TY  - JOUR
A1  - Stuenzi, Simone Maria
A1  - Kruse, Stefan
A1  - Boike, Julia
A1  - Herzschuh, Ulrike
A1  - Oehme, Alexander
A1  - Pestryakova, Luidmila A.
A1  - Westermann, Sebastian
A1  - Langer, Moritz
T1  - Thermohydrological impact of forest disturbances on ecosystem-protected permafrost
JF  - Journal of geophysical research : Biogeosciences
N2  - Boreal forests cover over half of the global permafrost area and protect underlying permafrost. Boreal forest development, therefore, has an impact on permafrost evolution, especially under a warming climate. 

Forest disturbances and changing climate conditions cause vegetation shifts and potentially destabilize the carbon stored within the vegetation and permafrost. Disturbed permafrost-forest ecosystems can develop into a dry or swampy bush- or grasslands, shift toward broadleaf- or evergreen needleleaf-dominated forests, or recover to the pre-disturbance state. 

An increase in the number and intensity of fires, as well as intensified logging activities, could lead to a partial or complete ecosystem and permafrost degradation. We study the impact of forest disturbances (logging, surface, and canopy fires) on the thermal and hydrological permafrost conditions and ecosystem resilience. 

We use a dynamic multilayer canopy-permafrost model to simulate different scenarios at a study site in eastern Siberia. We implement expected mortality, defoliation, and ground surface changes and analyze the interplay between forest recovery and permafrost. We find that forest loss induces soil drying of up to 44%, leading to lower active layer thicknesses and abrupt or steady decline of a larch forest, depending on disturbance intensity. 

Only after surface fires, the most common disturbances, inducing low mortality rates, forests can recover and overpass pre-disturbance leaf area index values. We find that the trajectory of larch forests after surface fires is dependent on the precipitation conditions in the years after the disturbance. Dryer years can drastically change the direction of the larch forest development within the studied period.
KW  - permafrost
KW  - boreal forest
KW  - periglacial process
KW  - Siberia
KW  - larch forest
KW  - disturbance
Y1  - 2022
U6  - https://doi.org/10.1029/2021JG006630
SN  - 2169-8953
SN  - 2169-8961
VL  - 127
IS  - 5
PB  - American Geophysical Union
CY  - Washington
ER  -