Impact of planting Lycium barbarum L. on the carbon–land–water nexus of a Haloxylon ammodendron nature reserve in the Qaidam basin, China

Abstract Desert ecosystems are an important component of terrestrial ecosystems and land use change directly affects their composition and function. However, there have been few studies on how land use change impacts the carbon–land–water nexus in desert ecosystems. We studied the effects of replacing sacsaoul ( Haloxylon ammodendron ), a typical natural vegetation in the Qaidam basin, China, with artificially planted goji berry ( Lycium barbarum L.) using the denitrification‐decomposition (DNDC) model. Our results showed that DNDC model coefficient of determination () and Nash‐Sutcliffe modelling efficiency (NSE) both reached 0.92 for sacsaoul and goji berry, and the root mean square error (RMSE) of the simulation was 495 kg ha −1 and 116 kg ha −1 for sacsaoul and goji berry, respectively. The land use change from sacsaoul to goji berry induced a significant increase in global warming potential (GWP) and the water footprint, but decreased the water user efficiency (WUE). The WUE decreased by 1.2, 2.9, and 3.5 kg m −3 for the core zone, buffer zone, and experimental zone when the land cover changed from sacsaoul to goji berry, respectively. Meanwhile, the total water footprint and the GWP increased 2214 m 3 t −1 and 4744 CO 2 eq. ha −1 , 2295 m 3 t −1 and 5297 CO 2 eq. ha −1 , and 2316 m 3 t −1 and 5224 CO 2 eq. ha −1 for the core zone, buffer zone, and experimental zone, respectively. In conclusion, we suggest that the maintenance of natural vegetation (sacsaoul) in desert ecosystems may be the optimal choice to cope with climate change and mitigate land desertification.