摘要
【目的】研究秦岭中段红桦(Betula albo-sinensis)次生林的更新特征,为红桦林的近自然恢复提供理论依据。【方法】应用典型样地法,调查红桦次生林的更新状况,分析林下木本植物更新特征及生物和非生物因子对其的影响。【结果】更新层共有木本植物59种,其中乔木树种有25种,占所有木本植物总数的42.4%。更新的木本植物中以灌木种居多,优势种有箭竹(Fargesia spathacea)、悬钩子(Rubus corchorifolius)等,红桦在群落更新层中的优势地位不明显。红桦次生林木本植物幼苗在40～60cm高度级内数量最多,0～20cm高度级内分布很少。林下木本植物的更新方式以萌生为主。林分密度对木本植物幼苗、幼树更新密度的影响相似,即其更新密度均随着林分密度的增加呈先增加后减少的趋势。阳坡(南偏西40°)利于幼树生长,随着坡向转为阴坡,幼苗密度逐渐增加,而幼树密度呈不同程度的减少。海拔对红桦次生林林下木本植物的更新也有明显影响,当海拔从1 825m增加到2 449m时,幼苗密度下降,幼树密度增大;但当海拔增加到2 467m时,幼苗密度增加,幼树密度减少。【结论】秦岭中段的红桦次生林处于演替后期,林分更新能力较差。
[Objective] This paper focused on regeneration characteristics of the Betula albo-sinensis secondary forests in the middle range of Qinling Mountains, to provide theoretical reference for the near-na- ture recovery of Betula albo-sinensis forests. [Method] By the typical sample plots method,we investigated the regeneration of the Betula albo-sinensis secondary forests, analyzed regeneration characteristics of un- derstory woody plant and the impacts from the biotic and abiotic factors. [Result] There were 25 arbor tree species,accounting for 42.4% of all 59 woody species in regenerational layer. Shrubs were the majority spe- cies among the regeneration woody plant and the dominating species were Fargesia spathacea ,Rubus cor- chorifolius, ect. Dominance of Betula albo-sinensis in the community renewal layers was not obvious. The maximum of secondary forest woody plant seedlings of Betula albo-sinensis was in the class of 40--60 cm height while there was much less in the class of 0--20 cm height. The main regeneration type in understory was sprouting. The effects of stand density on saplings and seedlings density were similar,i, e. both of them increased initially and declined after the peak as the stand density increased. Saplings benefited from sunny slope（SW40°）. The seedlings density increased but sapling density decreased inordinately as the direction changed to shady slop. There were various effects of altitude on Becula albo-sinensis secondary forests reL generation woody plant. When the altitude rose up from 1 825 m to 2 449 m,the density of seedlings de- creased gradually, while the density of saplings increased. The density of saplings decreased and the density of seedlings increased when the altitude increased to 2 467 m. [Conclusion] Betula albo-sinensis secondary forests in the middle range of Qinling Mountains are in the late stage of succession,the regeneration of tree species is not intensive.
出处
《西北农林科技大学学报（自然科学版）》
CSCD
北大核心
2013年第1期163-169,共7页
Journal of Northwest A&F University(Natural Science Edition)
基金
国家林业公益性行业科研专项(200804022B)
国家自然科学基金项目(31070570)
国家科技基础性专项重点项目(2007FY110800)
关键词
秦岭山地
红桦次生林
更新特征
林分密度
环境因子
Qinling Mountains
Betula albo-sinensis secondary forests
regeneration characteristics
stand density
environmental factor
