Dai Lin-Li, Chen Yi-Tang, Wu Li-Hua, Liu Li, Ye Yi-Quan, Qiu Jing-Wen, Cao Shi-Jiang, Cao Guang-Qiu
College of Forestry, Fujian Agriculture and Forestry Univer-sity, Fuzhou 350002, China.
Fujian Yangkou State-Owned Forest Farm, Nanping 353200, Fujian, China.
Ying Yong Sheng Tai Xue Bao. 2022 Feb;33(2):311-320. doi: 10.13287/j.1001-9332.202202.002.
The growth, biomass, nutrient content and accumulation as well as the vertical distribution of nutrient accumulation in plantation across densities of 1800, 3000, 4500 trees·hm were stu-died in order to provide scientific basis for efficient cultivation of plantation. The total amounts of nutrients accumulated in plantation with 1800, 3000, 4500 trees·hm were 1311.57, 2531.55 and 2307.33 kg·hm, respectively. There were significant variations among different densities. Under the same density, the order of nutrient content and accumulation in plantation was total N > total K > total Ca > total Mg > total P. Moreover, the amount of nutrients in trunk and bark decreased with the increases of tree height. The amount of nutrient accumulation in persistent withered branch and leaf were allocated from middle to the upper part of tree, while the opposite was observed for fresh branch and leaf. N accumulation increased with the increases of stand densities, while the other nutrients first increased then decreased. The order of the amount of nutrient accumulation in trunk, bark, root, persistent withered branch, persistent withered leaf and litter among different densities was 4500 > 3000 > 1800 trees·hm, and was 3000 > 1800 > 4500 trees·hm in fresh branch and leaf, and 1800 > 3000 > 4500 trees·hm in understory. Under the densities of 1800 and 4500 trees·hm, the nutrient distribution ratio in bark was the largest, accounting for 21.6% and 19.4%. In 3000 trees·hm, the distribution ratio of fresh leaves reached its maximum, accounting for about 22.9%, and the next was fresh branches, which had a distribution ratio of about 17.8%. 3000 trees·hm was the most appropriate density for nutrient accumulation and distribution in plantation.
为给人工林高效培育提供科学依据，研究了1800、3000、4500株·hm密度下人工林的生长、生物量、养分含量与积累以及养分积累的垂直分布。1800、3000、4500株·hm密度人工林的养分积累总量分别为1311.57、2531.55和2307.33 kg·hm，不同密度间差异显著。在相同密度下，人工林养分含量与积累顺序为全氮＞全钾＞全钙＞全镁＞全磷。此外，树干和树皮中的养分含量随树高增加而降低。多年生枯枝落叶的养分积累量从树中部向上部分配，而当年生枝叶则相反。氮素积累量随林分密度增加而增加，其他养分则先增加后降低。不同密度下树干、树皮、根、多年生枯枝、多年生枯叶和凋落物的养分积累量顺序为4500＞3000＞1800株·hm，当年生枝叶为3000＞1800＞4500株·hm，林下为1800＞3000＞4500株·hm。在1800和4500株·hm密度下，树皮中养分分配比例最大，分别为21.6%和19.4%。在3000株·hm时，当年生叶片分配比例最高，约为22.9%，其次是当年生枝条，分配比例约为17.8%。3000株·hm是人工林养分积累与分配的最适宜密度。
