[Dynamic response and variance of vegetation in China from 1982 to 2015 under the asymmetric rate of temperature fluctuation.].

The impact of global warming on the growth and development of natural vegetation is an important concern worldwide. Based on the data from the vegetation normalization index, daytime temperature (T), nighttime temperature (T), precipitation, and elevation from 1982 to 2015, we examined the day-night warming response of 42 types of natural vegetation in China. The results showed that both the temperature at day and night was significantly increased in the study area, with obvious asymmetry.

[Pollution Characteristics and Health Risk Assessment of Heavy Metals in Wheat Grains Cultivated in Kaifeng Irrigation Area of the Yellow River].

In order to monitor heavy metal pollution in agricultural soils and assess the corresponding health risk in the Yellow River irrigation area, this study applied the Nemero index and the health risk index to evaluate heavy metal pollution in wheat grains and the health risks for residents in the lower reaches of the Yellow River. Four towns in Kaifeng, which are within the lower reaches of the Yellow River, were selected as the study area. The examination of wheat samples revealed that the average contents of Cd, Cr, Pb, Cu, Zn, Ni, and Hg in the wheat grains were 0.

[Spatial Distribution and Potential Ecological Risk Assessment of Heavy Metals in Sediments of Suya Lake].

In order to study the pollution status of heavy metals in sediments of Suya Lake, the concentrations of heavy metals Cu, Cd, Cr, Zn, Pb and Ni in sediments were measured at three locations in the center, middle and periphery of Suya Lake, the content characteristics and the pollution status of heavy metals in the study area were analyzed by the method of geoaccumulation index and potential ecological risk index, and the distribution and interrelation of heavy metals were evaluated by Kriging method and correlation analysis. The results showed that, on average, Zn was the highest, 112.87 mg·kg, followed by Cr, the smallest average of Cd was only 0.