阔叶红松林土壤微生物量及优势树种根际效应对增氮和减水的响应  

Soil Microbial Biomass and Rhizosphere Effects of Dominant Tree Species in a Broadleaf Korean Pine Forest in Response to Nitrogen Addition and Water Reduction

作　　者：刘东玲 王晓春 闫国永 邢亚娟 王庆贵 LIU Dong-ling;WANG Xiao-chun;YAN Guo-yong;XING Ya-juan;WANG Qing-gui(Ecological Research Center,College of Forestry,Northeast Forestry University,Harbin 150040,Heilongjiang,China;School of Life Sciences,Qufu Normal University,Qufu 273165,Shandong,China)

机构地区：[1]东北林业大学林学院生态研究中心,黑龙江哈尔滨150040 [2]曲阜师范大学生命科学学院,山东曲阜273165

出　　处：《林业科学研究》2025年第1期127-138,共12页Forest Research

基　　金：国家自然科学基金项目(42230703、42377477)。

摘　　要：[目的]气候变化下氮沉降增加和降水减少显著影响森林生态系统的结构和功能。根际是植物、土壤和微生物相互作用的核心区域,然而关于增氮和减水对根际微生物影响的研究仍较为匮乏。本研究旨在探讨土壤微生物量及优势树种根际效应对增氮和减水的响应,以预测阔叶红松林在气候变化下的适应策略及养分循环机制。[方法]设置增氮(50 kg·hm^(-2)·a^(-1))、减水(30%穿透雨)及其交互处理,进行野外模拟氮沉降和控水试验。使用“抖根法”采集红松(Pinus koraiensis Siebold&Zucc.)和紫椴(Tilia amurensis Rupr.)的根际与非根际土壤样品。[结果](1)增氮和氮加水处理显著降低了土壤pH值,同时增加了土壤铵态氮、硝态氮和总氮含量。(2)增氮处理降低了紫椴根际与非根际土壤微生物量碳、微生物量氮和非根际土壤微生物量磷,降低了红松根际土壤微生物量氮和微生物量磷。减水和氮加水处理则增加了红松和紫椴根际土壤微生物量磷。(3)两个树种的根际土壤养分含量和微生物量均高于非根际,表现出正根际效应;且在增氮和氮加水处理下,红松的土壤总碳、总氮和微生物量的根际效应高于紫椴。(4)根际土壤微生物量主要受硝态氮和土壤含水率的影响,而非根际土壤微生物量由铵态氮、硝态氮和总氮驱动。[结论]本研究揭示了根际与非根际土壤微生物量对氮添加和降水减少的响应机制,以及不同树种根际效应在环境变化中的差异,为未来森林管理与保护提供了科学依据。[Objective]Increased nitrogen deposition and reduced precipitation due to climate change significantly affect the structure and function of forest ecosystems.The rhizosphere as the core area of interaction among plants,soil,and microorganisms plays a pivotal role in ecosystem processes.however,studies on the effects of nitrogen addition and water reduction on rhizosphere microorganisms remain limited.This study aims to explore the soil microbial biomass and the rhizosphere effects of dominant tree species in response to these changes,in order to predict the adaptation strategies and nutrient cycling mechanisms of broadleaf Korean pine forests under climate change.[Methods]Two treatments were established for field simulations of nitrogen addition and water reduction:nitrogen addition(50 kg·hm^(-2)·a^(-1)),water reduction(30%rainfall penetration),and their combination.The"shaking root method"was used to collect rhizosphere and bulk soil samples from Pinus koraiensis and Tilia amurensis.[Result](1)The treatments of nitrogen addition and nitrogen-water combination significantly reduced soil pH while increasing the contents of ammonium,nitrate,and total nitrogen in the soil.(2)Nitrogen addition reduced microbial biomass carbon and nitrogen in both the rhizosphere and bulk soil of Tilia amurensis,and microbial biomass phosphorus in bulk soil.It also decreased microbial biomass nitrogen and phosphorus in the rhizosphere soil of Pinus koraiensis.In contrast,the treatments of water reduction and the combined nitrogen and water reduction significantly increased microbial biomass phosphorus content in the rhizosphere soil of both species.(3)The nutrient content and microbial biomass in the rhizosphere soil of both species were higher than those in the bulk soil,demonstrating a positive rhizosphere effect.Moreover,under the treatments of nitrogen addition and nitrogen-water combination,the rhizosphere effect on total carbon,nitrogen,and microbial biomass was greater in Pinus koraiensis than in Tilia amurensis.(4)Rhizospher

关 键 词：阔叶红松林 土壤微生物量 根际 氮添加 降水减少 

分 类 号：S154.1[农业科学—土壤学]