Dong Ruizhen, Yang Shihai, Wang Xiaoli, Xie Lele, Ma Yushou, Wang Yanlong, Zhang Litian, Zhang Min, Qin Jinping
Qinghai Provincial Key Laboratory of Adaptive Management on Alpine Grassland, Qinghai Academy of Animal and Veterinary Science, Qinghai University, Qinghai Province, Xining, Qinghai, China.
Tibet Yunwang Industrial Co., Ltd, R & D Department, Shigatse, Tibet, China.
Front Plant Sci. 2023 Jan 11;13:1060686. doi: 10.3389/fpls.2022.1060686. eCollection 2022.
The alpine sandy dune ecosystem is highly vulnerable to global climate change. Ecological stoichiometry in plants and soils plays a crucial role in biogeochemical cycles, energy flow and functioning in ecosystems. The alpine sandy dune ecosystem is highly vulnerable to global climate change. However, the stoichiometric changes and correlations of plants and soils among different types of sandy dunes have not been fully explored. Three sandy dune types (moving dune, MD; semifixed dune, SFD; and fixed dune, FD) of the shrub in the middle reaches of the Yarlung Zangbo River were used as the subjects in the current study. Plant community characteristics, soil physicochemical properties, carbon (C), nitrogen (N), and phosphorus (P) contents of leaves, understorey herbs, litter, and soil microbes were evaluated to explore the C:N:P stoichiometry and its driving factors. Sandy dune type significant affected on the C:N:P stoichiometry in plants and soils. High soil N:P ratio was observed in FD and high plant C:P and N:P ratios in SFD and MD. The C:N ratio decreased with sand dune stabilization compared with other stoichiometric ratios of soil resources. Leaf C:P and N:P ratios in were higher than those in the understorey herb biomass, because of the low P concentrations in leaves. C, N and P contents and stoichiometry of leaves, understorey herbs, litter and microbe were significantly correlated with the soil C, N and P contents and stoichiometry, with a higher correlation for soil N:P ratio. P was the mainly limiting factor for the growth of population in the study area and its demand became increasingly critical with the increase in shrub age. The variation in the C:N:P stoichiometry in plants and soils was mainly modulated by the soil physicochemical properties, mainly for soil moisture, pH, available P and dissolved organic C. These findings provide key information on the nutrient stoichiometry patterns, element distribution and utilization strategies of C, N and P and as well as scrubland restoration and management in alpine valley sand ecosystems.
高山沙丘生态系统极易受到全球气候变化的影响。植物和土壤中的生态化学计量在生物地球化学循环、能量流动及生态系统功能中起着关键作用。高山沙丘生态系统极易受到全球气候变化的影响。然而，不同类型沙丘间植物与土壤的化学计量变化及相关性尚未得到充分研究。本研究以雅鲁藏布江中游的三种沙丘类型（流动沙丘，MD；半固定沙丘，SFD；固定沙丘，FD）的灌木为研究对象。通过评估植物群落特征、土壤理化性质、叶片、林下草本植物、凋落物及土壤微生物的碳（C）、氮（N）和磷（P）含量，来探究C:N:P化学计量及其驱动因素。沙丘类型对植物和土壤中的C:N:P化学计量有显著影响。在固定沙丘中观察到高土壤N:P比，在半固定沙丘和流动沙丘中观察到高植物C:P和N:P比。与土壤资源的其他化学计量比相比，随着沙丘稳定，C:N比降低。叶片中的C:P和N:P比高于林下草本植物生物量中的比值，这是因为叶片中P浓度较低。叶片、林下草本植物、凋落物和微生物的C、N和P含量及化学计量与土壤C、N和P含量及化学计量显著相关，与土壤N:P比的相关性更高。P是研究区域内灌木种群生长的主要限制因素，且随着灌木年龄的增加，其需求变得越来越关键。植物和土壤中C:N:P化学计量的变化主要受土壤理化性质调节，主要是土壤湿度、pH值、有效P和溶解有机碳。这些发现为高山河谷沙地生态系统中养分化学计量模式、C、N和P的元素分布及利用策略以及灌丛恢复与管理提供了关键信息。
