This paper introduces for the first time the equal intercept transformation radar chart—an improved form—to the assessment of soil environmental quality of Nanling commodity grain base. The equal intercept transformation radar chart, a visual graphical data analysis method, translates data from a numerical to graphical format. This visualization enables data presentation, analysis process and results stick out a mile and is capable of fully retaining information contained in data and excavating it in depth from geometry. Moreover, it overcomes pertinently the main defect of the conventional radar chart that the evaluation result depends heavily on the order of arrangement of indicators. The results indicated that the soil environmental quality at depths of 0–60 cm in the low mountain area of the Nanling commodity grain base was the second grade, while that in the hilly and plain areas were both first grade. The indicators of poor soil environmental quality in the low mountain area were exogenous Cd and endogenous As; those in the hilly area were exogenous Cd and endogenous As and Hg; and that in the plain area was exogenous Cd. The results were in line with the actual situation of the study area.

Vegetation root water uptake is one of the most central water transport processes along the soil-vegetation-atmosphere interface particularly in (semi-)arid ecosystems. The identification and quantification of root activities and water uptake patterns of arid vegetation remain challenging. This paper aims at the quantitative examination of water uptake behaviors of Nitraria, a prevalent desert species in arid environments, during the growth phase via a multivariate linear mixed model based on water stable isotopes, with a main focus on the time interval from a precipitation pulse. The observations indicate that the precipitation events exert periodic significant pulse-effects on vegetation water uptake through direct absorption (contribution of almost 75%) and activation of deep root activity at a certain depth. While in most occasions without rainfall, Nitraria relies on its extremely extensive shallow roots in surface-near lateral zone (contribution of about 60%) to extract massive soil as well as the hydraulic lifting mechanism to survive drought. Achievements would be beneficial to enhancing the understanding of entangled water transport processes and eco-hydrological feedbacks along soil-vegetation interface in arid ecosystems and contribute to a scientific allocation to water resources with the consideration of ecological protection.

Vegetation root water uptake plays a significant role in water transport processes and has multiple effects along the soil–vegetation–atmosphere interface, particularly in semi-arid and arid ecosystems. The objective of this study was to quantitatively examine the water uptake in Cynanchum sibiricum, a common desert rattan plant in arid regions, during its growth period, as well as to assess the relevance of the contributions of various water sources via a multivariate linear mixed model based on water-stable isotopes and eliminating the significant short-term impact of precipitation pulses on root water uptake. The results indicated that when the influence of a precipitation event was minimized, 0–10 cm soil water was the dominant water source for Cynanchum sibiricum in its growth phase, and that the species’ relative uptake of rainfall was positively proportional to that of 10–70 cm soil water while negatively proportional to that of 0–10 cm soil water. We concluded that Cynanchum sibiricum relies on its active roots extending transversely to extract water from shallow soil to survive under extreme drought conditions and would be inseparable from the symbiosis formed with other deep-rooted vegetation. Additional research into disentangling the water transport processes and studying the ecohydrological feedback along the soil–vegetation interface in arid ecosystems would be beneficial and could contribute to the evidence-based management of water resources for ecological protection.