不同林龄湿地松林土壤酶活性与土壤养分特征

以大鹤国有防护林场3种不同林龄(15、23、34 a)的湿地松林为研究对象,研究了不同林龄湿地松林土壤酶活性及其养分含量变化特征。结果表明:土壤pH值随着林龄增加呈先降低后升高,随着土层深度的增加逐渐升高。随着林龄的增长,土壤有机质先增加后降低;土壤水解氮、有效磷和速效钾含量逐渐降低。土壤中的脲酶、蔗糖酶、过氧化氢酶和多酚氧化酶活性随林龄的增长逐渐降低;酸性磷酸酶活性仅在表层土随着林龄的增长逐渐降低,而随着土层的加深表现为先增长后降低。土壤养分和酶活性随土层深度的变化均存在显著性变化。相关分析表明,土壤脲酶、蔗糖酶和酸性磷酸酶均与土壤有机质、水解氮、有效磷和速效钾存在极显著正相关(P<0.01),多酚氧化酶与速效钾呈显著负相关(P<0.05)。滨海地区湿地松在林龄较低阶段土壤养分较为充足,随着林龄的增长,土壤肥力逐渐下降,不利于森林可持续发展。     

湿地松种子园家系生长表现

为进一步开展湿地松优良家系培育试验,筛选速生、丰产等不同功能品系,为我国造纸业、建筑以及板材业提供优质原材料及优质生态产品;通过将美国引进的三代湿地松种子园半同胞家系和全同胞家系及本项目组自主培育的湿地松家系放在一起开展子代测定试验。参试的湿地松半同胞家系14个、全同胞家系8个。对其3年生测定林胸径和树高进行了测定分析与比较。结果表明:1)不同湿地松半同胞和全同胞家系间,在树高和胸径生长方面均存在显著差异;2)综合比较每个家系树高和胸径生长状况,通过Duncan法选出了生长性状优良的半同胞家系S4、S11、S13、S16、S25,以及全同胞家系S14、S23、S17。     

湿地松、火炬松适应性分析

在同样的立地条件和抚育条件下,在1~20 a内,湿地松的生长明显优于火炬松和马尾松。20~30 a内,国外松生长不如马尾松,而且对地力的适应性也不如马尾松。作为短轮伐期的速生丰产纸浆林,湿地松是适应性比较强的速生丰产的引进树种,但在立地差、集约度低或海拔高处应以本地树种马尾松为主。     

湿地松等5树种在太湖滩地造林耐淹水性比较试验

在太湖滩地用湿地松、美国白蜡、水杉、池杉和柳树（对照）进行了不同树种、不同区域、不同淹水期和不同淹水深度的耐水湿对比造林试验。在淹水深度20～60．5cm、连续淹水时间达40d时观察结果为：①湿地松和柳树（对照）的成活率分别为99．7％和99．5％;美国白蜡、水杉和池杉的成活率分别为19．5％,30．2％和31．1％。②在太湖滩地湿地松表现与柳树（对照）一样,生长势和生长量一切正常,湿地松为常绿树种,病虫害较少,从绿化、美化和景观考虑,建议湿地松作为太湖滩地造林树种之一,并建议作为我国太湖地区淡水森林湿地植被恢复与重建的的适生树种之一。     

杂种松松脂化学成分研究

杂种松是湿地松×加勒比松杂交的后代。采用GC/MS仪DB-5毛细管柱对湿地松、加勒比松、杂种松三种松脂及其松香、松节油进行定性、定量分析。结果表明,杂种松松脂中枞酸型树脂酸及蒎烯含量较双亲湿地松和加勒比松低。     

Dynamic modulus of elasticity and bending properties of large beams of Taiwan-grown Japanese cedar from different plantation spacing sites

The effect of plantation spacings (types A-E) on the bending strength and dynamic modulus of elasticity of 41-year-old Taiwan-grown cedar (Cryptomeria japonica D. Don) was investigated. The results indicate that the highest values for the static bending modulus of elasticity (MOE), modulus of rupture (MOR), and dynamic modulus of elasticity (E_D, E _Dt) occurred in trees obtained from those most densely planted (type A); there was a significant difference between type A and the other four spacing types (B, C, D, and E), but there were no significant differences among those four types. Interrelations among MOE, MOR, E _D, and E _Dt could be represented by positive linear regression formulas, which revealed highly significant differences. The relations among the square value of stress-wave transmission velocity (V_t ² and V_t ²⁾ and MOE, MOR, E _Dl, and E _Dt, respectively, could be represented by positive linear regression formulas. The differences were highly significant.Part of this report was presented at the International Wood Engineering Conference '96, New Orleans, LA, USA, October 1996     

湿地松成熟合子胚直接器官发生及植株再生

以湿地松成熟胚为外植体诱导不定芽发生,初步建立植株再生体系.先用含不同浓度6-BA的液体培养基处理湿地松成熟胚12～36 h,吸干后转移到无激素的培养基上培养.6周后,经60mg·L-1 6-BA液体培养基预处理12 h的胚不定芽诱导率最高达69%,预处理24 h平均每个外植体产芽数达到最高(9～12个),但芽体较小,在继代培养基中伸长较慢;经30 mg·L-1 6-BA液体培养基预处理的胚不定芽诱导频率较低,仅25%～38%,但芽体健壮,在继代培养基中伸长较快;6-BA浓度大于80 mg·L-1时不利于不定芽分化.不定根诱导的研究结果表明,NAA对不定芽生根具有促进作用,在改良1/2GD NAA0.05mg·L-1培养基中培养4周后,生根率达50%,移栽成活率为60%左右.     

