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The formation and development of blowouts is an important surface indication of sand drift activity in the Hulun Buir sandy grassland and the main cause of landscape pattern heterogeneity. In this study, dynamic changes and determinants of blowouts in this region were studied via analysis of multi‐period high‐resolution remote sensing data from 1959 to 2018. The different stages of activity and dominant factors of the fixation and activation of blowouts were analysed with Lancaster's M‐index. The results show that the activity of blowouts in Hulun Buir sandy grassland can be divided into three stages from 1959 to 2018: (I) growth and expansion stage, from 1959 to 2004; (II) fixation and grassland recovery stage, from 2005 to 2010; (III) redevelopment stage, from 2011 to 2018. The two geomorphic units of depressions and depositional lobes exhibit different responses to changes in climatic factors. The depositional lobes are more sensitive to the change in external factors with better feedback and their areas and numbers change with the variation of stage, while depressions exhibit relatively slow changes. The wind regime is the dominant factor explaining the variation of activity of blowouts, with precipitation and potential evapotranspiration as secondary factors for this region. Roads have little effect on the development and deformation of blowouts, but the movement of cattle and sheep across the region has a big influence. Therefore, the desertification process of Hulun Buir grassland is driven by both natural and human factors. [ABSTRACT FROM AUTHOR]

The Xilingol steppe, located in Inner Mongolia, northern China, is a natural grassland well known for producing high-quality feed for grazing animals. Our regression analysis using the meteorological data recorded at the Xilingol Meteorological Observatory from 1953 to 2000 (48 years) indicated that the annual mean temperature rose by 2.66°C during 50 years from 1953, while the mean temperature during the plant growing season (April-October) rose by 2.10°C during the same period. These temperature rises at the Xilinhot Observatory are more than twice that found in other regions of China. In the same 48-year period, no significant changes in annual precipitation amounts were noted; however, the annual precipitation days significantly decreased. We must clarify the factors causing climate change in this region and how such change will impact future productivity and biodiversity in this semiarid grassland. [ABSTRACT FROM AUTHOR]

Annual growth rings of roots in perennial forbs have been used in studies of climate change and the ecology of grasslands. However, little has been done in this aspect of research in China. In this study, we report the characteristics of growth rings in the main roots of 13 herb species sampled in Duolun of the Inner Mongolia grassland in northern China. The results show that around two thirds of the species possess clearly demarcated annual rings in the root xylem. Some species of the same genera show different patterns in anatomical structure of the root xylem. Standardized annual ring widths of three species, Potentilla anserine L., Cymbaria dahurica L. and Lespedeza daurica (Laxm.) Schindl., show a common linear trend, indicating a continued favorable growth condition in the sampling sites. Our results provide evidence that growth rings in roots of some perennial forbs in the Inner Mongolia grassland can serve as a new and useful indicator of past changes in the grassland environment. [ABSTRACT FROM AUTHOR]