摘要
[目的]与阔叶树混交是提升杉木人工林土壤肥力的重要措施,探究不同杉阔混交模式下不同深度土壤氮矿化特征,对杉木人工林土壤养分循环的研究具有重要意义。[方法]选取两种经典混交模式的林分(杉-阔套种林、杉-阔混交林)与杉木纯林为研究对象,测定不同深度土壤(0~5 cm、5~20 cm、20~40 cm、40~60 cm)的理化性质、有效氮含量及氮矿化速率。[结果]0~5 cm土层的净氮矿化速率显著高于其他土层。混交和套种显著提高了0~5 cm土壤有效氮含量与净氮矿化速率。与杉木纯林相比,杉-阔套种林的土壤净氮矿化速率增加了111.19%,杉-阔混交林的土壤净氮矿化速率增加了70.73%。RDA分析表明:总碳和总氮含量是影响杉木人工林土壤氮矿化速率的主要因素,土壤含水率、碳氮比、可溶性有机碳和可溶性有机氮等对土壤氮矿化速率也有影响。相关性分析表明氮矿化速率最显著的0~5 cm土壤的碳氮比是净氮矿化速率的重要影响因素,而土壤理化性质在不同土层间对氮矿化的影响不同。[结论]土壤氮矿化与土壤深度密切相关,其主要发生在浅表层土壤且受多种土壤性质影响。杉阔混交和套种可以促进土壤氮矿化,对土壤氮矿化过程的正向影响利于维持和提升杉木人工林地的土壤肥力。
[Objective]Mixing with broad-leaved trees is an important measure to enhance soil fertility in Chinese fir(Cunninghamia lanceolata)plantations forests.Exploring the effects of mixing with broad-leaved trees on soil nitrogen mineralization at different depths in Chinese fir plantations can provide a reference for the effects of mixing with broad-leaved trees on soil nutrient cycling in Chinese fir plantations.[Method]Mixed forests of two classical mixed patterns(Mixed forests formed by replanting broad-leaved trees in the understory of pure forests after intercutting and mixed forests formed by simultaneous planting of Chinese fir and broad-leaved trees.)and pure forests of Chinese fir were selected for the study.Physicochemical properties,effective nitrogen content and nitrogen mineralization rate of soil at different soil depths in the understory(0~5 cm,5~20 cm,20~40 cm and 40~60 cm)were determined.[Results]The net N mineralization rate was significantly higher in the 0~5 cm soil layer than in the other soil layers.Mixing and intercropping with broad-leaved trees significantly increased the soil effective N content and net N mineralization rate in the 0~5 cm layer.Compared with the pure forest,the net soil N mineralization rate increased by 111.19% in the mixed forests formed by replanting broad-leaved trees in the understory of pure forests after intercutting and by 70.73% in the mixed forests formed by simultaneous planting of Chinese fir and broad-leaved trees.Redundancy analysis showed that the amount of total carbon and total nitrogen content was the important factor affecting the rate of nitrogen mineralization,water content,carbon to nitrogen ratio,dissolved organic carbon and nitrogen,and also had an effect on the rate of nitrogen mineralization.Correlation analysis showed that the soil carbon to nitrogen ratio in 0~5 cm was an important influencing factor on nitrogen mineralization,whereas soil physical and chemical properties had different effects on nitrogen mineralization among different soil layers.[Conclusion]Soil nitrogen mineralization is closely related to soil depth,mainly occurring in the shallow surface soil and affected by a variety of soil properties.Mixing and interplanting with broad-leaved trees can promote soil nitrogen mineralization in Chinese fir plantations,and the positive effect on the soil nitrogen mineralization process is beneficial to maintain and improve soil fertility of Chinese fir plantations.
作者
高畅
付若仙
沐炜杰
陈良喜
吴望榕
俞元春
GAO Chang;FU Ruo-xian;MU Wei-jie;CHEN Liang-xi;WU Wang-rong;YU Yuan-chun(College of Ecology and Environment,Nanjing,Co-Innovation Center for the Sustainable Forestry in Southern China,Nanjing Forestry University,Nanjing 210037,Jiangsu,China;Hulushan State-owned Forest Farm,Nanping 353015,Fujian,China)
出处
《林业科学研究》
CSCD
北大核心
2024年第5期23-32,共10页
Forest Research
基金
国家“十四五”重点研发计划项目(2021YFD2201304)
江苏高校优势学科建设工程资助项目(PAPD)。
关键词
杉木人工林
杉阔混交
套种
土壤氮矿化
Chinese fir plantation
mixed plantation of Chinese fir and broad-leaved trees
understory planting
soil nitrogen mineralization
作者简介
通讯作者:俞元春,教授,博士生导师,主要研究方向:森林土壤。电话:13951010679,E-mail:ycyu@njfu.edu.cn。
