Hariliku kuuse tüvelõhede analüüs Alatskivi katsekultuuris
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Kuupäev
2019
Kättesaadav alates
10.09.2019
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Tüvelõhesid tekitavaks faktoriks peetakse puusisest stressi, mis on tingitud külmast,
põuast, tuulest ja äikesest. Tüvelõhed harilikul kuusel tekivad enamasti viljakamates
kasvukohatüüpides, lõuna poolt imporditud taimedel, tavaliselt siis, kui kuuse vanus
ületab 20 aastat. Uurimuses leiti, et lisaks välimistele tüvelõhedele sisaldasid puud ka
sisemisi tüvelõhesid. Bakalaureusetöö eesmärk oli uurida Alatskivi katsekultuuri hariliku
kuuse tüvelõhede tekkeaastaid, suunda, ning seoseid kliimaga. Mudelpuud võeti 16
erinevast päritolust. 29 mudelpuu peale saadi kokku 389 prooviketast.
Töö käigus selgus, et tüvelõhed tekkisid aastatel 1985 – 2018. Välimisi tüvelõhesid oli
kokku 64. Kõige rohkem välimisi tüvelõhesid tekkis 2002. aastal. Kõige rohkem esines
välimisi tüvelõhesid põhja suunas. Analüüsis tuli välja, et kõige rohkem sisemisi
tüvelõhesid esines loode suunas. Klimaatilised seosed olid uuritud töös 1992 ja 2002.
aastal olevate põuaperioodidega.
Stem cracks in trees may occur due extreme climatic conditions, such as cold, drought, wind and lightning. Based on previous studies, stem cracks in Norway spruce more often occur in trees growing on fertile site types, in plants imported from Southern regions that are older than 20 years. During the current study it was found that, in addition to the external cracks, the trees also contained internal cracks that are not observable outside the tree. The aim of this Bachelor's thesis was to study external and internal stem cracks formed in different Norway spruce trees, growing in Alatskivi provenance trail. It was also aimed to establish the year of crack formation and to relate it to climatic conditions. Occurrence of internal cracks were studies along the tree stem. Twenty nine model trees with 16 different seed origin were felled and cross-sections sampled along the stem. Altogether for crack dating 389 cross-sections were used to date cracks. Data analysis revealed that external stem cracks occurred over period of 1985 – 2018. External stem cracks usually formed on the North side of the tree, whereas most of the internal stem cracks were present in the Northwest. Stem crack number was high in extremely dry years, but also was related to low mean temperatures in October.
Stem cracks in trees may occur due extreme climatic conditions, such as cold, drought, wind and lightning. Based on previous studies, stem cracks in Norway spruce more often occur in trees growing on fertile site types, in plants imported from Southern regions that are older than 20 years. During the current study it was found that, in addition to the external cracks, the trees also contained internal cracks that are not observable outside the tree. The aim of this Bachelor's thesis was to study external and internal stem cracks formed in different Norway spruce trees, growing in Alatskivi provenance trail. It was also aimed to establish the year of crack formation and to relate it to climatic conditions. Occurrence of internal cracks were studies along the tree stem. Twenty nine model trees with 16 different seed origin were felled and cross-sections sampled along the stem. Altogether for crack dating 389 cross-sections were used to date cracks. Data analysis revealed that external stem cracks occurred over period of 1985 – 2018. External stem cracks usually formed on the North side of the tree, whereas most of the internal stem cracks were present in the Northwest. Stem crack number was high in extremely dry years, but also was related to low mean temperatures in October.
Kirjeldus
Bakalaureusetöö
Metsanduse õppekaval
Märksõnad
bakalaureusetööd, dendrokronoloogia, tüvelõhed, aastarõngad, harilik kuusk