Abstract: To investigate the effects of different management models on the growth of Magnolia sumatrana plantations and the soil physicochemical properties, this study established three treatments: target tree management (T1), traditional thinning management (T2), and no thinning (CK). Tree diameter at breast height (DBH), tree height increment, and soil physicochemical indicators were measured. The results showed that, the growth increments of diameter at breast height (DBH), tree height, individual tree volume, and stand volume under T1 and T2 treatments were all higher than those under the CK treatment, with T2 significantly exceeding CK. Except for soil bulk density, total porosity, capillary porosity, capillary moisture capacity, organic carbon, total nitrogen, total phosphorus, and total potassium contents all decreased with increasing soil depth. The T1 treatment showed the lowest bulk density and higher contents of organic carbon and total phosphorus. It also exhibited superior performance in total porosity, capillary porosity, capillary moisture capacity, total nitrogen, and total potassium, indicating better water retention and fertility. Correlation analysis revealed a significant positive correlation between DBH and tree height growth(P<0.05), and a highly significant positive correlation between DBH growth and organic carbon(P<0.01). Tree height growth was significantly negatively correlated with bulk density and total nitrogen(P<0.05), and highly significantly positively correlated with organic carbon and total phosphorus(P<0.01). The stand volume growth was significantly positively correlated with soil organic carbon(P<0.05). Principal component analysis further confirmed the superiority of the T1 treatment in terms of overall soil quality. The comprehensive evaluation scores of soil quality indicators were T1>T2>CK. In conclusion, target tree management could effectively improve the soil ecological environment and promote the growth of Magnolia sumatrana, making it a preferred strategy for high-quality cultivation and sustainable management of plantations.

Key words: Magnolia sumatrana, target tree management, traditional thinning, soil physicochemical properties, tree growth