Mullahingamise muutused põlengujärgses aegreas
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Kuupäev
2016
Kättesaadav alates
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Abstrakt
Käesoleva uurimustöö eesmärgiks on hinnata metsapõlengujärgseid muutusi
mullahingamises ja anda ülevaade mullahingamist mõjutavatest teguritest.
Välitöid teostati 2015. aasta maist novembrini Vihterpalu ja Nõva põlengualadel, kus
mõõdeti mullahingamist, mullatemperatuuri ja mullaniiskust. Proovialasid oli kuus ja
need kõik olid erineva häiringu esinemise ajaga – metsapõlengud toimusid aladel aastatel
1837, 1940, 1951, 1982, 1997 ja 2008. Kogutud andmed analüüsiti kasutades programmi
Microsoft Excel.
Tulemustest selgus, et kõige madalam oli mullahingamise keskmine väärtus (0,074 mg
CO2m-2 s
-1
) 2008. aasta proovialal ehk hiljuti põlenud alal. Võrreldes hiljuti põlenud alaga
oli mullahingamine teistel proovialadel stabiliseerunud. Kõrgeim keskmine
mullahingamise väärtus oli 1940. aasta proovialal (0,161 mg CO2m-2 s
-1
). Kõige kõrgemad
keskmised mullatemperatuuri väärtused registreeriti hiljuti põlenud aladel
Uurimistöö tulemusena leiti, et mullatemperatuuri ja mullahingamise vahel esineb tugev
seos. Erinevalt mullatemperatuurist, ei leitud meie uuringualadel mullaniiskuse ja
mullahingamise vahel seoseid
Uurimistöö tulemuste põhjal võib järeldada, et 2008. aasta proovialal pole
mullahingamine taastunud. Seda tõestavad nii mullahingamise kui ka mullatemperatuuri
näitajad. Teistel proovialadel on mullahingamine taastunud ja jõudnud stabiilsete
väärtusteni.
The aim of this thesis is to evaluate soil respiration changes after disturbances (forest fire) and to give overview of the possible factors affecting soil respiration values in fire disturbed areas. Fieldworks were carried out from May till November 2015 in Vihterpalu and Nõva fire disturbed areas, where in addition to measurements of soil respiration, soil temperature and soil moisture content were measured. There were six sample areas where fires occurred in years 1837, 1940, 1951, 1982, 1997 and 2008. Collected data was analysed with program Microsoft Excel. Results showed that lowest average soil respiration value (0.074 mg CO2 m-2 s -1 ) was measured at the sample area burned in 2008, where the most recent fire disturbance occurred. In the other sample areas soil respiration was recovered and has reached to stable levels. The highest average soil respiration value (0.161 mg CO2 m-2 s -1 ) was measured in area where the last forest fire occurred in a year 1940. The highest average soil temperatures were measured in a newly burned area (last forest fire in year 2008). There was a correlation between soil temperature and soil respiration values, meaning that with higher soil temperatures there were in most cases higher soil respiration values in our study areas. There was no correlation between soil moisture and soil respiration. It can be concluded that in recently burned areas (last forest fire in a year 2008) the soil respiration was not recovered. This is evidenced by both the rates of soil respiration and soil temperature values. In the other sample areas soil respiration has been recovered and the respiration values have reached to stable levels.
The aim of this thesis is to evaluate soil respiration changes after disturbances (forest fire) and to give overview of the possible factors affecting soil respiration values in fire disturbed areas. Fieldworks were carried out from May till November 2015 in Vihterpalu and Nõva fire disturbed areas, where in addition to measurements of soil respiration, soil temperature and soil moisture content were measured. There were six sample areas where fires occurred in years 1837, 1940, 1951, 1982, 1997 and 2008. Collected data was analysed with program Microsoft Excel. Results showed that lowest average soil respiration value (0.074 mg CO2 m-2 s -1 ) was measured at the sample area burned in 2008, where the most recent fire disturbance occurred. In the other sample areas soil respiration was recovered and has reached to stable levels. The highest average soil respiration value (0.161 mg CO2 m-2 s -1 ) was measured in area where the last forest fire occurred in a year 1940. The highest average soil temperatures were measured in a newly burned area (last forest fire in year 2008). There was a correlation between soil temperature and soil respiration values, meaning that with higher soil temperatures there were in most cases higher soil respiration values in our study areas. There was no correlation between soil moisture and soil respiration. It can be concluded that in recently burned areas (last forest fire in a year 2008) the soil respiration was not recovered. This is evidenced by both the rates of soil respiration and soil temperature values. In the other sample areas soil respiration has been recovered and the respiration values have reached to stable levels.
Kirjeldus
Märksõnad
bakalaureusetööd, metsatulekahjud, mullad, mullaniiskus, mullatemperatuur, süsinikdioksiid