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Vegetation characteristics of pastoralist households' pastures at different economic levels were quantified to compare the grassland conditions in Sunite Right Banner, Inner Mongolia, China in 2011 and 2012. The results showed that the heights of Stipa klemenzis and Cleistogenes songorica were similar among economic treatments. And the height of Allium polyrhizm had no significant differences between high-economic-level (HEL) and low-economic-level (LEL) treatments. There were no significant difference among treatments in the canopy cover of C. songorica. The densities of dominant species (S. klemenzis, C. songorica and A. polyrhizm) were significantly similar among treatments. Aboveground community biomass in reference area (CK) was higher than that in other three treatments in 2011, but their biomass showed no significant difference among three economic treatments; for 2012, biomass in HEL was higher than low-economic-level treatment (LEL), while the biomass in middle-economic-level treatment (MEL) and CK was similar to that in HEL and LEL, respectively. Aboveground biomass of S. klemenzis and C. songorica was similar among treatments in both 2011 and 2012. Biomass of A. polyrhizum had no significant difference between HEL and MEL. Households of LEL had rented out excess lands and those of HEL had leased their available lands thus resulting uniform utilization and convergence of pastoralist households' pastures across all economic levels.

Vegetation classification models play an important role in studying the response of the terrestrial ecosystem to global climate change. In this paper, we study changes in global Potential Natural Vegetation (PNV) distributions using the Comprehensive Sequential Classification System (CSCS) approach, a technique that combines geographic information systems. Results indicate that on a global scale there are good agreements among maps produced by the CSCS method and the globally well-accepted Holdridge Life Zone (HLZ) and BIOME4 PNV models. The potential vegetation simulated by the CSCS approach has 6 major latitudinal zones in the northern hemisphere and 2 in the southern hemisphere. In mountainous areas it has obvious altitudinal distribution characteristics due to topographic effects. The distribution extent for different PNV classes at various periods has different characteristics. It had a decreasing trend for the tundra and alpine steppe, desert, sub-tropical forest and tropical forest categories, and an increasing trend for the temperate forest and grassland vegetation categories. The simulation of global CSCS-based PNV classes helps to understand climate-vegetation relationships and reveals the dynamics of potential vegetation distributions induced by global changes. Compared with existing statistical and equilibrium models, the CSCS approach provides similar mapping results for global PNV and has the advantage of improved simulation of grassland classes.

Snow is an important land cover on the earth's surface. It is characterized by its changing nature. Monitoring snow cover extent plays a significant role in dynamic studies and prevention of snow-caused disasters in pastoral areas. Using NASA EOS Terra/MODIS snow cover products and in situ observation data during the four snow seasons from November 1 to March 31 of year 2001 to 2005 in northern Xinjiang area, the accuracy of MODIS snow cover mapping algorithm under varied snow depth and land cover types was analyzed. The overall accuracy of MODIS daily snow cover mapping algorithm in clear sky condition is high at 98.5%; snow agreement reaches 98.2%, and ranges from 77.8% to 100% over the 4-year period for individual sites. Snow depth (SD) is one of the major factors affecting the accuracy of MODIS snow cover maps. MODIS does not identify any snow for SD less than 0.5 cm. The overall accuracy increases with snow depth if SD is equal to or greater than 3 cm, and decreases for SD below 3 cm. Land cover has an important influence in the accuracy of MODIS snow cover maps. The use of MOD10A1 snow cover products is severely affected by cloud cover. The 8-day composite products of MOD10A2 can effectively minimize the effect of cloud cover in most cases. Cloud cover in excess of 10% occurs on 99% of the MOD10A1 products and 14.7% of the MOD10A2 products analyzed during the four snow seasons. User-defined multiple day composite images based on MOD10A1, with flexibilities of selecting composite period, starting and ending date and composite sequence of MOD10A1 products, have an advantage in effectively monitoring snow cover extent for regional snow-caused disasters in pastoral areas.

Alpine meadow plays important roles in the animal production and conservation of water resources in the upper basin of Yellow River. In recent decades, desertification of this alpine meadow has resulted in changes in vegetation and soil features, as well as threatening the ecosystem functions and security. A field study was conducted to explain the response of vegetation pattern and soil features to desertification of alpine meadows. Results of vegetation studies indicated that hygrophytes were gradually replaced by mesophytes, xerophytes, and some annual psammophilous plants, and that cover and herbaceous biomass decreased along with the progressive desertification. Vegetation height increased in the slightly desertified stage, and then decreased in the very severe stage. Species diversity decreased, suggesting that desertification of alpine meadow contributedto species loss. This study also indicated that soil features gradually declined with increasing desertification of alpine meadow with soi...

Expansion of turf area together with irrigation have caused concern because of the increased demand for the scarce water resources in arid and semi‐arid regions. Kentucky bluegrass (KBG) (Poa pratensis) has been widely used to establish turf, and selecting varieties with good drought resistance is important in reducing irrigation requirements. Its seedling stage is the key step to successful establishment. Therefore, pot experiments in the greenhouse were carried out to assess drought resistance in 11 KBG varieties. The rate of germination, survival rate, and vertical growth rate of each variety increased as field water capacity (FWC) decreased from 70% (FWC 70) to 50% (FWC 50), and then decreased from 50% to 30% (FWC 30). Tillering rate and shoot‐to‐root ratio decreased as FWC decreased from FWC 70 to FWC 30. Proline content and electrolyte leakage (EL) in leaves of KBG at FWC 50 was lower than those at FWC 30 and FWC 70. Under FWC 30, representing drought stress, rate of germination, survival r...

Vitis piasezkii var. pagnucii is a Chinese wild grape species with high stress resistance, which could be used as a rootstock for wine grapes and table grapes. The present study was the first attempt for its in vitro micropropagation. Research was carried out regarding factors affecting shoot production and root initiation responses. ½ Murashige & Skoog (MS) medium supplemented with 0.2 mg/litre indoleacetic acid (IAA) resulted in the highest shoot production rate, earliest shoot development, most leaves, and least abnormal and etiolated leaves and shoots in the initial culture. ½ MS was the most suitable medium for rooting, shoot proliferation, and plantlet production of V. piasezkii var. pagnucii and Gansu (GS) medium was the second most suitable one. The highest rooting rate of shoots was obtained in ½ MS supplemented with 0.2 mg/litre IAA, 0.5 mg/litre indole‐3‐butyric acid (IBA) or 0.5 mg/litre α‐naphthaleneacetic acid (NAA). Rooting rate, root numbers per shoot, and root length decreased wh...