喀斯特峰丛洼地4种典型植物蒸腾作用及其影响因素

Transpiration of 4 Typical Plants and Its Affecting Factors in Karst Peak Cluster Depression Area

[目的]对广西壮族自治区喀斯特峰丛洼地4种典型植物(甘蔗、五节芒、灰毛浆果楝和青冈)蒸腾作用及其影响因素进行研究,为进一步开展区域植被生态需水研究提供科学依据。[方法]于2015年4月至2016年1月对4种主要植物群落不同季节蒸腾速率(Tr)、叶面积指数(LAI)和相关环境因子开展现场观测。[结果]4种植物Tr夏季与春、秋、冬3季呈极显著差异(p<0.01),不同植物类型其Tr也存在差异,其中,甘蔗Tr的季节变化为96.55~197.42g/(m2·h),五节芒为95.26~169.13g/(m2·h),灰毛浆果楝为97.20~239.11g/(m2·h),青冈四季Tr为81.65~124.42g/(m2·h)。4种植物Tr均与空气温度(Ta)呈极显著(p<0.01)或显著正相关关系(p<0.05),与土壤含水率(SWC),LAI,土壤容重(ρb),空气相对湿度(RH)呈显著或极显著相关关系。SWC和Ta对甘蔗Tr起主导作用,是主要决策变量;Ta是五节芒Tr的主要决策变量;SWC和ρb是灰毛浆果楝Tr的主要影响因子;LAI,SWC和Ta是青冈Tr的主要影响因子。[结论]研究区域4种典型植物蒸腾作用存在差异,且均呈季节性变化趋势,不同植物Tr影响因素不同,可通过人工诱导水、光、热等环境因子进而合理调控植被生态需水。

[Objective]Studying the transpiration and its influencing factors of four typical plants communities（Saccharum officinarum,Miscanthus floridulus,Cipadessa cinerascens and Cyclobalanopsis glauca）in karst peak cluster depression areas of Guangxi Zhuang Autonomous Region to provide scientific basis for the research on regional vegetation ecological water demand.[Methods]Field measurements of transpiration rate（Tr）,leaf area index（LAI）,and related environmental factors in different seasons were conducted from April 2015 to January 2016.[Results]There was an extremely significant difference（p〈0.01）between plants transpiration rates in summer and in other three seasons.The seasonal change of transpiration rates of Saccharum officinarum,Miscanthus floridulus,Cipadessa cinerascens and Cyclobalanopsis glauca were96.55~197.42,95.26~169.13,97.20~239.11 and 81.65~124.42 g/（m2·h）,respectively.An extremely significant and positive correlation（p〈0.01）or a significant positive correlation（p〈0.05）was found between transpiration rate and air temperature for the four typical plants,and extremely significant or significant correlation significant correlation with soil water content（SWC）,LAI,soil bulk（ρb）,and air relativehumidity（RH）.Air temperature（Ta）and soil water content（SWC）were the key variables for transpiration in Saccharum officinarum;Air temperature was the key variables for Miscanthus floridulus;In the case of Cipadessa cinerascens,soil water content and soil capacity were the main influence factors on transpiration;Leaf area index,soil water content and air temperature were the main influence factors on transpiration for Cyclobalanopsis glauca.[Conclusion]The differences between transpiration rates of different plant communities existed and all of them showed seasonal variation trends.The effects of environmental factors on transpirations of the 4 typical plants were different,which can be artificially induced to regulate the ecological water demand of vegetation.