Research on the Water Consumption Rule and Water Requirement of Main Desert Shrub in Southern Margin of Junggar Basin, China
|Course||Agricultural Soil and Water Engineering|
|Keywords||Junggar Basin Desert vegetation Water law Suitable for water demand Water use efficiency|
Water resources are coordinated development of the key factors constraining socio-economic and ecological environment of the western arid zone. Water consumption characteristics and suitability of the study the natural vegetation of the arid region need to water plants, artificial restoration of important significance for regional ecological water demand and determination as well as desert vegetation. Haloxylon, Tamarix Calligonum are widely distributed in the arid region of western China, is planted sand-fixing species. In this paper, the water balance method barrels planted plot experiment, carried out in the southern edge of the Junggar Basin, Fukang desert ecosystem National Station Calligonum three drought Haloxylon, Tamarix and sand raw water law and water plants growth characteristics the study, the main conclusions are as follows. (1) Tamarix elongata has a wide range of moisture adaptation, with the intensification of soil drought, water consumption peak appeared earlier and water consumption and reduces the duration of the peak period. Normal moisture 50% -60% of field capacity (0f) treatment of Tamarix elongata ten-day water consumption with the mid-surface of the water under evaporation correlation coefficient of 0.88. When adequate soil moisture, meteorological factors will play a leading role in its water consumption regularity. Normal water treatments (2) the total dry weight of Tamarix elongata are mild water stress and severe water stress 1.13 times and 5.06 times, its root to shoot ratio with the soil moisture decreased from 0.91 cases of normal water increased to moderate water stress under 1.43. Allocated significant effect of water stress on the amount of dry matter growth above and below ground biomass of Tamarix elongata. (3) of Tamarix elongata the angle of biomass water use efficiency (transpiration water consumption with biomass ratio, g / kg) and water consumption (kg) meet the conic function model. Analyzed 2 years of growth spike the Tamarix most suitable water demand for 280mm, the upper limit of the optimum soil moisture content of 50% Of. Tamarix photosynthetic angle long water use efficiency (μmol CO2/mmol H2O) on further analysis of the optimum soil moisture range of 40% -45.8% 0f. The Haloxylon woodland suitable soil moisture range of 35% -40% Of. Of Calligonum zaolin land suitable soil moisture range with 39% -49? (4) the Haloxylon woodland soil moisture content of 40.8% -50% Of the amount of soil water storage capacity is the dominant factor of the woodland evapotranspiration, the disabilities soil moisture content in 50% of the above, the combined effects of meteorological factors become woodland actual evapotranspiration determinants. (5) based on the principle of water balance, determined to control moisture gradient under different forest species of water consumption and water quota. The Bge and fine Tamarix 50% -60% of the water consumption is 50% of the 1.70 and 1.07 times, respectively, when Guests soil moisture content is abundant, water consumption will increase. Non-irrigated treatment of Tamarix, following the 50% Of Water consumption is the Haloxylon the 1.23 times, with higher water consumption than Haloxylon Tamarix under natural conditions. (6) under different water conditions Haloxylon, the fine Tamarix and the Calligonum three kinds of desert shrubs in the efficiency of water use (evapotranspiration, water consumption and biomass ratio, g / kg) has a larger difference. Desert shrub Haloxylon fine Tamarix and l Calligonum water use efficiency under the same moisture conditions (50% -60?) Were 1.24g/kg 1.93g/kg and 2.54g/kg; 40% -50? under Haloxylon, Tamarix elongata Calligonum water use efficiency of three kinds of desert shrubs were 0.91g/kg, 2.81 g, kg and 0.74g/kg, to reflect fine Tamarix higher water use the efficiency of water use efficiency Calligonum sufficient soil moisture is high, the deficit when the lowest.