TITLE:
Soil CO2 Efflux Dynamics and Its Relationship with the Environmental Variables in a Sub-Tropical Mixed Forest
AUTHORS:
Deepa Dhital, Rabina Manandhar, Puruswattam Manandhar, Sanu Raja Maharjan
KEYWORDS:
Soil CO2 Efflux, Environmental Parameters, Temperature Sensitivity (Q10), Sub-Tropical Forest, Climate Change
JOURNAL NAME:
Open Journal of Forestry,
Vol.12 No.3,
June
15,
2022
ABSTRACT: Soil CO2 efflux is an ongoing process of respiration from
soil; plant parts/ microbes
below the ground to the atmosphere which is known for faster cycling of carbon
sources. A large portion of carbon sequestered and fixed by forests is returned
to the atmosphere through soil CO2 efflux and multiple controlling
parameters mainly temperature, precipitation, and growth factors interact with the soil CO2 efflux
variation. This study assessed the soil CO2 efflux every
month for consecutive 2-years (August 2015 to July 2017) by using the closed
chamber method to determine the role of ecological parameters that govern the
soil CO2 efflux and its temporal modification in a sub-tropical
mixed forest of central region in Nepal. The results of this study manifested
that soil CO2 efflux accounted 63.2% (y = 31.96e0.128x),
71.3% (y = 44.77e0.123x) and 64.5% (y = 44.11e0.117x)
variations in soil temperature with significantly (p 10) of the soil CO2 efflux was 3.6, 3.4, and 3.2, respectively. Soil water content also expressed
significantly (p 2 efflux and accounted 62.0% (y = 138.3e0.057x), 46.1% (y = 88.42e0.052x)
and 40.5% (y = 133.1e0.0447x) in its variability in different years
and the merged years. Evident variations of soil CO2 efflux, soil
temperature, soil water content, and litter were observed in the forest
seasonally and inter-annually. Two years mean total annual soil CO2 efflux of the forest was estimated at 904.76 g C·m-2·y-1. The study revealed that sub-tropical forests could
be more influenced by precipitation regimes in progressing warm climates i.e.
vulnerable to climate change, illustrating the comprehensive dynamics of
the representative forest carbon cycle in the tropical region.