Urban green space has been considered as an ecological measure to mitigate urban heat islands (UHI). However, few studies investigate the cooling effect of the adjacent area of the urban park; as the transition region from a green space to a hardened surface where more complex heat exchange occurs, it deserves to be paid more attention. This paper examines the relationship between the urban greening patterns and the cooling effect in the surrounding areas of the Olympic Forest Park in Beijing. Results showed that the forestland and waterbodies could cool 6.51% and 12.82% of the impervious surface temperatures, respectively. For every 10% increase in the green space ratio, the land surface temperature drops by 0.4°C, and per kilometer increase in the distance from the forest park, the land surface temperature increases by 0.15 °C. The aggregation index (AI) and largest patch index (LPI) of the green space patterns presented a strong negative correlation with surface temperature. This study confirms the cooling effects in the adjacent area of the urban park and highlights their dependence on urban greening patterns. Therefore, we should not only develop more green spaces but also scientifically plan their spatial configuration in the limited urban land for the improvement of the cooling effect.

The pattern of grain self-sufficiency plays a fundamental role in maintaining food security. We analyzed the patterns and determinants of grain production and demand, as well as grain self-sufficiency, in China over a 30-year period. The results show that China’s total grain production, with an obvious northeast–southwest direction, increased by 63%, and yields of rice, wheat, corn, tubers, and beans increased by 16, 49, 224, 6, and 103%, respectively. The trends in ration and feed grain consumption changes at the provincial scale were roughly the same as at the national scale, with the ration consumption ratio decreasing and the ratio of feed grain consumption increasing. The ration consumption in Northwest China was relatively high, while the feed grain consumption rates in Shanghai, Guangdong, Beijing, Tianjin, and Chongqing were higher. Compared with ration and feed grain, the proportions of seed grain and grain loss were relatively small. China’s grain consumption mainly concentrated in the central and eastern regions of China. Total grain, rice, corn, wheat, tubers, and beans consumption in feed grain showed a northeast–southwest trend, with consumption centers all shifting southward in the 30-year period. Corn accounted for the largest proportion in feed grain, followed by beans. Urban feed grain and urban ration hot spot areas have gradually transferred from the northwest to southeast coastal areas. The hot spots of rural feed grain consumption and rural ration consumption remained almost unchanged, located in the south of the Yangtze River and Central and Southern China, respectively. The grain self-sufficiency level developed well in the study period, while the areas with grain deficit were Beijing, Tianjin, Shanghai, Zhejiang, Fujian, Guangdong, and Hainan. The areas with high supply and high demand were mainly located in Central and East China, the areas with high supply and low demand were mainly distributed in Northeast China, and the areas with low supply and low demand were mainly located in Western China. The pattern of self-sufficiency of corn in feed grain has remained basically unchanged; the areas with corn feed grain deficit were Central and Southeast China, while North China had corn feed grain surplus. Compared with corn feed, the surplus of soybean feed was relatively poor. Factor detector analysis revealed that in different periods, the same impact factor had different explanatory power in the supply and demand pattern, and the comprehensive consideration of any two factors will enhance the explanatory power of grain supply and demand pattern.

We investigated community structure and tree species diversity of six subtropical mountain forests in relation to 11 topographical and edaphic factors in Lower Lancang River Basin, Yunnan Province, China, based on a census of all trees with diameter at breast height ≥5 cm in 45 0.06-ha plots. The forests were as follows: a river valley monsoon forest, semi-humid evergreen broad-leaved forest, monsoon evergreen broad-leaved forest, mid-mountain humid evergreen broad-leaved forest, summit mossy dwarf forest, and warm needle-leaved forest. Owing to the variation in microenvironment, forest structure (tree density, mean height, mean diameter at breast height, mean basal area at breast height) and tree diversity indices (the number of species, Margalef richness, Shannon-Wiener diversity, Simpson’s index, and Pielou’s evenness) differed significantly among forest types but did not differ among sites. We recorded a total of 5155 canopy trees belonging to 204 tree species, 104 genera, and 50 families at three sites, and the co-occurrence of tree species between adjacent communities was higher. A clear forest community distribution along an altitudinal gradient suggested that elevation was important in tree species distribution. Ordination identified elevation, slope degree, slope position, soil pH, organic matter, total nitrogen, and available nitrogen as significant explanatory variables of tree species distribution and showed that elevation was more important than the rest of the environmental variables in affecting local woody plant distribution. Understanding relationships between tree species distribution and environmental factors in subtropical mountain forests of the Lower Lancang River Basin would enable us to apply these findings to forest management and vegetation restoration.

Grain self‐sufficiency (GSS) is gaining increased attention throughout the world, and this holds particularly true for China. This study, therefore, investigated spatial and temporal patterns of GSS at the county level in China from 1980s to the 2010s; then explored future GSS changes in the 2035s according to China's 2016 dietary nutrition guidelines, under the circumstances of maximum, average and minimum grain yield increase rate; and finally discussed the ability of a county to purchase grain to meet its demands. The results indicate that the number of counties with self‐insufficiency for total grain and ration decreased, and the amount of counties with high‐level self‐sufficiency for total grain and ration increased. However, the change in the number of counties with feed grain self‐insufficiency and high‐level self‐sufficiency is opposite to that of ration and total grain. Eastern China was characterised by high GSS of total grain, ration and feed grain. As for different kinds of grain, high level of GSS distributed in main grain producing areas, such as rice in south China, wheat in western China and Huang Huai Hai Plain, maize in north and northwest China and soybean in northeast China. Qinghai‐Tibet plateau has undergone poor food security in the last 30 years. In the 2035s, China's total GSS level and ration self‐sufficiency level will be improved under the maximum and average grain yield increase rate, whilst for feed grain, the self‐sufficiency level will be improved only under the maximum grain yield increase rate. The Qinghai‐Tibet plateau has always been a fragile area of food security. This study plays the vital function in understanding China's food security and contributes to the optimisation of agricultural production as well as the utilisation of both internal and external markets.