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窄冠黑杨、窄冠黑白杨的选育及应用 总被引:2,自引:0,他引:2
通过杂交育种 ,选出了 6个窄冠黑杨、1个窄冠黑白杨无性系 ,材积生长量分别接近对照I—6 9/ 5 5、中林4 6和窄冠白杨 3号。窄冠黑杨单株立木干物质产量超过中林 4 6 ,冠幅比对照小 1/ 2~ 1/ 3,适用于农田林网及农林间种。窄冠黑杨耐盐碱能力较强 ,容易扦插繁殖 ,造林成活率高。木材基本密度 36 0~ 394kg/m3 ,木材纤维长 1mm左右 ,随年龄增长而加长 ,5a生时趋于稳定。因此从制浆造纸来看 ,以 5a生以上利用为好。经制浆及检测、胶合板制作证明 ,木材适用于制浆造纸及作胶合板原料。 相似文献
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应用窄冠白杨无性系进行林粮间作定位试验,11年的测试结果表明,以每公顷120株的密度进行林粮间作,农田内平均遮光率为15%左右,在小麦灌浆期可以有效地降低气温,减少干热风危害,对小麦有增产作用,每公顷增产可在225kg以上,间作可使玉米减产,但减产损失远小于小麦增益,特别是拥有树木的农户,其立木收入显著地高于减产损失。 相似文献
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窄冠白杨5号、6号的选育,是作者进行的白杨派树种杂交育种工作的一部分,目的是育出一批适于林粮间作和农田林网采用的优良无性系。经过室内杂交、苗期无性系测定、观察性造林试验,多点无性系对比试验,根系及材性研究和杨粮间作试验,证明窄冠白杨5号(12—3)、6号(4—3),具有树冠窄、根系深、生长快、材质好、抗性强、主干圆满通直等特性。两无性系用于林粮间作,行距15—20m,株距4m,每亩8—10株,10年生,可长成30cm的中径材,间作区粮棉基本不减产。 相似文献
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窄冠型杨树品种的选育 总被引:10,自引:0,他引:10
经杂交和无性系选择,育成了窄冠白杨、窄冠黑青杨、窄冠黑白杨、窄冠黑杨等4大类13个窄冠型杨树新无性系,并用窄冠白杨5个无性系进行杨粮间作的研究。11a研究结果表明,窄冠型杨树用于农林间作“胁地很轻”是适用于农田林网和农林间作的优良品种,可在华北和中原地区推广。 相似文献
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对选自河南省淮阳县的窄冠刺槐优良无性系的选育过程及其生物生态学特性、无性系繁殖与育苗方法以及无性系林分在不同立地条件下的生长表现进行了研究.多点测定结果表明:窄冠刺槐生长快,在不同栽培条件下4~8年生时,树高年平均生长量达1.5~I.8 m,胸径2.1~2.5 cm;干形好,树干通直,形率达0.7~0.8;树冠窄,紧凑而圆满,分枝角度<35°;托叶刺少或无.窄冠刺槐无性系是营建速生丰产用材林、生态防护林、农林复合系统以及园林绿化的优良无性系. 相似文献
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[目的]以无人机高清影像为数据源,结合样地实地调查数据,研究杨树冠幅提取及其与胸径和林分蓄积量的相关性,为无人机森林调查技术提供一种思路和方法。[方法]基于无人机高分影像及实地调查数据,采用面向对象法,对杨树林木冠幅进行分割与提取,通过实地测量数据建立冠幅-胸径模型,利用一元材积表计算样地蓄积量,并进行相关性分析与精度检验。[结果]影像分割效果良好,但提取得到的冠幅比实际值偏小,研究区最适宜的杨树冠幅分割尺度为10,平滑度0.1,紧致度0.5。杨树冠幅与胸径建立相关模型,其中一元线性方程拟合效果最好,相关系数为0.75。通过模型计算的样地蓄积与实测样地蓄积进行双侧T检验,结果 sig=0.0580.05,两组数据差异不显著。[结论]采用面向对象法,通过无人机高分影像能自动分割并提取了杨树林木冠幅信息,提取效果良好;利用影像提取林木平均冠幅,通过冠幅-胸径相关关系模型得到林木胸径,进而推算林分蓄积的方法可以满足森林资源调查精度要求。 相似文献
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The mixed plantation of poplar (Populus spp.) and black locust (Robinia pseudoacacia) is one of the typical mixed stands with nitrogen-fixing and non-nitrogen-fixing species. Interaction between the two species
in the mixed stand is harmonious and productivity is high, making this kind of mixed plantation a very successful pattern
on poor sandy sites in north China. In this study, the fine root decomposition of the two species was investigated in the
mixed plantation of 27-year-old Canadian poplar (P. canadansis) and 22-year-old black locust on sandy sites along the Chaobai River in Beijing. Mechanism of harmonious interaction between
the two species was observed in the view of the nutrient cycle of fine roots. Results showed that: (1) the fine root decomposition
of Canadian poplar and black locust trees was different. Concentrations of N, Ca and Mg gradually increased and those of P
and K gradually decreased in the fine roots of poplar during the period of decomposition. Concentrations of N, P and K gradually
decreased in the fine roots of black locust during decomposition. The speed of nutrient decomposition in mixed fine roots
of the two species fell between the speed of the two pure samples. (2) During decomposition, the annual return amount of N,
K and Mg in fine roots of black locust was highest, followed by the mixed fine roots of the two species, and then the fine
roots of poplar. (3) The increased return amount of N in mixed fine roots could improve the N nutrient condition of poplar
trees. The return amount of P in poplar fine roots was greater than that of black locust, which could improve the P nutrient
of black locust trees. The interaction of mutual supplements of N and P nutrient cycle of fine roots between these two species
formed.
Translated from Scientia Silvae Sinicae, 2004, 4(4) (in Chinese) 相似文献