Temperature and substrate availability regulate soil respiration in the tropical mountain rainforests, Hainan Island, China

doi:10.1093/jpe/rtt034

Abstract

Abstract: Aims Tropical forest plays a key role in global C cycle; however, there are few studies on the C budget in the tropical rainforests in Asia. This study aims to (i) reveal the seasonal patterns of total soil respiration (R T), litter respiration (R L) and soil respiration without surface organic litter (R NL) in the primary and secondary Asian tropical mountain rainforests and (ii) quantify the effects of soil temperature, soil moisture and substrate availability on soil respiration.
Methods The seasonal dynamics of soil CO₂ efflux was measured by an automatic chamber system (Li-8100), within the primary and secondary tropical mountain rainforests located at the Jianfengling National Reserve in Hainan Island, China. The litter removal treatment was used to assess the contribution of litter to belowground CO₂ production.
Important findings The annual R T was higher in the primary forest (16.73±0.87 Mg C ha^-1) than in the secondary forest (15.10±0.26 Mg C ha^-1). The rates of R T, R NL and R L were all significantly higher in the hot and wet season (May–October) than those in the cool and dry season (November–April). Soil temperature at 5cm depth could explain 55–61% of the seasonal variation in R T, and the temperature sensitivity index (Q 10) ranked by R L (Q 10 = 3.39)> R T (2.17)> R NL (1.76) in the primary forest and by R L (4.31)> R T (1.86)> R NL (1.58) in the secondary forest. The contribution of R L to R T was 22–23%, while litter input and R T had 1 month time lag. In addition, the seasonal variation of R T was mainly determined by soil temperature and substrate availability. Our findings suggested that global warming and increased substrate availability are likely to cause considerable losses of soil C in the tropical forests.

Key words: soil respiration, soil temperature, litter, tropical mountain rainforest

摘要：
Aims Tropical forest plays a key role in global C cycle; however, there are few studies on the C budget in the tropical rainforests in Asia. This study aims to (i) reveal the seasonal patterns of total soil respiration (R T), litter respiration (R L) and soil respiration without surface organic litter (R NL) in the primary and secondary Asian tropical mountain rainforests and (ii) quantify the effects of soil temperature, soil moisture and substrate availability on soil respiration.
Methods The seasonal dynamics of soil CO₂ efflux was measured by an automatic chamber system (Li-8100), within the primary and secondary tropical mountain rainforests located at the Jianfengling National Reserve in Hainan Island, China. The litter removal treatment was used to assess the contribution of litter to belowground CO₂ production.
Important findings The annual R T was higher in the primary forest (16.73±0.87 Mg C ha^-1) than in the secondary forest (15.10±0.26 Mg C ha^-1). The rates of R T, R NL and R L were all significantly higher in the hot and wet season (May–October) than those in the cool and dry season (November–April). Soil temperature at 5cm depth could explain 55–61% of the seasonal variation in R T, and the temperature sensitivity index (Q 10) ranked by R L (Q 10 = 3.39)> R T (2.17)> R NL (1.76) in the primary forest and by R L (4.31)> R T (1.86)> R NL (1.58) in the secondary forest. The contribution of R L to R T was 22–23%, while litter input and R T had 1 month time lag. In addition, the seasonal variation of R T was mainly determined by soil temperature and substrate availability. Our findings suggested that global warming and increased substrate availability are likely to cause considerable losses of soil C in the tropical forests.

Zhang Zhou, Lai Jiang, Enzai Du, Huifeng Hu, Yide Li, Dexiang Chen, Jingyun Fang. Temperature and substrate availability regulate soil respiration in the tropical mountain rainforests, Hainan Island, China[J]. J Plant Ecol, 2013, 6(5): 325-334.

