Hariliku kuuse kasvu ja vaiguvoolu seosed viljakates kasvukohatüüpides

Abstract

Harilik kuusk on ökoloogiliselt ja majanduslikult oluline puuliik Põhja-Euroopas, kelle esmast kaitset tagavat mehhanismi – vaiguvoolu, on erinevates tingimustes vähe uuritud. Kahes viljakas metsakasvukohatüübis (jänesekapsa ja sinilille) uuriti erinevate keskkonnategurite (sh segametsa) potentsiaalset mõju vaiguvoolu kujundavatele teguritele ning kasvu ja vaiguvoolu seostele. Selgus, et puude kasv on otseselt seotud vaiguvooluga peamiselt läbi vaigukäikude produktsiooni. Suuremad, kiiremini kasvavad puud toodavad rohkem ja suurema läbimõõduga vertikaalseid vaigukäike; erinevates puistutes on seosed sarnased. Samas esineb tugev aastatevaheline erinevus nii vaigukäikude arvus kui puude juurdekasvus, olles ilmselt enim mõjutatud põuast. Vaiguvoolu hulk ja seos vaigukäikudega erineb rohkem puistute vahel ja erinevused seletuvad tõenäoliselt puude kasvutingimuste ja kasvukäiguga.

Relationships between growth and resin flow of Norway spruce in fertile site types The Norway spruce is an ecologically and economically important tree species in Northern Europe, whose primary defense mechanism—resin flow—has been little studied under different conditions. In two fertile site types (Oxalis and Hepatica), the potential influence of various environmental factors, including the impact of mixed forests, on factors shaping resin flow, as well as the relationship between growth and resin flow, were investigated. Growth was found to be directly related with resin flow primarily through the production of resin ducts. Larger and faster-growing trees produce more and larger diameter vertical resin ducts, and the relationships are similar across different stands. However, there is a significant year-to-year variation in both the number of resin ducts and tree growth, likely being most affected by drought. The amount of resin flow and its relationship with resin ducts varies more between stands, and these differences are likely explained by the growth conditions and growth history of the trees.