Porovnání růstu douglasky tisolisté a smrku ztepilého podle dat lesních hospodářských plánů a osnov

Forest management documents related to the whole Czech Republic contain detailed information about the state of forest stands and tree species. A subset of the data was prepared for stands of Douglas-fir (Pseudotsuga menziesii; 46,929 records) and Norway spruce (Picea abies; 37,761 records from stands where Douglas-fir was also present). Growth models for both species were constructed in the form of simplified Korf ’s function. The data set was divided into subsets according to forest vegetation (altitudinal) zones (FAZ) and groups of edaphic categories. On acidic habitats, both tree species reached maximum growth rate in the 5th FAZ. However, on habitats affected by water this occurred in the 4th FAZ. In the model example at the age of 140 years, Douglas-fir shows an average of 4% higher stand volumes in comparison to Norway spruce, while the felling volume as part of thinning, or left in the stand to decay, is about 32% higher in Douglas-fir.