Understanding the impact of rock bareness on the transpiration in karst plants is essential to karst rocky desertification control and sustainable management of plantation in karst area.This study focused on the varia...Understanding the impact of rock bareness on the transpiration in karst plants is essential to karst rocky desertification control and sustainable management of plantation in karst area.This study focused on the variations in sap flow of Zenia insignis caused by different rock bareness rate,and the impact of climate factors,soil water content(SWC)and leaf area index(LAI) on transpiration in karst plants,by continuously measuring sap flux densities (Fcd)of 12 sample trees using thermal dissipation probes and monitoring micrometeorology and SwC on a typical karst hill in north Guangdong of China during the year of 2016.Results show that:(1)the maximum hourly sap flux density occurred at11:00-14:00 and the peak daily sap flux density occurred in September.(2)Sap flow density of Zenia insignis increased with rock bareness rate at all hourly,daily and monthly scales,with the sequence of extremely severe>severe>moderate>mild rock bareness.(3)The transpiration of Zenia insi.gnis is controlled by different factors at different temporalscales.At hourly scale,transpiration was highly(n=144,R^2>0.72)correlated to Solar radiation(Rs),Air temperature(Ta),relative humidity(RH),and water vapor pressure deficit(VPD).At daily scale,transpiration was greatly(n=366,R2>0.31)affected by Solar radiation(Rs),Air temperature(Ta),and water vapor pressure deficit (VPD).While at monthly scale,transpiration was mainly(n=12,R^2=0.85)controlled by LAI.Our study proved that Zenia insi.gnis has a good physiecological adaption to fragile karst environment,and Zenia insignis plantation has long-term sustainability even in extremely rocky landscapes.The results may provide scientific basis for plantation management and ecological restoration in karst area.展开更多
The research about the properties and utilization of fast growing trees have caused wide public concern with the background of the severe shortage of forest and the urgent need for its protection.According to the rece...The research about the properties and utilization of fast growing trees have caused wide public concern with the background of the severe shortage of forest and the urgent need for its protection.According to the recent reports,we have only exploited few kind of fast growing trees, and utilize grade and utilization ratio were lower,so that in this paper,based on analyzing growth speciality and tiny structure and fibre shape and chemical composition and physics properties of fast growing trees species Zenia insignis Chun.. The results showed that it is feasible to use Zenia insignis Chun, as raw material to manufacture flame retardant MDF and flame retardant PB and flame retardant LVL,its physical and mechanical properties,surface physical and chemical properties and flame retarding properties are accord to the correlative standard.Zenia insignis Chun.popularize planting and comprehensive utilization exploitation that is of especial importance to industry.展开更多
基金supported by the project of the National Natural Science Foundation of China entitled ‘‘Impact of rocky desertification on stand transpiration of Zenia insignis plantation and the mechanism’’ (No. 41401108)the project of the National Natural Science Foundation of China entitled ‘‘The impact of development of soil cracks in collapsed walls on wall collapsing stability in granite red soil region of south China’’ (No. 41371041)
文摘Understanding the impact of rock bareness on the transpiration in karst plants is essential to karst rocky desertification control and sustainable management of plantation in karst area.This study focused on the variations in sap flow of Zenia insignis caused by different rock bareness rate,and the impact of climate factors,soil water content(SWC)and leaf area index(LAI) on transpiration in karst plants,by continuously measuring sap flux densities (Fcd)of 12 sample trees using thermal dissipation probes and monitoring micrometeorology and SwC on a typical karst hill in north Guangdong of China during the year of 2016.Results show that:(1)the maximum hourly sap flux density occurred at11:00-14:00 and the peak daily sap flux density occurred in September.(2)Sap flow density of Zenia insignis increased with rock bareness rate at all hourly,daily and monthly scales,with the sequence of extremely severe>severe>moderate>mild rock bareness.(3)The transpiration of Zenia insi.gnis is controlled by different factors at different temporalscales.At hourly scale,transpiration was highly(n=144,R^2>0.72)correlated to Solar radiation(Rs),Air temperature(Ta),relative humidity(RH),and water vapor pressure deficit(VPD).At daily scale,transpiration was greatly(n=366,R2>0.31)affected by Solar radiation(Rs),Air temperature(Ta),and water vapor pressure deficit (VPD).While at monthly scale,transpiration was mainly(n=12,R^2=0.85)controlled by LAI.Our study proved that Zenia insi.gnis has a good physiecological adaption to fragile karst environment,and Zenia insignis plantation has long-term sustainability even in extremely rocky landscapes.The results may provide scientific basis for plantation management and ecological restoration in karst area.
文摘The research about the properties and utilization of fast growing trees have caused wide public concern with the background of the severe shortage of forest and the urgent need for its protection.According to the recent reports,we have only exploited few kind of fast growing trees, and utilize grade and utilization ratio were lower,so that in this paper,based on analyzing growth speciality and tiny structure and fibre shape and chemical composition and physics properties of fast growing trees species Zenia insignis Chun.. The results showed that it is feasible to use Zenia insignis Chun, as raw material to manufacture flame retardant MDF and flame retardant PB and flame retardant LVL,its physical and mechanical properties,surface physical and chemical properties and flame retarding properties are accord to the correlative standard.Zenia insignis Chun.popularize planting and comprehensive utilization exploitation that is of especial importance to industry.