[1]	Huayue Nie, Chenrui Wang, Meirong Tian, Jixi Gao. Exogenous enzyme addition affects litter decomposition by altering the microbial community and litter nutrient content in planted forest [J]. J Plant Ecol, 2023, 16(6): 0-rtad031.
[2]	Pei Zheng, Ruonan Zhao, Liangchao Jiang, Guojiao Yang, Yinliu Wang, Ruzhen Wang, Xingguo Han, Qiushi Ning. Increasing nitrogen addition rates suppressed long-term litter decomposition in a temperate meadow steppe [J]. J Plant Ecol, 2023, 16(3): 0-rtac078.
[3]	Youli Yu, Huiyuan Cheng, Congyan Wang, and Daolin Du. Heavy drought reduces the decomposition rate of the mixed litters of two composite invasive alien plants [J]. J Plant Ecol, 2023, 16(1): 0-.
[4]	Guodong Zhang, Guiyao Zhou, Xuhui Zhou, Lingyan Zhou, Junjiong Shao, Ruiqiang Liu, Jing Gao, Yanghui He, Zhenggang Du, Jianwei Tang and Manuel Delgado-Baquerizo. Effects of tree mycorrhizal type on soil respiration and carbon stock via fine root biomass and litter dynamic in tropical plantations [J]. J Plant Ecol, 2023, 16(1): 0-.
[5]	Meixia Zhang, Yan Luo, Qingquan Meng, Wenxuan Han. Correction of leaf nutrient resorption efficiency on the mass basis [J]. J Plant Ecol, 2022, 15(6): 1125-1132.
[6]	Yuan-Yuan Zhao, Zhuo-Ting Li, Ting Xu and An-ru Lou. Leaf litter decomposition characteristics and controlling factors across two contrasting forest types [J]. J Plant Ecol, 2022, 15(6): 1285-1301.
[7]	Huajie Diao, Xiaopeng Chen, Ge Wang, Qiushi Ning, Shuya Hu, Wei Sun, Kuanhu Dong and Changhui Wang. The response of soil respiration to different N compounds addition in a saline–alkaline grassland of northern China [J]. J Plant Ecol, 2022, 15(5): 897-910.
[8]	Bowen Li, Wangwang Lv, Jianping Sun, Lirong Zhang, Lili Jiang, Yang Zhou, Peipei Liu, Huan Hong, Qi Wang, Wang A, Suren Zhang, Lu Xia, Zongsong Wang, Tsechoe Dorji, Ailing Su, Caiyun Luo, Zhenhua Zhang and Shiping Wang. Warming and grazing enhance litter decomposition and nutrient release independent of litter quality in an alpine meadow [J]. J Plant Ecol, 2022, 15(5): 977-990.
[9]	Qiang Guo, Ruo-Hui Zhang, Xue-Li Li, Xiao-Wei Liu, Ya-Nan Li and Fu Xing. Nitrogen addition overrides the effects of Stellera chamaejasme litter on the growth of Leymus chinensis and its associated mycorrhizal fungi [J]. J Plant Ecol, 2022, 15(5): 1007-1020.
[10]	Xingchang Wang, Qi Wang, Yue Chen, Rui Zhao, Jiahui Zhang, Xiankui Quan, Fan Liu and Chuankuan Wang. Coloration and phenology manifest nutrient variability in senesced leaves of 46 temperate deciduous woody species [J]. J Plant Ecol, 2022, 15(4): 700-710.
[11]	Shuli Wang, Xi Yuan, Ling Zhang, Fusheng Chen, Xiangmin Fang, Xiaojun Liu, Bangliang Deng, Nasir Shad, Wenyuan Zhang, Xiaofei Hu, Xiaomin Guo and Evan Siemann. Litter age interacted with N and P addition to impact soil N₂O emissions in Cunninghamia lanceolata plantations [J]. J Plant Ecol, 2022, 15(4): 771-782.
[12]	Yuhang Dai, Fanxi Gong, Xueqin Yang, Xiuzhi Chen, Yongxian Su, Liyang Liu, Jianping Wu, Xiaodong Liu and Qingling Sun. Litterfall seasonality and adaptive strategies of tropical and subtropical evergreen forests in China [J]. J Plant Ecol, 2022, 15(2): 320-334.
[13]	Mei Liu, Jia-Hao Wen, Ya-Mei Chen, Wen-Juan Xu, Qiong Wang and Zhi-Liang Ma. Warming increases soil carbon input in a Sibiraea angustata-dominated alpine shrub ecosystem [J]. J Plant Ecol, 2022, 15(2): 335-346.
[14]	Lihua Zhang, Junfeng Wang, Ruifeng Zhao, Yafei Guo and Lianyi Hao. Aboveground net primary productivity and soil respiration display different responses to precipitation changes in desert grassland [J]. J Plant Ecol, 2022, 15(1): 57-70.
[15]	Miyuki Matsuda and Shiro Tsuyuzaki. Role of Salix reinii patches in spatio-temporal patterns of cohabitants on a Japanese volcano [J]. J Plant Ecol, 2022, 15(1): 71-84.