喀斯特地貌人工林群落特征.doc

贵州喀斯特地区人工林群落特征 及养分循环规律 摘要：贵州山地造林困难立地主要集中在岩溶地质地区，特殊的自然地理属性决定了植被恢复的可能性和造林的困难程度。本文用空间代替时间的方法，调查和分析了贵州典型喀斯特山区退耕还林工程区不同林龄的香椿（Toona sinensis）、楸树（Catalpa bungei）和滇柏（Cupoessus duclouxiana）3种人工林的植被基本特征、林下土壤质量和各树种器官养分含量，研究各树种的生态特性和养分循环规律，初步探讨了喀斯特造林困难立地的植被退化机理和恢复措施。3种人工林中的研究结果表明：（1）楸树林的总生物量大，各器官养分含量较其他两树种大，有较好的保肥含养能力，养分转移利用率高，且对钾的积累相对最高；（2）香椿林无性繁殖能力强，林下土壤理化性质较楸树、滇柏林好，且对氮的需求量大，养分转移能力比滇柏强；（3）滇柏林适应性强，能较好地生长于富钙缺磷的薄层土上，体内养分含量比其他两个阔叶树种小，养分转移率小，体内大量积累了钙素，有利于调节碱性土pH。作者认为，综合立地条件与树种特性等因素，以合理配置针阔或乔灌混交林，有利于促进植被的恢复。 关键词：喀斯特；人工林; 养分循环; 植被恢复 The characteristics and nutrient cycle of different plantations in Guizhou Karst area Abstract: The difficult regions for afforestation in Guizhou province were mainly concentrated in Karst rocky mountain, where special natural geographical characters determine the possibility and difficulty of vegetation recovery. By means of the substitution of space for time, the soil propertities, vegetation characteristics and nutrient content of three plantation species were studied. Based on their nutrient cycle and ecological characters of different species, the vegetation degeneration causes and recovery methods of the Karst rocky area were discussed. Main results were as follows:(1)Catalpa bungei forest with high nutrient carrying capacity had the biggest gross biomass, high nutrient content ,nutrient transfer rate and relatively high K accumulation.(2)Toona sinensis with high asexual reproduction rate had a high demand for N, higher transfer rate than Cupoessus duclouxiana and the soil quality under its forest was better than those of the other two. (3)Cupoessus duclouxiana had better fitness for the poor soil, low nutrient content and transfer rate and its high Ca accumulation improved soil condition. (4)Finally, reasonable mix of different species with consideration of site factors and ecological characters would facilitate karst vegetation restoration. Key words: Karst; plantation; nutrient cycle; vegetation restoration 目 录 1前言………………………………………………………………