Dependence of Soil Respiration on Soil Temperature and Soil Moisture in Successional Forests in Southern China

Abstract

The spatial and temporal variations in soil respiration and its relationship with biophysical factors in forests near the Tropic of Cancer remain highly uncertain. To contribute towards an improvement of actual estimates, soil respiration rates, soil temperature, and soil moisture were measured in three successional subtropical forests at the Dinghushan Nature Reserve (DNR) in southern China from March 2003 to February 2005. The overall objective of the present study was to analyze the temporal variations of soil respiration and its biophysical dependence in these forests. The relationships between biophysical factors and soil respiration rates were compared in successional forests to test the hypothesis that these forests responded similarly to biophysical factors. The seasonality of soil respiration coincided with the seasonal climate pattern, with high respiration rates in the hot humid season (April-September) and with low rates in the cool dry season (October-March). Soil respiration measured at these forests showed a clear increasing trend with the progressive succession. Annual mean (± SD) soil respiration rate in the DNR forests was (9.0 ± 4.6) Mg CO 2 -C/hm 2 per year, ranging from (6.1 ± 3.2) Mg CO 2 -C/hm 2 per year in early successional forests to (10.7 ± 4.9) Mg CO 2 -C/hm 2 per year in advanced successional forests. Soil respiration was correlated with both soil temperature and moisture. The T/M model, where the two biophysical variables are driving factors, accounted for 74%-82% of soil respiration variation in DNR forests. Temperature sensitivity decreased along progressive succession stages, suggesting that advanced-successional forests have a good ability to adjust to temperature. In contrast, moisture increased with progressive succession processes. This increase is caused, in part, by abundant respirators in advanced-successional forest, where more soil moisture is needed to maintain their activities.

Komposzt illetve műtrágya bioszén kezeléssel mutatott együttes hatásának vizsgálata karbonátos homoktalaj nedvességtartalmára és talajlégzésére

“…A talaj mikrobiális eredetű CO 2 kibocsátását a talaj szerves széntartalma, valamint az egyik elsődleges környezeti változó, a talaj nedvességtartalma erősen befolyásolja (DAVIDSON et al, 2000;TANG et al, 2006). A talaj nedvességtartalmát az előző fejezetben tárgyaltuk.…”

Soil Carbon Dioxide Fluxes from Three Forest Types of the Tropical Montane Rainforest on Hainan Island, China

“…5). Studies reported that soil temperature among numerous environmental factors plays an important role to affect soil CO 2 emissions (Han et al 2007;Tang et al 2006b;Wood et al 2013;Zanchi et al 2014). A report found that soil CO 2 emissions significantly correlated with soil temperature (R 2 = 0.87, P < 0.01) in the pine forest ).…”

“…This is probably because of the seasonal variation of environmental factors (Table 1). In other words, the seasonality of soil respiration coincides with the seasonal climate pattern, with high respiration rates in the hot humid season and low rates in the cool dry season (Itoh et al 2012;Tang et al 2006b). Moreover, we observed an interesting phenomenon that the CO 2 flux showed significant fluctuations during the wet season, from July 2013 to December 2013 and from May 2014 to June 2014 (P < 0.01), but only slight fluctuations during the dry season, from November 2013 to April 2014 (P > 0.05) (Fig.…”

Seasonal and daily variability of CO2 emissions from the Czerwone Bagno peat bog in Biebrza National Park (Poland)

“…such an approach causes a significant diversification of co 2 emission values, even if the difference of concentrations as per gauge readouts at the beginning and end of the measurement was identical for different times of day. many authors suggest that temperature as well as other atmospheric factors influence the co 2 exhalation process (davidson et al 1998, Tang et al 2006Tang et al , riederer et al 2014). Parkin and Venterea (2010) claim that temperature differences can have a marked effect on biological activity.…”

“…updegraff et al (1995) suggest that the change in carbon balance may depend on trophic status and biological activity. other researchers list the following as important factors: variability of volumetric density and differences in the ability to retain carbon by the biomass composed of different species of organisms (raich and schlesinger 1992, Thomas et al 1996), or variability of atmospheric conditions -mainly air temperature and pressure (moore and dalva 1993, davidson et al 1998, Tang et al 2006Tang et al , riederer et al 2014. recent climate change predictions suggest that conditions may become drier and will affect a part of the bog carbon resource.…”