[Influences of shallow groundwater on sap flow of riparian poplar plantations in northern China.].

Water use strategy in growing seasons plays a great role in the management of riparian poplar plantations in northern China. The research was conducted on a poplar (Populus × euramericana cv. '74/76') plantation located near the floodplain of Chaobai River in the northeastern su-burb of Beijing.

Analysis of Precipitation Characteristics during 1957-2012 in the Semi-Arid Loess Plateau, China.

Precipitation is the only water supply and most important factor affecting vegetation growth on the slopes of semi-arid Loess Plateau of China. Based on precipitation data from 7 synoptic stations in the study area over the period 1957-2012, the trends of precipitation and standardized precipitation index (SPI) were analyzed by using linear regression, Mann-Kendall, and Spearman's Rho tests at the 5% significance level. The results show that (1) the precipitation fluctuation of monthly precipitation was intense (coefficients of variation> 100%), and the drier years were recorded as 1965 and 1995 at all stations.