浙江农林大学学报2018，Vol.35Issue(3)：459-466,8.DOI:10.11833/j.issn.2095-0756.2018.03.009
米老排人工林皆伐迹地种子天然更新林密度调控效应
Tree density and growth of Mytilaria laosensis stands with natural seed regeneration on clearcut land
摘要
Abstract
To explore the effect of density on growth of young Mytilaria laosensis stands with na tural seed re-generation on clearcut land, a single factor randomized block design experiment with natural spacing (ck treatment, three replications) and spaced seedling (TA, TB and TC treatments, three replications) stands was es-tablished, and variance analysis of the stands were analysed with Least Significant Difference methods in Data Processing System (14.5), to test diameter at breast height (DBH), tree height, and single volume. Results showed that: (1) between ck and spaced seedling stands, during 3.5 years after spacing, stand density signifi-cantly decreased (P<0.01) the average growth of total growth and annual increment of DBH, tree height, and single volume in the ck stands types;whereas, the total growth of DBH, tree height, and single volume of domi-nant trees with both stands were not significantly affected (P>0.05). Spaced treatments (finished in 1.5 years old of seedling, remain density in hectare: TA 1650, TB 2800, and TC 2500)significantly improved (P<0.01) the average growth of the stands and reduced differentiation of diameter grades in the stands. (2) The higher stand density(ck), the earlier intersection time of the average growth curve and the annual growth curve for av-erage DBH or tree height of the stand was appeared. Also, the peak value of annual growth for average DBH of ck stands occurred in the second year, and the peak value of spaced stands was during the second and 4th year. Before the 5th year, it was fast growth period for the stands with natural seed regeneration, so spacing was very important with radial growth of the stands. (3) The time of intersection for curves of average growth and annual growth of tree height in the ck stands was between the second and third year, but with the spaced stands did not intersect before the 5th year. Growth for tree height of dominant trees in all stands before the 5th year was fast (the annul increment of top height in each treatment was more than 1.49 m in each year). (4) Different types of stands had different diameter distributions; the ck stand had an inverted J distribution, but the spaced stands had an approximately normal distribution. (5) In the spaced stands, after 3.5 years, the av-erage growth for DBH, tree height, and volume of less dense forest stands (TA treatment stands) was better than those with higher density treatments (TC or TB stands). Thus, understanding of the mature period for seeds, the seed falling-stage, and natural regeneration characteristics of Mytilaria laosensis could enhance the scientific cutting time, cutting methods, clean ways for removing residues, shrubs, and herbaceous plants, and methods for spacing seedlings to enable effective natural regeneration on cutover land thereby promoting forest growth.关键词
森林培育学/米老排/皆伐迹地/种子/天然更新/幼林生长/密度效应/间苗抚育Key words
silviculture/Mytilaria laosensis/clearcut land/seed/natural regeneration/growth of young stands/effect of density/spaced planting分类
农业科技引用本文复制引用
唐继新,雷渊才,曾冀,李忠国,李武志,农良书,赵总..米老排人工林皆伐迹地种子天然更新林密度调控效应[J].浙江农林大学学报,2018,35(3):459-466,8.基金项目
广西自然科学基金资助项目(2016GXNSFBA380087) （2016GXNSFBA380087）
中国林业科学研究院热带林业实验中心主任基金资助项目(RL2012-01) （RL2012-01）
