Influence of climate change on potential productivity of naked barley in the Tibetan Plateau in the past 50 years

This paper mainly analyzed climate trend during growth and crucial growth periods of naked barley in the Tibetan Plateau from 1965 to 2013. The study used average temperature, precipitation, sunshine duration and other meteorological data from 106 meteorological stations allocated in the Tibetan Plateau for the past 50 years. In the paper, tendency analysis, Thornthwaite Memorial model, geographical information system (GIS), statistical product and service solution (SPSS) techniques were used to analyze potential climate productivity of naked barley. Then the features of temporal and spatial variations and the effects of climate change on the development and yield of naked barley as well as the effects of various meteorological factors on the climate potential productivity of naked barley in the Tibetan Plateau in the past 50 years were analyzed. The results showed, 1) there was an increasing trend in temperature (0.53 ℃10a^-1) and precipitation (7.8 mm10a^-1) in the Tibetan Plateau in the past 50 years. While temperature increased significantly, the increase in precipitation was not significant. Also there was an obvious decrease in sunshine duration (16.9 h10a^-1). 2) While temperature (0.4 ℃10a^-1) and precipitation (7.2 mm10a^-1) increased during naked barley growth period in the Tibetan Plateau, sunshine duration (15 h10a^-1) significantly decreased during naked barley growing season. There was an obvious warming tendency in the northern zone of the Tibetan Plateau, significant increase in precipitation in the central region of the Tibetan Plateau and then an obvious decline in sunshine duration in the northeast part of the Tibetan Plateau. 3) Climate potential productivity of naked barley increased in the Tibetan Plateau (136.7 kghm^-210a^-1) from 1965 to 2013. The magnitude of increase was larger for the central region than for other regions of the Tibetan Plateau. However, there was a decreasing trend in climate potential productivity of naked barley in the southeastern edge of the plateau, the northern part of Qaidam Basin in Qinghai Province and the northwestern region of Tibet. 4) Precipitation and temperature had significantly positive correlation with climate potential productivity of naked barley. Conversely, sunshine duration was negatively correlated with climate potential productivity of naked barley. Precipitation was the most critical factor affecting climate potential productivity of naked barley during the growing season and the key growth stages, followed by temperature. Finally, the study proposed measures to use of climatic factors to enhance climate potential productivity of naked barley.