Harvendusraie mõju puude jämeduskasvule ning süsinikuvarudele ja -voogudele palumännikus
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Kuupäev
2018
Kättesaadav alates
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Õigeaegselt tehtud hooldusraiete abil on võimalik kujundada produktiivsem ja
kvaliteetsemat puitu tootev mets, harvendusraietega on võimalik parandada metsade
süsiniku sidumise võimet ning seeläbi leevendada kliimamuutusi. Käesoleva töö
eesmärgiks on selgitada harvendusraie mõju puude jämeduskasvule ning puistu
süsinikuvarudele ja -voogudele 27-aastases mustikamännikus. Töö on osa RMK
teadusprojektist „Raiete mõju metsade süsinikuringele“.
Rajati kõrvuti kaks 0,09 ha suurust proovitükki, ühel tehti harvendusraie ning teine jäeti
kontrollalaks. Raie teostamise hetkel oli puistu 25-aastane. Harvendusraie mõju hinnati
mudelpuude meetodil ning puursüdamike abil kaks aastat pärast raiet. Peenjuurte biomassi
ja produktsiooni hinnati mullamonoliitide põhjal ja varisevoogu varisekogujatest võetud
proovide alusel.
Harvendatud proovitüki puude jämeduskasv püsis 2016. aastal raie-eelsega samal tasemel
ning suurenes teisel raiejärgsel aastal, seevastu kontrollala puude diameetri juurdekasv on
viimasel kolmel aastal langenud. Männi peenjuurte produktsioon ühe puu kohta oli kaks
aastat pärast raiet harvendatud alal 0,70 kg, mis on enam kui kaks korda suurem
kontrollala omast (0,29 kg). Varisevooga jõudis mulda süsinikku harvendamata alal 1,83
t ha-1
ning harvendatud alal 1,44 t ha-1
.
Timely commercial thinnings can increase stand growth, quality of stemwood, and the forest´s ability to store more carbon and therefor relieve climate changes. The aim of this thesis was to study the effect of the thinning on the trees´ radial growth and carbon stocks and -fluxes in 27-years old pine stand growing on Myrtillus site type . This study is part of research project (RMK) „ Effect of clearcut and thinning on forest carbon cycling “. The study was based on two experimental plots with area of 0,09 ha (thinned vs. unthinned control plot). The thinning was carried out in 2015 when the stand was 25-years old. The effect of the thinning was estimated 2 years after the thinning using model tree method and increment cores from 15 trees from each plot. Fine-root biomass and production was estimated with sequential coring method and litter fluxes using samples taken from litterfall traps. The radial growth of the trees on the thinned plot stayed stable in 2016 and increased in 2017, but decreased on the control plot during last 3 years. Pine´s fine root production on tree level was 0,70 kg (two years after the thinning), which is more than twice as on the unthinned control plot (0,29 kg). Annual organic carbon flux to soil through litter was 1,83 t ha-1 on control plot and 1,44 t ha-1 on the thinned plot.
Timely commercial thinnings can increase stand growth, quality of stemwood, and the forest´s ability to store more carbon and therefor relieve climate changes. The aim of this thesis was to study the effect of the thinning on the trees´ radial growth and carbon stocks and -fluxes in 27-years old pine stand growing on Myrtillus site type . This study is part of research project (RMK) „ Effect of clearcut and thinning on forest carbon cycling “. The study was based on two experimental plots with area of 0,09 ha (thinned vs. unthinned control plot). The thinning was carried out in 2015 when the stand was 25-years old. The effect of the thinning was estimated 2 years after the thinning using model tree method and increment cores from 15 trees from each plot. Fine-root biomass and production was estimated with sequential coring method and litter fluxes using samples taken from litterfall traps. The radial growth of the trees on the thinned plot stayed stable in 2016 and increased in 2017, but decreased on the control plot during last 3 years. Pine´s fine root production on tree level was 0,70 kg (two years after the thinning), which is more than twice as on the unthinned control plot (0,29 kg). Annual organic carbon flux to soil through litter was 1,83 t ha-1 on control plot and 1,44 t ha-1 on the thinned plot.
Kirjeldus
Magistritöö
Metsamajanduse õppekaval
Märksõnad
magistritööd, biomass, produktsioon, süsinik, raie