辽东山区落叶松人工林地上生物量和养分元素分配格局

落叶松是我国北方最主要的人工用材林树种，由于人工林树种单一、结构简单等原因，导致土壤养分循环出现失衡.研究落叶松生物量和养分元素分配规律，可以为落叶松人工林的合理经营和养分循环研究提供科学参考.本文以辽东山区19年生二代落叶松人工林(胸径12.8 cm，树高15.3 m，密度2308株·hm^-2)为对象，研究其地上各器官(干、枝、皮、叶)生物量、碳和养分元素含量(N、P、K、Ca、Mg、Fe、Mn、Cu、Zn)的积累规律和分配格局.结果表明：单株落叶松生物量为70.26 kg，林分水平落叶松生物量为162.16 t·hm^-2,各器官生物量差异显著，排序为：树干>树枝>树皮>树叶；单株落叶松养分积累量为749.94 g，林分水平落叶松养分积累量为1730.86 kg·hm^-2，其中，大量元素和微量元素的养分积累量均为树干显著高于树枝、树皮和树叶.全叶期每砍伐一棵落叶松(19年生)，平均从系统中带出749.94 g养分元素；如果将树皮、树枝、树叶留在林地仅仅带走树干，带出的养分元素可减少40.7%.

Aboveground biomass and nutrient distribution patterns of larch plantation in a montane region of eastern Liaoning Province,China.

Larch is the main timber species of forest plantations in North China. Imbalance in nutrient cycling in soil emerged due to single species composition and mono system structure of plantation. Thus it is necessary to grasp its biomass and nutrients allocation for scientific management and nutrient cycling studies of larch plantation. We measured aboveground biomass (stem, branch, bark and leaf) and nutrient concentrations (C, N, P, K, Ca, Mg, Fe, Mn, Cu and Zn), and analyzed the patterns of accumulation and distribution of 19-year-old larch plantation with diameter at breast height of 12.8 cm, tree height of 15.3 m, and density of 2308 trees·hm^-2, in a montane region of eastern Liaoning Province, China. The results showed that aboveground biomass values were 70.26 kg and 162.16 t·hm^-2 for the individual tree of larch and the stand, respectively. There was a significant difference between biomass of the organs, and decreased in the order of stem > branch > bark > leaf. Nutrient accumulation was 749.94 g and 1730.86 kg·hm^-2 for the individual tree of larch and the stand, respectively. Nutrient accumulation of stem was significantly higher than that of branch, bark and leaf, whether it was macro nutrient or micro nutrient. Averagely, 749.94 g nutrient elements would be removed from the system when a 19-year-old larch tree was harvested. If only the stem part was removed from the system, the removal of nutrient elements could be reduced by 40.7%.