# An Overview of the Current Situation of European Poplar Cultures with a Main Focus on Hungary
## 1 Introduction  
After World War II, due to the rapid growth of poplars (_Populus_ spp.), there was growing interest in this species, and over the past few decades, the poplar genus has gained a unique position in ecology, commercial application, and science [1, 2]. The formation of the Hungarian poplar growing situation (Figure 1) is the result of several poplar tree-planting programs following World War II [3]. Poplar cultivation research in the second half of the 20 th century clarified the site conditions for the effective cultivation of hybrid poplars, the advisable and optimal cultivation technologies in the conditions in Hungary, and set up a selection of hybrid poplar species corresponding to their abilities. All of these, together with the generally safe timber sales opportunities, made the production of hybrid poplars economical and profitable [4, 5]. In addition, breeding has been going on all over Europe ever since [6, 7], and poplars seem to be a good model for tree physiology and genomics research [8, 9]. This shows that this issue is important across Europe and is still being addressed today.  
Fast-growing plantation tree species, such as poplars, provide raw materials to sectors of the wood industry as substitutes for harvesting from natural forests or imported wood products [5; 11]. The sub-sectors are industrial processing (pulp, paper, engineered wood products, plywood, veneer and other boards, saw timber, packing crates, pallets, furniture, and increasingly, bio-energy) and valuable non-wood products (e.g., livestock fodder, medicinal extracts, and food products) [12]. As described by [PERSON] et al. [13], the use of wood as a raw material will slowly increase in the future, while the use of wood for energetic purposes will increase dramatically. As evidenced, wood used for energetic purposes in Germany already exceeded the wood used for material purposes in 2012, which includes poplars, too. Besides all of these, it is environmentally important that it plays a role in the protection of soil, the regeneration of waste land, the restoration of natural river-bank environments, phytoremediation, and the reduction of the effects of climate change and air pollution [14; 15; 16; 11]. Their disadvantage is that poplar trees are allergenic, but in the case of industrial plants far from cities, this is not a real problem. One major advantage of poplars and willows (_Salix_ spp.) is that they have a relatively short cutting age, i.e., rotation time, to produce maximum yields of timber or fiber on a sustainable basis [8; 9]. Taking into account their large volume, future poplar utilization should be based on an integrated and total use concept, i.e., produce the highest-value products or product combinations from each given raw material input so that nothing is wasted [17]. In this case, energetic use is also considered waste because value creation is based on the manufacturing of products.  
This article provides an overview of the current data on poplars in Hungary, including the quantity, available in Europe. Among others, it analyzes features such as species variety, age group composition, and areas of use. Although most of these data are widely available, it would require more research to identify them individually, and they are often difficult to find in a comparable format. Thus, this article fills a gap in the information on poplar wood species and is therefore necessary to provide a fresh overview for professionals working in the field.  
Figure 1: The spread of poplars (_Populus_ spp.) in Hungary. The quantities indicated by the colors refer to the whole landscape unit, regardless of its area. The 92 official forest stands in the country shown were defined and used by the National Land Centre. The number of occurrences of the quantity categories is shown in parentheses (source of data: [10]).