Climate Changes and Trends in Phenology of Woody and Herb Plants in Inner Mongolia, 1981–2010

The phenology of plants is a comprehensive reflection of seasonal climatological and ecological conditions and may be used as an indicator of climate change (Thomas et al. 2000; Volker and Annette 2004; Li et al. 2005). Analysis was made of the dates of sprouting, flowering and defoliating of woody and herb plants observed on 24 Agricultural Meteorological Stations in Inner Mongolia, China from 1980 to 2010. To assess the potential future change data was analysed for the 2011 to 2050 period using the England Hadley Climate Centre scenario (Wei et al. 2012)

Impacts of Future Climate Change on Net Primary Productivity of Grassland in Inner Mongolia, China

Net Primary Productivity (NPP) of grassland is a key variable of terrestrial ecosystems and is an important parameter for characterizing carbon cycles in grassland ecosystems. In this research, the Inner Mongolia grassland NPP was calculated using the Miami Model and the impact of climate change on grassland NPP was subsequently analyzed under the Special Report on Emissions Scenarios (SRES) A2, B2, and A1B scenarios, which are inferred from Providing Regional Climates for Impacts Studies (PRECIS) climate model system. The results showed that: (1) the NPP associated with these three scenarios had a similar distribution in Inner Mongolia: the grassland NPP increased gradually from the western region, with less than 200 g/m2/yr, to the southeast region, with more than 800 g/m2/yr. Precipitation was the main factor determining the grassland NPP; (2) compared with the baseline (1961-1990), there would be an overall increase in grassland NPP during three time periods (2020s: 2011-2040, 2050s: 2041-2070, and 2080s: 2071-2100) under the A2 and B2 scenarios; (3) under the A1B scenario, there will be a decreasing trend at middle-west region during the 2020s and 2050s; while there will be a very significant decrease from the 2050s to 2080s for middle Inner Mongolia; and (4) grassland NPP under the A1B scenario would present the most significant increase among the three scenarios, and would have the least significant increase under the B2 scenario

Agriculture intensifies soil moisture decline in Northern China

Northern China is one of the most densely populated regions in the world. Agricultural activities have intensified since the 1980s to provide food security to the country. However, this intensification has likely contributed to an increasing scarcity in water resources, which may in turn be endangering food security. Based on in-situ measurements of soil moisture collected in agricultural plots during 1983–2012, we find that topsoil (0–50cm) volumetric water content during the growing season has declined significantly (p < 0.01), with a trend of −0.011 to −0.015 m3 m−3 per decade. Observed discharge declines for the three large river basins are consistent with the effects of agricultural intensification, although other factors (e.g. dam constructions) likely have contributed to these trends. Practices like fertilizer application have favoured biomass growth and increased transpiration rates, thus reducing available soil water. In addition, the rapid proliferation of water-expensive crops (e.g., maize) and the expansion of the area dedicated to food production have also contributed to soil drying. Adoption of alternative agricultural practices that can meet the immediate food demand without compromising future water resources seem critical for the sustainability of the food production system

Spatial and Seasonal Variation in Rain Use Efficiency in Semiarid Grasslands of Inner Mongolia

Rain use efficiency (RUE) is an important indicator for identifying the response of plant production to variation in precipitation patterns, especially in semiarid ecosystem grasslands of Inner Mongolia. We have investigated the response and spatial patterns of RUE to precipitation patterns based on five years (2006, 2007, 2008, 2012, and 2013) of records from semiarid ecosystem sites across Inner Mongolia. Our results showed that RUE ADM was lowest in the wettest year (2012) and highest in the year following the driest year (2008). There was no significant correlation between RUE ADM and RUE TDM in typical and desert steppe. RUE TDM was strongly correlated with both annual precipitation (AP) and growing season precipitation (GSP) compared to RUE ADM . RUE ADM , therefore, cannot be used in place of RUE TDM . RUE ADM increased with species richness. The relationship between RUE ADM and species richness was significantly correlated in meadow steppe, typical steppe, and desert steppe. Our findings can shed light on the spatial utilization pattern of seasonal rainfall in semiarid grassland ecosystems

Spatial and Seasonal Variation in Rain Use Efficiency in Semiarid Grasslands of Inner Mongolia

Rain use efficiency (RUE) is an important indicator for identifying the response of plant production to variation in precipitation patterns, especially in semiarid ecosystem grasslands of Inner Mongolia. We have investigated the response and spatial patterns of RUE to precipitation patterns based on five years (2006, 2007, 2008, 2012, and 2013) of records from semiarid ecosystem sites across Inner Mongolia. Our results showed that RUEADM was lowest in the wettest year (2012) and highest in the year following the driest year (2008). There was no significant correlation between RUEADM and RUETDM in typical and desert steppe. RUETDM was strongly correlated with both annual precipitation (AP) and growing season precipitation (GSP) compared to RUEADM. RUEADM, therefore, cannot be used in place of RUETDM. RUEADM increased with species richness. The relationship between RUEADM and species richness was significantly correlated in meadow steppe, typical steppe, and desert steppe. Our findings can shed light on the spatial utilization pattern of seasonal rainfall in semiarid grassland ecosystems

Warming and Dimming: Interactive Impacts on Potential Summer Maize Yield in North China Plain

Global warming and dimming/brightening have significant implications for crop systems and exhibit regional variations. It is important to clarify the changes in regional thermal and solar radiation resources and estimate the impacts on potential crop production spatially and temporally. Based on daily observation data during 1961&#8722;2015 in the North China Plain (NCP), the impacts of climate change associated with climate warming and global dimming/brightening on potential light&#8722;temperature productivity (PTP) of summer maize were assessed in this study. Results show that the NCP experienced a continuous warming and dimming trend in maize growing season during the past 55 years, and both ATT10 and solar radiation had an abrupt change in the mid-1990s. The period of 2000&#8722;2015 was warmer and dimmer than any other previous decade. Assuming the maize growing season remains unchanged, climate warming would increase PTP of summer maize by 4.6% over the period of 1961&#8722;2015, which mainly occurred in the start grain filling&#8722;maturity stage. On the other hand, as negative contribution value of solar radiation to the PTP was found in each stage, dimming would offset the increase of PTP due to warming climate, and lead to a 15.6% reduction in PTP in the past 55 years. This study reveals that the changes in thermal and solar radiation have reduced the PTP of summer maize in the NCP. However, the actual maize yield could benefit more from climate warming because solar radiation is not a limiting factor for the current low production level