Süsinikubilanss jänesekapsa-kõdusoo kasvukohatüübi sookaasikute vanusereas
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Kuupäev
2024
Kättesaadav alates
06.09.2024
Autorid
Siimson, Jan
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Käesoleva töö eesmärgiks oli koostada süsinikubilansid ja hinnata süsiniku varusid ning
sisend- ja väljundvooge jänesekapsa-kõdusoo kasvukohatüübi sookaasikute vanusereas.
Töö alusandmeteks kasutati metsakorraldusest tulenevaid takseerandmeid. Muud bilansi
koostamiseks vajalikud, puuduvad andmed leiti varem avaldatud teadustööde põhjal.
Süsinikubilansid koostati NEP meetodil.
Puitse biomassi aastane juurdekasv ehk produktsioon oli kõige intensiivsem keskealistes
puistutes ning väikseim küpsetes ja kõige nooremas puistus, jäädes vahemikku 0,86 ja 2,8
t C/ha.
Mulda suunduvast süsinikuvoost uuritud puistute puhul moodustas valdava osa lehtede,
peenjuurte, okste jne varis. Alustaimestiku osakaal mulda suunduvast süsinikuvoost
moodustas ligikaudu 7%. Mullast väljuv süsinikuvoog ületas kõikides puistutes
sisendvoo, seega mulla süsinikuvaru väheneb.
Uuritud puistute NEP väärtused näitasid, et 10- 40 aastased puistud osutusid süsinikku
siduvateks, 50 aastane puistu süsinikuneutraalseks ning 60 aastane ja vanemad puistud süsinikku emiteerivateks ökosüsteemideks. Eestis on sarnaseid uuringuid läbi viidud vähe,
kuid tulemused näitavad üldjoontes sarnaseid trende süsinikusidumises. Siiski näiteks
heterotroofse mullahingamise (Rh) väärtused võivad isegi ühe kasvukoha piires
varieeruda suurtes piirides, mistõttu jätkuvad uuringud selles valdkonnas on olulised.
The aim of this study was to compile carbon balances and assess carbon stocks, as well as input and output fluxes, in the differently aged downy birch (Betula pubenscens) stands growing on fertile oxalis full-drained swamp site type. The basic data for the study were derived from the forest management inventory data. Other necessary data for constructing the carbon balance were obtained from previously published scientific works. Carbon balances were calculated using the Net Ecosystem Productivity (NEP) method. The annual increment or production of woody biomass was most intensive in middle-aged stands and lowest in mature and very young stands, ranging from 0.86 to 2.8 t C/ha. Regarding the carbon flux from the stands to the soil, the dominant portion consisted of litter from leaves, fine roots, branches, etc. The proportion of carbon flux from the stands to the soil originating from the understorey vegetation was approximately 7%. The carbon efflux from the soil exceeded the input flow in all stands, resulting in a decrease in soil carbon stock. The NEP values for the studied stands indicated that stands aged 10-40 years acted as carbon sinks, while the 50-year-old stand was carbon-neutral, and stands aged 60 years and older acted as carbon-emitting ecosystems. Although there have been relatively few similar studies conducted in Estonia, the results generally show similar trends in carbon sequestration. However, for instance, values related to soil heterotrophic respiration (Rh) can vary significantly even within the same site, highlighting the importance of continued research in this field.
The aim of this study was to compile carbon balances and assess carbon stocks, as well as input and output fluxes, in the differently aged downy birch (Betula pubenscens) stands growing on fertile oxalis full-drained swamp site type. The basic data for the study were derived from the forest management inventory data. Other necessary data for constructing the carbon balance were obtained from previously published scientific works. Carbon balances were calculated using the Net Ecosystem Productivity (NEP) method. The annual increment or production of woody biomass was most intensive in middle-aged stands and lowest in mature and very young stands, ranging from 0.86 to 2.8 t C/ha. Regarding the carbon flux from the stands to the soil, the dominant portion consisted of litter from leaves, fine roots, branches, etc. The proportion of carbon flux from the stands to the soil originating from the understorey vegetation was approximately 7%. The carbon efflux from the soil exceeded the input flow in all stands, resulting in a decrease in soil carbon stock. The NEP values for the studied stands indicated that stands aged 10-40 years acted as carbon sinks, while the 50-year-old stand was carbon-neutral, and stands aged 60 years and older acted as carbon-emitting ecosystems. Although there have been relatively few similar studies conducted in Estonia, the results generally show similar trends in carbon sequestration. However, for instance, values related to soil heterotrophic respiration (Rh) can vary significantly even within the same site, highlighting the importance of continued research in this field.
Kirjeldus
Bakalaureusetöö
Kalanduse ja rakendusökoloogia õppekaval
Märksõnad
bakalaureusetööd, süsiniku sidumine, ökosüsteemi netoproduktsioon, süsiniku vood ja varud, kuivendatud soomets, Roheline Ülikool (töö toetab EMÜ Rohelise Ülikooli põhimõtteid), keskkond, jätkusuutlikkus, säästev areng