Amygdalus pedunculata Pall.is a major species that is widely planted in afforested soils with different textures in the transitional zone between Mu Us Desert and Loess Plateau,China.However,the responses of A.peduncu...Amygdalus pedunculata Pall.is a major species that is widely planted in afforested soils with different textures in the transitional zone between Mu Us Desert and Loess Plateau,China.However,the responses of A.pedunculata to increasing intensity of water stress in different textural soils are not clear.Here,we conducted a soil column experiment to evaluate the effects of different textures(sandy and loamy)on water consumption,water use efficiency(WUE),biomass accumulation and ecological adaptability of A.pedunculata under increasing water stress,i.e.,90%(±5%)FC(field capacity),75%(±5%)FC,60%(±5%)FC,45%(±5%)FC and 30%(±5%)FC in 2018.A.pedunculata grown in the sandy soil with the lowest(30%FC)and highest(90%FC)water contents had respectively 21.3%-37.0%and 4.4%-20.4%less transpiration than those with other water treatments(45%-75%FC).In contrast,A.pedunculata transpiration in the loamy soil decreased with decreasing water content.The magnitude of decrease in transpiration increased with increasing level of water deficit(45%and 30%FC).Mean daily and cumulative transpirations of the plant were significantly lower in the sandy soil than in the loamy soil under good water condition(90%FC),but the reverse was noted under water deficit treatments(45%and 30%FC).Plant height,stem diameter and total biomass initially increased with decreasing water content from 90%to 75%FC and then declined under severe water deficit conditions(45%and 30%FC)in the sandy soil.However,these plant parameters decreased with decreasing water content in the loamy soil.WUE in the sandy soil was 7.8%-12.3%higher than that in the loamy soil,which initially increased with decreasing water content from 90%to 75%FC and then declined under water deficit conditions(45%and 30%FC).The study showed that plant transpiration,biomass production and WUE responded differentially to increasing intensity of water stress in the sandy and loamy soils.The contrasting responses of A.pedunculata to water stress in different textural soils can guide future revegetation programs in the northern region of Chinese Loess Plateau by considering plant adaptability to varying soil and water conditions.展开更多
Understanding solute transport behaviors of deep soil profile in the Loess Plateau is helpful for ecological construction and agricultural production improvement. In this study, solute transport processes of a deep so...Understanding solute transport behaviors of deep soil profile in the Loess Plateau is helpful for ecological construction and agricultural production improvement. In this study, solute transport processes of a deep soil profile were measured by a conservative tracer experiment using 25 undisturbed soil cores （20 cm long and 7 cm diameter for each） continuously sampled from the surface downward to the depth of 500 cm in the Loess Plateau of China. The solute transport breakthrough curves （BTCs） were analyzed in terms of the convection-dispersion equation （CDE） and the mobile-immobile model （MIM）. Average pore-water velocity and dispersion coefficient （or effective dispersion coefficient） were calculated using the CDE and MIM. Basic soil properties and water infiltration parameters were also determined to explore their influence on the solute transport parameters. Both pore-water velocity and dispersion coefficient （or effective dispersion coefficient） generally decreased with increasing depth, and the dispersivity fluctuated along the soil profile. There was a good linear correlation between log-transformed pore-water velocity and dispersion coefficient, with a slope of about 1.0 and an average dispersivity of 0.25 for the entire soil profile. Generally speaking, the soil was more homogeneous along the soil profile. Our results also show that hydrodynamic dispersion is the dominant mechanism of solute transport of loess soils in the study area.展开更多
基金the National Natural Science Foundation of China(41601221)the Ministry of Science and Technology of China(2016YFC0501605)+4 种基金the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0306)the Strategic Priority Research Program of Chinese Academy of Sciences(XDA23070202)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2019052)the Bingwei Outstanding Young Talent Project from the Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences(2017RC203)the Scientific Research Program from State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Chinese Academy of Sciences&Ministry of Water Resources(A314021402-1602,A314021402-2010).
文摘Amygdalus pedunculata Pall.is a major species that is widely planted in afforested soils with different textures in the transitional zone between Mu Us Desert and Loess Plateau,China.However,the responses of A.pedunculata to increasing intensity of water stress in different textural soils are not clear.Here,we conducted a soil column experiment to evaluate the effects of different textures(sandy and loamy)on water consumption,water use efficiency(WUE),biomass accumulation and ecological adaptability of A.pedunculata under increasing water stress,i.e.,90%(±5%)FC(field capacity),75%(±5%)FC,60%(±5%)FC,45%(±5%)FC and 30%(±5%)FC in 2018.A.pedunculata grown in the sandy soil with the lowest(30%FC)and highest(90%FC)water contents had respectively 21.3%-37.0%and 4.4%-20.4%less transpiration than those with other water treatments(45%-75%FC).In contrast,A.pedunculata transpiration in the loamy soil decreased with decreasing water content.The magnitude of decrease in transpiration increased with increasing level of water deficit(45%and 30%FC).Mean daily and cumulative transpirations of the plant were significantly lower in the sandy soil than in the loamy soil under good water condition(90%FC),but the reverse was noted under water deficit treatments(45%and 30%FC).Plant height,stem diameter and total biomass initially increased with decreasing water content from 90%to 75%FC and then declined under severe water deficit conditions(45%and 30%FC)in the sandy soil.However,these plant parameters decreased with decreasing water content in the loamy soil.WUE in the sandy soil was 7.8%-12.3%higher than that in the loamy soil,which initially increased with decreasing water content from 90%to 75%FC and then declined under water deficit conditions(45%and 30%FC).The study showed that plant transpiration,biomass production and WUE responded differentially to increasing intensity of water stress in the sandy and loamy soils.The contrasting responses of A.pedunculata to water stress in different textural soils can guide future revegetation programs in the northern region of Chinese Loess Plateau by considering plant adaptability to varying soil and water conditions.
基金supported by the National Natural Science Foundation of China(41571130081,41530854)
文摘Understanding solute transport behaviors of deep soil profile in the Loess Plateau is helpful for ecological construction and agricultural production improvement. In this study, solute transport processes of a deep soil profile were measured by a conservative tracer experiment using 25 undisturbed soil cores （20 cm long and 7 cm diameter for each） continuously sampled from the surface downward to the depth of 500 cm in the Loess Plateau of China. The solute transport breakthrough curves （BTCs） were analyzed in terms of the convection-dispersion equation （CDE） and the mobile-immobile model （MIM）. Average pore-water velocity and dispersion coefficient （or effective dispersion coefficient） were calculated using the CDE and MIM. Basic soil properties and water infiltration parameters were also determined to explore their influence on the solute transport parameters. Both pore-water velocity and dispersion coefficient （or effective dispersion coefficient） generally decreased with increasing depth, and the dispersivity fluctuated along the soil profile. There was a good linear correlation between log-transformed pore-water velocity and dispersion coefficient, with a slope of about 1.0 and an average dispersivity of 0.25 for the entire soil profile. Generally speaking, the soil was more homogeneous along the soil profile. Our results also show that hydrodynamic dispersion is the dominant mechanism of solute transport of loess soils in the study area.
