Chin J Plant Ecol ›› 2017, Vol. 41 ›› Issue (8): 862-871.DOI: 10.17521/cjpe.2016.0363

• Research Articles • Previous Articles     Next Articles

Effect of Dicranopteris dichotoma on spectroscopic characteristic of dissolved organic matter in red soil erosion area

Hao ZHANG, Mao-Kui Lyu, Jin-Sheng XIE*()   

  1. Cultivation Base of State Key Laboratory of Humid Subtropical Mountain Ecology, Fuzhou 350007, China
    and School of Geographical Science, Fujian Normal University, Fuzhou 350007, China
  • Online:2017-08-10 Published:2017-09-29
  • Contact: Jin-Sheng XIE
  • About author:KANG Jing-yao(1991-), E-mail: kangjingyao_nj@163.com

Abstract:

Aims Dissolved organic matter (DOM) is the most active component of organic matters in soils, and plays an important role in carbon cycles. It is a mixed organic compound with varying molecular sizes and weights. We aimed to explore the impacts of Dicranopteris dichotoma coverage on quantity and structure of DOM after vegetation restoration in severely eroded red soil region. Methods A typical sequence of vegetation restoration (Y0, without ecological restoration; Y13, ecological restoration for 13 years; Y31, ecological restoration for 31 years) was selected as the research object in Hetian Town, Changting County, Fujian Province, China. At each experimental site, soils were subject to three treatments—NRd, not removed D. dichotoma; Rd, removed D. dichotoma; and CK, control, and the effects of D. dichotoma on the spectral characteristics of DOM were evaluated.Important findings The results indicated that the quantity of soil DOC under NRd treatment of the Y0, Y13 and Y31 was 7.61, 4.83, and 5.47 times higher than their CK treatment, respectively. The Rd treatment had significantly lower DOC than that under NRd treatments, and it was 1.84, 4.12, and 4.73 times higher than their CK treatments, respectively. Thus the D. dichotoma had exerted significant effects on the quantity of soil DOM. The Aromaticity index (AI), emission fluorescence spectrum humification index (HIXem) and synchronous fluorescence spectrum humification index (HIXsyn) of DOM under the NRd treatment were significantly higher than those of the CK treatments in Y13 and Y31, respectively. However, the ratio of ultraviolet-visible light absorption photometric quantity at 250 nm wavelength to ultraviolet-visible light absorption photometric quantity at 365 nm wavelength (E2:E3) had an opposite trend. It showed that the DOM structure in soils covered by D. dichotoma contained more aromatic nucleus and had higher aromaticity and humification, and DOM molecular was larger. In addition, the AI and humification index (HIX) of DOM under the Rd treatment was significantly decreased compared with the NRd treatment. Similar results were observed by analysis of emission and synchronous fluorescence spectrum, and by the Fourier infrared transmission spectrum analysis. These results suggest that D. dichotoma had positive impacts on the complexity of DOM structure, but it was a long and slow process. The DOM spectral analysis showed that the soil DOM covered by D. dichotoma had a stable and complex structure and was easily adsorbed by soil colloid. As a result, Dicranopteris dichotoma had a positive effect on the accumulation of soil organic carbon.

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Key words: vegetation restoration, dissolved organic matter, spectroscopic characteristic