摘要
为揭示土壤养分和细菌群落对林下植被调控的响应机制,调查了浙江开化3种林分密度(高密度(KH)、中密度(KM)和低密度(KL))的17年生杉木人工林林下植被和生物量,测定土壤理化性质,并基于16Sr DNA高通量测序技术分析细菌群落结构变化。结果表明, 3种密度的杉木林下植被地上部分总生物量为0.10–2.10 t·hm^(-2),且优势植物物种差异显著。理化性质测定分析发现,高密度与低密度林分的土壤pH、有效磷含量差异显著。相关性分析表明,土壤pH与林下植被中草本、灌木生物量及总生物量均呈显著正相关关系,土壤有机质含量与灌木植被生物量及林下植被总生物量呈显著正相关关系,速效钾含量与灌木植被生物量呈显著正相关关系。土壤微生物群落结构分析可知, 3种密度杉木林地土壤中酸杆菌门、变形菌门、放线菌门和绿弯菌门为优势菌群,总相对丰度占比超过80%。冗余分析(RDA)表明土壤pH、碱解氮、有效磷和速效钾含量是土壤细菌群落结构变化的关键影响因素。酸杆菌门的优势亚群为Gp2、Gp1、Gp3和Gp6,占酸杆菌群的51.32%–57.38%,且随林分密度降低,林下植被增多, Gp1占比增大, Gp2和Gp6占比下降;Gp6相对丰度与pH呈极显著负相关关系。可见,杉木纯林经营中适度降低林分密度有利于林下植被生长和良好细菌群落结构保持,有利于维持杉木林地土壤肥力,实现可持续经营。
Aims The aim of the present study was to investigate the responses of understory vegetation to soil nutrients and bacterial communities. Methods This study investigated the understory vegetation biomasses and species composition as well as soil physical and chemical properties in 17-year-old Chinese fir plantations with three densities(high-density(KH), medium-density(KM), and low-density(KL)) in Kaihua, Zhejiang. The changes of bacterial community structures were analyzed via 16 S rDNA high-throughput sequencing techniques. Important findings The result showed that the total above-ground biomass of the understory vegetation ranged from 0.10 to 2.10 t·hm^(-2) and the dominant plant species varied in three Chinese fir plantations. The soil pH and available phosphorus content were significantly different between high-density and low-density forest stands. Correlation analysis showed that soil pH was positively correlated with the biomass of herbs, shrubs and the total of understory vegetation, while the content of soil organic matter was just positively related with the last two factors, and the available potassium content was only affected by the biomass of shrub. Based on the analysis of the soil microbial community, the Acidobacteria, Proteobacteria, Actinobacteria, and Chloroflexi were the dominant phyla in the three Chinese fir plantations. Redundancy analysis showed that soil pH, available nitrogen, available phosphorus and available potassium contents played a crucial role in regulating the soil bacterial community structures. Gp2, Gp1, Gp3 and Gp6 were the dominant subgroups of Acidobacteria, accounting for 51.32%– 57.38% of the Acidobacteria. With the decline of the Chinese fir density, the biomass of understory vegetation and the proportion of Gp1 increased, while the proportion of Gp2 and Gp6 decreased and the relative abundance of Gp6 was negatively correlated with soil pH. Obviously, the moderate reduction in stand density of pure Chinese fir forests was beneficial in the growth of understory vegetation and in maintaining a reasonable bacterial community structure, which helps to maintain the soil fertility of the Chinese fir forests and to achieve sustainable management in the long run.
作者
丁凯
张毓婷
张俊红
柴雄
周世水
童再康
DING Kai;ZHANG Yu-Ting;ZHANG Jun-Hong;CHAI Xiong;ZHOU Shi-Shui;TONG Zai-Kang(The State Key Laboratory of Subtropical Silviculture,Zhejiang Agriculture and Forestry University,Hangzhou 311300,China;Kaihua Forestry Farm,Zhejiang Province,Kaihua,Zhejiang 324300,China)
出处
《植物生态学报》
CAS
CSCD
北大核心
2021年第1期62-73,共12页
Chinese Journal of Plant Ecology
基金
国家重点研发计划(2016YFD060030404)。
关键词
杉木
林下植被
生物量
土壤理化性质
细菌
酸杆菌
Chinese fir
understory vegetation
biomass
soil physical and chemical properties
bacteria
Acidobacteria
