The Research On Water Consumption Of 5 Kinds Of Ground Cover Plants In Hunan

Due to growth characteristics and irreplaceable role in the landscape,ground cover plant have been widely used in resent years. However,their management is more strenous and needs to consume a large amount of water. China is a country of a serious shortage of water resources,and Hunan Province located in southern China is plagued by the seasonal drought. For a long time,due to low awareness of scientific management for the water consumption, irrigation management of green spaces is blind which causes water inefficiency and huge waste of water resources. By taking 5 species dominant garden plants including Zoysia matrella,Cuphea hyssopifolia,Ophiopgon japonicus,Reineckea carnea and Zephyranthes candida in Hunan Province as its object,through potted seeding,the reasch studys on the water consumption in different sun conditions and water status, finds out water consumption characteristics in dry season,analyses the relationships between ground cover plants and the environmental factors, and makes a comparison and evaluation of water consumption ability. The aim is to be the reference for choosing low-water plants and building up scientific water saving system.The following is the main results in the research:With sufficient water supply,in different sun conditions,diurnal fluctuation of transpiration rate of 5 species ground cover plants such as Zoysia matrella,shows peak changes, and mostly single-peak curve,which is the same trend towards diurnal fluctuation environmental factors such as solar radiation.With.sufficient water supply,in different months,the water consumptions of every plant are compared. Under sunshine,the daily average water consumption rate is Cuphea hyssopifolia>Zoysia matrella. Under the semi-overshadow,the sequence is Zephyranthes candida,Cuphea hyssopifolia,Reineckea carnea,Ophiopgon japonicus,Zoysia matrella. Under the overshadow,the sequence is Ophiopgon japonicus,Zephyranthes candidaand,Reineckea carnea. Generally,the differences of their transpiration rate is small.With sufficient water supply,the funnction of shading is different for different plants: for Zoysia matrella and Cuphea hyssopifolia,some shade exerts a little influence;for Ophiopgon japonicus,Some shade exerts a big influence in August and November,a little influence in September and Octorber;for Reineckea carnea, Some shade exerts a little influence in August,a big influence in September,Octorber and November; for Zephyranthes candida,Some shade exerts a little influence in August and Octorber,a big influence in September and November.With sufficient water supply,though analyzing the relationship between environmental factors and transpiration, it is found that transpiration rate and stomatal conductance have a strong influnce and optimal models of Cuphea hyssopifolia and Zephyranthes candida about transpiration speed and enviromental factors are created.According to plant's transpiration rate and appearance features in different water supply,the soil moistures from soil water-storage capacity to languish moisture can be classified into 4 statuses:sufficient water supply,water potential is -0.03～0.2MPa,soil moisture is 18.3%～23.2%;in slight drought stress, water potential is -0.2～0.54MPa,soil moisture is 15.6%～18.3%;in medium drought stress, water potential is -0.54--1.38MPa,soil moisture is 13.1%～15.6%;in serious drought stress,water potential is less than -1.38MPa,soil moisture is less than 13.1%.In the drought environment,during different months and moisture gradients, Under sunshine, the daily average water consumption rate is mostly Cuphea hyssopifolia>Zoysia matrella,Under semi-overshade,Cuphea hyssopifolia and Zephyranthes candidaare mostly at the beginning of the sequence of the daily average water consumption rate,Zoysia matrella is mostly at the last;Under overshade,generally,the differences of transpiration rate of Ophiopgon japonicus,Reineckea carnea and Zephyranthes candidais small.In the past,the researches about water consumption often focus on the areas of the northern arid and semi-arid,in this thesis,it is introduced to the southern. It studies on water consumption of 5 specise mainly urban ground cover plants,calculates transpiration in different situations and can be the base of an irrigation system.