不同穗条类型、长度的欧洲云杉扦插苗质量评价

[目的]为欧洲云杉扦插穗条选择和扦插苗培育提供依据。[方法]采用完全随机区组试验设计,研究了2种穗条类型(嫩枝基部带1.5年生硬枝、嫩枝)、3种穗条长度(5 10、10 15、15 20 cm)的嫩枝扦插苗从移植当年到第3年的成活率、保存率和生长情况。[结果]2种穗条类型扦插苗间的移植成活率和保存率差异不显著,但移植后嫩枝基部带1.5年生硬枝扦插苗的苗高、新梢生长量、地径、侧枝数、冠幅、鲜质量、干质量差异显著,都是嫩枝基部带1.5年生硬枝扦插苗大于嫩枝扦插苗。3种长度扦插苗的移植成活率、保存率的差异均显著;其中,15 20 cm长度穗条扦插苗移植成活率和保存率最高,分别是98.00%和86.00%,不同长度穗条扦插苗移植成苗率逐年下降,而且与穗条长度有关,弱小穗条获得的扦插苗成苗率低;5 10 cm的扦插苗移植成活率为46.00%,到第3年时保存率仅为23.33%,且移植后苗高、新梢生长量、地径、侧枝数、冠幅、鲜质量、干质量的差异也显著,且都以15 20cm穗条的扦插苗值最高,10 15 cm穗条的扦插苗次之,5 10 cm的扦插苗最小。嫩枝带硬枝扦插苗的苗木质量指数(QI)是嫩枝的7.74倍,15 20 cm穗条的扦插苗质量指数(QI)是5 10、10 15 cm扦插苗的5.47、5.23倍。扦插苗地径初始值与移植当年地径、苗高初始值与移植当年苗高间呈极显著正相关关系。[结论]扦插苗最初的生根状况和穗条质量影响后期培育过程中的存活和生长,嫩枝基部带1.5年生硬枝扦插苗和15 20 cm穗条的扦插苗不仅移植成活率、保存率高,而且生长量、生物量、质量指数都比短而弱小穗条的扦插苗高。     

Thinning alters crown dynamics and biomass increment within aboveground tissues in young stands of Chamaecyparis obtusa

The stand density of a forest affects the vertical distribution of foliage. Understanding the dynamics of this response is important for the study of crown structure and function, carbon-budget estimation, and forest management. We investigated the effect of tree density on the vertical distribution of foliage, branch, and stem growth, and ratio of biomass increment in aboveground tissues; by monitoring all first-order branches of five trees each from thinned and unthinned control stands of 10-year-old Chamaecyparis obtusa for four consecutive years. In the control stand, the foliage crown shifted upward with height growth but the foliage quantity of the whole crown did not increase. In addition, the vertical distribution of leaf mass shifted from lower-crown skewed to upper-crown skewed. In the thinned stand in contrast, the foliage quantity of individual crowns increased two-fold within 4 years, while the vertical distribution of leaf mass remained lower-crown skewed. The two stands had similar production rates, numbers of first-order branches per unit of tree height, and total lengths of first-order branches. However, the mortality rate of first-order branches and self-pruning within a first-order branch were significantly higher in the control stand than in the thinned stand, which resulted in a higher ratio of biomass increment in branch. Thinning induced a higher ratio of biomass increment in foliage and lower in branch. The increased foliage quantity and variation in ratio of biomass increment after thinning stimulated stem growth of residual trees. These results provide information that will be useful when considering thinning regimes and stand management.     

银杏树冠结构对主干直径和干形的影响

以19年生实生银杏为研究对象,每木检尺,研究了银杏树冠的结构因子一级侧枝的层性、数量和基径对主干直径和干形的影响,主要结果如下:(1)银杏主干上一级侧枝分布的层性和不均衡,导致了主干不同部位生长量分配的差异,表现为随着树冠高度的增加,一级枝数量在树冠垂直方向上呈现“一年小一年大”的波动式变化;一级侧枝层的层间距在0.58~0.82m之间;某层侧枝数量少时,该层上方的层间距较大,反之亦然。(2)树冠上不同层次的一级侧枝及其数量和基径的差异引起主干直径与材积的不均匀分布,导致树干形质发生变化,表现为一级侧枝的基径随着树冠的高度增加呈现“升高-降低”的变化趋势,且树冠中部的一级侧枝的基径较大;每一轮的侧枝使该层侧枝上部的主干不同程度地变细。随着一级侧枝层的上移,侧枝层使胸高形率呈现缩小的变化趋势。一级侧枝直径生长影响着主干上下部直径增量的分配。     

