Valgustusraie mõju viljakate kaasikute alustaimestikule
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Kuupäev
2024
Kättesaadavus
03.09.2024
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Valgustusraie on oluline metsakasvatuslik võte, millega parandatakse allesjäänud puude kasvutingimusi ning kujundatakse tulevikupuistu liigiline koosseis. Seni on aga valgustusraiete mõju alustaimestiku biomassile ja liigilisele koosseisule uuritud vähe.
Käesoleva töö eesmärk oli hinnata kahe katseala põhjal erineva intensiivsusega valgustusraie mõju alustaimestiku biomassile, selle produktsioonile ning liigilisele koosseisule. Töö raames uuriti 2019. aastal Tartumaale rajatud jänesekapsa ja jänesekapsa-kõdusoo kasvukohatüübis kasvavate kaasikute alustaimestikku. Mõlemal katsealal oli kolm katsevarianti: kontrollala (KNT), kus raiet ei tehtud, tugeva valgustusraie läbinud proovitükk (VAT) ning nõrgalt valgustatud proovitükk (VAN). Lisaks oli Haage katsealale rajatud proovitükid 1000 ja 3500, kuhu oli kasvama jäetud vastavalt 1000 ja 3500 puud hektari kohta.
Mõlema katseala proovitükkide tulemustest selgus, et mida tihedam oli puistu, seda väiksem oli alustaimestiku maapealne biomass ja produktsioon. Niisamuti oli alustaimestiku üldkatvus mõlemal katsealal madalaim kontrollalal. Soontaimede liigiline koosseis oli mõlemal katsealal kõige suurem VAT proovitükil ning madalaim kontrollalal. Lennujaama katsealal samblarinne puudus ning Haage katseala samblakatvuse ja valgustusraie intensiivsuse vahel seost ei leitud.
Pre-commercial thinning (PCT) is a common silvicultural practice what improves the growing conditions of the remaining trees and shapes the species composition of the future stand. However, the effects of pre-commercial thinning on the biomass and species diversity of understorey vegetation have so far been little studied. The aim of this study was to compare the impact of pre-commercial thinning with different intensities on the biomass, production and species diversity of understorey vegetation, based on two experimental sites, established in Tartu county in 2019. The study was investigated in the Oxalis and Oxalis drained swamp types. In both sites there were three experimental plots with different thinning intensities: an unthinned control plot (KNT), a heavily thinned plot (VAT) and a moderately thinned plot (VAN). In addition, the Haage site had an extra 1000 and 3500 plots with respectively 1000 and 3500 trees per hectare. The results from the study in both experimental plots showed that the denser the stand, the lower the aboveground biomass and production of the understorey vegetation. Similarly, the overall coverage of understory vegetation was lowest in the control plots on both sites. The understory species composition of vascular plants was highest in the VAT plot and lowest in the control plot in both experimental areas. In this study no shrub cover was detected in Lennujaama plot and in Haage plot no correlation was found between the shrub cover and the intensity of pre-commercial thinning.
Pre-commercial thinning (PCT) is a common silvicultural practice what improves the growing conditions of the remaining trees and shapes the species composition of the future stand. However, the effects of pre-commercial thinning on the biomass and species diversity of understorey vegetation have so far been little studied. The aim of this study was to compare the impact of pre-commercial thinning with different intensities on the biomass, production and species diversity of understorey vegetation, based on two experimental sites, established in Tartu county in 2019. The study was investigated in the Oxalis and Oxalis drained swamp types. In both sites there were three experimental plots with different thinning intensities: an unthinned control plot (KNT), a heavily thinned plot (VAT) and a moderately thinned plot (VAN). In addition, the Haage site had an extra 1000 and 3500 plots with respectively 1000 and 3500 trees per hectare. The results from the study in both experimental plots showed that the denser the stand, the lower the aboveground biomass and production of the understorey vegetation. Similarly, the overall coverage of understory vegetation was lowest in the control plots on both sites. The understory species composition of vascular plants was highest in the VAT plot and lowest in the control plot in both experimental areas. In this study no shrub cover was detected in Lennujaama plot and in Haage plot no correlation was found between the shrub cover and the intensity of pre-commercial thinning.
Kirjeldus
Bakalaureusetöö
Metsanduse õppekaval
Märksõnad
bakalaureusetööd, arukask, sookask, liigiline koosseis, biomass, produktsioon