中国生态农业学报2017，Vol.25Issue(7)：949-957,9.DOI:10.13930/j.cnki.cjea.170070
短期增温及减少降雨对杉木人工林土壤DOM的数量及其光谱学特征的影响
Effects of short-term global warming and precipitation reduction on the quantity and spectral characteristics of soil DOM inCunninghamia lanceolata plantation
摘要
Abstract
As a small but reactive soil organic matter (SOM) pool, dissolved organic matter (DOM) is considered to be a sensi-tive indicator of the dynamic of SOM and an important component of terrestrial biogeochemical cycle. The quality and quan-tity of DOM are crucial in the dynamics of C, N and other nutrients in forest soils because these attributes are closely related to carbon accumulation in soil and nutrient availability to microorganisms and plants. Global warming has been widely recog-nized and has induced drastic changes in global precipitation patterns. Because temperature and precipitation are the two most important environmental drivers regulating forest SOM cycle, it is critical that we have a solid understanding of the response of soil DOM to such climatic changes. In this study, we conducted a short-term experiment in aCunninghamia lanceolata plantation in subtropical China that stimulated soil warming and precipitation decline. The objective of the study was to ad-dress the effects of the two factors (temperature and precipitation) on the quantity and composition of DOM. The experimental design was a randomized complete block factorial design, with warming and precipitation as fixed factors. The four treatments (each replicated three time) were set up in the experiment included no warming and natural precipitation (CT), warming and natural precipitation (W), no warming and reduced precipitation (P), warming with reduced precipitation (WP). We found that: 1) W treatment increased the quantity of labile soil dissolved organic carbon (DOC), but decreased the aromaticity and humi-fication degree of DOM. The 0-10 cm soil layer contained more alkanes and little esters, while the 10-20 cm soil layer had more carbohydrates. 2) P treatment resulted in a smaller soil water content, which limited DOC production. In the 0-10 cm soil layer, soil DOM was apparently less humified and less condensed, with much alkanes present. However, in the 10-20 cm soil layer, aromaticity and humification degree were enhanced, while the quantity of carbohydrates decreased. In addition, precipi-tation decline also improved the quantity of DON. 3) The combination of warming climate and declining precipitation in-creased the concentrations of DOC and DON, and reduced the aromaticity index and humification degree. The 0-10 cm soil layer had relatively more carbohydrates than the 10-20 cm soil layer. 4) In the 0-10 cm soil layer, warming climate was the only factor that significantly influenced the quantity and quality of DOM. With increasing soil depth, precipitation decline became the second significant factor influencing soil DOM structure. Our results provided a deeper insight into the dynamic changes of soil DOM under global warming and declining precipitation, which was helpful in more accurately predicting soil C and N cycle in response to future global climate change.关键词
杉木人工林/土壤增温/减少降雨/土壤可溶性有机质/芳香性指数/腐殖化程度/光谱学特征Key words
Cunninghamia lanceolata plantation/Soil warming/Precipitation reduction/Soil dissolved organic matter/Aro-maticity index/Humification degree/Spectral characteristics分类
农业科技引用本文复制引用
李欢,杨玉盛,司友涛,刘翥..短期增温及减少降雨对杉木人工林土壤DOM的数量及其光谱学特征的影响[J].中国生态农业学报,2017,25(7):949-957,9.基金项目
国家自然科学基金面上项目(31570606)和福建省自然科学基金面上项目(2015J01120)资助 This study was supported by the National Natural Science Foundation of China (31570606) and Fujian Natural Science Foundation (2015J01120). （31570606）
