摘要
喀斯特石漠化是我国西南地区最严重的地质灾害,其生境对植物的强烈胁迫作用阻碍了石漠化环境的恢复,在胁迫作用更为强烈的地区,木本植物并不能作为先锋物种,因此草本植物对环境的初步改良作用将起到很大的作用.在重庆不同程度的石漠化地区,均能发现矛叶荩草生存,因此确定矛叶荩草是石漠化环境适生种之一.该文通过研究不同石漠化程度下矛叶荩草茎形态的特征,分析了矛叶荩草茎对石漠化生境的适应策略,以期为喀斯特植被恢复及管理提供依据.实验结果表明:随着石漠化程度加深,矛叶荩草主茎及侧枝相关指标整体呈现出先降低后升高的趋势.分3个阶段:潜在石漠化阶段,轻度石漠化、中度石漠化阶段,重度石漠化、极度石漠化阶段.影响主茎长度的主要因子是主茎的节间长度,影响侧枝长度的主要因子是节间数,侧枝分枝格局显示随着石漠化程度加深,矛叶荩草倾向于产生更多的分枝.因此,矛叶荩草对石漠化生境具有较强的生存能力,其适应策略是随着石漠化程度加深,矛叶荩草生境从乔灌木群落过渡到草本群落,矛叶荩草主茎产生更多的较长节间以储备营养物质,而侧枝产生更多的较短节间增加侧枝的物理支撑能力,达到增加叶片附载的目的,增强光能的利用,尽管侧枝主要功能是增加叶片附载,但在营养储备功能上与主茎互补.
Karst rocky desertification is the most serious geological disaster in Southwest China.In Karst rocky areas,we found plants species are poor because of intensive stresses given to plants.And these factors hinder the revegetation of Karst rocky area.In the regions which receive intense stress,woody plants do not grow very well because they are not given suitable conditions from the soil habitats.With these features of the rapid growth cycle,simple growth condition and ameliorating soil habitat,herb will plays important role to ameliorate Karst rocky habitat.Based on the investigation of the vegetation,we found Arthraxon hispidus can survive in 5different degrees rocky desertification habitats,so we argued Arthraxon hispidus is suitable specie in Karst rocky areas.The paper studied Arthraxon hispidus stems morphological characteristics in 5different degrees of rocky desertification habitats,and analyzed adaptation strategies to rocky desertification habitats.In the last,we wished the paper can offer theoretical basis to restoration and management rocky areas.We analyzed the morphological data of main stem and lateral branches,we found the main stem and the main stem internodes becomes longer and coarser from in slight rocky desertification habitat to in extreme rocky desertification habitat.Branches number is increasing,and branches also become longer and coarser.But branches tend to produce shorter internodes and more nodes.In latent rocky desertification habitat,the main stem is longer and coarser than the main stems in slight rocky desertification habitat and medium rocky desertification habitat.And branches also show these feature.So we argued Arthraxon hispidus is more suitable for more serious rocky areas.And the adaptation strategies were summarized as:with the deepening of rocky desertification degree,the main stem produce more lengthier internodes to store nutrients to cope with less soil nutrients;with the change of vegetation types(Arbor community into herbaceous community),Arthraxon hispidus has stro
出处
《西南大学学报（自然科学版）》
CAS
CSCD
北大核心
2016年第11期40-49,共10页
Journal of Southwest University(Natural Science Edition)
基金
国家自然科学基金(30670334/C0309)
关键词
喀斯特石漠化
矛叶荩草
主茎
侧枝
适应策略
Karst rocky desertification
Arthraxon hispidus
main stem
lateral branches
adaptation strategies
