秦岭林区锐齿栎林木个体生长分析

应用植物生长分析方法,通过破坏性取样,对锐齿栎林木的光合器官、非光合器官的生长过程以及物质生产效率进行了研究。结果表明,光合器官的增长过程与非同化器官的生长过程并不同步,锐齿栎在展叶的前２０ｄ内,主要靠消耗树体先年贮存的营养物质维持生长;展叶２０ｄ以后,生长则依赖当年的光合产物。     

Spatial distribution of needle bright disease ofPinus sylvestris var.mongolica

The spatial distribution pattern of needle bright disease was mathematically studied. The results showed that it is tally with negative binomial distribution. The infected area and damaged amount can be forecasted with this spatial distribution pattern. Through the study on probability distribution of spatial points for single tree, the method and equations for calculation of the disease index of whole forest belt were determined. (Responsible Editor: Chai Ruihai)     

Production of haploids in bread wheat, durum wheat and hexaploid triticale crossed with pearl millet

Pearl millet is an efficient alternative to maize as a pollen source for haploid production in bread wheat. To compare haploid production frequencies in other Triticeae species, the crossabilities of two genotypes each of bread wheat, durum wheat and hexaploid triticale with four pearl millet genotypes and a maize control were examined. Embryos were obtained from crosses of all three species with both pearl millet and maize. However, significant differences in crossability were found among the three species (10.5–79.8% seed development and 1.4–15.8% embryo formation), as well as among genotypes of durum wheat (7.2–23.7% and 2.1–6.4%) and hexaploid triticale (0.3–20.6% and 0.1–2.7%). Crossability of bread wheat with pearl millet was relatively high. Haploid plants were regenerated from crosses of all three species with pearl millet. As in the case of maize crosses, low crossabilities of durum wheat and hexaploid triticale with pearl millet can be attributed to the absence of D-genome chromosomes.     

科尔沁沙地樟子松种源试验研究

本文利用樟子松 ( Pinus sylvestris L .var mongolica L itvin) 1 1个种源在科尔沁沙地 3个参试点的生长性状 ,进行联合方差分析。结果表明 :各种源树高间存在极显著差异 ;通过在各试点进行多维空间、多向量数学模型的综合分析 ,得出青山种源的生产力最高 ,高生长超出章古台 (对照 ) 3 0 .4 %,超出参试种源平均值 1 3 .5 6%,高峰、塔河、呼玛次之。经相关分析 ,樟子松不同种源树高与冠幅、当年生长量、地茎呈显著正相关。     

Investigation of change in tangential strain on the inner bark of the stem and root ofBetula platyphylla var.japonica andAcer mono during sap season

Although it is well known that sap exudation during early spring in temperate deciduous trees occurs in response to daytime warming and nighttime cooling, the mechanisms of the process are not yet fully understood. Previous theories suggested that changes in stress in the wood caused by daytime heating and nighttime cooling might be linked with sap flow. Consequently, a study of itaya-kaede maple (Aver mono) and shirakamba birch (Betula platyphylla var.japonica) looked at tangential strains. One-hour intervals for 3 years of the tangential strains on the inner bark of stem and root were measured in itaya-kaede maple and shirakamba birch during the sap exudation season. The measurements indicated different mechanisms of sap exudation in these two trees. During the sap exudation season in late March, when the temperature fluctuated around 0°C, the tangential strain in the root of itaya-kaede maple showed expansion in the daytime and contraction at night. Conversely, in early April the tangential strain in the root of shirakamba birch exhibited contraction in the daytime and expansion at night. The changes in tangential strains in itaya-kaede maple were attributed to conditioning, a known concept used to explain the uptake mechanism of soil water in maple and its exudation during early spring. However, because the change in tangential strain in the roots of shirakamba birch was similar to that found during the rampant season, sap exudation was not attributed to conditioning but to the plentiful supply of water from the roots. The implications of these mechanisms are that different sap harvesting techniques may be appropriate for different tree species.     

