Sinadoxa corydalifolia is a perennial grass with considerable academic value as a rare species owing to habitat destruction and a narrow distribution. However, its distribution remains unclear. In this study, we predicted the distribution of Sinadoxa corydalifolia in the three-river region (the source of the Yangtze River, Yellow River, and Lancang River) under the context of climate change using the maximum entropy (MaxEnt) model. Under the current climate scenario, the suitable distribution mainly occurred in Yushu County and Nangqian County. The suitable distribution area of Sinadoxa corydalifolia covered 3107 km², accounting for 0.57% of the three-river region. The mean diurnal air temperature range (Bio2), temperature seasonality (Bio4), and mean air temperature of the driest quarter (Bio9) contributed the most to the distribution model for Sinadoxa corydalifolia, with a cumulative contribution of 81.4%. The highest suitability occurred when air temperature seasonality (Bio4) ranged from 6500 to 6900. The highest suitable mean air temperature of the driest quarter ranged from −5 to 0 °C. The highest suitable mean diurnal temperature (Bio2) ranged from 8.9 to 9.7 °C. In future (2041–2060) scenarios, the suitable distribution areas of Sinadoxa corydalifolia from high to low are as follows: representative concentration pathway (RCP)26 (6171 km²) > RCP45 (6017 km²) > RCP80 (4238 km²) > RCP60 (2505 km²). In future (2061–2080) scenarios, the suitable distribution areas of Sinadoxa corydalifolia from high to low are as follows: RCP26 (18,299 km²) > RCP60 (11,977 km²) > RCP45 (10,354 km²) > RCP80 (7539 km²). In general, the suitable distribution will increase in the future. The distribution area of Sinadoxa corydalifolia will generally be larger under low CO₂ concentrations than under high CO₂ concentrations. This study will facilitate the development of appropriate conservation measures for Sinadoxa corydalifolia in the three-river region.

Human appropriation of net primary productivity (HANPP) is an important indicator for assessing ecological sustainability. However, the spatiotemporal dynamics of HANPP in the Qinghai grasslands remain unclear. In this study, we used the spatially explicit Biome-BGCMuSo model to quantify and map HANPP in the Qinghai grasslands from 1979 to 2018. Generally, the actual net primary productivity (NPP_act) was slightly lower than the potential net primary productivity (NPP_pot), and the difference between the NPP_pot and NPP_act increased slightly over time. From 1979 to 2001, the NPP_pot and NPP_act were relatively stable; however, from 2001 to 2018, both showed significant fluctuating upward trends. From 1979 to 2018, HANPP showed a fluctuating upward trend from 6.36 to 31.85 gC/m²/yr, with an average increase of 2.14 gC/m²/yr. The average HANPP was 16.90 gC/m²/yr, which represented 18.80% of the NPP_pot of Qinghai grasslands. High HANPP mainly occurred in eastern Qinghai, whereas it was low in central and western Qinghai. Conversely, from 1979 to 2018, the HANPP efficiency decreased in a fluctuating way from 98.28% to 72.05%, with an average annual decrease of 0.66%. The interannual variations in the HANPP efficiency and harvest were negatively correlated, with a correlation coefficient of −0.46 (p < 0.01). The average HANPP efficiency was 85.33%, and the values in most grids were between 80% and 100%, being relatively low in southern and eastern Qinghai. In rare cases, the HANPP efficiency was greater than 1. This study clarifies the details of spatiotemporal dynamics of HANPP in the Qinghai grasslands and indicates the need to optimize local management of grassland resources to ensure future ecological sustainability.

Background: Global warming can cause variation in plant functional traits due to phenotypic plasticity or rapid microevolutionary change. Seed mass represents a fundamental axis of trait variation in plants, from an individual to a community scale. Here, we hypothesize that long-term warming can shift the mean seed mass of species.Methods: We tested our hypothesis in plots that had been warmed over 18 years in alpine meadow communities with a history of light grazing (LG) and heavy grazing (HG) on the Qinghai-Tibet plateau. In this study, seeds were collected during the growing season of 2015.Results: We found that warming increased the mean seed mass of 4 (n = 19) species in the LG meadow and 6 (n = 20) species in the HG meadow, while decreasing the mean seed mass of 6 species in the LG and HG meadows, respectively. For 7 species, grazing history modified the effect of warming on seed mass. Therefore, we concluded that long-term warming can shift the mean seed mass at the species level. However, the direction of this variation is species-specific. Our study suggests that mean seed mass of alpine plant species appears to decrease in warmer (less stressful) habitats based on life-history theory, but it also suggests there may be an underlying trade-off in which mean seed mass may increase due to greater thermal energy inputs into seed development. Furthermore, the physical and biotic environment modulating this trade-off result in complex patterns of variation in mean seed mass of alpine plant species facing global warming.