Effects of Multi-gradient Nitrogen and Phosphorus Additions on Biomass and Nitrogen and Phosphorus Content of Alpine Meadow Plant Community [多梯度氮磷添加对高寒草甸植物群落生物量与氮磷含量的影响]

作者：Liu Y.; Chen M.-J.; Guo T.-T.; Cui J.; Li L.-P.; Liang D.-F.; Li Y.-H.; Zhang Z.-H.; Zhu X.-X.; Ren F.^*

来源：草地学报, 2023, 31(3): 751-759.

DOI：10.11733/j.issn.1007-0435.2023.03.015

• Alpine meadow
• Biomass
• Nitrogen and phosphorus addition
• Nitrogen phosphorus ratio
• Nutrient content

Under the background of global climate and environmental change, to explore the effects of different gradients of nitrogen and phosphorus additions on plant community biomass, plant nutrient content and stoichiometric ratio of alpine meadow, this paper analyzed the responses of the total aboveground biomass, the aboveground biomass of functional groups, total nitrogen and total phosphorus content, and nitrogen and phosphorus ratio of plants to the multi-gradient nitrogen and phosphorus additions of typical alpine meadow in Menyuan County, Qinghai Province. The results showed that: the additions of nitrogen and phosphorus had a significant effect on the aboveground biomass of the community (P< 0.001); the nitrogen addition significant effects on the biomass of grasses and legumes (P< 0.001); the phosphorus addition significant effects on the biomass of grasses and sedges (P< 0.001); the interaction of nitrogen additions and phosphorus additions significant effects on aboveground biomass of legumes and sedges (P< 0.05). At the community level, nitrogen addition significantly increased the total nitrogen (TN) content of the community plants, and had a positive effect on the nitrogen to phosphorus ratio (N: P) of the community plants. Phosphorus addition significantly increased the total phosphorus (TP) content of the community plants, and had a negative effect on plant N: P ratio in community. The negative effect of plant TP on N: P was greater than the positive effect of TN on plant N: P ratio. Our study demostrated that the addition of nitrogen and phosphorus may change the composition and nutrient content of alpine meadow plant community, and the community would gradually develop to grassland; In addition, the growth of alpine meadow plants tends to be restricted by both nitrogen and phosphorus.