大叶山杨与山杨木材比较解剖与材性分析

运用对比分析的方法对山杨和大叶山杨木材的解剖特征,纤维形态等进行了较详细的观察,测定与分析,对２种木材的气干密度,干缩系数,顺纹抗压强度,顺纹抗拉强度,抗震强度,抗弯强度,抗弯弹性模量,冲击韧性,硬度,抗劈力强度等进行了对比研究;对２种木材的冷水抽出物,热水抽出物,质量分数为１％的ＮａＯＨ抽出物,乙醚抽出物,苯醇抽出物,ｐＨ值,纤维素含量,半纤维素含量,木素含量等化学成分进行了测定。     

Response of advance lodgepole pine regeneration to overstory removal in eastern Idaho

Twenty-two stands of advance lodgepole pine released with overstory removal were sampled to determine height growth response. Tree and site characteristics correlated with release response were identified, and a mathematical model was developed to predict height growth in years 6 through 10 after release as a function of residual overstory basal area, height at release, percent rock cover, five-year cumulative growth prior to release, logging damage, stand elevation, and habitat type. Lodgepole pine responded to release with increased height growth in 97% of the trees sampled. Growth was similar to that of unsuppressed trees. Height growth is best when the entire overstory is removed and logging damage is avoided. Taller trees generally do not respond as well as shorter trees. However, trees growing fast before harvest continue to grow fast regardless of their height at release. Recommendations for selecting stands of advance lodgepole pine to release are provided.     

凹叶厚朴杉木混交林生物量及分布格局研究

应用平均标准木法和样方收获法对凹叶厚朴杉木混交林各经营模式林分的生物量、生物量组成及分布的研究结果表明：不同经营模式的林分中,以行间混交的生物量及生产力最高, 分别为７４．９６ ｔ／ｈｍ ２ 和６．２５ｔ／ （ ｈｍ ２·ａ）; 混交林各经营模式的营养空间分布均比杉木纯林合理,对林木生长有促进     

樟子松切根育苗试验

对樟子松进行切根育苗试验,结果表明,机械切根苗苗木质量优于移植苗和留床苗。切根２０ｃｍ的苗高、地径分别比移植苗高９４ｃｍ和粗０２ｃｍ,大于１ｍｍ的侧根数量,平均比移植苗多１１８条,比留床苗多１０条。机械切根可使２年生樟子松产苗量,比人工移植提高２４２９％～３７１４％,每公顷增加收入１５２８５～３０１１１元。     

裂壶藻对津新鲤(Cyprinus carpio var. Jian)生长、血液非特异性免疫指标及抗病力的影响

选用初始体重为(26.77±1.56)g的津新鲤(Cyprinus carpio var.Jian) 540尾,随机分为6组,每组3个重复,分别投喂含0、0.40％、0.80％、1.20％、1.60％和2.00％裂壶藻的等氮等能饲料,饲养56 d,探讨饲料中不同水平的裂壶藻对津新鲤生长、血液非特异性免疫指标及抗病力的影响.结果显示,在0.80％裂壶藻水平组中,增重率和特定生长率均显著提高(P＜0.05),肥满度则在1.20％水平组中达到最大值(P＜0.05),各组间成活率差异不显著(P＞0.05).不同水平的裂壶藻均可以显著提高津新鲤的抗氧化能力,其中过氧化氢酶、总超氧化物歧化酶和谷胱甘肽的含量均呈先上升后下降的趋势,且分别在1.20％、0.80％和1.20％组中达到最高(P＜0.05);而丙二醛含量呈先下降后上升的趋势,在0.80％组中达最低(P＜0.05).不同水平的裂壶藻均可以显著提高津新鲤的非特异性免疫力,溶菌酶呈先上升后下降的趋势,其中1.20％组活性最高(P＜0.05).一氧化氮含量随裂壶藻水平增加而增加,各添加组含量均显著高于对照组(P＜0.05).谷草转氨酶/谷丙转氨酶在0.80％组中达到最小值(P＜0.05).随着裂壶藻水平的增加,津新鲤血细胞呼吸爆发活性和免疫保护率得到显著提高,感染嗜水气单胞菌后的累计死亡率则显著降低(P＜0.05),其中,以0.80％组最佳.综合生长、血液非特异性免疫指标和抗病力来分析,饲料中裂壶藻的适宜添加水平为0.80％-1.20％.