香榧主产区SOC、STN和C∶N空间异质性及其关键影响因素  

Spatial Heterogeneity and Key Influencing Factors of Soil Organic Carbon,Soil Total Nitrogen,and Carbon to Nitrogen Ratio in main plantations of Torreya grandis cv.Merrillii

作　　者：何影 张勇 林松 杜芳芳 董佳琦 支裕优 傅伟军[1] 吴家森[1] 王增 HE Ying;ZHANG Yong;LIN Song;DU Fang-fang;DONG Jia-qi;ZHI Yu-you;FU Wei-jun;WU Jia-sen;WANG Zeng(College of Environment and Resource Sciences,Zhejiang A&F University,Lin'an 311300,China;Zhejiang Public Welfare Forest and State Forest Farm Management Station,Hangzhou 310020,China)

机构地区：[1]浙江农林大学环境与资源学院,临安311300 [2]浙江省公益林和国有林场管理总站,杭州310020

出　　处：《环境科学》2024年第9期5441-5450,共10页Environmental Science

基　　金：浙江省自然科学基金项目(LY20C160004);浙江省公益林和国有林场管理总站(H20220219)。

摘　　要：土壤有机碳(SOC)和全氮(STN)是反映森林生态系统平衡和土壤肥力质量的重要指标.全面掌握区域SOC、STN和C∶N的空间分布格局及其影响因素对于精准施肥和土壤健康至关重要.以浙江省特色经济林——香榧主产区为研究区域,基于1 km×1 km网格布点采集表层土壤样品(0~20 cm)117个.采用多元统计方法(随机森林模型、结构方程模型、冗余分析以及变异分解)结合多种空间分析手段(地统计学和Moran's I指数等),揭示香榧主产区的SOC、STN和C∶N的空间分布及其影响因素.结果表明,土壤ω(SOC)、ω(STN)和C∶N的平均值分别为17.63 g·kg^(−1)、1.48 g·kg^(−1)和12.65,与其他地区均值相比处于较高水平,其变异系数分别为68.08%、67.41%和46.03%,均存在中等程度变异;半方差函数结果表明,SOC、STN和C∶N存在中等程度的空间自相关,块基比[C0(/C0+C)]值分别为49.98%、45.88%和49.93%;空间分布结果表明,SOC、STN和C∶N由东北向西南逐渐降低,且绝大部分区域的SOC的肥力水平处于中等以上.相关分析和冗余分析结果表明,碱解氮、速效磷和速效钾与SOC和STN均呈显著相关(P<0.05).随机森林模型、结构方程模型和变异分解结果表明,土壤速效养分(碱解氮、速效磷和速效钾)是影响SOC和STN的主控因子.基于此,可通过合理施肥和种植林下植被等生态措施,提升浙江省特色经济林土壤碳、氮库潜力,增强林地应对区域气候变化的能力.Soil organic carbon(SOC)and soil total nitrogen(STN)serve as important indicators of the elemental balance within forest ecosystems reflecting soil fertility and quality.Accurate knowledge regarding the spatial variability of regional SOC,STN,and C∶N ratio and their influencing factors is of great significance for precise fertilization and soil health.In this study,a total of 117 topsoil samples(0-20 cm in depth)based on a 1 km×1 km grid were collected in the Torreya grandis cv.Merrillii plantation in Zhejiang Province.A combination of multi-dimensional statistical approaches(random forest model,structural equation model,redundancy analysis,and variation partitioning analysis)and diverse spatial analytical techniques(geostatistics,Moran's I index,etc.)were applied to reveal the spatial distributions and influencing factors of SOC,STN,and C∶N ratio in the Torreya.grandis cv.Merrillii region.The results showed that the averageω(SOC),ω(STN),and C∶N ratio were 17.63 g·kg^(−1),1.48 g·kg^(−1),and 12.65,respectively,and their coefficients of variation were 68.08%,67.41%,and 46.03%,respectively,indicating a moderate degree of variability.In general,the SOC,STN,and C∶N ratio of the Torreya grandis cv.Merrillii plantations were at an intermediate level in the national plantation.The semi-variance results showed that the nugget/sill values of SOC,STN,and C∶N ratio were 49.98%,45.88%,and 49.93%,respectively,demonstrating a moderate level of spatial autocorrelation.The spatial distribution results showed that SOC,STN,and C∶N ratio decreased from northeast to southwest,with the majority of the region exhibiting above-medium fertility levels of SOC.The results of correlation analysis and redundancy analysis indicated that AN,AP,and AK were significantly correlated with both SOC,STN,and C∶N ratio(P<0.05).The results of random forest,structural equation model,and variation partitioning analysis evidenced that the main influencing factors of SOC and STN were soil-available nutrients(AN,AP,and AK).Therefore,o

关 键 词：亚热带经济林 空间变异 影响因素 随机森林(RF) 结构方程 香榧 

分 类 号：X144[环境科学与工程—环境科学]