【作者】 刘春霞；

【导师】 陈存及；

【作者基本信息】 福建农林大学 ， 森林培育， 2003， 硕士

【摘要】 本文通过连续三年的田间试验，研究乳源木莲一年生播种苗的年生长发育规律，以及不同种子来源的播种苗的生长差异，探讨了乳源木莲苗木植株养分含量的季节动态变化及干物质积累的规律、以及不同育苗密度对苗木形态质量指标的影响，提出合理育苗密度及苗木出圃的等级划分，对田间育苗具有科学的指导意义。 1．通过生长曲线直观划分法及有序聚类划分法对乳源木莲一年生播种苗苗高生长期进行划分，结果表明，有序聚类法可对苗木生长期进行更为精确的划分，划分结果与苗木生物学特性相符合，可作为指导施肥等管理措施的依据。同时这种精确的定量划分法为其它苗木生长期的研究提供了科学方法。 从乳源木莲苗高年生长曲线上看出，苗高从5月开始快速生长，到7月份进入速生期，7月中旬达到生长高峰，9月生长速度变缓，10月净生长量开始下降，至11月生长逐渐趋于稳定。以乳源木莲定期观测的苗高净生长量为样本，采用有序样本聚类分析，将乳源木莲苗高生长过程划分为4个时期，出苗期为3月12日～4月30日，幼苗期为5月1日～6月30日，苗木速生期为7月1日～9月30日，苗木生长后期为10月1日～12月16日。根据各时期苗高的生长特点，提出了关键育苗措施，以提高成苗率、苗木质量与产量。 2．在田间试验条件下，研究乳源木莲天然林种子与人工林种子播种后苗木生长特性之间的差异性，为以后进行种源试验，建立种子园、良种繁育基地等奠定基础。结果表明，人工林种子的发芽率高于天然林种子发芽率，进一步证实了人工林种子品质较好，应建立人工母树林子代种子园。但在生长过程中，由于不同措施的交叉作用，天然林与人工林种子一年生播种苗的生长性状差异不明显，还需进一步实验研究。 3．植物养分含量变化决定于植物本身属性，同时也受土壤理化性质影响，养分浓度的变化是由于各个组织器官对不同元素的不同输入、输出比例引起的，各营养器官在不同生长阶段的结构和功能直接影响其对养分吸收的选择性。通过对乳源木莲一年生播种苗植株及各器官养分分析结果表明：养分含量浓度均随着时间的变化逐渐变小，到12月中旬又略有升高。 养分含量在不同器官分配不同，全N含量浓度在苗木各器官中的大小顺序：根、叶、茎；全P：根、茎、叶；全K：叶、根、茎。苗期乳源木莲对K的吸收最多，含量最高，其次为N，P含量最小。 结果表明，乳源木莲植株及各营养器官的养分贮量与植物组织的养分浓度和生物量有关，且植物的生物量对其养分贮藏起决定作用，养分贮量的季节动态与生物量的季节 乳源木莲苗木生物学特性及壮苗培育技术研究变化相一致。 4.乳源木莲一年生播种苗苗木根、茎、叶及全株干物质的积累呈“S”型曲线，用理查德模型进行拟合，效果较好。整个生长过程中，全株干物质生产有两个快速积累期，一为速生期，主要是因为速生期的叶片数大量增加的缘故;二为苗木生长后期，是因为在这个时期，根、茎木质化程度增快。 各营养器官干物质积累具明显规律性，根干物质所占比重在幼苗期较大，之后逐渐减小，速生期后期又不断上升;茎干物质比重在整个生长过程中一直呈上升状态:叶的干物质所占比重在幼苗期和生长后期较小，速生期最大。在整个生长期，叶干物质百分率高于根、茎干重百分率，保证了植物养分的制造和供应。 干物质在不同器官之间的分配规律，在生长初期和后期生物量均以根增长最快，生长盛期则以叶、茎增长最快。进一步证实了植物在生长过程中，物质总是运输到生长最旺盛的部位，同时也说明了植物在不同时期存在着不同的生长中心，光合产物优先输到生长中心。 通过根、茎生物量的异速生长数学模型进行拟合计算，根、茎生物量的异速生长常数K(l，说明乳源木莲苗木生长趋向于多枝性。 5.育苗密度对苗木质量起决定作用，合理育苗密度的研究对壮苗培育技术措施起着重要的指导作用。通过田间随机区组试验，说明密度对地径、根茎分集数、主根长等均有显著影响。苗木的生长，在密度较小和环境条件良好情形下，枝叶茂盛;相反在高密度和环境不良清况下，植株彼此之间竞争光、水、营养激烈，在有限的资源中，植株的生长率降低，个体变小，可能只有少数枝叶，器官构件数很少。 经回归拟合，密度与主根长、生物量呈线性负相关关系，与地径呈负指数相关关系，且回归关系显著。说明在一定范围内，苗木质量与育苗密度呈负相关关系，自然密度越小，苗木质量越高。 适宜的育苗密度应根据不同的培育目标、苗木质量、苗木产量和经济效益综合因素来确定。本文讨论的合理育苗密度仅适合造林所需。结果表明:乳源木莲定苗密度在60株/可时，亩产合格苗量最大，达2.04万株/亩，其经济效益最大，此时其合格苗率达85%。 6.通过三因子两次回归正交实验设计，研究施肥配比对苗高、地径生长的影响。说明在前茬为水稻田上育苗，土壤氮、磷、钾含量较高，尤其是钾，在这种情况下，施钾对苗高、地径生长无明显的影响，施氮、磷对植株生长有显著影响。并得到苗高、地径与各因子的回归?更多还原

