Fire-adapted Traits And Life History Strategy Of Common Fagaceae Plants In Central Of Yunnan

Fire plays an important role in the formation of biodiversity in central of Yunnan.Fagaceae is an important species in the semi-humid evergreen broad-leaved forest in central of Yunnan.In order to investigate whether fire disturbance affects it,in this study,we choose the close relative species of Fagaceae plants with Quercus glaucoidis & Q.glauca,Castanopsis delavayi & C.Sclerophylla,Q.delavayi &Q.gilva,and the same species of Fagaceae plants with Q.acutissima and Q.variabilis in different fire conditions.the survey area includes 26 sample sites in Yunnan Province,Hubei Province,Hunan Province,Fujian Province,and Zhejiang Province.Fire-adapted traits of Fagaceae species in different fire conditions were collected and measured,based on the results of differences fire-adapted traits and PCA,proposed fire-adapted life history strategies of Fagaceae species.The main results of this study were as follows:(1)The results of flammability traits show that litters in the high-fire area of central Yunnan have a low ignition point,high calorific value,and low ash content,which is more flammable than litter in the low-fire area of Eastern China;while bark has a high burning point,high calorific value,and low ash content,indicating that the bark has stronger fire resistance;(2)The results of protective traits show that the relative bark thickness of Fagaceae plants in the high fire area of central Yunnan are significantly higher than that of Fagaceae plants in the low fire area of the Eastern China(P<0.001),and outer bark of Fagaceae plants in the high fire area of central Yunnan are significantly higher than that of Fagaceae plants in the low fire area of the Eastern China(P<0.05).Linear regression analysis of the relationship between the DBH diameter and bark thickness can be seen,when at the same DBH level,species in the high fire area of central Yunnan appear thicker bark than species in the low fire area of the Eastern China;(3)The results of physiological traits show that most of the species in the high-fire area of central Yunnan have thicker leaves,smaller specific leaf area,greater leaf density,leaf dry matter content,and greater wood density,The traits of leavesshowed adaptability to flammable areas and droughts,and higher wood density indicated that species in central of Yunnan grew more slowly.(4)The results of germination show that the species of shoots and rates of germination in central of Yunnan are higher,and the phenomenon of germination is more common;in addition,the flammable habitat in central of Yunnan is verified by comparing the soil samples with carbon debris in the two places.(5)Through the regression analysis of fire-adapted traits and fire weather indices,it was found that relative bark thickness,leaf dry matter content were significantly positively correlated with Fire weather indices(P<0.01).Leaf thickness,leaf density,and wood density were significantly positively correlated with fire weather indices(P<0.05).The ignition points of litters were significant negatively correlated with fire weather indices(P<0.01).Specific leaf area were significant negatively correlated with fire weather indices(P<0.05).(6)The results of principal component analysis show that the presence of fire factors affects the changes in the properties of Fagaceae in central Yunnan and Eastern China.The differences of fire-adapted traits between species were adaptive to differences in fire regime in their distribution areas.The research results show that there were obvious differences in the fire adaptability characteristics of the family of Fagaceae species in the high fire area of central Yunnan and the low fire area of the Eastern China.Family species,Fagaceae species in the high-fire area of central Yunnan are more inclined to fire-tolerators fire-adapted life history strategy,which was conducive to their survival and reproduction in the frequent occurrence of forest fires in central of Yunnan.The results of the study support the original hypothesis that the fire factor has an effect on the evolution of the species of Fagaceae in central of Yunnan.