不同林龄杉木人工林土壤氮转化酶活性特征  

Soil Enzyme Activity Related to Nitrogen Cycling in Chinese Fir(Cunninghamia lanceolata)Plantation with Different Stand Age

作　　者：彭紫薇 焦鹏宇 高李文 郭文 刘先 胡亚林[1] 王玉哲 PENG Zi-wei;JIAO Peng-yu;GAO Li-wen;GUO Wen;LIU Xian;HU Ya-lin;WANG Yu-zhe(Forestry College,Fujian Agriculture and Forestry University,Fuzhou 350002,Fujian,China)

机构地区：[1]福建农林大学林学院,福建福州350002

出　　处：《林业科学研究》2022年第2期104-111,共8页Forest Research

基　　金：国家自然科学基金项目(31700378)。

摘　　要：[目的]探讨土壤氮转化酶活性及根际效应随杉木生长发育的变化特征,为杉木人工林的施肥管理和可持续经营提供科学依据。[方法]以不同发育阶段杉木人工林(7、15、24、34 a)为研究对象,测定根际与非根际土壤氮转化酶活性(β-葡萄糖苷酶(BG)、乙酰-β-D-氨基葡萄糖苷酶(NAG)、蛋白水解酶(PRO)、脲酶(URE)、亮氨酸氨基肽酶(LAP)、硝酸还原酶(NR)),探讨不同发育阶段杉木人工林土壤氮转化酶活性、根际效应及其与土壤理化性质的关系。[结果]林龄和根际对6种土壤氮转化酶活性影响均存在显著差异(p<0.05);杉木林根际和非根际土壤氮转化酶活性均随林龄增加先下降后上升,不同林龄杉木根际土壤BG、NAG、PRO、URE和LAP活性均显著高于非根际土壤(p<0.05),根际与非根际土壤的NR活性差异因林龄而异,15 a和24 a杉木林根际土壤的NR活性极显著高于非根际土壤的(p<0.01),而7 a和34 a杉木林根际与非根际土壤的NR活性差异不显著(p>0.05)。15 a杉木林土壤NR活性的根际效应显著高于7 a和34 a杉木林(p<0.05)。杉木根际与非根际土壤酶活性的关键因素是碳氮比与铵态氮含量。[结论]中亚热带杉木人工林在中龄林阶段土壤氮转化酶活性最低,说明在受氮沉降影响严重的中亚热带地区,氮仍可能是杉木速生期的主要限制因素之一,在今后的营林施肥措施上,应把重点放在中龄林阶段,以满足杉木对氮的需求,达到可持续经营管理的目的。[Objective]To study the variation of soil nitrogen(N)-cycling enzyme activities and rhizosphere effect during the development of Chinese fir(Cunninghamia lanceolata)plantation and its driving factors.[Method]Rhizosphere and non-rhizosphere soils were collected from Chinese fir plantation with the ages of 7,15,24 and 34.The enzyme activities regulating soil nitrogen cycling(β-glucosidase(BG),acetyl-β-Dglucosaminidase(NAG),proteolytic enzyme(PRO),urease(URE),leucine aminopeptidase(LAP)and nitrate reductase(NR))were measured.Redundancy analysis(RDA)and Pearson correlation were conducted to explore the relationship between soil nitrogen-cycling enzyme activities and the soil physico-chemical properties.[Result]Forest age and rhizosphere had significant effects on soil N-cycling enzyme activities(P<0.05).The enzyme activities regulating soil nitrogen cycling in the non-rhizosphere soil decreased at first and then increased with the increase of forest age.The activities of BG,NAG,PRO,URE and LAP in rhizosphere soil were significantly higher than those in non-rhizosphere soil(P<0.05).The difference of NR activity between rhizosphere and non-rhizosphere soil varied with forest age.The NR activity in rhizosphere soil was significantly higher than that of non-rhizosphere soil in 15-and 24-years-old Chinese fir plantations(P<0.01).The rhizosphere effects of soil NR activities in 15-years-old Chinese fir plantation were significantly higher than those in 7-years-old and 34-years-old Chinese fir plantations(P<0.05).The key factors regulating soil N-cycling enzyme activities in rhizosphere and non-rhizosphere soil were C/N and ammonium nitrogen content.[Conclusion]Soil N-cycling enzyme activities was the lowest in middleage Chinese fir plantations in mid-subtropical China,indicating that nitrogen may still be one of the main limiting factors in the fast-growing stage of Chinese fir plantations.In the future,we should focus on the middle-age Chinese fir plantation,so as to meet the nitrogen demand of Chinese fir and achieve t

关 键 词：杉木 林龄 氮 土壤酶 根际效应 

分 类 号：S714.3[农业科学—林学] S791.27