小黑杨防风固沙林土壤物理性质研究

通过烘干法和环刀法,对嫩江沙地不同林龄小黑杨防风固沙林的土壤容重、孔隙度和持水量进行了研究。结果表明:小黑杨防风固沙林对土壤物理性质有一定的改良作用,主要集中在0~20cm土层中;随着林龄的递增,土壤田间持水量、毛管持水量、最大持水量、非毛管孔隙度、毛管孔隙度、总孔隙度0~40cm土层表现出降低再升高的趋势,而容重表现则相反;40cm土层以下物理性质变化不明显。     

‘拟青×山海关杨’引种造林初报

通辽市林研所1990年从黑龙江省齐齐哈尔防护林研究所引进‘拟青×山海关杨’,经过圃地试验、定位观测、区域对比试验,‘拟青×山海关杨’引种获得成功,达到了筛选抗旱、耐瘠薄、速生、多用途无性系的预期目的。     

3个杨树品种在鲁西地区光合生理特性研究

在鲁西地区对鲁林2号、鲁林3号、2025杨(对照)3个杨树品种的净光合速率、蒸腾速率、气孔导度等生理指标进行测定的结果表明:鲁林2号、鲁林3号的净光合速率显著高于对照,具有高产潜能。相关性分析发现,蒸腾速率、空气温度与杨树净光合速率分别呈极显著和显著正相关关系,说明杨树要实现高产,必须有充分的水、热条件做保障。     

小胡杨对滨海苏打盐渍土改良效果研究

滨海苏打盐渍土修筑台田后种植小胡杨可以成活,18年后小胡杨林分基本郁闭。以未种植树木的台田作为对照(CK),对小胡杨林地内植被演替规律、土壤水分物理性质进行研究。结果表明,小胡杨成林后,林地内植被向良性方向发展,群落生态型由中度耐盐群落演替成轻度耐盐群落,群落高度也由0.2～0.6 m增加到0.5～0.8m,盖度则达到80%～90%,土壤也由苏打盐渍土转变成轻盐碱土;小胡杨可显著降低土壤容重,改善土壤孔隙状况,增加土壤持水性能,使土壤水分物理性质得到显著改良,其中,对0～10 cm土层的改良效果要好于10～30 cm土层。     

杨树伐根嫁接亲和力研究

以小美旱杨为砧木,选择了9个杨树品种作接穗进行伐根嫁接,研究了伐桩与接穗的亲和力。结果表明:以小美旱杨为伐桩,嫁接038杨,中林46杨,107杨,108杨,埃瑞达诺110杨,中林2001杨,中林2025杨和转基因杨的伐桩成活率均高于97.8%,第4年伐桩保存率均高于92.8%,可以满足林业生产的需要,表现出良好的亲和力。     

冀北土石山区天然次生林山杨、白桦种群的空间分布格局

分析冀北土石山区典型天然次生阔叶林中的山杨、白桦种群的径级结构、空间分布格局及种内/种间的空间关联。结果表明:山杨、白桦均以中径木为主,林下缺乏可供更新的幼苗、幼树,种群呈现衰退趋势;山杨、白桦的全部个体在本研究尺度上呈聚集分布,随尺度的增大其聚集强度先增大后减小,并趋于随机分布;山杨、白桦种群随龄级增大,聚集强度减小,以幼树的聚集强度最大;不同生长阶段同种个体间的关联性随尺度的变化,出现正关联、负关联和相互独立的空间关系,以负关联为主;不同生长阶段的山杨和白桦种群间未出现正关联,大多数种对在本研究尺度上为负关联或者在大部分尺度上为负关联;山杨、白桦的种内/种间竞争激烈,群落整体结构不稳定,处于演替初期向中期过渡阶段。     

新疆杨扦插育苗促进生根率技术研究

通过使用高锰酸钾、醋酸、双氧水等3种氧化剂和吲哚乙酸、吲哚丁酸、萘乙酸等3种外源激素不同浓度对新疆杨插穗进行处理,以探讨新疆杨扦插生根促进技术。结果表明:虽然不同氧化剂试验处理对新疆杨生根率与对照相比差异是显著的,但没有达到生产上对生根率的要求;不同的激素浓度水平会明显影响新疆杨的生根率,以吲哚丁酸浸泡插穗6h最佳浓度是200mg·L-1,扦插生根效果较好,生根率达到3.65%。     

大青杨人工林初植密度控制技术的研究

通过大青杨初植密度试验,掌握了初植密度和胸径、单株材积、单位面积蓄积量等生长指标之间的关系,了解了施肥对树木生长的影响,确定了培育大青杨纸浆材的适宜初植密度是1111～1667株·hm 2。     

Lignin Characterization of Triploid Clones of Populus tomentosa Carr.

In order to understand the structural characteristics of lignin in triploid clones ofPopulus tomentosa and its changes in the processes of pulping and bleaching, milled wood lignin （MWL）, lignin carbohydrate complex （LCC） and the residual lignin from kraft pulp （KP） and sulfite pulp （SP） were isolated and analyzed by Fourier transform infrared （FTIR） spectrum and ^13C nuclear magnetic resonance （NMR）. The most diagnostic peaks were assigned and the differences were discussed. The spectral patterns reveal that triploid P tomentosa shows the specific features of hardwood from temperate areas, but in the spectrum of FTIR, the strength ratio orAl270 cm^-1 to A1226 cm^-1 is 0.88, higher than the average of hardwood from temperate areas, which will make the lignin delignification more difficult during pulping and bleaching. The LCC from triploid P tomentosa is mainly composed of xyloglucan and glucuronic acid, and other glucides have much lower ratio. In LCC FTIR, there are three peaks at 1 427, 1 329 and 1 046 cm^-1, indicating that both semi-cellulose and cellulose could exist in LCC, and that there might be relationships between cellulose and lignin. Compared with the residual lignin from KP and SP, the condensed structure in KP is more than that in SP.     

Cross Breeding of Populus and Its Hybrids for Cold Resistance

Populus tomento a was crossed with P. tremuloidis, P grandiden ata, P. lba × P. grandidentata and P. alba × Ulmus s . ta pumila in order to maintain its rapid growth and high wood quality and improve its resistance to cold. Two methods were used to increase the germination rate from 1.5% to 41.1% and the remaining rate from 1.7% to 44.2%. Forty crossing combinations were conducted and 2 744 hybrid seedlings were obtained. MX. t4 × P grandiden ata (G-1-58), MX3 × P. tremuloidis (T-44-60), MX2 × P. tremuloidis (l-13-87-37) and MX2 × (P. alba × P. grandidentata) were regarded as superior combinations after analysis and selection. Thirty seedlings of these combinations and 11 triploid seedlings identified by counting their chromosomes were selected as super plants.