增温对荒漠草原不同退化程度草地恢复初期影响的研究

为探讨增温对短花针茅(Stipa breviflora)荒漠草原不同退化程度草地恢复初期的影响，本研究以天然草地为对照，在不同退化程度的自然恢复草地上设置增温处理。增温一年后，在2021年8月测定增温处理下天然草地和不同退化程度草地恢复初期植物的高度、密度和生物量，并计算重要值和植物多样性指数。结果表明：增温降低了天然草地和轻度退化草地的物种数；增温和退化的交互作用极显著降低群落地上生物量和C₃植物生物量(P<0.01)，增温显著增加了天然草地的地上生物量，显著降低了重度退化草地的地上生物量(P<0.05)；增温和退化的交互作用对物种多样性无显著影响，但增温增加了天然草地的群落多样性，降低了退化草地的群落多样性；增温增强了不同退化程度草地物种多样性与地上生物量和不同功能群生物量的相关性。综上所述，在未来全球持续变暖的趋势下，退化草地的初期恢复将变得更加困难。

Effects of Warming on Early Restoration of Degraded Grassland in Desert Steppe

To explore the effects of warming on the restoration of stipa breviflora desert steppe at different degraded stages,this study took natural grassland as the control,and set two treatments of natural restoration and warming on grassland with different degrees of degradation. In August 2021,the height,density,and biomass of plants under natural restoration and warming treatments were measured in natural grassland and different degraded grassland,and the important value and plant diversity index was calculated. The results showed that:Warming reduced the number of species in natural grassland and mildly degraded grassland; The interaction of warming and degradation significantly reduced aboveground biomass and C₃ plant biomass of the community (P<0.01),and warming significantly increased aboveground biomass of natural grasslands while significantly decreased aboveground biomass of heavily degraded grasslands (P<0.05); The interaction of warming and degradation had no significant effect on species diversity but warming increased the community diversity of natural grassland,while decreased that of degraded grassland; Warming increased the correlation between species diversity and aboveground biomass and biomass of different functional groups in grasslands with different degrees of degradation. In summary,the early recovery of degraded grasslands will become more difficult under the future trend of continued global warming.