共查询到19条相似文献，搜索用时 671 毫秒
1.
2.
１９９０～１９９３年连续４ａ，对马尾松球果和种子的生长发育与养分动态，进行了比较系统的分析研究。结果表明：（１）马尾松球果系２年成熟，授粉（４月上旬）后当年为幼球果形成期；第２年受精前的６月至以后的９月中旬为球果迅速生长期，９月下旬至１０月为球果成熟期。（２）在２年生球果生长期间，球果干物质不断增加，而水分含量逐渐减少，１０月底干物质与水分的含量达到平衡点。（３）球果养分的含量，ｌ年生球果幼期Ｎ＞Ｋ＞Ｐ，三者变化趋势近乎一致，２年生球果含Ｎ量明显下降。种子内的Ｎ、Ｋ含量在７月中两者相当，此后Ｎ含量上升直至成熟期，到１０中Ｋ与Ｐ的含量相近。（４）胚胎发育进程中，球果和种子的体积与养分含量在原胚和幼胚阶段（７月至９月中旬）的变化最大，以后渐趋平缓。 相似文献
3.
１９９０年至１９９２年我们对黄平马尾松种子园球果害虫进行了调查研究，结果为：１、危害马尾松种子园球果害虫主要是油松球果小卷蛾。２、球果害虫危害高峰期在５月底至６月初。３、种源间、无性系间、同一无性系个体之间球果害虫的危害程度无明显差异．４、球果害虫危害程度与定植密度（株行距）无明显差异。５、人工摘除虫害是防治球果害虫的有效方法之一． 相似文献
4.
分析了马尾松—火力楠混交林的土壤养分和生物空间分布，结果表明：马尾松混交林的总生物量要高于两者的纯林生物量，但营养元素无论是在于马尾松纯林、火力楠纯林或者是马尾松－火力楠混交林的树干中含量都是最小，在叶中的含量最大。并且马尾松根系中的部分元素（等）要大于火力楠，而在叶中马尾松养分含量要小于火力楠。 相似文献
5.
马尾松球果小卷蛾发生成片危害，致使当年球果提早枯落，损坏嫩梢造成枝枯顶秃，干形弯曲，严重影响马尾松的正常生长。 相似文献
6.
马尾松是我国南方飞播造林、绿化荒山及用材林的主要树种,每年种子需求量很大。由于马尾松球果取种困难,难以满足生产要求。为此,我们队1984年开始进行了马尾松球果处理工艺的试验研究工作。马尾松球果处理即从马尾松球果中得到带翅种子的过程,主要包括球果预处理、球果干燥、开裂球果脱籽三个工序。虽然近年引进并相继研制 相似文献
7.
贵州省黄平县地处马尾松中心产区，其地理位置为东经107°51'，北纬26°54'，海拔890～910m；土壤为山地黄壤，土层深厚，肥力中上，pH5.0～6．5；年均降雨量898gmm；年均温14．7℃，很适合马尾松的生长发育。1990年5月首次在黄平县桃子冲种子团发现马尾松幼果被害，经调查平均幼果被害率为67％。球果的被害直接影响了种子园生产种子的产量和质量。为有效地控制马尾松球果害虫危害，保证种子园稳产、高产，于1990～1992年在黄平县横坡林场进行球果害虫的调查和防治研究。现将有关结果通报如下。1研究方法门）害虫种类及发生时间的调查黄平… 相似文献
8.
芽梢斑螟幼虫危害特点及其密度估计的研究 总被引：4，自引：0，他引：4
芽梢斑螟是马尾松二年生球果的重要害虫。根据种子园雄花发生特点，研究了芽梢斑螟越冬幼虫转移危害及其在树冠和林中的分布规律。结果表明，７轮生枝的马尾松树冠上，芽梢斑螟越冬幼虫集中侵害第六、七轮生枝上的二年生球果，球果被害率达５３．６％，幼虫数量占总数的５８．８％。种子园内不同无性系有少雄（花）、中雄和多雄树之别，芽梢斑螟越冬幼虫转移后的危害率及其数量分布，随马尾松雄梢率的增加呈递增的趋势。危害率（ｙ１）和幼虫数量（ｙ２）与雄梢率（Ｘ）的回归方程式分别为ｙ１＝０．６６０＋０．４７３Ｘ，ｙ２＝－０．８２９＋０．３０３Ｘ 相似文献
9.
10.
11.
12.
13.
14.
