不同生境下剑叶耳草叶片功能性状及其可塑性对植物生长的影响OA

Most previous researches of plant adaptability to environmental changes were conducted using functional traits at species level.However,one species might display distinct ecological strategies in different habitats.Therefore,it's important to analyze the intraspecific variation of leaf functional traits and their plasticity for understanding the environmental adaption mechanisms and survival status of plant individuals.The present study determined the plant height,biomass and leaf functional traits such as morphological,stomatal,anatomical and chemical characters of medicinal plant Hedyotis caudatifolia from four habitats(grassland,shrub-grassland,forest edge and understory)in Mt.Dayao of Guangxi.Results showed that functional traits varied apparently among different habitats.Among all leaf functional traits,potential conductance index(PCI)exhibited the highest coefficient of variation(CV),while CV of leaf carbon content,looseness of leaf spongy tissue,spongy mesophyll thickness and leaf thickness were lower.Plasticity index(PI)ranked inconsistently with CV for some traits,i.e.potential conductance index displayed the highest PI,followed by mass-based chlorophyll content,leaf area,specific leaf area and ratio of leaf palisade to spongy mesophyll thickness,etc.Principal component analysis(PCA)indicated that the variations of leaf functional traits were closely correlated with light utilization,water conductivity and nutrient strategies,dominated by light adaptation.Analysis of Variable Importance in Projection(VIP)revealed that anatomical structure contributed to the most variances of plant height and biomass,followed by stomatal characters;chemical traits accounted for the least in the contribution rates.The changes of leaf functional traits and their syndromes of H.caudatifolia facilitated itself in utilizing natural environmental resources such as light and water.Thus,it was capable of coping with disadvantages in different habitats,and finally promoted the plant growth and biomass accumulation,which enabled its individuals to compete with other plants in the community for the further survival and reproduction.The study will provide references for the assessment of survival status and safety risk of H.caudatifolia under degraded habitats.