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植物叶脉和气孔性状的关系反映了叶片的水力特性,对认识它们与植物水分利用有关的生理功能间的关系及其调控作用具有重要意义。该文利用GIS(geographic information system)与实验生态学相结合的方法,采用标准化主轴估计方法,研究了兰州市北山不同坡向人工林刺槐(Robinia pseudoacacia)叶脉密度与气孔密度、气孔大小的关系。结果表明:随着坡向由南坡向东坡、西坡和北坡转变,植被群落的郁闭度、高度和土壤含水量呈逐渐增加的趋势,刺槐的净光合速率(Pn)、蒸腾速率(Tr)、光合有效辐射(PAR)、叶脉密度和气孔密度呈逐渐减小的趋势,气孔与叶面积呈逐渐增大的趋势;各个坡向的刺槐叶脉密度与气孔密度呈显著正相关关系,与气孔大小呈显著负相关关系,且在南坡达到极显著相关关系。生长在南坡的刺槐具有高的叶脉密度和密而小的气孔,生长在北坡的刺槐具有低的叶脉密度和疏而大的气孔。不同坡向刺槐叶脉密度与气孔特征间的资源分配模式,反映了植物在异质性生境中根据其功能需求在自身性状之间进行投资权衡机制的优化。
The relationship between leaf veins and stomatal traits of plants reflects the hydraulic characteristics of the leaves and is of great significance for understanding the relationship between them and their physiological functions related to plant water use and their regulation. In this paper, we use the method of geographic information system (GIS) and experimental ecology to study the relationship between leaf vein density and stomatal density and stomata size of Robinia pseudoacacia plantations in different slopes of Beishan, Lanzhou, using the method of standardized principal axis analysis. The results showed that the canopy density, plant height and soil water content tended to increase as the slope changed from south slope to east slope, west slope and north slope. The net photosynthetic rate (Pn), transpiration rate (Tr), photosynthetically active radiation (PAR), leaf vein density and stoma density tended to decrease, while stomata and leaf area tended to increase. There was a significant positive correlation between leaf vein density and stoma density, And stomatal size showed a significant negative correlation, and in the southern slope reached a significant correlation. Black locusts grown on the southern slope have high leaf vein density and dense and small stomata. Locusts grown on the northern slope have low leaflet density and sparse stomata. The pattern of resource allocation between leaf density and stomatal characteristics of Robinia pseudoacacia in different slopes reflects the optimization of the trade-off mechanism of plants in their heterogeneous habitats according to their functional requirements.