菇木林育苗造林试验初报

采用多年多点进行菇木多树种育苗造林试验，３年来共育苗１１ｈｍ２，营造试验林２０．８ｈｍ２，示范林６８．５ｈｍ２，树种１９个。试验结果表明，选用水稻田育苗，通过间苗补植等措施，使合格苗达８０％以上；选择山坡谷地的土层深厚、肥沃湿润地段造林，其成活率达８５．８％～９８．３％２年生桤木幼树，平均树高３．９３ｍ，平均地径４．１ｃｍ。初步看出桤木、杜英、马褂木是良好的速生菇木树种。     

配套栽培措施促进核桃大树丰产的研究*

1987～1990年在北京和山西两点分别进行了配套栽培措施促进核桃大树丰产的试验研究。结果表明:组装配套栽培措施不仅可以促进树体生长和大幅度提高产量,同时也能提高土壤有机质含量和改善土壤肥力状况。在一定范围内,配套栽培措施的迭加数目同增产幅度呈正相关。研究找出了两个试点的最佳处理组合。讨论了组装配套栽培措施的应用问题。     

亚硫酸盐酒糟醪液采脂对马尾松产脂量、木材生长量及木材物理力学性质的影响

作者通过七年的试验证明,亚硫酸盐酒糟醪液采脂其松脂产量比常法采脂增加27.2％;木材生长量比常法采脂少损失5.3％;木材物理力学指标,高于未采脂松树7—18％,而常法采脂基本上不改变松树木材的物理力学性质,不影响木材的利用价值。     

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.     

Salt distribution in response to optical stratification porosity and relative windspeed in a coastal forest in Niigata, Japan

Wind velocity, vertical stand structure and seasalt distribution were measured at various heights inside a plantation of coastal pine forest, with thinning and unthinning, to assess whether any relationships exist between the wind profile, stand structure and seasalt distribution in the coastal pine forest. The vertical stand structure, i.e., optical stratification porosity (OSP), which is defined as vertical distribution of the proportion of sky hemisphere not obscured by tree elements inside a forest stand, was determined for each height by computer analysis of digital images taken with a hemispherical lens. The distribution of OSP in the coastal forest follows the Lambert-Beer's law with absorbency coefficient (). The relative windspeed within canopy can be described using the exponential form with the attenuation coefficient (). The sea-salt was collected using salt gauze (a surgical dressing of loosely woven cotton) both inside and outside the coastal forest, and the distribution of sea-salt within canopy was also in accordance with an exponential function. The relationships among windspeed, OSP and sea-salt indicate that the distributions of both sea-salt and windspeed within canopy were very closely correlated with the distribution of OSP. A linear relationship between OSP and sea-salt has been found. Additionally, linear regression between coefficients and has been obtained as well. Based on these relationships between OSP, wind and sea-salt in the coastal forest, the sea-salt distribution and wind profile within the canopy of the coastal forest can be predicted according to OSP. These results may therefore be useful in analyzing the effects of sea-salt on vegetation and evaluating the filter functions of coastal forests.This revised version was published online in November 2005 with corrections to the Cover Date.     

Biomass production,nutrient cycling and distribution in age-sequence Chinese fir (<Emphasis Type="Italic">Cunninghamia lanceolate</Emphasis>) plantations in subtropical China

Biomass production and nutrient (N, P, K, Ca and Mg) accumulation, distribution and cycling were quantified in young, mature and over-mature (10-, 22-, and 34-year old) Chinese fir [Cunninghamia lanceolate (Lamb.) Hook] plantations in southern China. Total stand biomass of young, mature and over-mature stands was 38, 104 and 138 t ha^?1 respectively. Biomass production increased significantly with age. Stem wood represented the highest percentage of stand biomass, accounting for 41, 55 and 63 % in the young, mature and over-mature plantations respectively. Nutrients concentration was highest in live needles and branches, and lowest in stem wood. The plantations accumulated more N, followed by K, Ca, Mg, and P. Nutrient return amount, nutrient utilization efficiency, nutrient turnover time, the ratio of nutrient return and uptake increased with stand age, which implies that young Chinese fir deplete soil nutrients to maintain growth, and efficiently utilize nutrients to decrease dependence on soil nutrients as they age. Harvesting young Chinese fir plantations would therefore lead to high nutrient loss, but prolonging the rotation length could improve soil recovery, and help sustain productivity in the long-term. Improved nutrient return through litterfall as stands get older may also be beneficial to nutrient pool recovery.     

杜仲生长节律与施肥技术简报

杜仲高生长以4－7月份生长最快，6月份达最高峰；径生长以5－7月为旺盛期，其中6、9月各有一次生长高峰；杜仲林地施肥以4－5月为最佳；施肥量为一个区间，且因树龄而异；施肥按坡台地和平地进行沟施和穴施。     

汽车车厢底板用竹木复合板的研制

采用马尾松作芯板、竹片作表板、酚醛树脂作胶粘剂，制造汽车车厢底板用竹木复合板。在确定的涂胶量、热压温度、热压时间条件下，研究了不同的热压压力与竹木复合板性能的关系，得出了适宜的热压工艺条件。研究结果表明，竹木复合板的物理力学性能达到林业行业标准ＬＹ１０５５—９１规定的指标值，为充分、合理、经济、有效地利用竹木资源提供了依据     

间伐小径木指接技术研究

间伐材指接胶合加工，变短材为长材，弯材为直材，为合理，有效利用间伐材开辟了新路。对间伐材木材含水率，指接端压的大小和时间，指接后养护时间，涂胶量，指榫规格等对指接材抗弯强度的影响进行了研究，并测定了苯酚，间苯二酚，甲醛树脂胶胶合的指接材快速老化性能。