[Effects of elevated CO concentration on production and water use efficiency of spring wheat in semi-arid area].

In the present study, the response of spring wheat production and water use efficiency (WUE) to the elevated CO concentrations was investigated based on the open-top chamber (OTC) experiment platform in Dingxi, a typical semi-arid area. Three different CO concentrations (390 μmol·mol, 480 μmol·mol and 570 μmol·mol) were involved. The results showed that the air temperature above plant canopy increased and the soil temperature at depth of 10 cm decreased by elevated CO.

[Effects of increasng field temperature on growth, development and yield of spring wheat in semi-arid area].

A field infrared temperature-increasing simulation experiment was conducted to investi- gate the effects of air temperature increases (0, 1 and 2 °C ) on growth, development and yield of spring wheat at the Dingxi Arid Meteorology and Ecological Environment Experimental Station of the Institute of Arid Meteorology of China Meteorological Administration. The results showed that the growth period of spring wheat was shortened by 7-11 d when the temperature increased by 1-2 °C. The plant height and leaf area index increased at early growth stage, decreased after entering the jointing stage, and warming 2 °C had a higher effect than warming 1 °C.

[Effects of air temperature increase and precipitation change on grain yield and quality of spring wheat in semiarid area of Northwest China].

In order to predict effects of climate changing on growth, quality and grain yields of spring wheat, a field experiment was conducted to investigate the effects of air temperature increases (0 °C, 1.0 °C, 2.0° C and 3.

[Characteristics of evapotranspiration and crop coefficient of agroecosystems in semi-arid area of Loess Plateau, Northwest China].

Evapotranspiration (ET) is an important component of ground surface energy balance and water balance, and closely related to water cycle. By using eddy covariance technique, this paper studied the ET characteristics of agroecosystems in the semi-arid area of Loess Plateau in growth season (from April to September), 2010, and analyzed the relationships between crop coefficient and environmental factors. During the observation period, the diurnal variation of latent heat flux (LE) in each month was similar to single-peak curve, and the peak value (151.

[Effects of climate warming on oil flax growth and water use efficiency in semi-arid region of Loess Plateau, Northwest China].

By using the site-specific observation data of oil flax growth and related meteorological records in semi-arid region of Loess Plateau, this paper studied the effects of climate change on the oil flax growth, and analyzed the relationships between the oil flax water use efficiency and meteorological condition. In this region, the annual precipitation displayed a decreasing trend, and its climatic trend rate was -15.80 mm (10 a)(-1), with an annual periodic change of 3 a and 6 a, whereas the annual air temperature had an increasing trend, and its climatic trend rate was 0.

[Effects of climate change on potato growth in semi-arid region of Loess Plateau, China].

Based on the 1988-2008 located observation and 2007-2008 encrypted observation of potato growth and the 1957-2008 meteorological observation in semi-arid region of Loess Plateau, this paper studied the effects of climate change on the potato growth in this region. In 1957-2008, the annual precipitation in this region had a descending trend, with a linear fitting rate of the annual precipitation change curves being - 13.359 mm x (10 a)(-1), while the annual mean temperature displayed an ascending trend, with a linear fitting rate of the annual mean temperature change curves being 0.

[Effects of air temperature change on spring wheat growth at different altitudes in northwest arid area].

Based on the 1981-2006 observation data from agricultural meteorological stations at Minle (high altitude) and Zhangye (low altitude) in northwest arid area, the effects of air temperature change at the two altitudes on the growth and yield of spring wheat were studied. It was shown that during study period, the air temperature at the two altitudes had an increasing trend, and the increment was greater at high altitude than at low altitude. At high altitude, the growth duration of spring wheat shortened but the grain yield increased; while at low altitude, the growth duration shortened and the yield decreased.

[Responses of subalpine meadow Poa botryoides to climate change].

Based on the field plot observation and related meteorological data, the effects of climate change in 1985-2005 on the growth and development of subalpine meadow Poa botryoides in Maqu County of Gansu Province were analyzed. The results showed that during study period, the annual precipitation in the Maqu County had a decreasing trend, with a rate of -9.895 mm x (10 a)(-1) and a cycle of 3 years, while the annual air temperature had an increasing trend, with a rate of 0.