Umerjanje rezistografskih meritev gostote lesa na stoječih drevesih : pretvorba v osnovno gostoto

V prispevku predstavljamo proces in rezultate določitve korekcijskih količnikov za pretvorbo rezistografskih gostot, izmerjenih na stoječih drevesih, v osnovno gostoto lesa na primeru bukve (Fagus sylvatica L.), puhastega hrasta (Quercus pubescens Willd.) in črnega bora (Pinus nigraArnold.). Korekcijski količniki so bili določeni na podlagi sveže odžaganih kolutov, ki so bili povrtani z rezistografom. Kolute smo stehtali, izmerili njihovo prostornino ter jih posušili do absolutno suhega stanja. Iz zbranih podatkov smo nato izračunali osnovno gostoto lesa ter korekcijske količnike med osnovno in rezistografsko gostoto. V raziskavo je bilo zajetih 59 kolutov. Aritmetična sredina vseh izmerjenih količnikov znaša 1,41, vrednosti 95 % intervala zaupanja pa znašajo od 1,38 do 1,46. Razlike med drevesnimi vrstami so statistično neznačilne. Rezistografska gostota relativno dobro odraža osnovno gostoto kolutov (Pearsonov korelacijski koeficient = 0,91 p < 0,001), kar nakazuje na relativno dobro povezanost osnovnih gostot kolutov z rezistografskimi gostotami. Dobljeni rezultati so ključnega pomena za nadaljnji razvoj področja merjenja dejanskih gostot lesa v stoječih drevesih na hiter in relativno nedestruktiven način. In this article, we present the process and results of the determination of correction quotients for conversion of resistograph densities, measured in standing trees, into basic wood densities on the example of beech (Fagus sylvatica L.), pubescent oak (Quercus pubescens Willd.), and black pine (Pinus nigra Arnold.). The correction quotients were defined based on freshly sawn-off stem disks drilled with resistograph. We weighted the stem disks, measured their volume, and dried them to the absolutely dry state. From the gathered data, we then calculated basic wood density and correction quotients between the basic and resistograph density. The research comprised 59 stem disks. The arithmetic mean of all measured quotients amounts to 1.41, and the values of the 95 % of trust intervals amount from 1.38 to 1.46. The differences between the tree species are statistically insignificant. The resistograph density reflects the basic density of the reels (Pearson correlation coefficient = 0,91 p < 0,001) relatively well, which indicates a relatively good connection of the basic densities of the reels with their resistograph densities. The obtained results are crucial for further development of the field of measurement of actual wood densities in standing trees in a fast and relatively non-destructive way