Deciduous Broad-Leaved Species (Quercus Robur, Tilia Cordata, Acer Platanoides and Ulmus Laevis) Forest Stand Productivity in Latvia

Climate forecasts indicate that in the future the climate will become more and more suitable for growth of broad-leaved tree species in Latvia. It is therefore very important to recognise and understand the growth potential of these broad-leaved stands in Latvia and the factors affecting the increment of growing stock. The results of the study showed high volume yield, as already 60- to 80-year-old stand stock could reach 500–600 m³·ha^-1, and in later years even 700–1000 m³·ha^-1. Similarly, the results of our study showed that the increment of the stock and growth potential of individual forest elements varied significantly between the various broad-leaved species. Significant factors were the age of the forest stand or forest element (a set of trees of the same species, in one layer and belonging to one generation), the indicators of competition (basal area and/or relative density) and the indicators of the social status of the forest element, namely, the ratio of the mean diameter of the forest element and the mean diameter of the dominant species of the upper layer of the stand and the sum of the basal area of the larger forest elements). No significant differences were found in growing stock and growth potential between monospecies and mixed stands and between simple and complex stands, neither at the level of the stands, nor at the level of the individual forest element.