大兴安岭火后演替初期森林土壤磷的动态变化特征  

Dynamic characteristics of forest soil phosphorus in the early succession after fire in Great Xing'an Mountains

作　　者：孔健健[1] 张亨宇 荆爽 

机构地区：[1]沈阳师范大学生命科学学院,沈阳110034

出　　处：《生态学杂志》2017年第6期1515-1523,共9页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(41501200);森林与土壤生态国家重点实验室开放基金项目(LFSE2015-05);沈阳师范大学生态环境中心主任基金项目(EERC-P-201501);沈阳师范大学科学技术研究项目资助

摘　　要：林火是北方针叶林生态系统最重要的自然驱动力,影响元素的生物地球化学循环。火后演替初期(<15年)是决定火后植被结构与功能恢复的关键时期,火后土壤养分的变化是影响火后植被结构与功能恢复的重要因子。本文选择大兴安岭呼中自然保护区火烧迹地作为研究对象,并选择附近未火烧区作为对照区,分析了火后1、5和11年土壤矿物层总磷含量及有效磷供给速率的变化。结果表明:相较于对照区,火后1年,土壤总磷(TP)含量与有效磷供给速率均显著增加,其中TP显著增加了55%,有效磷含量增加了270%;且土壤TP含量、有效磷供给速率均与林火烈度呈显著正相关。火后5和11年时,土壤TP含量仍显著高于对照区,但土壤TP含量与林火烈度间不存在显著相关关系。而在火后11年时,土壤有效磷供给速率则已恢复至火前水平。土壤TP、有效磷供给速率则均与土壤水分含量之间存在显著正相关关系。本研究显示,火后演替初期土壤磷含量表现为火后立即增加,然后随火后时间增加而逐渐减少;林火烈度在短期内对土壤磷含量具有重要影响,随演替时间增加,土壤性质则成为影响土壤磷含量的重要因子。Fire is an important driver in boreal forest ecosystems, and deeply affects biogeochem- ical processes. The early succession after fire （ 〈15 years） is a critical period influencing recovery of post-fire vegetation structure and functions that are impacted by changes of soil nutrients after fire. In this study, we investigated the dynamic characteristics of forest soil phosphorus （P） in an unburned control and burned sites dating 1-year-post-fire, 5-year-post-fire and 11-year-post-fire, respectively at Huzhong Natural Reserve in the Great Xing＇ an Mountains of Northeastern China. Our results showed that wildfire immediately caused great increases of soil total P （TP） and available P supply rates, with increasing 55% and 270% respectively, compared to control plots. Such increases had significant positive relationships with fire severity. In the 5-year and 11-year post-fire plots, soil TP concentrations were still higher than those in the control plots. However, we did not find the significant relationship between soil TP and fire severity. In the 11-year-post- fire plots, soil available P supply rates recovered to pre-fire levels. Soil rip and available P sup- ply rates were significantly positively correlated to soil water content. This study indicated that soil P increased immediately after fire and then gradually decreased with time extension of last fire. Fire severity can exert important effects on soil P in the short term, but soil property may become a critical factor influencing soil P with succession.

关 键 词：林火 土壤 磷 林火烈度 兴安落叶松 

分 类 号：S714.2[农业科学—林学]