Intra–annual height growth of hybrid poplars in Latvia. Results from the year of establishment

S. Šēnhofa, M. Zeps, L. Ķēniņa*, U. Neimane, R. Kāpostiņš, A. Kārkliņa and Ā. Jansons

Latvia State Forest Research Institute Silava, Rigas street 111, LV–2169 Salaspils, Latvia
*Correspondence: laura.kenina@silava.lv

Abstract:

Fast growing hybrid poplars (Populus spp.) could be successfully used for bioenergy as well as wood production. Productivity of clones had been studied in Baltic States recently, however, little is known about the impact of weather conditions on poplar height growth, thus the potential effect of climate change. Therefore, the aim of this study was to characterize the intra–annual height growth of hybrid poplar clones in Latvia. Height increment of 12 hybrid poplar clones was measured on average with an 11–day interval in the first vegetation season in 2016. Annual shoot height was on average 81.0 ± 6.8 cm, significantly (p < 0.001) depending on the poplar clone. Use of long (0.5 m) instead of short (0.3 m) cuttings leaded to larger annual height increment during the year of establishment of the plantation. From June to September the mean growth intensity was 10 to 15 mm day^-1. The trend of height growth intensity, described by Gompertz model, indicated that the poplar clones with largest height had relatively fast increase of the growth intensity from June to July. Changes of growth intensity was linked both with the temperature and sum of precipitation. This tendency was not so pronounced for clones with largest height increment, emphasizing the importance of the phenotypic plasticity in selection of clones for plantations.

Key words:

Effects of nutrient supply and planting material quality on yield and survival rate of a short rotation coppice culture in Hungary

O. Szabó*, G. Kovács and B. Heil

Institute of Environmental and Earth Science, Faculty of Forestry, University of West–Hungary, Bajcsy–Zs. Street 4, H–9400 Sopron, Hungary
*Correspondence: szabo.orsolya@emk.nyme.hu, orsoy@freemail.hu

Abstract:

In May 2011, a short rotation woody energy plantation (SRC) was established near Dejtár village in Northern–Hungary. The goal of the experiment was comparative analyses of different fertilization treatments on three clones of Populus (AF2, Monviso, Pannonia) and one Salix cultivar (‘Dékány’). We used three fertilization treatments: (1) 5 t ha–1 of wood ash, (2) 40 t ha–1 of farmyard manure and (3) both 5 t ha–1 of wood ash and 40 t ha–1 of farmyard manure. The Monviso clone had the highest survival rate (92%), followed by Pannonia (80%) and AF2 (78%). Initially, the white willow ‘Dékány’ cultivar was also included in the experiment, but due to differing site preferences of this cultivar, it was not viable in the area. Based on the data of the first three growing seasons, it was demonstrated that the important nutrients had already been present in optimal amounts from the start of the experiment, and their contents were increased due to the treatments. At the end of the first growing season, the effect of the fertilization treatment could not be detected, but by the third year the results showed a significant positive effect. Already in the second, but mostly at the end of the third growing season, the wood ash + manure fertilizer treated plots showed significant increases in height growth and biomass yield.

Key words:

biomass production, Farmyard manure, Populus Spp, wood ash