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作 者 ：葛滢, 常杰, 刘珂, 秦国强

期 刊 ：植物生态学报 1999年 23卷 4期 页码：320-326

关键词：杭州石荠苧；蒸腾；濒危植物；

Keywords:Mosla hangchowensis, Transpiration, Endangered plant,

摘 要 ：根据连续3年的野外种群生态和生理生态学研究中发现的问题，研究了控制条件下杭州石荠苧蒸腾的生理生态特征。结果表明：1)杭州石荠苧的蒸腾日进程曲线峰高随土壤含水量(θ)的降低而降低；2)蒸腾速率(Tr)与空气相对湿度在饱和与中湿土壤上为负相关，而在干旱土壤上为正相关，体现了该种在土壤干旱时的自我保护机制；3)薄云、多水汽和中午多云的晴天，日蒸腾量均较低，分别为2.6和2.8mol·g-1·d-1，典型晴天的日蒸腾量较高，为3.4mol·g-1·d-1；4)在遮荫(40％全光照)条件下，Tr平均降低76％，且Tr对气温、湿度的响应程度小于全光照条件，对光强的响应则大于全光照条件；5)当气温为15～18℃时，在诸环境因子中Tr只与θ有关。该种的水分生理生态特性十分特别，具有从中生到旱生植物的某些生理生态特性。上述结果解释了杭州石荠苧种群占据现有生态位——向阳开阔地薄土生境的生理生态机制，分析了其不能向厚土生境扩展分布地的原因。

Abstract:After 3-year studies of population and physiological ecology in the field, the physioecological characters of transpiration of endangered plant Mosla Hangchowensis under controlled condition were studied. Results show that: 1 ) The peak height of the diurnal curves of the transpiration (Tr) decreased with the decrease of soil water content. 2) There was a negative regression between Tr and the air relative humidity in the soil of saturation and medium water content, and a positive regression in the dry soil. This indicates that M. hangchowensis bad the self-protection mechanism in the dry soil. 3) On fine clays with thin cloud and humid air or cloudy in midday, the daily Tr was lower (2.6 and 2.8 mol·g-1·d-1) than that on typical fine day(3.4mol·g-1·-1). 4) In shade(40% full sunlight) ,the mean Tr dropped by 76%, and the responds of Tr to temperature and relative humidity were little, but to FPD was bigger than that to full sunlight. 5) Under the condition of 15～18℃ ,the Tr was only correlated with soil water content among the ecological factors. M. hangchowensis has some physio-ecological characters which are usually found for mesic to xeric species. The physio-ecological mechanism by which M. hangchowensis could only occupy the existing ecological niche—thin soil on open sunny rocks and the reasons for the impossibility for the species to expand to thick soil habitat were put forwards.

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