A basal area increment model for individual trees growing in even- and uneven-aged forest stands in Austria

摘要: Abstract Because of the gradual shift from pure even-aged forest management in central Europe, existing yield tables are becoming increasingly unreliable for decisions. Individual tree-based stand growth modeling can make accurate predictions full range conditions between and mixed-species uneven-aged stands. The model such a simulator is basal area increment individual trees. Spatial information not needed, age site index intentionally used to gain generality all possible conditions. A developed main species Austria: spruce (Picea abies), fir (Abies alba), larch (Larix decidua), Scots pine (Pinus sylvestris), black nigra), stone cembra), beech (Fagus silvatica), oak (Quercus robur, Quercus petraea cerris), other broadleaf combined. Austrian National Forest Inventory provided 5-year 44 761 remeasured trees growing on 5416 forested plots 1980s. This large sample representative practices throughout Austria therefore provides an excellent data base development model. resulting explained 20 63% variation nine 33 if minor Pinus cembra excluded. These results compared quite closely with those Wykoff mixed conifer stands Northern Rocky Mountains. In model, size variables (breast height diameter crown length) accounted 14–47% increment, depending tree species. best competition measure was larger trees, which tree-specific without requiring spatial information; factor only improvement. Competition 9% average, up 15% some Topographic factors (elevation, slope, aspect) 3% variation, as did soil factors. Remaining factors; vegetation type district maximum increment. total, 2 6% variation. Even though account small percentage they significant, but serve localize particular prediction. species-specific interrelationships various size, competition, varibles correspond well ecological expectations silvicultural understanding these Austria. so strong, models be recommended surrounding regions similar