Wencun Zhou

The cropland area is closely related to food production. Previously, more focuses were paid on impacts of extreme events on food production, but less on cropland dynamics. This study used the piecewise linear regression, the correlation analysis, and the ridge regression to explore the spatiotemporal dynamics of cropland and its drivers in three time periods (1992–2020, 1992–2010, and 2010–2020) at the Farming-Pastoral Ecotone of Northern China (FPEN). Specifically, 13 driving factors were considered from the perspectives of extreme events, environmental conditions, socioeconomic development, urban sprawl, and ecological construction. Results showed that the cropland area increased significantly at a rate of 333.5 km²/a during 1992–2020 and was spatially clustered in the eastern FPEN. The impact extent and size of each driving factor on the cropland trend presented large spatiotemporal differences, but ecological construction had, overall, the greatest impact on cropland area changes, followed by urban sprawl. In comparison, extreme low temperature had the smallest. Since the 2010s, areas with urban sprawl being the dominant factor in cropland dynamics have increased by 41.9%, but it is still less than the ecological construction impact. Furthermore, this study found that extreme event effects on the cropland area trend evidently increased. Particularly, extreme high temperature displayed the highest increase (~99.4%). Cropland area changes dominated by extreme temperature events in 2010–2020 increased by nearly six times compared to those in 1992–2010. These results suggest that policy and planning makers should caution increasing impacts of regional extreme weather events on cropland area changes.

Cropland area is closely related to food production. More previous focuses were paid on impacts of extreme events on food production, but less on cropland dynamics. This study took the Farming-Pastoral Ecotone of Northern China (FPEN) as a case area, to investigate its cropland area dynamics and driving factors in view of perspectives of extreme events, environmental conditions, socioeconomic development, urban expansion, and ecological construction. We used ridge regression approach to quantify contributions of these drivers to cropland area dynamics. Results showed that cropland area increased significantly at a rate of 333.5km2/a during 1992−2020 and were spatially clustered in east of the FPEN. Impact extent and size each driving factor on cropland trend presented large spatiotemporal differences, but ecological construction (EC) had overall the greatest impact on cropland area changes, followed by urban expansion (UE). In comparison, TL10p has the smallest. UE-dominated areas increased 41.9% since 2010s, but still less than EC. Furthermore, we found that extreme events effects on cropland area trend evidently increased. Particularly, TH90p displayed the most increase (~99.4%). Cropland area changes dominated by extreme temperature events in 2010−2020 increased nearly six times than that in 1992−2010. These findings suggest that increasing impacts of extreme weather events on cropland area changes should be cautioned.