桂西北干热河谷区不同林龄香合欢天然次生林土壤理化性质分析  

Analysis on Soil Physical and Chemical Properties of Natural Secondary Forests of Albizia odoratissima at Different Ages in Dry-hot Valley of Northwest Guangxi

作　　者：欧汉彪 王丰胜 韦铄星[1] 吴建律 高风 韦秋思 李成星 郭宏祥 涂茂粟 Ou Hanbiao;Wang Fengsheng;Wei Shuoxing;Wu Jianlü;Gao Feng;Wei Qiusi;Li Chengxing;Guo Hongxiang;Tu Maosu(Guangxi Forestry Research Institute,Key Laboratory of National Forestry and Grassland Administration on Cultivation of Fast-Growing Timber in Central South China,Nanning,Guangxi 530002,China;Guangxi State-owned Yachang Forest Farm,Baise,Guangxi 533099,China)

机构地区：[1]广西壮族自治区林业科学研究院中南速生材繁育国家林业和草原局重点实验室,广西南宁530002 [2]广西壮族自治区国有雅长林场,广西百色533099

出　　处：《广西林业科学》2023年第3期297-304,共8页Guangxi Forestry Science

基　　金：广西林业科技项目(桂林科研[2022ZC]第105号);广西重点研发计划项目(桂科AB21220026)。

摘　　要：香合欢(Albizia odoratissima)为我国干热河谷区植被恢复的先锋树种,研究其天然次生林群落演替进程对干热河谷区植被恢复有重要意义。为促进干热河谷区植被恢复和香合欢树种发展,以不同林龄(幼龄林、中龄林和成熟林)香合欢天然次生林为研究对象,以时间换空间,分析香合欢天然次生林群落演替过程中土壤理化性质的变化特征,了解干湿两季对土壤理化性质的影响。结果表明,土壤pH值和容重均随林龄增加呈逐渐下降趋势,均在成熟林中最低;总有机碳、全氮、全磷和速效氮含量均随林龄增加呈先升后降的趋势,均在中龄林中最高;雨季土壤pH值、总有机碳、全氮、速效氮和铵态氮含量均高于旱季;旱季土壤硝态氮含量高于雨季;林龄和季节对土壤理化性质均有一定影响。回归分析表明,土壤容重为影响林分丰富度和多样性指数的重要因子。在香合欢天然次生林更新过程中,土壤养分总体呈先升后降的趋势,在中龄林中最高。在香合欢幼龄林中,土壤养分含量较低,但植株生长速度较快,需消耗大量营养物质,应加强对香合欢幼龄林的抚育管理,在旱季增加水分供给,提高土壤养分含量。Albizia odoratissima is pioneer for vegetation restoration in dry-hot valley of China.Studies on com⁃munity succession process of its natural secondary forest is of great significance for vegetation restoration in dry-hot valley.In order to improve vegetation restoration in dry-hot valley and development of A.odoratissima,taking natural secondary forests at different ages(young forest,half-mature forest,mature forest)as objects,change characteristics of soil physical and chemical properties during community succession of A.odoratissima natural secondary forests were analyzed by exchanging time to space.Effects of wet and dry seasons on soil physical and chemical properties were studied.Results showed that soil pH and bulk density decreased gradual⁃ly with increase of age,which were the lowest in mature forest.Contents of total organic carbon,total nitrogen,total phosphorus and available nitrogen increased firstly and then decreased with increase of age,which were the highest in half-mature forest.Soil pH,contents of total organic carbon,total nitrogen,available nitrogen and ammonium nitrogen at rainy season were higher than those at dry season.Contents of nitrate nitrogen at dry sea⁃son were higher than those at rainy season.Age and season had certain effects on soil physical and chemical properties.Regression analysis showed that soil bulk density was important factor affecting richness and diversi⁃ty indexes of stands.During regeneration of A.odoratissima natural secondary forest,total soil nutrient in⁃creased firstly and then decreased,with the highest content in half-mature forest.In A.odoratissima young for⁃est,soil nutrient content was low,but growth speed of plants was fast which needed to consume a lot of nutri⁃ents.It was necessary to strengthen tending management of A.odoratissima young forests,increase water supply in dry season,and improve soil nutrient contents.

关 键 词：土壤理化性质 香合欢 干热河谷 天然次生林 

分 类 号：S792[农业科学—林木遗传育种]