Responses of water-carbon coupling to seasonal drought in different land use types in Northwest China

Climate warming has led to frequent drought events, and moisture factors have become important indicators limiting ecosystem carbon cycling, which enhances the uncertainty about the water-carbon coupling process in response to seasonal droughts. Our results on the relationship between water-carbon coupling function and drought in Northwest China show: (1) The degree of water-carbon coupling coordination (WCccd) in all seasons was summer (0.388) > fall (0.335) > spring (0.275) > winter (0.198), spatially reflected as high in the east and low in the west. (2) WCccd was highly resistant to mild drought. Mild drought in spring, summer and fall led to an increase in WCccd by 18.57%, 11.99% and 10.21%, respectively. As severe and extreme droughts can break the resilience of ecosystems, we should select afforestation or drought-tolerant vegetation according to regional water deficit and surplus situations, and increase artificial interventions to mitigate the negative impacts of drought on the water-carbon coupling function.