Abstract:The objective of this study was to investigate the fine root dynamics of Caragana korshinskii Kom, a shrub species widely planted to control soil erosion and land desertification in the semiarid area of China, in a 5-year-old planttion in the Loess Plateau area of Northwest Shanxi, China, using the minirhizotron technique. By defining the fine root growth rate (RLDgr, mm?cm-3?d-1), fine root death rate (RLDdr，mm?cm-3?d-1), and ratio of growth to death (Rgd, i.e. RLDgr/RLDdr) as basic parameters, their change patterns and the relationships of RLDgr and RLDdr with environmental factors (i.e. air temperature, precipitation, soil temperature and soil water content) in the growth season (from April to September) in 2007 were analyzed. The results showed that the average RLDgr and RLDdr in the growing season were 01264mm?cm-3?d-1 and 0.0354mm?cm-3?d-1, respectively. The average RLDgr in the deep soil layer (50-100cm) was higher than in the top soil layer (0-50cm), while the average RLDdr in the deep layer was lower than in the top layer. The RLDgr increased rapidly from April to July and peaked in August, and then decreased rapidly. The RLDdr increased gradually from early April to early July, accelerated rapidly, and peaked until the end of the growing season (late September). The Rgd decreased gradually from April to September and fell to <1 at the end of the growing season. The seasonal changes of RLDgr were significantly correlated with air temperature (P<0.01), and correlated with soil temperature (P<0.05). There were, however, no significant correlations between seasonal trends of RLDdr and the environmental factors (P>0.05).