不同复混肥对湿地松中龄林的施肥效应研究

为了研究不同复混肥对湿地松中龄林的施肥效应,以8年生湿地松林为研究对象,分别以施用2种普通复混肥和自制松树专用复混肥为施肥处理,各处理的施肥量均为700 g·株^-1;同时以不施肥为对照,进行施肥对比试验。结果表明:3种不同施肥处理中,以自制松树专用复混肥对湿地松林分生长的促进作用最大;施肥3年后林分的平均胸径、树高、单株材积分别较对照增长3.1%、4.7%、10.0%;施肥3年后自制松树专用复混肥处理的平均胸径、单株材积与2种普通复混肥处理间均存在极显著差异,树高均有显著差异;施用有长效作用并具针对性的松树专用复混肥能获得较高的木材增产效益。     

The flexural properties of young Pinus elliottii x Pinus caribaea var. hondurensis timber from the Southern Cape and their prediction from acoustic measurements

The objectives of this study were to determine the bending strength and stiffness properties of young Pinus elliottii x P. caribaea var. hondurensis timber from the Southern Cape, South Africa, and to evaluate the predictability of these properties from acoustic measurements on standing trees, logs and their sawn boards. The timber has good bending strength (MOR) properties but the mean stiffness (MOE_stat) was significantly lower than that required for structural-grade timber. The mean MOE_stat was also about 30% lower than a P. radiata control sample. The MOE_stat of sawn boards could be predicted from acoustic stress wave measurements on standing trees with a correlation (r) of 0.48 and from acoustic resonance frequency measurements on sawn boards with a correlation of 0.85. The MOR of sawn boards was not significantly correlated with acoustic stress wave measurements on standing trees and only moderately correlated with acoustic resonance frequency measurements on sawn boards (r = 0.45).     

马尾松、湿地松幼树生物量及养分积累

在福建省政和县杨源乡对相似生境下4年生的马尾松、湿地松幼树生物量和养分积累进行研究,结果表明:除枝生物量为湿地松小于马尾松之外,湿地松幼林的干、皮、叶、主根、侧根生物量均高于马尾松幼林,林分生物量为湿地松大于马尾松;林分不同养分元素的平均含量,C、K、Mg含量为湿地松大于马尾松,N、P、Ca、Fe含量为马尾松大于湿地松;不同部位养分元素含量以叶最大,其次为侧根、枝和皮;不同养分积累量,N、P、Ca的积累量为马尾松大于湿地松,C、K、Mg、Fe的积累量为湿地松大于马尾松。养分利用效率计算表明,湿地松幼林对各养分元素的利用效率高于马尾松,在干物质产出相同的情况下,湿地松幼林从土壤中带走的养分少于马尾松。     

间伐对湿地松纸浆材材性的影响

在纸浆林培育过程中,纸浆材材性及纸浆特性是十分重要的内容,它涉及到纸浆林能否持续利用及发展的问题.因此,各项培育措施的确定都要考虑对纸浆材性的影响.造纸用纤维原料的化学成分随原料品种、产地及不同的栽培措施而不同,原料的化学成分是选择和评价原料质量的重要指标,也是确定制浆、造纸工艺的重要依据.因此不同的化学成分在制浆中有着不同的意义.一般说来,在同样的条件下,纤维素含量最高的原料,质量较好,成浆得率较高,木素含量较高的原料,蒸煮比较困难.……     

Production of Oleoresin from Pinus elliottii var. elliottii Stands on Tilbury Estate in the Melsetter District of Zimbabwe

Effective mechanical and chemical control techniques have been developed for almost all the important woody, alien, invasive plants in Natal. Despite this, progress with the actual control of these plants has been disappointing. Possible reasons for this include poor control practices, a lack of extension work, wrong attitudes and too much reliance on biological control. An approach is proposed which will address these and other problems. Research is to concentrate on the implementation of available control techniques to determine their cost-effectiveness when applied on a large scale and also over the long term, e.g. aspects such as post control management of the vegetation. This is to be done with the so-called “land-unit based” approach which will also serve to transfer the most suitable technology to the end-user.     

Autumn frost hardiness of Pinus sylvestris offspring from seed orchard grafts of different ages

Autumn frost hardiness of offspring from clones (originating from 66.0–68.8° N) in six southern (62° N) and one northern (66.5° N) Pinus sylvestris seed orchards in Finland, was evaluated. One‐year‐old seedlings derived from open pollinated grafts of young, intermediate, and fairly mature age, and natural stand seedlings, were artificially freeze tested. The northerly located orchard produced the least injured offspring. There were no significant systematic differences between age classes. Neither were there any indications of decreased freezing injury with later age classes. The family variance was significant in four orchards. The estimated injury levels of orchard offspring were, in general, closer to those of natural stands in the neighbourhood of the orchard than natural stands at the place of clonal origin. It is suggested that not only differences in mother clone hardiness but also clonal differences in pollen contamination rate caused the observed family variation.     

