检索规则说明:AND代表“并且”;OR代表“或者”;NOT代表“不包含”;(注意必须大写,运算符两边需空一格)
检 索 范 例 :范例一: (K=图书馆学 OR K=情报学) AND A=范并思 范例二:J=计算机应用与软件 AND (U=C++ OR U=Basic) NOT M=Visual
机构地区:[1]河北省林业科学院
出 处:《东北林业大学学报》1998年第4期28-31,共4页Journal of Northeast Forestry University
摘 要:对大量临时标准地和固定样地的调查研究表明:刺槐个体开花量主要受自身遗传特性制约,同时受光照等环境条件影响,其无花和少花个体所占比例约为20.3%;蜜源林的培育可采用以间伐代修枝的办法,采取以下层间伐抚育为主的方式,疏伐无花和少花个体,保留单株及林冠层的最大有效枝量;利用具有高产遗传特性的个体或高蜜源品系,逐步更新改造现有蜜源林;蜜源林培育的合理郁闭度为0.6~0.8,适宜培育周期为15~20a。The investigation results for abundant temporary and permanent plots show that the flower mass of individual tree is mainly determined by its genetic factor, and also affected by environmental conditions such as sunlight. No flower or few flower trees are about 20 3% in the population. The pruning of nectariferous forest should be replaced by thining, reserving efficient shoot in canopy class. Cut no flower and few flower individuals. The present nectariferous forest should be regenerated by high yield trees or new varieties. Its reasonable canopy density is 0 6~0 8, the management period is 15~20 a.
分 类 号:S727.304[农业科学—林木遗传育种] S792.260.5[农业科学—林学]
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在链接到云南高校图书馆文献保障联盟下载...
云南高校图书馆联盟文献共享服务平台 版权所有©
您的IP:216.73.216.170