摘要
土壤养分有效性是影响杉木人工林可持续经营的重要调控因子,然而目前关于杉木人工林根际和非根际土壤可溶性有机质(DOM)数量与组成随林龄的动态变化规律尚不明确。本研究以6年、18年、42年杉木人工林为研究对象,研究林龄对杉木人工林根际与非根际土壤可溶性有机碳(DOC)、可溶性有机氮(DON)、碳水化合物、酚类化合物和微生物生物量碳(MBC)、微生物生物量氮(MBN)含量的影响。结果表明:在亚热带杉木人工林中,根际区域DOC、DON及碳水化合物含量均显著高于非根际区域。根际土壤DOC、DON和碳水化合物浓度随着林龄的增加而显著降低(P<0.05),但MBN随着林龄的增加而增加(P<0.05)。非根际土壤DOC、DON和MBC含量随林龄的增加而降低,土壤酚类化合物随林龄增加而提高(P<0.05)。线性回归结果表明,在根际和非根际区域,MBC含量与DOC、DON、碳水化合物含量具有显著正相关关系;在根际区域,MBN含量与DOC、DON、碳水化合物具有显著的负相关关系。综上所述,尽管根际区域DOM有效性均显著高于非根际区域,然而根际与非根际区域均表现出随着林龄增加DOC、DON和碳水化合物含量降低的现象。因此,今后的研究应更加关注杉木人工林的根际区域,且需对中龄林和成熟林实行施肥抚育措施,以提高人工林的养分有效性,维持人工林的可持续发展。
Soil nutrient availability is one of the important regulatory factors affecting the sustainable management of Chinese fir(Cunninghamia lanceolata)plantation.However,the dynamic changes of the quantity and composition of soil dissolved organic matter(DOM)in rhizosphere and bulk soils across the Chinese fir age sequence are still unclear.This study investigated the effects of stand age on DOC,DON,carbohydrates,phenolic compounds and microbial biomass carbon and nitrogen contents of the rhizosphere and bulk soils at different Chinese fir stages:6-year(young-aged plantation),18-year(middle-aged plantation),and 42-year(mature-aged plantation).The results showed that the contents of DOC,DON and carbohydrate in the rhizosphere region were significantly higher than those in the bulk soil region in subtropical Chinese fir plantation.The concentrations of DOC,DON and carbohydrate in rhizosphere soil significantly decreased with the increase of stand age(P<0.05),while MBN raised with the increase of stand age(P<0.05).In bulk soil,the contents of DOC,DON and MBC significantly dropped with stand age,while soil phenolic compounds significantly increased with stand age(P<0.05).Linear regression results showed that MBC content was positively correlated with DOC,DON,and carbohydrate content in rhizosphere and bulk soil regions,while MBN content was negatively correlated with DOC,DON,and carbohydrate content only in rhizosphere region.In conclusion,although the composition of DOC,DON,carbohydrates and phenolic compounds in the rhizosphere soil were higher than those in the bulk soil,DOM availability decreased with stand age in both rhizosphere and bulk soil.Therefore,more attention should be paid to the rhizosphere region of Chinese fir plantation in the future study,and fertilization and nursing measures should be carried out for the middle-aged and mature forests to improve the nutrient availability of the plantation and maintain the sustainable development of the plantation.
作者
黄施楚
郑裕雄
杨智杰
张雅婷
陈娟
HUANG Shichu;ZHENG Yuxiong;YANG Zhijie;ZHANG Yating;CHEN Juan(School of Geographical Sciences,Fujian Normal University,Fuzhou 350117,China;Sanming Forest Ecosystem National Observation and Research Station,Sanming 365000,Fujian,China)
出处
《亚热带资源与环境学报》
2023年第1期63-70,共8页
Journal of Subtropical Resources and Environment
基金
国家自然科学基金项目(31670623)。
关键词
杉木人工林
可溶性有机质
根际与非根际土
林龄序列
Chinese fir plantation
dissolved organic matter
rhizosphere and bulk soil
stand age
