| 互花米草入侵对杭州湾滨海湿地土壤碳氮磷生态化学计量特征的影响 |
| 摘要点击 1397 全文点击 1597 投稿时间：2022-06-18 修订日期：2022-08-09 |
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| 中文关键词 互花米草 生态化学计量 冗余分析 增强回归树 偏最小二乘结构方程模型 |
| 英文关键词 Spartina alterniflora ecological stoichiometry redundancy analysis boosted regression tree PLS-SEM model |
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| 中文摘要 |
| 互花米草入侵对滨海湿地生态系统产生极大威胁.选取杭州湾滨海湿地为研究区，采用方差分析研究互花米草入侵下滨海湿地土壤碳氮磷生态化学计量特征，结合冗余分析（RDA）、增强回归树（BRT）和偏最小二乘结构方程模型（PLS-SEM）进一步探讨滨海湿地环境因子与土壤碳氮磷生态化学计量特征之间的驱动耦合关系.结果表明：①互花米草入侵后，湿地土壤全氮和氮磷比（N ：P）显著增加；随入侵时间增加，土壤全氮和N ：P显著降低，有机碳、碳氮比（C ：N）和碳磷比（C ：P）显著增加.② RDA分析表明，冬季影响表土C ：N ：P生态化学计量特征的主要因子表现为有机碳>电导率>全氮，夏季为有机碳>容重>全氮.③ BRT分析表明，互花米草入侵下，全氮是影响土壤C ：N和N ：P的关键因子，而有机碳对C ：P影响最强.④ PLS-SEM分析表明，互花米草入侵下，黏粒和含水率直接影响有机碳，进而影响C ：N和C ：P；黏粒和电导率直接影响全磷，进而影响N ：P和C ：P；电导率直接影响全氮，进而影响C ：N和N ：P.综上，互花米草入侵对研究区土壤C ：N ：P生态化学计量特征影响显著，土壤物理性质和养分含量在不同程度上直接或间接影响土壤C ：N ：P生态化学计量特征. |
| 英文摘要 |
| The invasion of Spartina alterniflora poses a great threat to coastal wetland ecosystems. In this study, the stoichiometric characteristics of soil carbon, nitrogen, and phosphorus under a Spartina alterniflora invasion were explored using ANOVA in a coastal wetland in Hangzhou Bay, and the driving coupling relationship between soil environmental factors and soil C:N:P stoichiometric characteristics of the coastal wetland were further explored based on the redundancy analysis (RDA), boosted regression tree (BRT), and partial least squares-structural equation (PLS-SEM) model. The results showed that:① after the invasion of Spartina alterniflora, soil N:P and total nitrogen (TN) in the wetland increased significantly, and with the increase in invasion time, TN and N:P decreased significantly, whereas soil organic carbon (SOC), C:N, and C:P increased significantly. ② The RDA model revealed that the main factors affecting the stoichiometric characteristics of topsoil C:N:P were SOC>electrical conductivity (EC)>TN in winter and SOC>bulk density (BD)>TN in summer. ③ The BRT model showed that under the invasion of Spartina alterniflora, TN was the key factor affecting soil C:N and N:P, and SOC was the key factor affecting C:P. ④ The PLS-SEM model showed that clay and water content directly affected SOC, thus affecting C:N and C:P; the clay and EC directly affected total phosphorus (TP), thus affecting N:P and C:P; and the EC directly affected TN, thus affecting C:N and N:P. In conclusion, the invasion of Spartina alterniflora had a significant impact on soil C:N:P stoichiometric characteristics in the study area. Soil physical properties and nutrient content directly or indirectly affected soil C:N:P stoichiometric characteristics to varying degrees. |
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