from 43.9% (THN3) to 97.8% (TCK1). The average daily birch sap leakage from trees growing in the mixed broadleaved forest site ranged from 0.78 dm\({}^{3}\)/24 h (tree: THN1) to 12.43 dm\({}^{3}\)/24 h (TCK2) (Table 1). The minimum recorded leakage was 0.00 dm\({}^{3}\)/24 h (THN1). This was due to the earlier termination of leakage from this tree compared to the others. The maximum leakage was obtained from tree TCK2--22.50 dm\({}^{3}\)/24 h. The variability of the amount of sap obtained \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Tree** & **Mean** & **Minimum** & **Maximum** & \
\begin{tabular}{c} **Standard** \\ **Deviation** \\ \end{tabular} &
\begin{tabular}{c} **Coefficient** \\ **of Variation** \\ \end{tabular} \\ \hline \multicolumn{6}{c}{Site: Mixed Coniferous Forest} \\ \hline THN1 & 6.45 & 0.12 & 13.52 & 4.06 & 62.9\% \\ THN2 & 3.49 & 0.05 & 6.92 & 1.80 & 51.7\% \\ THN3 & 10.88 & 1.95 & 17.15 & 4.77 & 43.9\% \\ MED1 & 11.50 & 0.07 & 19.21 & 5.80 & 50.4\% \\ MED2 & 3.05 & 0.00 & 7.51 & 2.14 & 70.1\% \\ MED3 & 8.38 & 0.40 & 16.24 & 4.77 & 56.9\% \\ TCK1 & 3.80 & 0.00 & 11.83 & 3.71 & 97.8\% \\ TCK2 & 3.84 & 0.80 & 9.88 & 3.05 & 79.5\% \\ TCK3 & 3.46 & 0.90 & 9.21 & 2.40 & 69.5\% \\ \hline \multicolumn{6}{c}{Site: Mixed Broadleaved Forest} \\ \hline THN1 & 0.78 & 0.00 & 2.91 & 0.85 & 109.2\% \\ THN2 & 4.39 & 2.30 & 6.17 & 1.18 & 26.9\% \\ THN3 & 6.05 & 0.33 & 9.76 & 2.55 & 42.1\% \\ MED1 & 3.19 & 0.40 & 7.39 & 2.06 & 64.7\% \\ MED2 & 6.42 & 2.71 & 9.56 & 1.99 & 31.0\% \\ MED3 & 2.83 & 0.96 & 4.77 & 1.08 & 38.1\% \\ TCK1 & 3.63 & 0.53 & 9.02 & 2.31 & 63.6\% \\ TCK2 & 12.43 & 1.26 & 22.50 & 6.80 & 54.7\% \\ TCK3 & 5.99 & 1.26 & 12.69 & 3.55 & 59.3\% \\ \hline \multicolumn{6}{c}{Site: Broadleaved Forest} \\ \hline THN1 & 5.04 & 0.38 & 12.90 & 3.68 & 72.9\% \\ THN2 & 6.36 & 3.47 & 9.83 & 1.71 & 26.9\% \\ THN3 & 1.24 & 0.15 & 4.94 & 1.20 & 97.1\% \\ MED1 & 4.07 & 1.36 & 8.69 & 2.00 & 49.2\% \\ MED2 & 2.15 & 0.48 & 5.25 & 1.48 & 69.0\% \\ MED3 & 8.99 & 1.74 & 16.61 & 4.29 & 47.8\% \\ TCK1 & 5.87 & 0.57 & 13.56 & 3.67 & 62.4\% \\ TCK2 & 2.43 & 0.70 & 4.98 & 1.06 & 43.6\% \\ TCK3 & 2.53 & 0.43 & 7.39 & 2.05 & 81.1\% \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Summary statistics for daily sap leak volume (dm\({}^{3}\)/day). on individual days, expressed by the standard deviation, ranged from 0.85 dm\({}^{3}\)/24 h (THN1) to 6.80 dm\({}^{3}\)/24 h (TCK2). The coefficient of variation of daily birch sap yield was the lowest for tree THN2 (26.9%) and the highest for tree THN1 (109.2%). The average sap leakage from trees growing in the broadleaved forest site ranged from 1.24 dm\({}^{3}\)/24 h (THN3) to 8.99 dm\({}^{3}\)/24 h (MED3) (Table 1). The lowest daily leakage was recorded for tree THN3--0.15 dm\({}^{3}\)/24 h--and the maximum for MED3--16.61 dm\({}^{3}\)/24 h. The standard deviation of the daily birch sap yield ranged from 1.06 dm\({}^{3}\)/24 h (TCK2) to 4.29 dm\({}^{3}\)/24 h (MED3). The values of the coefficient of variation of the daily birch sap yield ranged from 26.9% (THN2) to 97.1% (THN3).