Browsing by Subject "water-table"

Soil respiration (Rs), especially from drained peatland, has a significant role in the global carbon cycle. Drained peatland adds more CO2 effluxes due to the aerobic condition and fast decomposition rate of organic matter. In such condition, peatlands are no more carbon sink rather than a source. However, soil respiration (Rs) is known to be markedly variable with time and space. Many ecological studies showed an exact measurement of Rs is critical. Even a spatial variability of Rs is less known at a plot scale. This study investigated the spatial variation of Rs and its relationship with some explanatory factors (soil temperature, water-table level, moss cover, drainage ditch distance, and vegetation cover) in Lettosuo-peatland, Tammela, Finland. Soil respiration (Rs), soil temperature (Ts), and water-table level (WTL) were measured at 98 sampling plots during May to August 2017. A closed chamber system is known as Environmental Gas Monitor (EGM) was used to measure soil respiration. Once at the end of the measurement in August, vegetation site type (St), ditch distance (Dd), field layer vegetation (FLV), and ground layer vegetation (peat moss (Mp), forest moss (Mf)) were measured. The results showed that the mean rate of CO2 efflux was 0.49 ± 0.1 ( ± Std) g CO2 m-2 h-1 at 13.51 ± 0.8 ( ± Std) °C (at 5 cm depth) ranging from 0.15 to 0.98 g CO2 m-2 h-1. A multiple linear model indicated (R2 =0.18) that about 18% of the spatial variation of Rs could be explained by Ts, WTL, and Dd collectively, but only WTL (R2 = 0.12) could explain 12% variation alone. The spatial variability of soil respiration was mainly driven by the variability in WTL.