Screening Of Water-saving Plants And Allocation Mode And Annual Water Consumption Estimation In Beijing

As a city with serious water shortage,The amount of water resources per capita in Beijing is about 161m3.which is only I/15 of the national per capita water resources and 1/47 of the world's per capita water resources(7500m3).Therefore,it is very important to save water resources.Aiming at the problem of city greenbelt water-saving,water consumption of common green plants in Beijing city were compared and summarized.Through literature research,water consumption of 79 plants per unit leaf area or unit green area were compared.And low water trees,shrubs and herbaceous plants are screened.The water saving plant allocation mode was screened,and the annual water consumption of arbors,shrubs and herbaceous plants in Beijing was estimated.It provided theoretical basis for water-saving tree species selection,water-saving green space allocation mode and water-saving irrigation in urban green space.The main results are as follows.(1)Screening of water-saving plants.According to the water consumption per plant area,low water consumption trees were selected,including Malus micromalus(1020.1 g·m-2),Robinia pseudoacacia(952.3g·m'2),Sophora japonica(898.3g·m-2),Ginkgo biloba(713.2g·m-2),Platanus acerifolia(935.6g·m-2),Quercus variabilis(930 g·m-2),Rhus chinensis(920 g·m-2),Quercus dentata(920.4 g·m-2),Rhus typhina(198.7 g·m-2),ilanthus altissima(872.8g·m-),Populus tomentosa(829.7g·m-2),Sabina chinensis cv.Beijingensis(61 0.1 g·m-2),Pinus bungeana(485.6g·m-2),Pinus tabuliformis(814.2g·m-2)and Platycladus orientalis(531.2g·m-2).Shrubs include Forsythia suspensa(1159.7g·m-2),Hippophae rhamnoides(11 50.3g·m-2),Caragana Korshinskii(1141.0g·m-2),Syringa oblata(1099.5g·m-2),Leptopus chinensis(1060.0g·m-2),Berberis thunbergii(1 047.8g·m-2),Cotinus coggygria(290.3g·m-2),Buxus microphylla(266.3g·m-2),Syringa pekinensis(659.1g·m-2),Ligustrum vicaryi(610.7g·m-2),Euonymus japonicus(699.1 g·m-2),Lespedeza bicolor(680 g·m-2),Weigela florida(804.2g·m-2),Myripnois dioica(870 g·m-2),Spiraea salicifolia(980 g·m-2),Amorpha fruticosa(550g·m-2)Amygdalus davidiana(760 g·m-2),Sabina vulgaris(265 g·m-2)and Sabina procumbens(451.4 g·m-2).Herbs are compared by the amount of water consumption per unit green area.Herbs with low water consumption include Sedum.spectabil(161.4kg·m-2),Sedum aizoon(195.1 kg·m-2),Ranunculus japonicus(168.8 kg·m-2),Chrysanthemum morifolium(1 77.5kg ·m-2),Iris tectorum(186.9kg·m-2),Iris lactea var.chinensis(207.2 kg·m-2).Hemerocallis fulva(332.4 kg·m-2),Festuca glauca(333.5 kg·m-2),Gaillardia aristate(340.5 kg·m-2),Viola philippica(394.8 kg·m-2)and Dianthus chinensis(432.6kg·m-2).(2)Through the calculation and comparison of the water consumption of different configuration modes of greenland,the configuration mode of water saving greenland is screened out.In shrub greenland,annual water consumption of Buxus microphylla per plant is 466.6kg,which has the best water-saving effect.In the deciduous shrub greenland,the annual water consumption of the low water consumption shrub is less than 1000kg.The annual water consumption of water saving allocation mode of arbor and herb green space is less than 300 kg·m-2.The annual water consumption of water saving allocation mode of shrub green ball and herb green space is less than 500 kg·m-2.The annual water consumption of water saving allocation mode of deciduous shrubs and herb greenland is less than 300 kg·m-2.The annual water consumption of water saving allocation mode of arbor and shrub green ball and herb green space is less than 400 kg·m-2.The annual water consumption of water saving allocation mode of arbor and deciduous shrubs and herb greenland is less than 300 kg·m-2.(3)Water consumption of arbors.According to the DBH and leaf area expansion model and the survey results of eighth landscaping resources in Beijing,the annual water consumption of coniferous trees in Beijing is 864920 cubic meters.The annual water consumption of broad-leaved trees is 133616940 cubic meters.And the total annual water consumption of all arbor species is about 134 million cubic meters.(4)Water consumption of shrubs.According to the leaf area model and the survey results of eighth landscaping resources in Beijing,the total annual water consumption of all deciduous shrubs in Beijing city is 5872300 cubic meters.On the basis of hedgerow leaf area index and green area,the total annual water consumption of all shrubs is 8560251 cubic meters.(5)Water consumption of herb.According to the area of herbaceous plants and the survey results of eighth landscaping resources in Beijing,the annual total water consumption of lawn is 17435300 cubic meters.The annual total water consumption of ground cover plants is 1800400 cubic meters.And the annual total water consumption of herbaceous plants is 1 9235700 cubic meters.(6)Water consumption of arbors,shrubs and herbs in Beijing city is totally about 168 million cubic meters.