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以7、17、30和40年生4个发育阶段(幼龄、中龄、近熟和成熟阶段)的日本落叶松人工林为对象,研究了林龄对生物量、碳储量和养分特征的影响.结果表明:在单木水平上,不同发育阶段干、枝、皮、叶、根生物量和养分浓度差异显著.随年龄增加,各器官生物量呈增大趋势,N、P、K浓度呈下降趋势,Mg浓度先降后升,Ca浓度持续升高.优势木、平均木和劣势木的各器官生物量之间差异显著,但养分浓度差异不显著,表明竞争对各器官养分浓度影响不大.在林分水平上,总生物量、碳储量和养分储量随林龄增加呈增大趋势,与幼龄林相比,成熟林分别增加217.9%、218.4%和56.4%,表明日本落叶松林生长后期能以较少的养分生产较多的干物质,养分利用效率较高.5种元素的积累量除P和K在近熟林(30年生)略有降低外,其他元素都随林龄增加而增加.N集中在叶中,Ca集中在树干,K和Mg主要集中在根,P在不同器官中的分配较均匀.日本落叶松林分年均生物量积累率、固碳率和养分积累率均随林龄的增加而降低,从幼龄林每年7.16 t·hm~(-2)、3.40 t·hm~(-2)、104.64 kg·hm~(-2)降低到成熟林的3.99t·hm~(-2)、1.89 t·hm~(-2)、28.64 kg·hm~(-2),表明日本落叶松林幼、中龄阶段固碳潜力大,但养分消耗也高.
The effects of stand age on biomass, carbon storage and nutrient characteristics were studied in a Japanese larch plantation at 4, 7, 17, 30 and 40 years of age (young, middle, near and mature stages) The results showed that biomass and nutrient concentration of stem, branch, skin, leaf and root at different developmental stages were significantly different.With increasing age, the biomass of all organs showed an increasing trend, while the concentrations of N, P and K The Mg concentration decreased first and then increased, and the Ca concentration continued to increase.The difference of biomass of various organs between the dominant wood, the average wood and the inferior wood was significant, but the difference of nutrient concentration was not significant, indicating that the competition did not affect the nutrient concentration of different organs At the stand level, the total biomass, carbon storage and nutrient storage tended to increase with the increase of stand age, and the mature stand increased by 217.9%, 218.4% and 56.4% respectively compared with the young stand, indicating that the growth of Japanese stand larch The latter could produce more dry matter with less nutrients and had higher utilization efficiency of nutrients.The accumulative amount of five elements increased slightly with the increase of P age except for P and K in the near-mature forest (30-year-old) But increased.N concentrated in the leaves, Ca concentrated in the trunk, K and Mg mainly concentrated in the roots , P was more evenly distributed in different organs.The average biomass accumulation rate, carbon fixation rate and nutrient accumulation rate of Larix olgensis decreased with the increase of forest age. From the young plantation 7.16 t · hm ~ (- 2, 3.40 t · hm -2 and 104.64 kg · hm -2 decreased to 3.99 t · hm -2, 1.89 t · hm -2, 28.64 kg · hm ~ (-2), indicating that Larix kaempferi forest age, middle-aged stage of carbon sequestration potential, but nutrient consumption is also high.