【作者】 魏红旭；

【导师】 徐程扬；

【作者基本信息】 北京林业大学 ， 森林培育， 2011， 博士

【摘要】 长白落叶松(Larix olgensis Henry.)是我国东北林区重要的速生用材树种之一。目前生产上对长白落叶松苗木的人工培育以裸根播种苗为主,并习惯性采用大肥式的培育方法。这不仅不利于该树种的苗木质量,而且易导致肥料的浪费。本研究基于生产上对长白落叶松裸根苗木常规的培育方法,以提高其苗木质量为目的,以经典的“目标苗木”和“养分库”等理论为基础,以节约肥料中氮、磷养分的供给量为目标探讨了不同等级苗木地上和地下部分生长和氮磷的吸收利用机理及效率对无机氮磷养分的基肥、稳态加载和生长季后期施肥或有机肥料的响应,重点研究了苗木移栽后的早春碳水化合物积累与损耗、夏季养分的重新分配,秋季养分库的建立以及苗木细根的生长动态等苗木生理、生态学现象。同时,本研究对经过稳态养分加载的播种(1-0)苗木与复合国家Ⅰ级质量标准的移栽(1-1)苗木进行了早期造林效果的对比研究,以期探讨通过缩短苗木出圃前培育周期的方法实现对其培育成本降低的可行性。本研究结果表明：(1)长白落叶松1-0苗木对施肥处理的显著响应开始于夏末时期；(2)100 kg N和P hm-2的无机施肥或10000 kg FM鸡粪hm-2的有机肥添加处理均有利于较大形态苗木的生长和养分吸收,同时能有效减少土壤养分淋失,并提高翌年早春苗木碳积累速率；(3)低量磷酸二铵基肥处理(23.76 kg N hm-2,60.72 kg P hm-2)可以有效提高1-1苗木对土壤养分的吸收利用效率、减少养分淋溶、改变养分在苗体内的再分配,并有促进苗木生长的潜力；(4)生长季后期对1-1苗木同时或分别施入30和60kg hm-2的磷、氮养分会提高苗木养分库水平,但不会影响苗木生长；(5)氮磷供给比例为2：1时,根系中谷氨酰胺合成酶(Glutamine synthetase, GS)活性较低,但叶片中GS活性较高；当供给比例为1：2时,根系中酸性磷酸酶(Acid phosphatase, AP)活性较高,叶片中AP活性较低；(6)和每株500 mgN株-1的指数施肥处理相比,135 mgN株-1的指数施肥处理下苗木叶绿素和可溶性蛋白含量较低,但养分利用效率较高,并且其早期造林成活率与Ⅰ级1-1苗木间差异不显著。更多还原

【Abstract】 Larix olgensis Henry. is one of the most important timber species planted in northeastern China. Bareroot stocks are the main type of seedlings cultured as production in local nurseries, for which high rate fertilization is widely operated. This was believed to degrade their seedling quality and result in a big fertilizer-waste. Based on operational culture practice and classic theories, such as "Target seedling" and "Nutrient reserves", and aiming at improving seedling quality at an economical rate, we studied responses of above- and below-ground growths and N and P uptake and utilization in seedlings with different sizes to inorganic fertilization, steady-state nutrient loading and late-season nutrient addition. Carbohydrate accumulation and depletion in early spring, summer nutrient retranslocation, fall nutrient reserves and fine root development were monitored. Germinated (1-0) seedlings subjected to nutrient loading in nursery were compared, for the first time, with transplanted (1-1) gradeⅠseedlings in their early performance after out-planting, so as to determine the possibility of a cost culture-regime with a shortened culture period.The results revealed that:(1) significant response of 1-0 seedlings to fertilization treatments began in late summer locally; (2) Compared to the inorganic fertilization treatment at a rate of 200 kg N and P hm-2, that at the rate of 100 kg N and P hm-2 could improve larger seedling growth and nutrient uptake, decrease nutrient leaching, and raise their carbohydrate accumulation rate in following early spring, so did organic fertilization treatment (10000 kg FM Chicken manure hm"2); (3) Basal fertilization treatment at a low rate of 23.76 kg N hm-2 and 60.72 kg P hm-2 could enhance nutrient uptake from current soils, decrease nutrient leaching and retranslocation, and tended to strengthen nutrient reserves in 1-1 seedlings; (4) Late-season fertilization at a rate of 30 kg P hm-2 and 60 kg N hm-2 could increase nutrient accumulation in reserves in 1-1 seedlings without affecting their growth; (5) GS activity was higher in needles and lower in roots of seedlings subjected to the treatment of N to P supply ratio of 2:1 than other treatments, while AP activity was higher in roots and lower in needles of seedlings subjected to the treatment of N to P supply ratio of 1:2 than other treatments; (6) Relative to the rate of 500 mg N seedling-1, seedlings subjected to the nutrient loading treatment at a rate of 135 mg N seedling-1 had lower chlorophyll and soluble protein contents, but higher nutrient utilization efficiency, and they had a mortality as low as gradeⅠ1-1 seedlings after planting.更多还原