文献类型：期刊文献

中文题名：生境异质性对金沙江干热河谷锥连栎天然更新幼苗早期生长的影响

英文题名：Effects of Habitat Heterogeneity on Early Growth of Quercus franchetii Natural Regeneration Seedlings in the Jinsha River Dry-hot Valley

作者：刘方炎[1,2] 张志翔[1] 王小庆[2] 李昆[2] 孙永玉[1] 张春华[2]

第一作者：刘方炎

机构：[1]北京林业大学生命科学与技术学院,北京100083;[2]中国林业科学研究院资源昆虫研究所,国家林业局元谋荒漠生态系统定位观测站,昆明650224

年份：2011

卷号：17

期号：3

起止页码：338-344

中文期刊名：应用与环境生物学报

外文期刊名：Chinese Journal of Applied & Environmental Biology

收录：CSTPCD;;Scopus;北大核心:【北大核心2008】；CSCD:【CSCD2011_2012】；

基金：国家科技支撑计划项目(Nos.2011BAD38B04,2006BAD03A03)资助~~

语种：中文

中文关键词：金沙江;干热河谷;生境异质性;锥连栎;天然更新;幼苗

外文关键词：Jinsha River; dry-hot valley; habitat heterogeneity; Quercus franchetii; natural regeneration; seedling

分类号：S792.180.2

摘要：锥连栎林是金沙江干热河谷仅有的几种重要天然植被之一,由于恶劣的气候环境以及长期严重的人为干扰作用,林地生境破碎化程度较高,幼苗天然更新极为困难.分析了锥连栎林更新幼苗主要生长的落叶堆积洼地、落叶堆积平地、菁沟冲积台地和缓坡草丛等4种微生境特点,并比较研究了不同微生境下天然更新幼苗生长的形态特征、生物量分配以及幼苗生存状况.结果表明：1）锥连栎天然更新幼苗生长的4种微生境,在土层厚度、枯落物厚度以及不同季节尤其是旱季时表层土壤水分含量上均存在明显差异,在定居幼苗数目上,落叶堆积洼地〉菁沟冲积台地〉落叶堆积平地〉缓坡草丛.2）不同微生境下天然更新幼苗形态特征的差异主要表现在苗高、主根长度以及比叶面积,地径和叶片数目等差异不显著,其中,生长在落叶堆积洼地上的锥连栎幼苗的苗高、地径、主根长以及叶片数均为4种微生境中最高,而生长在缓坡草丛中的幼苗均为最小.落叶堆积洼地上幼苗的比叶面积最大,缓坡草丛的最小.3）不同微生境下幼苗地上部分、地下部分、根茎比以及植株生物量干重均存在极显著差异,其中,根茎干重比为缓坡草丛〉菁沟冲积台地〉落叶堆积平地〉落叶堆积洼地,而全株干重为落叶堆积洼地〉落叶堆积平地〉菁沟冲积台地〉缓坡草丛.4）不同微生境下幼苗经过旱季以后的生存状况表现出了明显的差异,有69.2%~95.2%的幼苗出现不同程度的死亡、茎干或叶片枯萎现象,其中,菁沟冲积台地上幼苗死亡比例最高,达到了64.3%,缓坡草丛中幼苗死亡比例最低,为23.1%.以上结果表明,落叶堆积洼地和落叶堆积平地是锥连栎林下幼苗定居相对较为理想的微生境;缓坡草丛上虽然幼苗定居较为困难,但一旦定居成功,其成活机率较大;菁沟冲积台地上能够聚积较多种子,从而形成较多幼苗,但由于土层薄,保水性能差,旱季时幼苗容易大量死亡.
Quercus franchetii forest is one of the very important natural vegetations in dry-hot valley of the Jinsha River,China.Now it is very difficult for seedling natural regeneration because of serious habitat fragmentation resulting from bad climatic environment and long-term serious human disturbance.Seedlings in the Q.franchetii forest are mainly located at low land covered by litter（LLCL）,flat ground covered by litter（FGCL）,terrace along water ditch（TAWD） and grassland in gentle slope（GGS）.To know the seedling growth characteristics in different microhabitats and the best microhabitat for seedlings to settle down in natural forests,the characteristics of the four microhabitats were investigated,and the morphological characteristics,biomass allocation and survival status of the seedlings growing in different micro-habitats were studied comparatively.The results showed that there were obviously different among 4 microhabitats in depth of soil and defoliation,and surface soil water content in different seasons,especially in dry season.Of number of seedlings,LLCL TAWD FGCL GGS.Of seedling morphologic characteristics,significant differences were mainly in seedling height,main root length and specific leaf area（SLA）,while slight differences in basal diameter and number of leaves.The seedlings growing in LLCL and GGS respectively had the maximum and the minimum values of seedling height,basal diameter,main root length and number of leaves.Of SLA,LLCL TAWD FGCL GGS.There were extremely significant differences among different microhabitats in dry biomasses of seedlings,aboveground and underground parts,ratios of root and stem.Of ratio of root and stem,GGS TAWD FGCL LLCL,and of dry biomass of seedlings,LLCL FGCL TAWD GGS.There was obviously different among different microhabitats in survival status of the seedlings in dry season,and the dead seedlings and stem-or leaf-withered seedlings occupied 69.2%~95.2%.The number of dead seedlings at TAWD was the highest（64.3%）,and that at GGS the lowest（23.1%）.In summary,LLCL and FGCL were the best microhabitats for Q.franchetii seedlings growing.It was very difficult for seedlings growing in GGS,but they would be well survived if germinating.The seeds could accumulate at TAWD,but the seedlings might be dead in dry season because of thin soil layer with weak water retention.Fig 2,Tab 7,Ref 22