喀斯特弃耕地草本植物根茎叶经济型谱间协调及其对极端降雨的响应  

Coordination of root,stem,and leaf economic spectrum of herbaceous plants and their response to extreme rainfall in karst abandoned farmland

作　　者：昝瑛 马竟文 索朗玉珍 余钰淋 万玛吉 袁佳佳 陶建平 ZAN Ying;MA Jingwen;Suolangyuzhen;YU yulin;WAN Maji;YUAN Jiajia;TAO Jianping(School of Life Sciences,Southwest University,Key Laboratory of Eco-environments in Three Gorges Reservoir Region(Ministry of Education),Chongqing 400715,China)

机构地区：[1]西南大学生命科学学院,三峡库区生态环境教育部重点实验室,重庆400715

出　　处：《生态学报》2024年第9期3676-3688,共13页Acta Ecologica Sinica

基　　金：重庆市科委自然科学基金项目(cstc2020jcyj-msxmX0244)。

摘　　要：植物功能性状之间的关系是反映植物在资源获取和资源保守策略之间权衡的有力指标。喀斯特是全球最脆弱的陆地生态系统之一,其中的植被长期遭受干旱的胁迫,对极端天气和极端降水高度敏感。在降雨极端化的背景下,喀斯特地区植物生态策略的变化还不得而知。以西南喀斯特弃耕地演替初期群落中12种草本植物为对象,通过保持年降水量不变,人为控制单次降水量以及降水频率,以自然降雨为对照组(CK),设置中雨频率增强处理组(T10),大雨频率增强处理组(T25)和暴雨频率增强处理组(T50)3个处理组。模拟在全球变化导致的降雨极端化情境下,研究植物根茎叶功能性状的响应特征及经济型谱之间的关系。主要结果如下:(1)根茎叶的功能性状对降雨极端化的响应不同,其中根的理论导水率随着降雨极端化增强而增加,而茎和叶的理论导水率仅在T25增加,根茎叶三种器官中对降雨极端化最敏感的是茎;(2)根茎叶各器官均有自身稳定的“快-慢”经济型谱。降雨极端化仅T50的植物会选择介于资源获取和资源保守策略之间稳定的经济型谱;(3)不同植物器官之间的经济型谱的协调并不一致,其中茎根经济型谱之间的相关系数在三个处理组中均变大,而叶根经济型谱之间的相关系数仅在T25变大,叶茎经济型谱之间的相关系数仅在T10变大。总之,喀斯特弃耕地演替初期群落中草本植物的根茎叶有自身稳定的经济型谱,降雨极端化导致了以根茎叶经济型谱所反映的植物地上和地下资源保存和获取策略的解耦;本研究中的植物最容易发生功能性状变异的器官是茎。本研究提高了对植物不同器官各功能性状之间关系和植物地上与地下部分关联性的理解,揭示了植物不同器官的“快-慢”植物经济型谱以及由此反映的植物适应能力的差异和功能策略的多样性,促进了对植物资源获取与The relationship between plant functional traits is a powerful indicator of the tradeoff between resource acquisition and resource conservation strategies.Karst is one of the most vulnerable terrestrial ecosystems in the world,where vegetation has been stressed for a long time by drought and was highly sensitive to extreme weather and extreme precipitation.Under the background of extreme rainfall,the changes of plant ecological strategies in karst areas are still unknown.Therefore,in this study,herbaceous plants in the early succession stage of karst abandoned farmland community in southwest China were selected as the research object.Under the condition that annual precipitation remained unchanged,four treatment groups were set up by artificially controlling the size and frequency of single precipitation.Natural rainfall was used as the control group(CK),and three treatment groups were set up:moderate rain frequency enhancement group(T10),heavy rain frequency enhancement group(T25),and rainstorm frequency enhancement group(T50).We simulated the treatment of rainfall extreme in order to study the relationship between the response characteristics of functional traits of plant roots,leaves,stems and the the relationship between economic spectrum.The main results are as follows:(1)the responses of functional traits of roots,leaves,stems to rainfall extremes were different.The theoretical hydraulic conductivity of roots increased with rainfall extremes,while the theoretical hydraulic conductivity of stems and leaves increased only in heavy rain frequency enhancement group.Stems were the most sensitive organ in plants to rainfall extremes.(2)Each organ of roots,stems,and leaves had its own stable“fast⁃slow”economic spectrum.In the rainfall extreme treatment,only the ecological strategies of plants in rainstorm frequency enhancement group changed,that is,plants would choose a stable economic spectrum between resource acquisition and resource conservation strategies.(3)Roots,stems,and leaves showed similar and stab

关 键 词：降雨格局变化 植物 经济型谱 喀斯特 

分 类 号：Q948[生物学—植物学]