Study On Water Consumption Characteristics Of Main Shrubs In Kubuqi Sandland

For the limited of water, intending to provide some theoretical proof on tree species selection and stand density ascertainment for the vegetation restoration in arid and semi-arid region in China, based on the theory of soil-plant-atmosphere continuum, the paper studies the transpiration Characteristics of Salix Psammophila, Elaeagnus angustifolia, Caragana microphylla Lam, Atripldex canescens and the factors which affect the transpiration. The main problems discussed in the dissertation are as follows: rule of transpiration of four forest stands; the relation between water consumption and the main factors which affect it; rule of soil evaporation of four forest stands; actual evapotranspiration of each forest stands in growing season; The distribution coefficient between evaporation and transpiration in growing season of four forest stands; water requirement of four shrubs and soil water shortage of four forest stands.Main research results are as follows:· The evaporation of the forest stand in experimental zones from 2005 to 2006 was calculated on the basis of Penman-Monteith model. The comparison between the values gained from calculation and measurement shows the equation is feasible. The relative errors are under 10%. In 2005 the annual evaporation of Salix Psammophila, Elaeagnus angustifolia, Caragana microphylla Lam, Atripldex canescens respectively is 181.94mm,159.98mm, 128.03mm and 112.53 mm; in 2006 the annual evaporation of four shrubs respectively is 195.96mm,182.24mm, 134.48mm and 129.75mm.· The relation of transpiration rate and stomatic resistance value is close, Rst is the main inherent factors which affect transpiration; Air temperature and photosynthesis active radiation have positive effects on Tr. while relative humidity has negative effects. The study also shows that air temperature and relative humidity have more effects than photosynthesis active radiation on Tr.· Based of Water Consumption of four shrubs of whole growing season in 2006 and soil evaporation of forest Land, calculating the actual evaporation. The actual evaporation of Salix Psammophila, Elaeagnus angustifolia, Caragana microphylla Lam, Atripldex canescens respectively is 328.92mm, 337.8mm, 291.44mm, 298.46mm.· The distribution coefficients are 1.47, 1.17, 0.86, 0.77 for the forest stand of Salix Psammophila, Elaeagnus angustifolia, Caragana microphylla Lam, Atripldex canescens respectively in 2006, with biggish variability.· The water requirement of Salix Psammophila, Elaeagnus angustifolia, Caragana microphylla Lam, Atripldex canescens have little difference in growing season of 2005 and 2006. The water requirement of Salix Psammophila, Elaeagnus angustifolia is more than that of Caragana microphylla Lam. The water requirement of four shrubs in 2005 respectively is 469.28mm, 477.16mm,449.83mm and 397.14mm;that in 2006 respectively is 458.72mm, 465.14mm, 436.70mm and 386.99mm.· The phenomenon of lacking water in every land exist in 2006, capacity of water lacking is and 370.12mm in 2006,the main month of seriously lacking water is May, June and July. Make analysis of the water requirement in suitable water conditions and soil water shortage ,the result is that the water shortage of four shrubs in 2005 respectively is 129.79mm, 107.33 mm, 145.27mm and 88.53mm.