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• There was significant spatial consistency between the water budget imbalance index and soil aridification. • The more dramatic increase in the actual evapotranspiration (ET) compared to precipitation has kept the trend of soil aridification persisting. • The weaker water storage capacities of croplands than of grasslands resulted in a higher incidence and intensity of soil aridification in croplands than in grasslands. • Cropland-to-grassland conversions enhanced the water storage capacity and mitigated the threat of soil aridification compared to grassland-to-cropland conversions. • Irrigation had a negative impact on the surrounding soil water ecosystems at least 2,000 m away. Understanding the impact of human activities on changes in surface dryness/wetness is crucial for the sustainable development of terrestrial ecosystems. The farming-pastoral ecotone of northern China (FPENC) is experiencing obvious soil aridification under ongoing climate change. The impacts of human activities on cropland and grassland vary. However, how human activities affect soil aridification in terms of cropland and grassland remains unclear. To fill this knowledge gap, this impact mechanism based on the remote sensing retrieval of aridification index and the construction of water budget mismatch index(WMI) is quantified in this study. The results demonstrate a strong spatial consistency between the WMI and the trend of soil aridification. In particular, the trend of soil aridification in the west-central and northeastern areas remained unmitigated where the WMI was less than one. This was due to a more dramatic increase in evapotranspiration (ET) (+64.7 mm) compared to precipitation after subtracting runoff (P i) (+53.9 mm) in the decade between 2001 and 2019. Under the same climatic conditions, croplands had higher crop evapotranspiration and lower soil water storage capacities (WSC) than grasslands, resulting in the aridification intensity of croplands being 1.3 times greater than that of grasslands. Moreover, irrigation exacerbated the depletion of regional groundwater and intensified soil aridification in adjacent drylands and grasslands within a radius of at least 2000 m. These findings provide a scientific foundation for comprehending the mechanism of aridification, developing ecological restoration strategies, and promoting regional sustainable development in the FPENC. [ABSTRACT FROM AUTHOR]

Understanding the impact of climate change on terrestrial wet and dry changes and the relationship between the two is of great significance to the sustainable development of terrestrial ecosystems. The farming-pastoral ecotone of northern China (FPENC) is an area that is sensitive to climate change, suffering from perennial drought and a clear aridification trend. Unlike previous single-factor, single-timescale studies, we identified aridification in the region based on a dataset established by remote sensing and ground-based monitoring stations from a combination of two perspectives: climate and soil. The results show that, in terms of climate, the period from 2000 to 2019 was the driest in the region during the last 120 years , and the summer drought was the most severe and shifted from a summer to spring drought; in terms of soil, the soil aridification trend in the region was severe, with 16.1% of the areas becoming significantly drier (P < 0.1) among the years and 41.6% in spring, respectively. Similar to climate change, soils exhibited recessive aridification due to the counterbalancing effect of the dry and wet seasons within the year. Then the coupling relationship between climate change and soil aridification was established in time and space. Moreover, the spatiotemporal response patterns of both were obtained. The results showed that the frequency of soil drought under meteorological drought conditions showed an increasing trend and that the sensitivity of soil drought occurrence increased. Among them, the effect of precipitation on relative soil moisture (RSM) was immediate, and the effect of prolonged warming on RSM is greater. The area of soil aridification that was caused by climatic aridification in spring accounted for 13.7% of the entire area. The regional aridification research mode proposed in this paper can provide ideas for subsequent studies. [Display omitted] • A comprehensive judgment mode of the regional aridification combining climate elements, soil moisture was established. • Over the last 20 years, the central part of the FPENC showed overall warming and wetting of the climate. • Over the last 20 years, the trend of the soil aridification in the central part of the FPENC remained severe. • The counterbalancing effect of the dry and wet seasons leads to recessive aridification. • The sensitivity of the occurrences of soil drought to the climate drought anomalies continuously became stronger. [ABSTRACT FROM AUTHOR]

Understanding the impact of climate change on terrestrial wet and dry changes and the relationship between the two is of great significance to the sustainable development of terrestrial ecosystems. The farming-pastoral ecotone of northern China (FPENC) is an area that is sensitive to climate change, suffering from perennial drought and a clear aridification trend. Unlike previous single-factor, single-timescale studies, we identified aridification in the region based on a dataset established by remote sensing and ground-based monitoring stations from a combination of two perspectives: climate and soil. The results show that, in terms of climate, the period from 2000 to 2019 was the driest in the region during the last 120 years , and the summer drought was the most severe and shifted from a summer to spring drought; in terms of soil, the soil aridification trend in the region was severe, with 16.1% of the areas becoming significantly drier (P < 0.1) among the years and 41.6% in spring, respectively. Similar to climate change, soils exhibited recessive aridification due to the counterbalancing effect of the dry and wet seasons within the year. Then the coupling relationship between climate change and soil aridification was established in time and space. Moreover, the spatiotemporal response patterns of both were obtained. The results showed that the frequency of soil drought under meteorological drought conditions showed an increasing trend and that the sensitivity of soil drought occurrence increased. Among them, the effect of precipitation on relative soil moisture (RSM) was immediate, and the effect of prolonged warming on RSM is greater. The area of soil aridification that was caused by climatic aridification in spring accounted for 13.7% of the entire area. The regional aridification research mode proposed in this paper can provide ideas for subsequent studies. [Display omitted] • A comprehensive judgment mode of the regional aridification combining climate elements, soil moisture was established. • Over the last 20 years, the central part of the FPENC showed overall warming and wetting of the climate. • Over the last 20 years, the trend of the soil aridification in the central part of the FPENC remained severe. • The counterbalancing effect of the dry and wet seasons leads to recessive aridification. • The sensitivity of the occurrences of soil drought to the climate drought anomalies continuously became stronger. [ABSTRACT FROM AUTHOR]