The crown shape of an evergreen oak,Quercus glauca, in a hardwood community

The spatial pattern of the crown spread ofQuercus glauca in a hardwood community was investigated in order to consider the effect of the patterns on its survival in a secondary hardwood community. The shape of a crown was defined by the spatial spread of the leaves (PCM crown), and by the spread of their branches (elliptic cylinder crown). The stem volume growth rate of a tree was strongly correlated with the corresponding total leaf area, which was then significantly correlated with the defined crown volume. This indicated that the stem volume growth depended on the crown volume as well as the total leaf area. An increase in leaf area was largely attained by the spatial volume of the crown, not by an increase in the leaf area density. The leaves inside the crown began to spread horizontally relative to the crown size as the total leaf area and tree size increased. On the other hand, for the crowns representing the branch spread, the crown shape (crown width/depth ratio) did not differ by internal leaf area and tree size. Such a spatial pattern was likely to be adaptive for a species that dominates at a mid-stage of secondary sere.     

Survival and juvenile growth of Populus ‘Rasumowskiana’ cuttings from different stem and branch positions

The influence of ortet position on rooting and sprout growth of Populus Rasumowskiana cuttings was studied in the nursery over a period of two years using cuttings from 1-year-old stem shoots and side branches. Apical parts of the plants were not included in the material used in this trial. For branch cuttings, survival decreased with location of the cutting from base to apex; and for stem cuttings, height growth decreased from base to apex. In neigther was the trend significant. As a rule, branch cuttings rooted and grew better than stem cuttings, although the stem cuttings were thicker.     

Functional relationships between crown morphology and within-crown characteristics of understory saplings of three codominant conifers in a subalpine forest in central Japan

Light-related plasticity of crown morphology and within-crown characteristics were investigated in understory sun and shade saplings of three codominant subalpine conifers, Abies mariesii M.T. Mast., Abies veitchii Lindl. and Picea jezoensis var. hondoensis (Mayr) Rehd. Compared with those of sun saplings, current-year shoots of shade saplings allocated less biomass to needles, resulting in less dense needle packing and hence less mutual needle shading. The proportion of lateral branch biomass in foliage was either similar in sun and shade saplings or greater in shade saplings, depending on the species, suggesting that, over the lifetime of a branch, greater needle longevity in shade compensates for reduced biomass investment in needles of current-year shoots of shade saplings. Saplings with slower-growing branches tended to have greater needle life spans, suggesting that plasticity of branch growth rate and plasticity of needle life span are interdependent. Both Abies species showed greater light-related plasticity of needle life span and branch growth than P. jezoensis. The greater shade tolerance of the Abies species derives from their broad flattened crowns with slow-growing branches. This type of crown development incurs substantial support costs, but the long needle life span of shade saplings of the Abies species compensates, at least in part, for their low annual investment in foliage, especially in the case of A. mariesii, which has a longer needle life span and slower-growing and stouter branches than A. veitchii. Compared with the Abies species, P. jezoensis had a less plastic crown morphology, and less variability of needle life span and branch growth in response to light, resulting in lower shade tolerance. However, compared with the flattened crown of Abies shade saplings, the conical crown of P. jezoensis saplings imposes a smaller support cost, making this species better adapted to rapid height growth than to survival in shade.     

Branch growth and biomass allocation in Abies amabilis saplings in contrasting light environments

Aboveground biomass allocation, and height and branch growth were studied in saplings of the shade-tolerant conifer, Abies amabilis Dougl. ex Forbes growing in large openings and in the understory of an old-growth forest in western Oregon. The presence of annual overwintering budscale scars was used to infer extension growth histories; annual growth rings in branches and stems were used in combination with extension histories to compute partitioning of new biomass among leaves, branches and stems. Saplings growing in large gaps had conical crowns, whereas understory saplings had umbrella shaped crowns as a result of much greater rates of branch extension than stem extension. Understory saplings grew slowly in height because of low rates of biomass production and low allocation of biomass to stem extension. About 40% of new biomass was allocated to foliage in both groups, but understory saplings allocated more of the remaining growth increment to branches and less to stem than did saplings growing in large gaps. These results differ from the patterns observed in shade-tolerant saplings of tropical forests, where allocation to foliage increases with shading and branch allocation is much lower than observed here. This difference in allocation may reflect mechanical constraints imposed by snow loads on the evergreen A. amabilis crowns, particularly on flat-crowned understory saplings.     

