The degree of ﬁre-induced eﬀects on boreal forest soils substantially depends on the intensityof ﬁre. Especially high-intensity ﬁres may drastically alter the quality and quantity of the soilorganic matter pool. In this study, we investigated the eﬀects of low and high intensityprescribed ﬁres on soil carbon and nitrogen contents, soil pH, soil temperature, and soilmoisture in a Canadian boreal forest. The study was based on intensive ﬁeld sampling duringAugust 2018 in Jack pine (Pinus banksiana) forest stands located 50 km north of FortProvidence, Northwest Territories (61.582˚ ; -117.165˚). We measured the soil parametersfrom two short-term ﬁre chronosequences — one with high-intensity prescribed ﬁreshappening in years 2000, 2012, 2015, 2016, and 2017; and the other with low-intensityprescribed ﬁres happening in years 2015, 2017, and 2018. Additionally, we measured soiltemperature and moisture before and after a low-intensity prescribed ﬁre. In thehigh-intensity ﬁre chronosequence, the study site burned in year 2012 had the lowest soiltemperature. Even though temperatures seemed slightly higher in the most recent years ofthe ﬁre chronosequence (2015, 2016, and 2017), we did not identify a clear trend.Soil moisture was the lowest in the study site burned in year 2000, with mostly nosigniﬁcant diﬀerences between the following years. We did not ﬁnd signiﬁcantdiﬀerences in soil moisture and soil temperature before and after a low-intensityprescribed ﬁre. However, both time-after-ﬁre and ﬁre intensity were important forsoil moisture prediction, whereas only ﬁre intensity was important for predictingsoil temperature. Soil pH in the humus layer of the study site burned in 2012 wassigniﬁcantly lower compared to the other age classes (no pH data for year 2000) of thehigh-intensity ﬁre chronosequence. Neither C nor N content were signiﬁcantly diﬀerentbetween the ﬁre age classes at the humus layer or at the mineral layers. We believethat the small sample size did not allow the identiﬁcation of further diﬀerencesbetween the age classes, and it prevented direct comparisons between high and lowintensity ﬁres. Despite its exploratory nature, this study oﬀers some insight intoshort-term eﬀects of ﬁre on some soil parameters, for example, the observed changeson soil moisture, soil temperature, and soil pH. Therefore, we will progress thiswork by increasing the sample size and analysing autotrophic and heterotrophic soilrespiration to directly infer on ﬁre-induced changes on the soil organic matter pool.
|Tila||Julkaistu - 2019|
|Tapahtuma||EGU General Assembly 2019 - Vienna, Itävalta|
Kesto: 7 huhtikuuta 2019 → 12 huhtikuuta 2019
|Konferenssi||EGU General Assembly 2019|
|Ajanjakso||07/04/2019 → 12/04/2019|
- 4112 Metsätiede
Ribeiro-Kumara, C., Köster, K., Berninger, F., & Pumpanen, J. (2019). Fire-induced changes of high and low intensity prescribed fires in a Canadian boreal forest. Abstraktin lähde: EGU General Assembly 2019, Vienna, Itävalta.