杉木不同优良品种早期生长对比试验

通过对2年生杉木不同优良品种对比试验林连续2 a的调查分析,结果表明,试验林1年生时的成活率和2年生时的保存率分别为94.38%和93.67%,优良品种适应性强且品种间差异极显著;试验林生长良好,1年生时平均树高为0.78m,2年生时达到1.98 m,当年平均抽高达到1.20 m,不同优良品种在树高性状上差异极显著;杉木优良品种适应性和早期速生性具有一致性。除了2号无性系和3号无性系表现较差外,其他杉木优良品种均表现良好。     

杉木与拟赤杨混交林的效益

杉木与拟赤杨混交类型应选择在缓坡，低洼，有季节性积水的地块造林，采用１：１行间混交方式，这样可以形成相对稳定的复层林相，经济效益显著；但在大多数山坡地块上，到中龄林时形成了同层林，拟赤杨有被淘汰的趋势，而杉木长势良好，高径生长量比纯林杉木显著。     

杉木人工林神经网络密度效应模型

基于人工神经网络具有逼近任意非线性映射的特性,将其应用于建立杉木人工林密度效应模型,并用免疫进化算法优化求解人工神经网络参数。结果表明：基于人工神经网络及免疫进化算法的杉木人工林密度效应模型,建模方法科学合理,林分蓄积量和平均胸径预测误差小,一定程度上优于以往传统的林分密度效应模型,在林分密度控制中有推广应用价值。     

Characteristics of carbon and nitrogen of soil microbial biomass and their relationships with soil nutrients in Cunninghamia lanceolata plantations

The soil microbial biomass and nutrient status under the native broadleaved forest and Cunninghamia lanceolata plantations at the Huitong National Research Station of Forest Ecosystem (in Hunan Province, midland of China) were examined in this study. The results showed that after the native broadleaved forest was replaced by mono-cultured C. lanceolata or C. lanceolata, soil microbial biomass and nutrient pool decreased significantly. In the 0–10 cm soil layer, the concentrations of soil microbial carbon and nitrogen in the broadleaved forest were 800.5 and 84.5 mg/kg, respectively. These were 1.90 and 1.03 times as much as those in the first rotation of the C. lanceolata plantation, and 2.16 and 1.27 times as much as those in the second rotation of the plantation, respectively. While in the 10–20 cm soil layer, the microbial carbon and nitrogen in the broadleaved forest were 475.4 and 63.3 mg/kg, respectively. These were 1.86 and 1.60 times as much as those in the first rotation, and 2.11 and 1.76 times as much as those in the second rotation, respectively. Soil nutrient pools, such as total nitrogen, total potassium, NH₄ ⁺-N, and available potassium, also declined after the C. lanceolata plantation replaced the native broadleaved forest, or Chinese fir was planted continuously. Less litter and slower decay rate in pure Chinese fir plantation were the crucial factors leading to the decrease of soil microbial biomass and nutrient pool in this area. Human disturbance, especially slash-burning and site preparation, was another factor leading to the decrease. There were significant positive correlations between soil microbial carbon and nitrogen and soil nutrients. To improve soil quality and maintain sustainable productivity, some measures, including planting mixed conifer with hardwood, preserving residues after harvest, and adopting scientific site preparation, should be taken. Translated from Chinese Journal of Applied Ecology, 2006, 17(12): 2,292–2,296 [译自: 应用生态学报]     

豫南山区杉木更新模式研究

豫南山区杉木林采伐后,及时栽种柳杉、水杉、马尾松有利于杉木林的自然更新。采用栽针萌杉更新模式可节约营林投资近 1 /3,高生长量可提高 0. 7~2. 4倍。     

运用RAPD技术进行杉木无性系识别研究

以湖北省的４０个杉木优树为研究材料,初步开展了运用ＰＣＲ—ＲＡＰＤ技术对杉木优树进行识别的研究。研究表明,运用 ８个引物的 １７个分子标记可以对其中的３８个无性系进行识别,只有２个无性系相互不能识别。说明湖北省杉木遗传资源变异幅度较大,可以运用 ＤＮＡ技术对优树进行品系管理。     

用“t”检验选择法筛选杉木优良种源子代耐瘠薄优株

根据杉木子代性状分离遵循的遗传生长规律,应用杉木高世代种子园良种子代在Ⅲ~Ⅵ类立地造林,选择具有速生表现与较强生长适应性的优势木且未间伐林分作为预选林分,采用树高与地径作为评价指标,利用“t”检验选择法确定优株筛选标准,筛选耐瘠薄-速生优株13株。所选择优株树高与地径生长量与所在样地林分平均木比较有很好的适应性,生产应用价值较高。     

南方杉木人工林树高曲线模型研究

采用多模型对比选优法,以639组南方杉木人工林胸径-树高调查值为依据,求解了24组树高曲线模型的参数和评价指标.经检验,双曲线、Gompertz和Logistic模型均能取得较好的拟合效果,且模型用于杉木树高估计的精度高于98％;双曲线模型略优于其他模型;杉木人工林胸径和树高呈紧密相关关系,双曲线、Gompertz和L...     

广西大青山12年生杉木人工林的生物生产力

通过对广西大青山实验林场12年生杉木（Cunninghamia lanca）lata）人工林的生长量、生物量和生产力进行研究,结果表明：12年生杉木人工林平均胸径、平均树高和蓄积年均生长量分别为13．7cm、11．8m、18．6m^3／hm^2;林分生物量和净生产量分别为92．502t／hm^2、9．763t／（hm^2．a）,其中,乔木层的生物量及净生产量分别占林分总量的96．06％和93．78％,灌木层和草本层的生物量及净生产量依次占林分总量的0．97％、2．98％、1．59％、4．63％。由于该实验区位于两山夹一沟,气候湿润,水热条件很适宜杉木的生长,所以生产力水平较高。     

微生物对杉木木材渗透性的影响

分别在杉木产区古杉的创伤处采集被微生物感染木材样品和活体杉木上采集感染病的叶进行分离培养，培养后得到交链胞(Paeudomonas cunuinghamiae Nanjing F.)和多毛胞(Pestalotia zhirdiana P.Henn.)将两种微生物接种到杉木木材上，处理90d后，木材液体渗透性提高达55．3％-60．5％，经方差分析，对照与处理差异显著；微生物处理对心材没有作用；微生物处理改善杉木木材渗透性主要作用在边材，前6h的单位体积吸水量占总吸水量为55．3％-60．5％，达到24h后吸水量差异甚微。