【Abstract】 This paper basing on the field test for three years in succession, gives a series of studies including the growth orderliness of Manglietia yuyuanensis Law semination seedlings, and the growth difference of seedlings of sources of different seeds, the season change of nutrient content and accumulated biomass law of nursery stock, the effect of different density on quality index of the nursery stock, and putting forward adequate seedlings density and the grade of nursery stock produce divided rationally. It has scientific directive significance to cultivate the seedlings in field.1. the growth curve and order cluster methods were used and contrasted in compartmentalizing periods of seedling tallness. The result indicating that the latter method could make for a more precision partition, and this partition was accord with the seedling biological characteristic, this partition also can be regard as gist of administering measures of the seedlings. It also established the base of a series of researches during the seedling period.It is showed from the growth curve of height that height grow rapidly from May, accelerate in July with the peak of the height growth in mid-Jul, and decline from Sep., and the growth stop in Dec. from the curve of the growth of height of Manglietia yuyuanensis Law seedlings. Taking the height net growth increment of Manglietia yuyuanensis Law seedlings as samples, the height growth process is divided into 4 stages in order by the sequential sample cluster analysis: emergence stage (first ten days- Mar. - first ten days- Apr.), young growth stage (first ten days- Apr. - last ten days-Jun.), rapid growth stages (last ten days-Jun. - first ten days-Oct), and later stage (first ten days-Oct. - mid-Dec.). According to high growth characteristic of every stage, the key managements of seedlings for cultivating is proposed to improve the rate of survival, the quality and the quantity of seedlings.2. Under field test in nursery, the study of grow difference of characteristic of seedlings from seed of nature-stand and artificial-stand, give the base of setting up seed garden. Result indicate germination percentage of seed from artificial-stand is higher than nature-stand’s, which proved seed quality of artificial-stand better than nature-stand, and should set up the subgeneration seed garden of artificial seed forests. But in the course of growing, because different function of crossing of measure, the difference of growth properties of seedling from the nature-stand seed and artificial-stand seed is not obvious, which still need to test and study further.3. Nutrient content change of plant decide by plant attribute of itself mainly, affect by soil physics and chemistry nature too. With different proportion of each organ to different input and output, the nutrient content change, and the structure and function of every nutrition organ in different growth stage of stage influence to alternative that nutrient absorb directly. Throughevery organ nutrient analysis, results indicate that the density of nutrient content diminish gradually with change of time, rise slightly from mid-December.Nutrient content distribute differently in various organ, the order of content of whole N of different organ in nursery stock is root, followed leaf, and stem; the whole P is root, stem, leaf; the whole K: leaf, root, stem. The content of whole K of unit quality plant is highest, and N mid, and P lower.The storing amount of nutrient of the plant relates to density of nutrient and biomass amount of plant organ, and biomass amount play a decisive role to nutrient store, and season change of nutrient store conform with seasonal change of biomass amount.4. The accumulated biomass of root, stem, leaf, the whole nursery stock of Manglietia yuyuanensis Law seedling present" S" type curve, Fitting with Richard’s model, the result is better. In the course of growing entirely, material production of mean stock have two period of accumulated rapidly, one is rapid growth stage with increasing a large am更多还原