两种一年生草本对喀斯特土壤厚度及供水的生长响应  

Growth response of two annual herbs to karst soil depth and water supply

作　　者：李素慧 陈金艺 王佳敏 宋海燕[1] 张静[1] 陶建平[1] 刘锦春[1] Li Su-Hui;Chen Jin-Yi;Wang Jia-Min;Song Hai-Yan;Zhang Jing;Tao Jian-Ping;Liu Jin-Chun(Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, China)

机构地区：[1]三峡库区生态环境教育部重点实验室,重庆市三峡库区植物生态与资源重点实验室,西南大学生命科学学院,重庆400715

出　　处：《植物科学学报》2021年第3期258-267,共10页Plant Science Journal

基　　金：国家自然科学基金项目(31500399)。

摘　　要：以一年生草本苍耳(Xanthium sibiricum Patrin ex Widder)和鬼针草(Bidens pilosa L.)为材料,模拟喀斯特地区不同土壤厚度以及不同水分处理,研究了两者的形态及生物量积累与分配特征。结果显示:资源减少(供水、土壤厚度及供水+土壤厚度)3种处理均抑制了植物的生长,植物生物量积累显著减少,对根和叶的投资比均未下降,而对茎的投资比显著下降;供水量减少对两者的根冠比、根长及比叶面积均无显著影响,而在土壤厚度下降及供水量与土壤厚度同时下降时,根冠比、根长与比叶面积均显著增加。研究结果表明,土壤厚度降低对2种草本植物的负面影响大于供水降低的影响。资源轻度降低时,植物以牺牲茎投资为代价保持对根和叶的稳定投资,从而保证对水分的吸收和光合合成;资源严重降低时,植物通过增加比根长等地下系统的投资以对抗地下环境压力的加剧。The morphology,biomass accumulation,and distribution characteristics of Xanthium sibiricum Patrin ex Widder and Bidens pilosa L.were studied under simulated karst habitats with different soil depths and water availability.Results showed that decreased resources(i.e.,water supply,soil depth,and water supply+soil depth)inhibited plant growth.The biomass accumulation and stem investment ratio of both plants decreased significantly.The decrease in water supply had no significant effect on the root-shoot ratio,root length,or specific leaf area of the species,whereas the root-shoot ratio,root length,and specific leaf area of both species increased significantly with the decrease in soil depth and water supply+soil depth.Results also showed that the inhibition effect of reduced soil depth on plant growth was greater than that of reduced water supply.When resources were slightly reduced,the root and leaf investment ratios were stable at the expense of stem investment to ensure water absorption and photosynthesis.When resources were severely reduced,plants countered the increased pressure of the underground environment by investing in underground systems,e.g.,increasing specific root length.

关 键 词：岩溶干旱 土壤浅薄 植物功能性状 权衡 

分 类 号：Q945[生物学—植物学]