Response of Humic Acids and Soil Organic Matter to Vegetation Replacement in Subtropical High Mountain Forests. Issue 12 (7th December 2019)

• Record Type: Journal Article
• Authors: Wang, Hsueh‐Ching; Tian, Guanglong; Chen, Chiou‐Pin; Chang, Ed‐Haun; Chou, Chiao‐Ying; Chiou, Chyi‐Rong; Chiu, Chih‐Yu
• Is Part Of: Journal of geophysical research. Volume 124:Issue 12(2019)
• Page Start: 3727
• Page End: 3736
• Publication Date: 2019-12-07
• Subjects: land use change -- plantation -- humification -- NMR spectroscopy -- soil organic carbon; Geobiology -- Periodicals; Biogeochemistry -- Periodicals; Biotic communities -- Periodicals; Geophysics -- Periodicals; 577.14
• DOI: 10.1029/2019JG005139
• Languages: English
• ISSNs: 2169-8953

Abstract

Abstract: Reforestation can alter the chemical composition of soil organic matter (SOM) and humification; however, information on how specific plant types impact SOM lability and humification is not well documented. In this study, we used solid‐state 13 C nuclear magnetic resonance spectroscopy, photometric analysis, and chemical fractionation to examine carbon (C) components and lability of SOM in a Japanese cedar ( Cryptomeria japonica ) forest and bamboo ( Phyllostachys edulis ) plantation that reforested a cutover primary broadleaf forest. The ∆logK value of soil humic acids, the inverse index of SOM humification, was lowest in the bamboo plantation, suggesting a higher SOM humification stage in the bamboo plantation. The soil labile C/Total C ratio was highest in the bamboo plantation, and this can be attributed to low aromaticity and alkyl‐C/O‐alkyl‐C ratio (A/O‐A) in the bamboo litter. Intensive cultivation of the bamboo plantation accelerated litter breakdown in the strongly acidic soil, resulting in the depletion of SOM. Cedar coniferous leaves, with their high recalcitrant substances and slow decomposition, only slightly lowered SOM humification due to the substantial broadleaf understory. Our results suggest that the type of plants involved in reforestation and understory reestablishment is critical to how SOM humification and lability change during the reforestation through the control of litter C components. Further research into the interaction between microclimate change and forest type in forest conversion will be useful for increasing understanding on the impact of forest conversion on SOM lability and humification in subtropical high mountain forest ecosystems. Key Points: Highly labile C litter and intensive cultivation in the bamboo plantation accelerated litter breakdown, resulting in the depletion of SOM Substantial broadleaf understory in cedar forests reduced impacts from reforestation Plant types involved in reforestation and understory reestablishment are critical to the SOM humification stage