施肥和透光抚育对红皮云杉幼龄人工林林木生长的影响.

The period of cultivation of large-diameter timber stands is affected by the relatively slow initial growth of Picea species. The combination of fertilization and nurturing measures can promote the growth of tree height and ground diameter. In this paper, 12 fixed plots of 10m×10m were randomly set up in a larch understory with 10 a juvenile Picea koraiensis plantations as the study subjects. Fertilizer types were selected as N (N - urea), NP (NP - urea+superphosphate), NPK (NPK - urea+superphosphate+potassium phosphate). Two types of fertilization time were set: (1) pre-middle-late growing seasons fertilization: fertilizer was applied per year at the beginning (mid-May), middle (mid-July), and late (mid-August) of the growing season, with fertilization repeated for four consecutive years. (2) Pre-middle-end growing seasons fertilization: fertilizer was applied per year at the beginning ( mid - May), middle (mid-July) and end (mid-September) of the growing season, with fertilization repeated for four consecutive years. Light-felling was set as follows, after one growing season of fertilization, accretion cutting the upper larch trees, and the stand density was 0. 6 after tending. By studying the effects of fertilization and light-felling on the growth of trees, the aim was to develop fertilization management techniques to promote the growth of juvenile P. koraiensis, so as to shorten the growth cycle of young plantation. The effect of applying NPK fertilizer on promoting the height and diameter growth of juvenile P. koraiensis was better than applying only a single fertilizer or a mixture of nitrogen and phosphorus fertilizers. The annual tree height and ground diameter growth were 41.11 % and 49.81 % higher in the treatments NPK fertilizer applied pre-mid-end growing seasons than those treated with NPK in the premid-late growing seasons. After light-felling, the annual growth of tree height between different years was not significantly different, but that of the ground diameter was significantly different. The annual growth of tree height and ground diameter after three growing seasons were not significantly different from that before light-felling. By combining fertilizer application in the pre-middle-late growing seasons with light-felling treatments, the annual growth of tree height and ground diameter were significantly different from the control group after two growing seasons, only the annual growth of ground diameter was significantly different from the control group after three growing seasons. After three growing seasons of nitrogen, phosphorus and potassium fertilizers (NPK2) combined with light-felling in the pre-mid-end of growing seasons, the annual growth of ground diameter was 153.16 % and 10.31 % higher than that of the control and pre-middle-late of growing seasons NPK fertilizers (NPK1) combined with light-felling. The combination of fertilization and light-felling treatments can increase the annual growth of P. koraiensis ground diameters, reaching a significant level at four consecutive years of fertilization. Fertilizer application at the pre-mid-end stages of the growing season is more effective than at pre-mid-late stages. The research provides a basis for solving the problem of slow growth of P. koraiensis plantation at a young age and shortening the cultivation period of large-diameter timber plantation of P. koraiensis. [ABSTRACT FROM AUTHOR]