[Responses of soil invertase and urease activities to warming and plant removal during the growing season in an alpine scrub ecosystem.].

To understand the effects of climate warming and vegetation disturbance on soil ecological process during different stages of growing season in the alpine scrub ecosystem, the responses of soil invertase and urease activities to warming (0.6-1.3 ℃) and plant removal were investigated in a Sibiraea angustata scrubland on the eastern Qinghai-Tibetan Plateau, China. The results showed that experimental warming significantly increased soil invertase activity by 3.7%-13.3% in the removal- and unremoval-plant plots throughout the entire growing season. Warming significantly increased soil urease activity by 10.8%-56.3% in the removal- and unremoval-plant plots, except the late growing stage, during which warming had no significant effect on soil urease activity in the unremoval-plant plots. The effects of plant removal treatments on soil invertase and urease activities varied with warming and growing stages. Plant removal significantly decreased soil invertase activity of the warmed plots during the entire growing season and the unwarmed plots during the early and late growing stages, but did not affect soil invertase activity in the unwarmed plots during the mid-growing stage. Plant removal only significantly decreased soil urease activity by 10.5% in the unwarmed plots during the late growing stage. However, in the warmed plots, plant removal significantly decreased soil urease activity by 16.0%-18.7% during the early and mid growing stages. The results would increase our understanding of soil carbon and nitrogen cycling process in the alpine scrub ecosystems.