不同凋落物配比对杉木土壤微生物量碳氮的影响

发布时间：2018-08-04 07:48

【摘要】：【目的】探讨土壤微生物对不同配比杉木—火力楠凋落物分解的响应,为促进我国南方杉木人工林的可持续经营与发展提供科学依据。【方法】在我国南方典型酸雨区福建省邵武市4、15和32年生杉木人工林内,设5个凋落物分解试验处理,分别为杉木(C)、火力楠叶(M)、杉木∶火力楠叶=2∶1(C2M1)、杉木∶火力楠叶=1∶1(C1M1)、杉木∶火力楠叶=1∶2(C1M2),采用网袋法分析不同配比处理杉木人工林0~5 cm表层土壤微生物量的碳、氮含量及微生物量碳氮比的差异。【结果】4和15年生杉木人工林中土壤微生物量碳含量最高的处理分别为C2M1和C1M1,显著高于C、M单一配比处理(P0.05,下同),32年生杉木人工林中各处理间土壤微生物量碳含量随时间波动变化;4、15和32年生杉木人工林中,不同混合凋落物与单一凋落物的土壤微生物生物量氮含量差异随时间的变化存在差异。各林龄土壤微生物量碳氮比在凋落物分解的不同时段存在明显波动变化,且分解时间为120和240 d时出现最低值。土壤温度与水分含量对4年生和15年生杉木人工林表层土壤微生物量碳氮的影响显著,对32年生杉木人工林影响不明显;各林龄表层土壤微生物量碳氮含量与土壤pH呈显著相关。方差分析结果表明,受林龄、杉木—火力楠凋落物配比及凋落物分解时间的多重影响,各林分表层土壤微生物量碳氮含量在凋落物整个分解周期内呈波动变化,其中微生物量碳含量的峰值出现在60和240 d,微生物量氮含量的峰值出现在120和240 d。【结论】对纯杉木幼龄林和中龄林的混交改良采用杉木—火力楠以2∶1和1∶1混交效果更佳,而在生产实践中对杉木—火力楠配比的选择还应综合考虑杉木林龄、土壤pH、土壤温度和水分含量等环境因子及季节变化的影响。
[Abstract]:[objective] to study the response of soil microbes to litter decomposition of Cunninghamia lanceolata (Cunninghamia lanceolata) with different ratios. To provide scientific basis for sustainable management and development of Chinese fir plantations in southern China. [methods] five litter decomposition experiments were conducted in 415 and 32 year old Chinese fir plantations in Shaowu City, Shaowu City, South China. Chinese fir (C), Chinese fir (C2M1), Cunninghamia lanceolata (C1M1), Cunninghamia lanceolata (Cunninghamia lanceolata) 1: 1: 2 (C1M2) were used to analyze the microbial biomass in the surface soil of Chinese fir plantation (0 ~ 5 cm) with different ratios. [results] the highest soil microbial biomass carbon content in 4 and 15 years old Chinese fir plantation was C2M1 and C1M1, respectively, which was significantly higher than that of CZM single proportion treatment (P0.05, the same below). 32 year old Cunninghamia lanceolata plantation had the highest soil microbial biomass carbon content. Soil microbial biomass carbon content fluctuated with time between different treatments in Chinese fir plantation. The differences of soil microbial biomass nitrogen content between mixed litter and single litter varied with time. Soil microbial biomass, carbon and nitrogen ratio of different forest ages fluctuated obviously in different period of litter decomposition, and the lowest value appeared when decomposition time was 120 days and 240 days. The effects of soil temperature and water content on soil microbial biomass carbon and nitrogen in the surface soil of 4-year-old and 15-year-old Chinese fir plantation were significant, but the effects on 32-year-old Chinese fir plantation were not obvious. Soil microbial biomass carbon and nitrogen content was significantly correlated with soil pH at different forest ages. The results of variance analysis showed that under the influence of forest age, litter ratio of Chinese fir and decomposition time of litter, microbial biomass carbon and nitrogen content in surface soil of each stand fluctuated during the whole decomposition period of litter. The peak of microbial biomass carbon content appeared in 60 days and 240 days, and the peak of microbial biomass nitrogen content appeared in 120 and 240 days. [conclusion] for the mixed improvement of pure Chinese fir young forest and middle age forest, Chinese fir and firewood were used at 2:1 and 1. The mix of 1: 1 is better. In the production practice, the influence of environmental factors such as forest age, soil pH, soil temperature and moisture content on the seasonal variation of Chinese fir / fir ratio should also be considered.
【作者单位】：福建农林大学资源与环境学院/土壤生态系统健康与调控福建省高校重点实验室;国家林业局杉木工程技术研究中心;福建农林大学林学院;福建省上杭白砂国有林场;邵武市林业科学技术推广中心;
【基金】：国家重点研发计划项目(2016YFD0600301) 国家自然科学基金项目(31270676)
【分类号】：S714.3;S791.27

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