2023年5月11日 · Total NPP and other subtypes of regional NPP of drylands increased in the past 20 years, with the highest growth rate of 5.15 g C m −2 yr −1 in the dry sub-humid area, followed by the semi-arid area (3.21 g C m −2 yr −1), the hyper-arid area (0.91 g C m −2 yr −1), and the arid area (0.91 g C m −2 yr −1).