Comparison of the growth pattern of black walnut (Juglans nigra L.) in two riparian forests in the region of South Moravia, Czech Republic

The black walnut (Juglans nigra L.), an introduced species into the Czech Republic, is planted for its production of valuable timber. A systematic study of the black walnut growth rate at different localities and consequently the creation of standard volume tables under Central European conditions therefore appear to be of high relevance. The aim of our study was to reveal the black walnut growth pattern in its pure stands in two riparian forests along the Morava and Svratka River (Straznice locality and Zidlochovice locality, respectively). To describe and to compare relationships among diameter at breast height (dbh), tree height and age, we used a forest management plan and measured 573 and 670 trees in pure sample stands at Straznice and Zidlochovice, respectively. We found out that the measured mean DBH and mean height were consistently higher in Straznice, however the relationships of DBH to height, age to DBH, and age to height showed the same pattern at both localities. The mean heights of trees were 16.3, 24.1, 28.7, 31.9, and 34.5 m in 20, 40, 60, 80, and 100 year age classes and were consistently taller in comparison with other, mainly European, regions. Therefore our results suggest the high potential of black walnut in timber production in riparian forests in the Czech Republic, mainly in the South Moravian region.