长白山北坡不同林分类型细根-土壤C、N、P化学计量特征

C,N,and P stoichiometric characteristics of fine root and soil in different stand types on the north slope of Changbai Mountain

细根是植物吸收养分和水分的主要器官,也是土壤养分归还的重要途径。研究细根的化学计量特征对了解森林生态系统植物-土壤养分循环具有重要意义。以吉林省八家子林业局蒙古栎天然林、天然阔叶混交林和落叶松人工林中龄林为对象,基于15块30 m×30 m样地的林分调查数据以及细根和土壤样品的测定数据,研究了不同林分类型细根和土壤的C、N、P化学计量特征以及两者的关系。结果表明:不同林分的细根和土壤C、N、P化学计量特征差异显著(P<0.05)。3种林分类型细根均受N限制,天然阔叶混交林土壤养分丰富,但蒙古栎天然林土壤P较贫乏。落叶松人工林和天然阔叶混交林的细根化学计量特征与土壤化学计量特征的相关程度明显高于蒙古栎天然林。3种林分的细根C∶N、C∶P和C含量受土壤化学计量特征影响较大。土壤C∶P是影响3种林分细根化学计量特征的最主要因素。研究结果可为长白山林区蒙古栎天然林、天然阔叶混交林和落叶松人工林的土壤养分管理和森林可持续经营提供一定的理论依据。

Fine roots are the main organ for plants to absorb nutrients and water,and their decomposition is an important pathway for soil nutrient return.Studying the stoichiometric characteristics of fine roots is of great significance for understanding plant-soil nutrient cycle in forest ecosystems.This study focused on the middle-aged natural Mongolian oak forest,natural broad-leaved mixed forest and larch plantation in Bajiazi Forestry Bureau,Jilin Province.Based on the stand survey data of 15 plots of 30 m×30 m,the C,N,P stoichiometric characteristics of fine roots and soils(0-20 cm)in different stand types and their relationships were analyzed.The results showed that fine-root and soil C,N,P stoichiometric characteristics differed across different stands(P<0.05).Fine roots of all the three stand types were limited by N.Soil nutrients were rich in the natural broad-leaved mixed forest,but soil P of the natural Mongolian oak forest were relatively poor.The correlations between fine-root and soil C-N-P stoichiometric characteristics were significantly higher in larch plantation and natural broad-leaved mixed forest than that in the natural Mongolian oak forest.As for the three stand types,fine-root C∶N,C∶P,and C were more affected by soil C-N-P stoichiometric characteristics with soil C∶P as the major affecting factor.Our results provide a certain theoretical basis for soil nutrient management and sustainable forest management of natural Mongolian oak forest,natural broad-leaved mixed forest and larch plantation in Changbai Mountain forested area.