Hariliku kuuse (Picea abies) puidu tiheduse muutumine vertikaal- ja horisontaalsuunas
Laen...
Kuupäev
2017
Kättesaadav alates
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Antud bakalaureusetöö annab ülevaate hariliku kuuse (Picea abies) puidu tiheduse
muutumisest vertikaal- ja horisontaalsuunas. Samuti uuriti seost aastarõngaste laiuse,
sügispuidu osakaalu ja tiheduse vahel.
Töös kasutati 176 katsekeha, mis oli võetud puude kännust ladvani 3 meetrise sammuga
ning vastavate kõrguste juures puidu juveniil-, lüli-, ja maltspuidu osa. Et tagada
võrdsed katsetel tingimused, kuivatati katsekehad niiskusesisaldusele 0%.
Aastarõngaste laius ja sügispuidu osakaal leiti digitaalselt programmiga WinDendro,
kus katsekehade üks lihvitud külg skaneeriti arvutisse. Seejärel kaaluti ning mõõdeti
katsekehade maht, et arvutada nende tihedused.
Selgus, et tihedus oli kõige suurem puidu maltspuidu osas, kus olid aastarõngad kõige
kitsamad ja sügispuidu osakaal kõige suurem. Kõige vähem tihedam oli juveniilpuidu
osa, kuna seal olid aastarõngad kõige laiemad ja sügispuidu osakaal vähim. Puu
kõrguse kasvades ka väheneb puidu tihedus teatud kõrguseni, kus tihedus hakkab
suurenema jälle, kuna puu vananedes muutusid aastarõngad kitsamaks ja sügispuidu
osakaal samuti tõusis.
Katsekehade väikse valimimahu tõttu tekkisid mõningad ebakorrapärasused. Mõõtmisi
võiks teha rohkemate katsekehadega, et näha, kas tulemused tulevad täpsemad.
The bachelor’s thesis gives an overview of the change in wood basic density in axial and radial directions within Norway spruce (Picea abies). Also the relationship between annual ring width, late wood percentage and density was investigated. There were 176 samples used in the study, which were taken from stump to tree-top with 3 meter gap and juvenile-, heart-, and sapwood pieces from corresponding heights. To ensure equal conditions for the tests, the subjects were dried to the point where humidity was 0%. Annual ring width and percentage of the late wood was found digitally with a program WinDendro, where test subjects one polished side was scanned to computer. After that the samples were weighted and volume was measured to calculate their density. Tests showed that density was the largest in sapwood, where annual rings were the narrowest and the percentage of late wood was the greatest. Juvenile wood had the lowest density, where annual rings were the widest and late wood percentage was the lowest. In axial direction wood density started to lessen from stump to tree-top till a certain point, where it began to grow, because mature woods annual rings started to get narrower and latewood percentage started to grow. Because of the small amount of test subjects, there were a few irregularities. There should be more tests with more subjects to see, if the results get more accurate.
The bachelor’s thesis gives an overview of the change in wood basic density in axial and radial directions within Norway spruce (Picea abies). Also the relationship between annual ring width, late wood percentage and density was investigated. There were 176 samples used in the study, which were taken from stump to tree-top with 3 meter gap and juvenile-, heart-, and sapwood pieces from corresponding heights. To ensure equal conditions for the tests, the subjects were dried to the point where humidity was 0%. Annual ring width and percentage of the late wood was found digitally with a program WinDendro, where test subjects one polished side was scanned to computer. After that the samples were weighted and volume was measured to calculate their density. Tests showed that density was the largest in sapwood, where annual rings were the narrowest and the percentage of late wood was the greatest. Juvenile wood had the lowest density, where annual rings were the widest and late wood percentage was the lowest. In axial direction wood density started to lessen from stump to tree-top till a certain point, where it began to grow, because mature woods annual rings started to get narrower and latewood percentage started to grow. Because of the small amount of test subjects, there were a few irregularities. There should be more tests with more subjects to see, if the results get more accurate.
Kirjeldus
Bakalaureusetöö
Metsanduse õppekaval
Märksõnad
bakalaureusetööd, aastarõngad, sügispuit, tihedus, harilik kuusk