Soil respiration in tropical seasonal forests: An essential process for carbon cycling
Soil respiration is a crucial process in the carbon cycle of tropical seasonal forests. It refers to the release of carbon dioxide (CO2) from the soil as a result of microbial and root respiration. Understanding soil respiration dynamics in these forests is important for predicting their response to climate change and assessing their role in the global carbon balance.
Tropical seasonal forests are characterized by distinct wet and dry seasons, which significantly influence soil respiration rates. During the wet season, high soil moisture and temperature create favorable conditions for microbial activity, leading to increased decomposition rates and thus higher soil respiration. Conversely, the dry season is characterized by reduced soil moisture and lower temperatures, which limit microbial activity and result in lower respiration rates.
Studies have shown that soil respiration in tropical seasonal forests can vary greatly across different forest types and geographical locations. For instance, research conducted in the Amazon rainforest reported annual soil respiration rates ranging from 6 to 16 tons of carbon per hectare. In contrast, studies in the dry forests of Mexico recorded lower rates, ranging from 3 to 8 tons of carbon per hectare. These variations can be attributed to differences in soil properties, vegetation composition, and climatic conditions.
The factors influencing soil respiration in tropical seasonal forests are multifaceted. Soil moisture and temperature are key drivers, as they directly affect microbial activity and decomposition rates. Additionally, soil nutrient availability, organic matter content, and vegetation characteristics play important roles. For example, forests with high nutrient availability and abundant litterfall tend to have higher respiration rates due to increased microbial biomass and activity.
Climate change poses significant challenges to the soil respiration dynamics in tropical seasonal forests. Rising temperatures and altered precipitation patterns can impact soil moisture availability and temperature, thereby influencing microbial activity and decomposition rates. Studies have predicted that increasing temperatures could enhance soil respiration rates in these forests, potentially accelerating carbon losses to the atmosphere.
In conclusion, soil respiration is a critical process in the carbon cycle of tropical seasonal forests. Its dynamics are influenced by seasonal variations in soil moisture and temperature, as well as other factors such as soil properties and vegetation composition. Understanding these dynamics is essential for predicting the response of these forests to climate change and assessing their role in the global carbon balance. Further research is needed to elucidate the mechanisms underlying soil respiration in tropical forests and to develop accurate models for predicting future changes.
Soil respiration in tropical seasona 篇三
Soil respiration in tropical seasonal rain forest in Xishuangbanna, SW China
With the static opaque chamber and gas chromatography technique, from January 2003 to January 2004 soil respiration was investigated in a tropical seasonal rain forest in Xishuangbanna, SW China. In this study three treatments were applied, each with three replicates: A (bare soil), B (soil+litter), and C (soil+litter+seedling). The results showed that soil resp
iration varied seasonally, low from December 2003 to February 2004, and high from June to July 2004. The annual average values of CO2 efflux from soil respiration differed among the treatments at 1% level, with the rank of C (14642 mgCO2· m-2. h-1)>B (12807 mgCO2· m-2. h-1)>A (9532 mgCO2· m-2. h-1). Diurnal variation in soil respiration was not apparent due to little diurnal temperate change in Xishuangbanna. There was a parabola relationship between soil respiration and soil moisture at 1% level. Soil respiration rates were higher when soil moisture ranged from 35% to 45%. There was an exponential relationship between soil respiration and soil temperature (at a depth of 5cm in mineral soil) at 1% level. The calculated Q1o values in this study,ranging from 2.03 to 2.36, were very near to those of tropical soil reported. The CO2 efflux in 2003was 5.34 kgCO2· m-2. a-1 from soil plus litter plus seedling, of them 3.48 kgCO2· m-2. a-1 from soil (accounting for 62.5%), 1.19 kgCO2· m-2. a-1 from litter (22.3%) and 0.67 kgCO2·m-2. a-1 from seedling (12.5%). 作 者: SHA Liqing ZHENG Zheng TANG Jianwei Wang Yinghong ZHANG Yiping CAO Min WANG Rui Liu Guangren WANG Yuesi SUN Yang 作者单位: SHA Liqing(Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650223, China;Graduate School of Chinese Academy of Sciences, Beijing 100039, China)ZHENG Zheng,TANG Jianwei,Wang Yinghong,ZHANG Yiping,CAO Min,WANG Rui(Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650223, China)
Liu Guangren,WANG Yuesi,SUN Yang(Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China)
刊 名:中国科学D辑(英文版) SCI 英文刊名: SCIENCE IN CHINA (EARTH SCIENCES) 年,卷(期): 200548(z1) 分类号: P4 关键词: seasonal rain forest soil respiration CO2 efflux Q10 Xishuangbanna