# An Overview of the Current Situation of European Poplar Cultures with a Main Focus on Hungary
## 3 Results and Discussion
It is interesting to note that despite being a hybrid (albeit a natural hybrid), grey poplar is widespread over a very large area and, in many cases, is treated as native, while it is an inter-specific combination of _P. alba_ and _P. tremula_[6]. Mainly, the native poplar species have the highest average age, as well as some hybrid poplar species that have been available for a longer period of time (Figure 8). With regard to the average diameter at breast height, the situation is not so obvious. This feature is influenced by several factors, such as the conditions at the site, the target range to be produced, the specific growth characteristics of the poplar species, etc. According to [PERSON] [19], the optimal ecological cutting age of the hybrid poplars in Hungary is 18-20 years, which can, of course, be modified by the aforementioned factors. Presently (data are from 2021), it is about 24 years for the hybrid poplars, while it is about 34 years for the native poplars. It can be seen that some hybrid species, such as the 'Pannonia' and the 'Kopecky'  
Figure 5: Changes in area and standing tree volume of poplars (_Populus_ spp.) in Hungary (based on [10]). _P. \(\times\) euramericana cv. Pannonia_ and _P. \(\times\) euramericana cv. Koltay_, respectively, despite the lower average age, have similar average diameters at breast height as some older native or hybrid poplar species. Overall, the average age of the hybrid poplars is 21 years, while the average age of the native poplars is 26 years. \begin{table}
\begin{tabular}{l r r r r} \hline \hline \multicolumn{1}{c}{**Species Groups**} & \multicolumn{1}{c}{**2019**} & \multicolumn{1}{c}{**2020**} & \multicolumn{1}{c}{**2021**} & \multicolumn{1}{c}{**Average**} \\  & \multicolumn{1}{c}{**Gross Thousand m\({}^{3}\)**} & \multicolumn{1}{c}{**Yearly Ratio**} \\ \hline Beech (_Fagus sylvatica_) & 670 & 674 & 683 & 9.5\% \\ Black locust (_Robinia pseudoacacia_) & 1502 & 1303 & 1421 & 19.7\% \\ Hornbeam (_Carpinus betulus_) & 248 & 223 & 234 & 3.3\% \\ Noble oak (_Quercus_ spp.) & 935 & 892 & 972 & 13.1\% \\ Turkey oak (_Quercus cerris_) & 751 & 721 & 801 & 10.6\% \\ Other high-density hardwoods & 329 & 319 & 341 & 4.6\% \\
**High-density hardwoods total** & **4435** & **4132** & **4452** & **60.8\%** \\ \hline Hybrid poplar & 1174 & 952 & 1306 & 16.0\% \\ Native poplar & 250 & 239 & 287 & 3.6\% \\ Willow (_Salis_ spp.) & 46 & 28 & 39 & 0.5\% \\ Other low-density hardwoods & 264 & 201 & 241 & 3.3\% \\
**Low-density hardwoods total** & **1734** & **1420** & **1873** & **23.5\%** \\ \hline
**Conifers** & **1145** & **1029** & **1198** & **15.7\%** \\ \hline
**Altogether** & 7314 & 6581 & 7523 & **100.0\%** \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Total tree filling volume by species groups in Hungary. The bold rows show the summary for the three main categories and finally the total amount (based on [10]). Figure 6: Annual production of poplar (_Populus_ spp.) seedlings in Hungary. Note that the diagram shows only the top quartile. The two specified hybrids are _P. \(\times\) euramericana cv. 1-214_ and _P. \(\times\) euramericana cv. Pannonia_ (based on [10]). * Sawlog (512,458 m\({}^{3}\); 78,119 m\({}^{3}\); 50%). * Other logs used by sawmills (118,961 m\({}^{3}\); 27,413 m\({}^{3}\); 40%). * Logs for fiberboard production (137,967 m\({}^{3}\); 41,870 m\({}^{3}\); 29%). * Logs for paper production (63,385 m\({}^{3}\); 47,575 m\({}^{3}\); 49%). * Industrial wood chips and their raw material (roundwood equivalent) (57,610 m\({}^{3}\); 90 m\({}^{3}\); 79%). * All other industrial log assortments (50,492 m\({}^{3}\); 7640 m\({}^{3}\); 28%). * Logs for energetic purposes (107,562 m\({}^{3}\); 47,103 m\({}^{3}\); 3%). The poplars, whose wood can be used in various ways, provide the most important raw material for mass wood production (boxes, pallets, plywood, etc.). The largest part of the sawmill industry's purpose is the production of pallet elements.