Effects of sand burial on litter decomposition rate and salt content dynamics in an extremely arid region
Lin-Jie Fan1,2,4, Cheng-Dao LI1,2,4, Xiang-Yi LI,,1,3,*, J. SUN Henry5, Li-Sha LIN1,2,3, Bo LIU61Xinjiang Key Laboratory of Desert Plant Roots Ecology and Vegetation Restoration, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, ürümqi 830011, China 2State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, ürümqi 830011, China 3Cele National Station of Observation and Research for Desert-Grassland Ecosystems, Cele, Xinjiang 848300, China 4University of Chinese Academy of Sciences, Beijing 100049, China 5Desert Research Institute, Las Vegas 89119, USA 6Linyi University, Linyi, Shandong 276000, China
Abstract Aims Due to the extremely low precipitation, low vegetation coverage, strong solar radiation, and poor soil stability, litter turnover in extremely arid areas differs from that in non-arid areas. This study aimed to determine the patterns of leaf litter decomposition of contrasting initial qualities in an extremely arid region. Methods We used the litter bag method to investigate changes of the mass and water-soluble salt content in the leaf litter of three dominant species, Karelinia caspia, Alhagi sparsifoliaand Populus euphratica,in the desert- oasis transitional zone of the southern edge of the Taklimakan Desert, in responses to three levels of sand burial treatments, including placement of letter samples at the surface, and 2 cm and 15 cm soil depths, respectively, that represented different incubation environments under natural conditions. Important findings The relationships of litter decomposition rate with the initial litter quality indicators, including carbon (C) content, nitrogen (N) content, C:N and lignin content, differed between the extremely arid sites and the non-arid sites. The litter placed on the surface had higher lignin content and faster mass loss than those subjected to other treatments. The losses of litter mass and changes in water-soluble salt content significantly varied with the level of burial treatments. Litter samples placed on the surface and at 2 cm depth had a significantly greater rate of losses in mass and water-soluble salt content than those at 15 cm depth. The surface litter had a greater amount of dissolved water-soluble salt in the early stage of decomposition. This study shows that the driving mechanism of litter decomposition in the extremely arid areas is unique. Under conditions of extremely low precipitation and the low activity of soil microorganisms, the buried depth is not the main factor driving the litter decomposition, whilst other abiotic processes such as solar radiation controlled the rate of decomposition. Keywords:litter decomposition;extremely arid area;burial depth;salt
PDF (1338KB)元数据多维度评价相关文章导出EndNote|Ris|Bibtex收藏本文 引用本文 范琳杰, 李成道, 李向义, Henry J. SUN, 林丽莎, 刘波. 极端干旱区沙土掩埋对凋落物分解速率及盐分含量动态的影响. 植物生态学报, 2021, 45(2): 144-153. DOI: 10.17521/cjpe.2020.0273 Fan Lin-Jie, LI Cheng-Dao, LI Xiang-Yi, Henry J. SUN, LIN Li-Sha, LIU Bo. Effects of sand burial on litter decomposition rate and salt content dynamics in an extremely arid region. Chinese Journal of Plant Ecology, 2021, 45(2): 144-153. DOI: 10.17521/cjpe.2020.0273
凋落物在维持生态系统物质循环和能量流动方面发挥着重要作用(曾加芹, 2017)。凋落物分解是生态系统中碳周转和矿质养分循环的重要过程(Fu et al., 2009)。据统计, 全球每年因凋落物分解释放的CO2约占全球年碳通量的70% (Raich & Schlesinger, 1992)。在全球陆地生态系统中, 有80%的有机碳储存于土壤中(Eswaran et al., 1993), 而凋落物又是土壤碳输入的重要来源, 凋落物分解以可溶性有机碳和稳定态腐殖质的形式向土壤输入碳(Rubino et al., 2010)。因此, 了解凋落物分解的影响因素对于理解全球碳循环至关重要。
Fig. 2Ratio of remaining litter mass at different times of decomposition in extremely arid region (mean ± SE). A, Karelinia caspia. B, Alhagi sparsifolia. C, Populus euphratica. Different lowercase letters indicate that the significant differences between treatments (p < 0.05).
Fig. 3Values of the litter decomposition constant (k) for different burial treatments in extremely arid region (mean ± SE). Different lowercase letters indicate significant differences between species under the same treatments (p < 0.05).
Fig. 4Ratio of litter water-soluble salt residue at different times of decomposition in extremely arid region (mean ± SE). A, Karelinia caspia. B, Alhagi sparsifolia. C, Populus euphratica. Different lowercase letters indicate significant differences between treatments (p < 0.05).
Fig. 5Relationships between litter mass and water-soluble salt residue in extremely arid region. A, Surface. B, 2 cm depth. C, 15 cm depth. The solid line represents the fitting curve of the relationship, and the dotted line represents y = x (1:1).
Fig. 6Litter dissolved water-soluble salt at different times of decomposition in extremely arid region (mean ± SE). A, Karelinia caspia. B, Alhagi sparsifolia. C, Populus euphratica. Different lowercase letters indicate significant differences between treatments (p < 0.05).
Fig. 7Ratio of litter water-soluble salt residue of three species under different treatments in extremely arid region (mean ± SE). Different lowercase letters indicate significant differences between treatments (p < 0.05).
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Decomposition of 51 semidesert species from wide-ranging phylogeny is faster in standing and sand-buried than in surface leaf litters: implications for carbon and nutrient dynamics 2 2015