白花泡桐树冠结构、生长性状的选择对于形改良的影响*

为了改良白花泡桐的干形，对树冠结构，生长性状与干形的遗传相关进行了剖析和通径分析，计算出主要树冠性状、生长性状对于干形的６３个选择指数方程。结果表明，胸径、小枝数、分枝总长、冠表面积和树高对形数，圆满度的决定系数在０．４０５～０．９４０和０．４２６～１．０６４之间。由以上５性状和形数或圆满度组成的综合选择指数方程效果最好。对形数选择遗传进度，相对效率分别为０．１５５和１５９．０１５７％。对圆满度选     

树冠结构对主干生长量垂直分配的影响

1985—1986年用定位测量方法研究了Ⅰ-69杨(Populus deltoides Bartr.cv.“Lux”ex.Ⅰ-69/55)树冠结构对主干生长量垂直分配的影响和主干、侧枝生长量分配的关系。结果表明,空旷地与人工林树干生长量分配趋势不同,前者树冠以下主干生长量较大,而后者的大生长量集中在冠部;人工林树干直径增量以地径处最大,向上逐渐变小,从枝下高处又开始增大,直到冠部。冠部树干直径增量一般都大于枝下干部,且呈波动式起伏;断面积与材积增量的分配,以树干基部较大,向上逐渐减小,随着修枝高度的上移,上部材积分配比额增大;侧枝生长影响主干上下生长量的分配,侧枝断面积增加1cm~2,可使分枝部位上下断面积的差值扩大0.7cm~2左右。修枝对调节树干的直径材积生长量分配有显著作用。可以促进树干上部直径材积生长。     

Morphological variance and natural types' division of plus trees ofLarix principis-rupprechtii Mayr.

The phenotypic characteristics of the plus trees ofLarix principis-rupprechtii such as stem form, branch angle, branch/stem ratio, branch density, the crown width, crown length, number of short branch over 5-cm branch segment in length, and the leaf number of each short branch were investigated in seed orchard in the Changcheng Mountain, Shaanxi Province. According to the morphological characters, the plus tree clones ofLarix principis-rupprechtii were classified into 4 natural types: the narrow-dense-crown type, wide-dense-crown type, wide-sparse-crown type, and the narrow-sparse-crown type. The result of the cluster analysis showed there was a very significant difference in tree growth among the four natural types. While comparing the tree growth of four natural types for the last ten years, it was found that the performance order of various types from good to bad is as follows: the narrow-dense crown type > the wide-dense crown type > the wide-sparse crown type > the narrow-sparse crown type. The plus trees of narrow-dense-crown, as a fine type, should be paid great attention to production and prepared to popularize. Biography: ZHANG Xin-bo (1956-), male, Senior engineer of Shanxi Academy of Forestry Science and Northern Research Institute of Forestry of China, Taiyuan 030012, P. R. China Responsible editor: Chai Ruihai     

Morphological acclimation to understory environments in Abies amabilis, a shade- and snow-tolerant conifer species of the Cascade Mountains, Washington, USA

Light-related plasticity in a variety of crown morphology and within-tree characteristics was examined in sun and shade saplings of Abies amabilis Dougl. ex J. Forbes growing in two late-successional forests with different snow regimes in the Cascade Mountains of Washington, USA. Compared with sun saplings, shade saplings typically had broad flat crowns as a result of acclimation at several scales (needle, shoot, branch, crown and whole sapling). Shoots of shade saplings had a smaller needle mass per unit of stem length than shoots of sun saplings, a feature that enhances light-interception efficiency by reducing among-needle shading. The low annual rate of needle production by shade saplings was associated with a longer needle lifespan and slower needle turnover. Reduced needle production within a shoot was reflected at the branch level, with lateral branches of shade saplings having a smaller needle mass than branches of the same length of sun saplings. Reduced allocation to needles permits greater investment in branches and stems, which is necessary to support the horizontally expanding branch system characteristic of shade saplings. Mean branch age of shade saplings was significantly higher than that of sun saplings. Shade saplings had lower needle mass per unit of trunk biomass or total biomass, reflecting greater investment in the trunk as a support organ. Increased investment in support organs in shade was more evident in the snowier habitat. The observed morphological acclimation makes A. amabilis highly shade and snow-tolerant and thus able to dominate in many late-successional forests in snowy coastal mountain regions.     

