湖南5种园林地被植物蒸腾耗水特征初探

Transpiration water-consumption characteristics of five kinds of landscape ground cover plants in Hunan,southern China

该研究旨在掌握湖南5种园林地被植物在缺水季节的耗水特性,为制定科学合理的灌溉制度及配置方式提供依据。采用盆栽控水法,从8—11月,通过模拟实际栽植中植物所处的不同光照状况,测定了马尼拉草、细叶萼距花、麦冬、吉祥草和葱兰在不同光照条件下土壤水分不断降低过程中的蒸腾速率。结果为:①根据植物在控水期间蒸腾速率的变化及生长状况划分了4种土壤水分梯度,即水分充足、轻度胁迫、中度胁迫和重度胁迫,土壤水势分别为-0.20～-0.03MPa、-0.54～-0.20MPa、-1.38～-0.54MPa和<-1.38MPa。②不同月份在前3种土壤水分梯度下,全光照时,细叶萼距花的日均蒸腾速率大于马尼拉草;半光照时,蒸腾速率大、入选前2位较多的是细叶萼距花和葱兰,蒸腾速率低、处于最后一位较多的是马尼拉草;全遮荫时,麦冬、吉祥草和葱兰的蒸腾速率相差不大。③控制土壤水分、光照强度所达到的节水效果是不同的,可根据节水效益和实际需要来选择优化的节水方式。

The research aims to master water consumption characteristics of 5 kinds of ground cover plants in water shortage season in Hunan and provide the basis for determination of rational irrigation system and configuration mode. Water controlling experiment was used to measure the transpiration rate of Zoysia matrella,Cuphea hyssopifolia,Ophiopgon japonicus,Reineckea carnea and Zephyranthes candida by pot experiment through simulating plant growth process under different soil water and light conditions. Results showed that 4 kinds of soil water gradient were recognized,i. e. sufficient water supply,slightly water deficiency,medium water deficiency and serious water deficiency,according to variation of transpiration rate and growth status of plants. Different soil water potential corresponding to the soil water gradient was -0.20-0.03 MPa,-0.54-0.20 MPa ,-1.38-0.54 MPa and 〈-1.38 MPa,respectively. In different months under the first three soil water gradient conditions,daily mean transpiration rate of C. hyssopifolia was larger than that of Z. matrella under full illumination; as for C.hyssopifolia and Z.candida,the transpiration rate was higher and most of them was in the first two position under half full illumination; as for Z. matrella,its transpiration rate was lower and most of them was in the last position; as for O. japonicus,R. carnea and Z. candida,there was small difference among them under full shade conditions. Water saving effects by controlling soil water and light intensity were significanty different,so optimized water saving irrigation mode was chosen according to water-saving benefit and practical needs.