塞罕坝华北落叶松人工林天然更新影响因子  

Factors affecting natural regeneration of Larix principis-rupprechtii plantations in Saihanba of Hebei,China

作　　者：张树梓[1,2] 李梅[3] 张树彬[2] 张志东[2] 黄选瑞[2] 

机构地区：[1]中国林业科学研究院,森林生态环境与保护研究所,北京100091 [2]河北农业大学林学院,保定071000 [3]中国林业科学研究院资源信息研究所,北京100091

出　　处：《生态学报》2015年第16期5403-5411,共9页Acta Ecologica Sinica

基　　金：国家十二五科技支撑计划(2012BAD22B0304);国家自然科学基金项目(31370636)

摘　　要：为了探讨影响塞罕坝地区华北落叶松(Larix principis-rupprechtii)人工林天然更新的关键因子,基于两个龄级(Ⅲ龄级,20—30a、Ⅳ龄级,30—40a)共计18块(50m×50m)华北落叶松人工林标准地的调查资料,采用冗余度分析法(RDA)对标准地中不同高度等级华北落叶松更新苗密度与环境因子之间的关系进行了分析,并运用偏冗余度分析法(partial RDA)对影响林分更新的土壤-枯落物因子、林分结构因子进行了定量分解。结果表明:(1)土壤-枯落物因子是影响该地区华北落叶松人工林林分更新的关键因子。(2)Ⅲ龄级林分更新主要影响因子有林分密度、土壤有机质含量、土壤速效磷、土壤碱解氮含量和枯落物厚度;Ⅳ龄级林分更新主要影响因子有枯落物厚度、土壤全钾、林分密度、土壤p H值和基面积。两个龄级林分更新都表现出高个体数,低成活率的现象,枯落物厚度是造成这种现象的主要因素。(3)Ⅲ龄级林分更新苗在早期生长中受土壤-枯落物因子限制比较大,而后林分结构因子逐渐成为主要的限制性因子;在Ⅳ龄级林分中,除基面积外的林分结构因子与5个高度等级更新苗密度呈正相关。The Larix principis-rupprechtii plantation, which is the dominant forest type in Saihanba, Hebei Province, accounts for 70.6% of the total forest area. However, natural regeneration in the L. principis-rupprechtii plantation is extremely poor due to the low seedling and sapling recruitment rate. Exploring the limiting factors that affect the natural regeneration and growth of L. principis-rupprechtii seedlings in stands of different ages is not only urgent but also important for forest management and natural resource conservation. In this study, we conducted a field vegetation survey and collected environmental samples （soil and litter） from 18 plots （50 m × 50 m） of two age classes （ Ⅲ age class, 20--30 year-old stand; Ⅳ age class, 40--30 year-old stand）. Redundancy analysis （RDA） and partial RDA were applied to study the relationship between the density of naturally recruited seedlings and environmental factors, and the relative importance of soil-litter and stand structure factors, respectively. Our objective was to answer the following questions ： （ 1 ） What is the dominant factor affecting natural regeneration in the L. principis-rupprechtii plantation？ （2） Are there any differences infactors affecting the natural regeneration of L. principi-rupprechtii in two stands of different ages？ （3） Is there any change in the relative importance among environmental factors affecting the growth of L. principis-rupprechtii seedlings in different growth stages？ Our results showed that ： （ 1 ） soil-litter factors played a dominant role in the natural regeneration of L. principis-rupprechtii. The total variance explained by soil physical-chemical properties and litter was more than 55%. On the contrary, the effect of pure stand structure was relatively weak ; （2） the dominant factors that affect the natural regeneration of L. principis-rupprechtii in stands of two age classes were different. For stands of the Ⅳ age class, the main factors affecting stand regeneration wer

关 键 词：天然更新 RDA 因子分解 华北落叶松 人工林 

分 类 号：S791.22[农业科学—林木遗传育种]