Soil respiration in response to year‐to‐year variations in rainfall in a tropical seasonal forest in northern Thailand

Abstract

In a tropical deciduous forest in northern Thailand, an area affected by the Asian monsoon, we made soil respiration measurements for 4 years to determine their inter‐annual variability. We also made continuous measurements of soil moisture, soil temperature, and soil CO2 concentration. Annual soil respiration rates were estimated using two methods: multiple regression analysis and Fick's first law of diffusion. During the study period, between June 2000 and December 2004, the annual rainfall and the length of the wet period showed considerable year‐to‐year variation, differing by 1162–1435 mm year−1 falling over 146–189 days, respectively. In response to the inter‐annual variability in rainfall, annual soil respiration rates estimated by the two models also showed large inter‐annual variations for the 4 years (coefficient of variation = 14–17%). The range in the inter‐annual variation for soil respiration was comparable with values for net ecosystem exchange reported in other Southeast Asian tropical forests. Historical rainfall records at this site showed further large inter‐annual variations that occurred in times other than in the study period, suggesting that long‐term monitoring would be required for a better understanding of the C balance at this site. Copyright © 2012 John Wiley & Sons, Ltd.

Different responses of soil respiration to environmental factors across forest stages in a Southeast Asian forest

“…Similarly, soil OM was generally higher in the dry period across forest succession, which may be associated with the higher litterfall in these sites during the dry season. In all forest stages, SR was significantly higher in the wet than in the dry period, which is consistent with previous studies on soil respiration in various forests in Thailand (Adachi et al, 2009;Boonriam et al, 2021;Hashimoto et al, 2004;Kume et al, 2013;Takahashi et al, 2011).…”

“…Our results could not be directly compared with any of these studies because it was unclear if any of these studies was conducted in similar seasonal evergreen forest. However, our SR values were within the ranges of those found in other Thai forests of various phenology, including dry evergreen forests (Adachi et al, 2009;Boonriam et al, 2021), dry dipterocarp forests (Hanpattanakit et al, 2015;Intanil et al, 2018), an evergreen forest (Hashimoto et al, 2004), a teak plantation (Kume et al, 2013), and a mixed deciduous forest (Takahashi et al, 2011).…”

Separating physical and biological controls on long‐term evapotranspiration fluctuations in a tropical deciduous forest subjected to monsoonal rainfall

“…The soil is Loamy Paleustults (Thai classification) or Ultisol (U.S. Department of Agriculture, soil taxonomic classification) with 35.5% sand, 43.5% silt, and 21.0% clay, with a total porosity of 35–40%. Most fine and coarse roots were detected in the top 0.4 m below the soil surface [ Kume et al ., ].…”

CO2 efflux from subterranean nests of ant communities in a seasonal tropical forest, Thailand

“…In temperate and boreal ecosystems, temperature affects total soil CO 2 efflux more strongly than does moisture, whereas in tropical ecosystems, the opposite situation can occur (Malhi et al 1999). In particular, in tropical seasonal forests, total soil CO 2 efflux clearly fluctuates with changes in soil moisture because there are distinct dry and wet seasons characterized by large differences in rainfall (Kume et al 2012). The total soil CO 2 efflux includes the CO 2 produced by all living soil organisms; plant roots, soil microbes, and animals (Luo and Zhou 2006).…”