1982年以来在湖南省汉寿进行了Ⅰ-69杨人工林生长规律与营养特性的定位研究。前三年(1982～1984年)结果表明,当地的气候、土壤生态因子适于Ⅰ-69杨生长,胸径生长年、月变异极显著。第一年生长慢,8月为高峰期;第三年较第二年次之,6月为高峰期。三年胸径年平均增长4.78 cm。主要营养元素(除Mg外)的月变异极显著,与胸径生长规律一致。年变化无显著差异,年平均含量较高,N为3.25％～3.31％,P_2O_5为0.58％～0.59％,K_2O为1.59％～1.61％,CaO为3.17％～3.28％,MgO为0.54％～0.70％,反映了Ⅰ-69杨生长与主要营养元素吸收、利用以及土壤养分的供给,处于动态平衡的良好状态。 相似文献
15.
1982年以来在湖南省汉寿进行了I－69杨人工林生长规律与营养特性的定位研究,前三年（1982－1984年）结果表明,当地的气候、土壤生态因子适于I－69杨生长,胸径生长年、月变异极显著,第一年生长慢,8月为高峰期;第三年较高第二年次之,6月为高峰期,三年胸径年平均增长4．78cm。主要营养元素（除Mg外）的月变异极显著,与胸径生长规律一致,年变化夫显著差异,年平均含量较高,N为3．25％－3．31％,P2O5为0．58％－0．59％,K2O为1．59％－1．61％,CaO为3．17％－3．28％,MgO为0．54％－0．70％,反映了I－69杨生长与主要营养元素吸收,利用以及土壤养分的供给,处于动态平衡的良好状态。 相似文献
16.
17.
Branches of Pinus contorta Dougl. bearing two-year-old female cones initiated fewer lateral buds than vegetative branches. However, the number of lateral shoots that differentiated and grew was not reduced on female cone-bearing branches. Neither the number nor the weight of female cones influenced the length of the terminal shoot. The total length of all lateral shoots was positively associated with the weight of two-year-old female cones. Branch units with two-year-old female cones produced significantly more total dry weight in the current year than vegetative branch units. There was, however, no significant reduction in the dry weight of terminal and lateral shoots. Branches bearing female cones allocated between 17 and 45% of the current year's dry weight to two-year-old cones and between 1 and 5% was allocated to one-year-old female cones. Female cones therefore apparently do not reduce the photosynthetic potential of trees. The influence of female cones compared with male cones on the growth of trees is discussed. 相似文献
18.
Experimental studies of forest trees’ intraspecies variations in reproduction and reproductive allocation are scarce. Such studies are relevant for the Siberian stone pine (Pinus sibirica Du Tour) because of the high value of its seeds and wood. To reveal growth and reproductive variations among Siberian stone pine ecotypes in relation to the climate of the provenances, we examined their growth height, crown diameter, stem volume, number of female cones, and male shoots, at different ages, in the clonal common garden experiment established in 1996 in Russia. Scions were obtained from 11 to 19 randomly selected 100–170-year old trees in each of four natural stands located on the latitudinal transect on the West Siberian plain. They were grafted onto local 4 year old Siberian stone pine seedlings and grown in a common garden experiment comprising nine plots near the southern margin of the species’ natural range. Growth traits were affected by climatic conditions in the provenances: generally, a warmer climate was associated with more rapid growth. Variation among the ecotypes at the graft age of 12 years was not large; however, it significantly increased by the age of 19. The relationship was ambiguous between reproductive traits and the climate of the provenances. The proportion of female, male and bisexual clones varied among years in all ecotypes. Most of the clones had only female cones; male clones were less common. The southern ecotype showed rapid growth and formed the lowest number of male shoots and female cones. The northern ecotype showed the weakest growth and moderate cone bearing, along with abundant male flowering. The intermediate ecotypes had a moderate growth and the highest numbers of cones, along with moderate numbers of male shoots. These results demonstrate the fundamental differences in the patterns and nature of variation in growth and reproductive traits. 相似文献
19.
杉木幼龄林叶片营养元素含量与林木生长的相关性 总被引：3，自引：0，他引：3
本文重点论述丘陵立地条件下 ,1、2代杉木幼龄林高生长、当年高生长、胸径生长与叶片中营养元素N、P、K、Ca、Mg、Cu、Mn、Zn、Fe含量的相关关系 ,进而从林木营养这个角度 ,为提高林木产量、防治地力衰退提供可靠的科学依据。研究结果表明 :2代杉木幼龄林生长与N、P、Mg、Cu、Mn、Fe含量呈密切的正相关。 1代杉木幼龄林生长虽与P、Mg、Cu、Mn、Fe含量呈正相关 ,但复相关系数数值偏低。也就是说土壤养分含量尚没有明显影响 1代杉木幼龄林正常生长 相似文献