The most widespread tree species in the Western Carpathians is clearly the Norway spruce (Picea abies) – its occurrence is natural in these mountain areas. But do we know which ecological factors most influence the height increase of spruces? And to what extent? Thanks to the study on which the team of Ing. Bošeľa from FLD worked, we can see what affects growth in these conditions.
Wood production is one of the most important functions in commercial forests. Several factors affect the stock of the stand, the main one of which is the height growth. Understanding the relationship between habitat ecology and height growth has thus become a major focus of research for FLD scientists.
They used data collection from the National Forest Inventory in Slovakia for their research. The main dependent variable became the average height of 20 % of the highest spruces in the entire Western Carpathians. This was subsequently linked to the local climate, soil nutrient content and substrate acidity.
Researchers have developed models of upper height growth (determined by the thickest trees in the stand), which is considered to be the best indicator that is influenced by forest management. Thanks to this model, it was possible to clarify almost 80% of the causes that affected the height increase. Spruce is a woody plant sensitive to changes in the nutrient cycle, so this factor also had a significant effect on the results. Specifically, in the case where the ratio of carbon and nitrogen was lower, the height increased by 3-5 m. The same effect can be achieved by increasing the acidity of the soil from 7 to 4. Positively the greatest influence is the length of the growing season – in this study days with a temperature above 5° C. The difference between the upper heights of the stands can be up to 10 m, depending on the number of these days.
Due to the proven fact that ecological factors thus dramatically affect the height of spruce, raster maps were created as the final output of the study. These show the places with the most suitable natural conditions and can thus serve for more effective planning in forest management.
Bošeľa, M., Máliš, F., Kulla, L., Šebeň, V., Deckmyn, G. 2013: Ecologically based height growth model and derived raster maps of Norway spruce site index in the Western Carpathians. Europen Journal of Forest Research 123: 691–705.
Ing. Michal Bošeľa, Ph.D.
Ing. Michal Bošeľa, Ph.D., (* 1981) graduated from the Technical University in Zvolen. He received his doctorate in forestry typology in 2011 from the same university. He currently works at the National Forestry Center as a researcher and at the same time works at the Faculty of Forestry and Wood Sciences at the CULS in Prague as a teacher and researcher.
Prepared by: Michaela Veselá