Dynamic modulus of elasticity and bending properties of young Taiwania trees grown with different thinning and pruning treatments

The effects of different thinning and pruning methods on the bending strength and dynamic modulus of elasticity (DMOE) of young Taiwania (Taiwania cryptomerioides Hay) were investigated. The average DMOE, modulus of elasticity (MOE), and modulus of rupture (MOR) in the thinning treatments showed the following trend: no thinning > medium thinning > heavy thinning. This indicates that thinning reduces average bending properties. The average DMOE, MOE, and MOR in the pruning treatments showed the following trend: medium pruning > no pruning > heavy pruning. According to this tendency, better average qualities of lumber and specimens were from wood subjected to no-thinning and medium-pruning treatments according to an ultrasonic wave technique and static bending tests. However, most results showed no statistically significant differences among thinning, pruning, and thinning and pruning treatments. The average values of DMOE, MOE, and MOR of visually graded construction-grade lumber were significantly greater than those of below-grade lumber. Moreover, there were very significant positive relationships between density, ultrasonic velocity, DMOE, MOE, and MOR, although the determination coefficients were small.     

不同立地指数湿地松纸浆林生长研究

于泰格林纸集团公司在岳阳地区营造的不同立地指数的湿地松纸浆林设置样地,对不同立地指数林分的生长进行调查研究。结果表明:立地指数为15、13、11的14年生湿地松纸浆林平均树高分别为10.0、7.9、6.0 m,平均胸径分别为14.5、12.6、10.9 cm,林分单位面积蓄积量分别为145.4、92.0、55.7 m~3/hm~2。不同立地指数湿地松林单位面积蓄积量差别极大,立地指数为11的林分蓄积量仅为立地指数为15林分的38.3%,立地指数为13的林分单位面积蓄积量也仅为立地指数为15林分的63.3%。因此,在岳阳地区营造湿地松速生丰产纸浆林,应尽可能选择立地指数为15的林地。     

Index selection for growth and construction wood properties in Pinus elliottii open-pollinated families in southern China

The initial introduction of Pinus elliottii (PEE) to China occurred in the 1930s, and the planting of this conifer species has now attained close to 3 million ha in the subtropical zone of southern China. A large-scale genetic improvement program for PEE was implemented in southern China to produce fast-growing trees with high wood quality to address the severe shortage of timber production over the last two decades. In this paper, selection for stem volume, basic wood density (DEN) and modulus of elasticity (MOE) was based on the Smith–Hazel index, and a total of approximately 2 000 individual trees from 158 PEE open-pollinated families were selected at 22 years of age. The DEN and MOE for each tree were determined by non-destructive evaluation techniques using the Pilodyn and Hitman Director ST300® acoustic velocity device. The heritabilities and genetic and phenotypic correlations for the traits that were measured were estimated using the residual maximum likelihood approach in the flexible mixed modelling program ASReml-R. The results showed that the heritability estimates for the wood properties were between 0.292 and 0.309, and the heritabilities of the growth traits ranged from 0.129 to 0.216. The genetic correlation between the DEN_P and acoustic velocity (V?) with MOE_P was 0.45 and 0.95, respectively. An indirect selection based on V was observed to be highly effective for determination of MOE. It indicated that V can be integrated into tree improvement programs as a useful index of MOE by ranking candidate families or individuals within the selection population. The genetic correlations between the growth traits and wood properties were not significant. By contrast, the phenotypic correlations between them were significantly positive, but the correlation coefficients were very low. The appropriate selection index (I₄), which placed 10 times as much weight on DEN and MOE as the equal emphsis method, was determined as the appropriate selection index.     

湿地松不同整地方式造林效益分析

研究了不同整地方式对湿地松生长及造林效益的影响，结果表明：不同整地方式影响到幼树的栽植当年和栽植第2年的新梢生长量、地径生长、苗木的保存率。5种整地方式中SPA方式整地后的幼树栽植当年和栽植第2年的新梢生长量和苗木保存率最高，而用SPE整地后的栽植翌年地径生长量最大。整地方式不同而导致造林成本产生显著差异。SPE和SPA整地方式总投入最高，SPC和SPD最低。     

连江县湿地松人工林造林密度试验

对连江县不同造林密度6年生湿地松人工林的树高、胸径进行方差分析,结果表明：4种密度（1352／hm2、1605hm2、1890hm2和2500株/hm2）对6年生湿地松树高生长影响不明显,但胸径的差异性显著,且随着密度的增大而呈递减趋势。同时,对冠幅、生物量和生长曲线的比较分析结果也说明：福建省引种湿地松宜适当稀植。最后,通过胸径和冠幅线性关系的回归分析,计算出不同径级湿地松林分的保留株数。