Normalized difference vegetation index (NDVI) is commonly used to indicate vegetation density and condition. NDVI was mostly correlated with climate factors. We analyzed changing trends of NDVI in different types of grassland in Inner Mongolia and the response of NDVI to climatic variation from 1982 to 2011. NDVI of meadow steppe increased significantly in spring while it decreased in other seasons. The annual mean NDVI in typical steppe and desert steppe increased significantly in the last 30a. However, in the greatest area of steppe desert, the NDVI had no significant change in summer, autumn, and the growing season. In meadow steppe, typical steppe, and desert steppe, the area showed a positive correlation of NDVI to temperature as highest in spring compared to other seasons, because warming in spring is beneficial to the plant growth. However, in the greatest area of steppe desert, the correlation of NDVI to temperature was not significant. The NDVI was positively correlated to precipitation in four types of grassland. In the steppe desert, the precipitation had no significant effect on the NDVI due to the poor vegetation cover in this region. The NDVI was not significantly correlated to the precipitation in autumn because of vegetation withering in the season and not need precipitation. Precipitation was a more important factor rather than temperature to NDVI in the region. The response of NDVI to temperature and precipitation in different seasons should be studied in more detail and the effect of other factors on NDVI should be considered in future research.

The Stipa grandis steppe is a type of steppe in the Central Asian sub-region, and it is an important resource for livestock production in China. Mowing is one of the main management methods for this steppe. Verifying the response of the Stipa grandis steppe communities to different mowing frequencies is essential for the rational utilization of pastures and the protection and recovery of natural steppe. In this study, we investigated the community characteristics and compensatory growth of important species of the Stipa grandis steppe community under four mowing frequencies (TAY: twice a year; OAY: once a year; OTY: once every other year; NM: no mowing/enclosure), and found that different frequencies of mowing significantly influenced the community characteristics and the compensatory growth of dominant plant species. In the enclosure, species density was significantly lower, and height and biomass were significantly greater than in the mowing treatments. At the beginning of the growing season, mowing had a significant impact on the individual miniaturization of Stipa grandis, Leymus chinensis, and Anemarrhena asphodeloides. Mowing also had a significant impact on the diversity of the community. The Shannon diversity index, the Pielou evenness index, and the richness index were higher under OTY than other mowing frequencies. Under different mowing frequencies, growth rates were significantly different after the aboveground portions were cut, while the levels of biomass were not significantly different. Stipa grandis, Leymus chinensis, and Anemarrhena asphodeloides had less compensatory height growth under OAY compared to the other treatments; however, there were no significant differences in the relative growth rates of the three species under different treatments. Stipa grandis exhibited equivalent compensatory height growth; both Leymus chinensis and Anemarrhena asphodeloides exhibited over-compensatory growth. Based on the results of community characteristics and the compensatory growth of the dominant species, mowing every other year is currently the most practical mowing system.

The temporal stability of aboveground net primary productivity is generally regulated by plant community structure and species diversity. There are recurring debates on the mechanisms by which environmental changes impact productivity stability in semiarid steppes. Here we revealed that plant community structure, rather than species diversity, regulates productivity stability in a semiarid Steppe. We conducted a decade-long in situ warming and precipitation addition experiment in a semiarid steppe in Inner Mongolia, China, to monitor plant productivity, species asynchrony, species diversity, and stability. We found that Leymus chinensis productivity increased and the Shannon–Wiener decreased under warming conditions, while Stipa krylovii productivity decreased under precipitation addition. Warming reduced the stability of Stipa krylovii and the plant community stability, whereas it did not affect the stability of L. chinensis. These results deepen our understanding of the regulatory role played by community structure and species diversity regarding productivity stability in semiarid steppes.

Located in the interior of Eurasia, the Mongolian Plateau (MP) is extremely sensitive to global warming and become a critical area for studying precipitation patterns. Based on the monthly data of 135 meteorological stations during 1976–2017, we analyze the spatiotemporal change in precipitation and discuss its response to atmospheric circulation. The results show that: (1) Precipitation shows increasing trends in spring, autumn, and winter, but a decreasing trend at a rate of 5.3 mm/decade in summer. The annual precipitation also shows an overall slight decreasing trend. (2) The spatial distribution is uneven, the annual precipitation in the northern Great Khingan Mountains is more, but it gradually decreases at the rate of 10–30 mm/decade, showing a trend of “wet gets dry”; while there is less in the southwest Gobi Desert region, but it gradually increases with the rate of 10–20 mm/decade, showing a trend of “dry gets wet”. (3) Over decades, the East Asian summer monsoon (EASM) and westerly circulation show a seesaw change in MP. Affected by the weakening of the EASM, the area of arid regions has gradually expanded. The results also demonstrate that the EASM has a higher impact on the annual precipitation change pattern, particularly in the southeastern MP. The conclusion indicated that the variation in the position and orientation between EASM and the westerly circulation may be an explanation for the spatiotemporal precipitation pattern, providing a new viewpoint to the question of circulation mechanisms behind climate change in MP in recent 40 years.