Stellera chamaejasme L. increases soil N availability, turnover rates and microbial biomass in an alpine meadow ecosystem on the eastern Tibetan Plateau of China.
Stellera chamaejasme L. increases soil N availability, turnover rates and microbial biomass in an alpine meadow ecosystem on the eastern Tibetan Plateau of China.
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DOI：
10.1016/j.soilbio.2008.09.022
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发表时间：
2009
影响因子：
9.7
通讯作者：
Geng Sun;P. Luo;N. Wu;P. Qiu;Yong-heng Gao;Huai Chen;F. Shi
中科院分区：
文献类型：
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作者：
Geng Sun;P. Luo;N. Wu;P. Qiu;Yong-heng Gao;Huai Chen;F. Shi
植物物种已被证明对土壤养分库和动态具有显着影响。狼毒（Stellera chamaejasme L.）是一种有毒的多年生杂草，自20世纪60年代以来已在中国青藏高原东部的高山草甸中生长并大量繁殖。我们量化了狼毒对两个地形栖息地（平坦的山谷和朝南的斜坡）碳和氮循环的影响，狼毒最有利于在研究区域内传播。测量了地上凋落物生物量以及地上凋落物和根的组织化学，以解释狼毒对土壤碳和养分循环的可能影响。各种土壤池的大小，例如测定了硝酸盐、铵、无机磷、微生物量、土壤呼吸和周转率，包括净矿化、总硝化和反硝化。结果表明，狼毒产生的地上垃圾比每个共生物种都多。与其他物种相比，狼毒的地上凋落物具有较高的组织氮和较低的木质素：N。狼毒显着增加了表层土壤（0-15厘米）的有机质，而狼毒斑块内和斑块之间的底土（15-30厘米）的有机碳和总磷没有显着差异。平坦山谷和朝南斜坡上的 Stellera 表土土壤可提取硝酸盐浓度分别高出 113% 和 90%。狼毒表层土壤的微生物生物量 C 和 N 均显着较高。平谷和朝南坡地的斯特勒拉表层土壤总硝化作用和微生物呼吸显着较高，而反硝化作用仅在平谷上存在显着差异。地上枯落物数量和质量的差异可能是导致土壤性质变化的机制。
Plant species have been shown to have significant effects on soil nutrient pools and dynamics. Stellera chamaejasme L., a toxic perennial weed, has established and is now abundant in the alpine meadow on the eastern Tibetan Plateau of China since the 1960s. We quantified the effects of Stellera on carbon and nitrogen cycling in two topographic habitats, a flat valley and a south-facing slope, where Stellera was favored to spread within the study area. Aboveground litter biomass and tissue chemistry of aboveground litter and root were measured to explain the likely effects of Stellera on soil carbon and nutrient cycling. The sizes of various soil pools, e.g. nitrate, ammonium, inorganic phosphorus, microbial biomass, soil respiration and turnover rates including net mineralization, gross nitrification and denitrification were determined. The results showed that Stellera produced more aboveground litter than each of the co-occurring species. Aboveground litter of Stellera had higher tissue N and lower lignin:N than the other species. Stellera significantly increased surface soil (0–15cm) organic matter, whereas no significant differences were found for organic C and total P in subsoil (15–30cm) within and between patches of Stellera. Soil extractable nitrate concentrations in Stellera surface soil were 113% and 90% higher on the flat valley and on the south-facing slope, respectively. Both microbial biomass C and N were significantly higher in Stellera surface soil. Gross nitrification and microbial respiration were significantly higher in Stellera surface soil both on the flat valley and on the south-facing slope, whereas significant differences of denitrification were found only on the flat valley. The differences in the quantity and quality of aboveground litter are a likely mechanism responsible for the changes of soil properties.