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• Increased precipitation consistently promotes biomass production in both grasslands. • Elevated temperature suppresses biomass production in temperate grassland. • Elevated temperature promotes biomass production in alpine grassland. • Climatic factors play a pivotal role mainly by soil factors. Comparisons of vegetation production between temperate and alpine grasslands are not well studied, and the understanding of the underlying mechanisms is still incomplete. To address this issue, we selected the Inner Mongolia and Tibet regions to conduct large-transect surveys for temperate grassland (TG) and alpine grassland (AG), respectively, in China, to reveal the universal and differential mechanisms of above- and belowground biomass production (GB, AGB and BGB) and precipitation use efficiencies (PUE) in the two grasslands. The relative importance of climatic factors on biomass and PUE is greater than that of soil and biological factors. Elevated mean annual precipitation (MAP) consistently increased GB in both TG and AG. Increased mean annual temperature (MAT) reduced GB by weakening the soil nutrient status in TG, whereas it increased GB by improving the soil nutrient status in AG. MAP promoted more AGB than BGB in TG, whereas MAT affected BGB more than AGB in AG. When the multicomponent heterogeneity of other factors in grasslands was eliminated, the effect of MAP on GB remained significant for both TG and AG. After removing the effect of multifactorial heterogeneity, however, the significant effect of MAP on PUE of the two grasslands was largely enhanced. From these results, we can conclude that climatic factors do not always exert identical effects on different grasslands. In particular, highlighting the divergent mechanisms of biomass production and precipitation use efficiency between temperate and alpine grasslands can improve the understanding of the carbon sink and hydraulic sensitivity of various grasslands. [Display omitted] [ABSTRACT FROM AUTHOR]

Precipitation fluctuations with high nitrogen (N) deposition severely impact terrestrial ecosystem functioning, particularly in arid areas. Here, with rainout shelter facility, a field experiment with a large variation in precipitation and N addition was conducted to disentangle the responses of the plant community to normal precipitation, less precipitation, and rewetting conditions in a desert steppe, Inner Mongolia, northern China. The field experiment established a unique annual precipitation change cycle across normal precipitation, less precipitation, and rewetting processes to quantify drought resistance, recovery and resilience by calculating functional differences among three years. Furthermore, the relationships between plant community functional traits and response indices (i.e., the resistance, recovery, and resilience) were tested to clarify the mechanisms driving their responses to precipitation regimes and N addition. The aboveground net primary production (ANPP) increased with annual precipitation and was enhanced by N addition. ANPP with reduced precipitation regimes was less resistant to drought but recovered significantly greater than that with increased precipitation regimes. The perennial species, C 3 plants, and forbs mainly contributed to the variations in vegetation productivity in response to drought and wet status cycles. Drought resistance and the recovery of species' functional diversity, evenness, and ANPP stability were closely associated with precipitation changes. The present findings suggested that altered precipitation patterns, community composition, and functional stability contribute to ecosystem stability during water change cycles and are mediated slightly by N deposition. These findings advance understanding of the mechanisms of ecosystem functioning underlying the responses to climatic change. • ANPP increased with increasing precipitation and it enhanced by N addition. • ANPP resistance increased, but recovery decreased with increasing precipitation. • Perennial, C 3 , forb species contributed to variations in vegetation production. • Resistance and recovery of biodiversity were closely related to ANPP stability. • Resistance, recovery and resilience were not significantly affected by N deposition. [ABSTRACT FROM AUTHOR]

• Plant responses to two warming levels were investigated across multiple years. • Decreased soil moisture related to warming caused a significant reduction of ANPP. • Warming and associated drought reduced temporal stability of the plant community. • Shift in plant community composition is crucial for the response to climate change. An investigation of the influences of climatic warming on ecosystem function and stability is crucial to project the impact of global climate change on terrestrial ecosystems. However, few studies have applied multiple warming treatments in arid ecosystems, which play a critical role in the global carbon cycle and are among the ecosystems most sensitive to future climatic change. To explore the effects of climatic warming on plant community function and stability, moderate warming and acute warming treatments were conducted in desert grassland, Inner Mongolia, China, using free-air temperature increase facilities. Aboveground net primary production (ANPP) of plant community significantly decreased with climatic warming, particularly in warmer years with drier conditions. The decrease in ANPP was mainly caused by decreased soil moisture induced by climatic warming. Climatic warming reduced the temporal stability of the plant community by weakening plant species asynchrony and shifting key functional groups, such as perennial vs annual grass and C 3 vs C 4 species. Our findings indicate that climatic warming could hamper plant community productivity via decreased soil moisture and constrain plant community functioning by weakening community stability. This result highlights that shifts in plant community composition and consequent functional changes can play a key role in predicting the responses of arid ecosystems to climatic change. [ABSTRACT FROM AUTHOR]