沙柳沙障腐烂过程对土壤碳氮磷化学计量特征的影响

探究沙柳沙障腐烂过程对土壤碳氮磷化学计量特征的影响，有助于深入了解荒漠生态系统土壤养分循环及土壤有效性。该研究以布设1、3、5、7、9 a的沙柳沙障为研究对象，通过原位取样与指标测定，探究影响土壤碳氮磷含量及其化学计量特征的主要环境因子。结果表明：沙柳沙障腐烂过程障体化学组分显著降低（P<0.05），土壤含水率和碱解氮（Available Nitrogen，AN）得到改善，β-1,4-葡萄糖苷酶（β-1,4-glucosidase，BG）和β-1,4-N-乙酰氨基葡萄糖苷酶（β-1,4-N-acetylglucosidase，NAG）活性于5 a时达到峰值；碳磷比和氮磷比在设障之后的5 a中显著增加，5 a时分别是1 a的1.83和1.76倍，而9 a的碳氮比较1 a显著增加了41.20%（P<0.05）；碳磷比和氮磷比与可溶性有机碳、碱解氮、全氮和BG呈显著正相关，但碳氮比与NAG、纤维素和木质素呈显著负相关，其仅与质量损失率呈显著正相关（P<0.05）；冗余分析研究结果进一步证实，纤维素和质量损失是影响土壤碳氮磷含量及其化学计量的主导因子。沙柳沙障的腐烂过程能够提高土壤碳氮磷含量，在辅助于沙漠地区植被恢复的过程中可作为长期有效的治理措施。

Effects of Salix psammophila sand barriers decay on soil carbon, nitrogen and phosphorus stoichiometry

One type of semi-buried mechanical barricade, the Salix psammophila sand barrier has been widely used in a wind-sand protection system in northwest China. However, the sand barriers are inevitably deteriorated under biodegradation, weathering, desorption-alternation, as well as the biological and abiotic factors, due to the exposure to the field environment for a long time. Decay and decomposition of sand barriers can alter the resource availability of dune soil, which is vital for understanding the biogeochemical process and nutrient cycling in desert ecosystems. Previous research has focused on the above-ground part of the sand barriers to intercept the wind and sand. But, it is still lacking in the ecological contributions and biogeochemical element cycling of the underground part of the desert soil during the long-term setting process. Therefore, this study aims to explore the effects of Salix psammophila sand barriers decay on the content and stoichiometric characteristics of the soil carbon (C), nitrogen (N), and P (phosphorus). The main environmental factors were determined to analyze the decay characteristics, soil physicochemical properties, and soil enzyme activities. The field test was conducted in the Hobq Desert (within the town of Duguitara, Inner Mongolia, China). The naturally degraded sample plots were selected in the windbreak and sand fixation areas adjacent to the roads with similar geographic characteristics and vegetation types for years 1, 3, 5, 7, and 9. The general situation of the sand barrier was determined at the experimental site. The test samples were collected and measured using the