State Key Laboratory of Desert and Oasis Ecology, Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
State Key Laboratory of Desert and Oasis Ecology, Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
Sci Total Environ. 2023 Dec 1;902:166059. doi: 10.1016/j.scitotenv.2023.166059. Epub 2023 Aug 4.
It is important to elucidate the changing distribution pattern of net primary productivity (NPP) to mechanistically understand the changes in aboveground and belowground ecosystem functions. In water-scarce desert environments, snow provides a crucial supply of water for plant development and the spread of herbaceous species. Yet uncertainty persists regarding how herbaceous plants' NPP allocation responds to variation in snow cover. The goal of this study was to investigate how variation in snow cover in a temperate desert influenced the NPP allocation dynamics of herbaceous species and their resistance to environmental change in terms aboveground and belowground productivity. In the Gurbantunggut Desert, wintertime snow cover depth was adjusted in plots by applying four treatments: snow removal (-S), ambient snow, double snow (+S), and triple snow (+2S). We examined their species richness, aboveground NPP (ANPP), belowground NPP (BNPP), and the resistance of ANPP and BNPP. We found that species diversity of the aboveground community increased significantly with increasing snow cover and decreased significantly Pielou evenness in plots. This resulted in greater ANPP with increasing snow cover; meanwhile, BNPP first increased and then decreased with increasing snow cover. However, this productivity in different soil layers responded differently to changed snow cover. In the 0-10 cm soil layer, productivity first rose and then declined, while it declined linearly in both the 10-20 cm and 20-30 cm soil layers, whereas in the 30-40 cm soil layer it showed an increasing trend. Belowground resistance would increase given that greater snow cover improved the BNPP in deeper soil and maintained the resource provisioning for plant growth, thus improving overall belowground stability. These results can serve as a promising research foundation for future work on how the functioning of desert ecosystems becomes altered due to changes in plant community expansion and, in particular, changes in snow cover driven by global climate change.
阐明净初级生产力(NPP)的变化分布模式对于从机制上理解地上和地下生态系统功能的变化非常重要。在水资源匮乏的沙漠环境中,雪为植物的生长和草本物种的传播提供了至关重要的水源。然而,对于草本植物的 NPP 分配如何响应积雪覆盖的变化,仍存在不确定性。本研究的目的是调查温带沙漠中冬季积雪覆盖的变化如何影响草本物种的 NPP 分配动态及其对地上和地下生产力的环境变化的抵抗力。在古尔班通古特沙漠,通过应用四种处理方法(去除雪 [-S]、环境雪、双倍雪 [+S] 和三倍雪 [+2S])来调整试验区的冬季积雪覆盖深度。我们检查了它们的物种丰富度、地上 NPP(ANPP)、地下 NPP(BNPP)以及 ANPP 和 BNPP 的抵抗力。我们发现,随着积雪覆盖的增加,地上群落的物种多样性显著增加,而在斑块中的 Pielou 均匀度显著下降。这导致随着积雪覆盖的增加,ANPP 增加;同时,BNPP 随着积雪覆盖的增加先增加后减少。然而,不同土壤层中的这种生产力对变化的积雪覆盖的响应不同。在 0-10 cm 土壤层中,生产力先上升后下降,而在 10-20 cm 和 20-30 cm 土壤层中,生产力呈线性下降,而在 30-40 cm 土壤层中,生产力呈上升趋势。由于更大的积雪覆盖可以改善深层土壤中的 BNPP 并维持植物生长的资源供应,因此地下阻力会增加,从而提高整体地下稳定性。这些结果可以作为未来研究的有希望的基础,研究由于植物群落扩张以及特别是全球气候变化驱动的积雪覆盖变化而导致沙漠生态系统功能如何发生变化。