喀斯特峰丛洼地不同植被恢复阶段优势种根系构型特征  

Root Architecture of the Dominant Species in Various Vegetation Restoration Processes in Karst Peak-Cluster Depression

作　　者：苏樑 杜虎[1,3] 王华[2] 曾馥平[1,3] 宋同清[1,3] 彭晚霞[1,3] 陈莉 张芳[1,3] 

机构地区：[1]中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室,长沙410125 [2]湖南农业大学生物科学技术学院,长沙410128 [3]中国科学院环江喀斯特生态系统观测研究站,广西环江547100

出　　处：《西北植物学报》2018年第1期150-157,共8页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家重点研发计划(2016YFC0502405);国家自然科学基金(31400412;31370485;31370623);广西重点研发计划(桂科AB16380255;桂科AB17129009);广西科技惠民项目(桂科转1599001-6);广西特聘专家项目

摘　　要：以喀斯特峰丛洼地不同植被恢复阶段灌丛、次生林、原生林为研究对象,采用全挖法分析了各阶段4个优势种的根系构型参数,探讨该特殊生境条件下植物根系构型的差异性、相似性以及资源合理高效的利用方式。结果表明:(1)各个植被恢复阶段优势种拓扑指数TI均趋向于0.5,呈叉状分支结构,并表现为次生林(0.57)>原生林(0.49)>灌丛(0.46),有利于根系在贫瘠且浅薄的土壤环境中拓展生存空间。(2)3种植被恢复阶段优势种的根系平均连接长度在34.29cm以上,平均为37.01cm,增加连接长度对植物在养分贫瘠的喀斯特土壤环境的生存有利。(3)次生林根系分支率低于灌丛和原生林,这是不同植被恢复阶段优势种对环境所采取的不同适应策略。(4)3种植被恢复阶段优势种根系的横截面积比均符合Leonardo da Vinci法则,且不随直径的变化而变化。(5)3种植被恢复阶段优势种在土壤养分、水分获取及土壤空间拓展方面没有显著差异性。研究认为,在喀斯特峰丛洼地异质性很强的生境下,3种植被恢复阶段优势种的根系均为叉状分支结构,且均以较长的连接长度和较低的分支率策略适应其特殊的生态环境。This study focused on the parameters of root architecture among four dominant species at three different stages of vegetation succession in a Karst peak-cluster depression by the method of whole digging sampling.（1）Root forms forked branches and the topological index（TI）tends to close to 0.5 with thesecondary forest 0.57,the primary forest 0.49 and the shrub 0.46.It is indicated that forked branches are beneficial for root to expand living space in poor and shallow soil.（2）The average root length of the dominant species in three various vegetation restoration was 37.01 cm,all above 34.29 cm.The increasing of connection length is beneficial for plants to survive better in nutrient-poor Karst soil.（3）Due to different adaptative strategies of plants under different succession stages,the root branching rate in secondary forest is lower than that in shrub and primary forest.（4）The area of the cross sections under the dominant species in three succession stages conform with the Leonardo da Vinci theory and do not change with diameter of branches.（5）There was no significant difference in soil nutrient,moisture acquisition,and soil space expansion among three vegetation restoration processes.It suggested that the same ecological adaptation strategies that root forms forked and longer root link length,lower branching rate were adopted under the dominant species in three succession stages despite the high variability in Karst peak-cluster depression.

关 键 词：根系构型 拓扑指数 Leonardo DA Vinci法则 根系连接长度 喀斯特 

分 类 号：Q944.3[生物学—植物学]