Vegetation change impacts on soil organic carbon chemical composition in subtropical forests

Leaf litter plays a major role in carbon and nutrient cycling, as well as in fueling food webs. The chemical composition of a leaf may directly and indirectly influence decomposition rates by influencing rates of biological reactions and by influencing the accumulation of soil organic carbon content, respectively. This study aimed to assess the impact of the chemical composition of rubber (Hevea brasiliensis (Willd. ex A. Juss.) Muell. Arg.) leaves on various soil properties of different ages of rubber (4–5, 11–12, and 22–23 year-old). Synchrotron-based Fourier transform infrared microspectroscopy (Sr-FTIR) was utilized for analyzing the chemical composition of plant leaves. The Sr-FTIR bands illustrated that the epidermis of rubber leaves from 4–5-year-old trees was found to contain a high quantity of polysaccharides while mesophyll from 22–23-year-old trees had a large number of polysaccharides. The change in soil properties in the older rubber plantation could be attributed to its chemical composition. The change in soil properties across all tree ages, i.e., increased litter and organic carbon content, was a relatively strong driver of soil biota evolution. The aliphatic of C-H in the leaves showed high correlation with soil organic carbon (SOC) and permanganate-oxidizable C (POXC) from 22–23 year-old trees. This study shows the differences in the organic chemical composition of leaves that are consequential to soil organic carbon.

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Chemical composition of soil organic carbon changed by long-term monoculture cropping system in Chinese black soil

Plant Soil and Environment ◽

10.17221/492/2018-pse ◽

2018 ◽

Vol 64 (No. 11) ◽

pp. 557-563 ◽

Cited By ~ 1

Author(s):

Yunfa Qiao ◽

Shujie Miao ◽

Yingxue Li ◽

Xin Zhong

Keyword(s):

Chemical Composition ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Relative Proportion ◽

Cropping System ◽

Black Soil ◽

Chemical Compositions ◽

Crop Species ◽

Rotation System

Monoculture is common to meet commodity grain requirements in Northeast China. The effect of long-term monoculture on chemical composition of soil organic carbon (SOC) remains unclear. This study was done to evaluate how changes in chemical compositions of SOC responded to long-term monoculture. To achieve this objective, the chemical compositions of SOC in maize-soybean rotation, continuous soybean and continuous maize were characterized with the nuclear magnetic resonance technique. Two main components, O-alkyl and aromatic C, showed a wider range of relative proportion in monoculture than rotation system across soil profiles, but no difference was observed between two monoculture systems. Pearson’s analysis showed a significant relationship between plant-C and OCH<sub>3</sub>/NCH, alkyl C or alkyl O-C-O, and the A/O-A was closely related to plant-C. The findings indicated a greater influence of monoculture on the chemical composition of SOC compared to rotation, but lower response to crop species.

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