Weeds in <Emphasis Type="Italic">Eucalyptus globulus</Emphasis> subsp. <Emphasis Type="Italic">maidenii</Emphasis> (F. Muell) establishment: effects of competition on sapling growth and survivorship

The effect of herbaceous vegetation on growth and survival was assessed in planted eucalyptus saplings grown under four levels of weed cover. Seedlings of Eucalyptus globulus subsp. maidenii were planted with 0 (W0), 25 (W25), 50 (W50) and 100% (W100) weed cover. Weed species composition and aboveground biomass was determined. Soil water content was evaluated by the gravimetric method. Seedling leaf area, diameter and height were evaluated at planting and during the 3 months following establishment. Tree height, diameter and stem volume was estimated at 12, 24 and 36 months. First year tree survival was recorded. The ratio of cumulative stem growth under W100: cumulative stem growth under W0 was used to measure competitive performance. Regression analysis was used to determine competition thresholds. Weeds seriously threaten the growth of E. globulus subsp. maidenii. Early negative effects of competition on growth were evident as from the second month after establishment, and both seedlings and 1-year-old saplings were more affected than 2- and 3-year-old ones. A “minimum-response threshold” was determined near 500 kg/ha (corresponding to W25 cover). No clear effect was found between sapling survival and weed biomass.     

银杏枝条部位和年龄对不定根形成的影响及其与非结构碳水化合物含量的关系

[目的]研究银杏枝条部位、年龄对不定根形成的影响,并探讨其相应的叶、茎段中非结构碳水化合物(NSC)含量变化与扦插生根的关系。[方法]以50年生银杏树冠上、下部枝条的1、2和3年生位置的茎段为材料截取插穗,500 mg·L-1IBA与纯水对照处理基部60 s,在全光喷雾状态下研究扦插生根情况,并利用HLPC法分析相应部位叶和茎段中NSC含量。[结果]表明:银杏扦插不定根形成过程分为4个阶段,即0～4周愈伤形成期、4～6周愈伤膨大期、6～8周不定根开始形成期、8周后不定根伸长;生根部位主要在切口处。树冠上、下部位插穗的生根率未见明显差异,但随着枝龄的增加而明显降低。NSC分析表明:下部叶片NSC组分中多糖和总糖含量明显高于上部的,但茎段NSC的所有组分在上下部均无明显差异;随着枝龄的增加,相应位置叶片NSC各组分含量没有明显差异,但相应茎段NSC组分中葡萄糖、果糖、多糖、总糖、淀粉含量却明显降低,与生根率的变化趋势一致。此外,500 mg·L-1IBA处理并未明显提高生根率,还需进一步优化处理浓度。[结论]银杏树冠上部和下部枝条对不定根形成无影响;未处理枝条的枝龄与生根率呈负相关,而茎段NSC含量与生根率呈正相关;叶片NSC含量对不定根形成影响较小;生根方式以愈伤生根类型为主。该结论将为今后银杏扦插生根及其机制研究提供参考。     

不同断根处理对云南拟单性木兰苗木生长影响的研究

不同断根处理对云南拟单性木兰苗木生长影响的研究结果表明:切断苗木的侧根会对苗龄为5年生的云南拟单性木兰苗木地上部分的生长产生负效应而有利于促进新侧根的萌发,其影响程度与断根的强度有关。其苗木经断根处理后新根萌发较快,50天左右有新的侧根生出,其中以切断云南拟单性木兰大苗的全部侧根于切口喷200 mg.L-1的ABT生根粉的A处理的生根效果最好。断根3个月后每株苗木萌发的新侧根平均数为138.8根,根长≥5 cm的侧根平均数为38.4根,侧根深度达32 cm,最长侧根长度14.4 cm,其苗木的新根萌发已经较为充分,可以出圃种植而能保证有高的成活率。     

Patterns of tree growth in a single tree selection silver fir–European beech forest

The basal area and height growth of trees and saplings in silver fir–European beech single stem selection forest were studied with regard to their social status and crown parameters of size, coverage, shading and vitality. On 24 permanent research plots (20 m × 20 m each) all trees [diameter at breast height (dbh) ≥10 cm] and saplings (≥1.3 m tall and dbh <10 cm) were surveyed. Repeated measurements of dbh (N = 1,608) and height (N = 1,135) 10 years apart enabled the calculation of annual basal area increment (BAI) of trees and saplings, and annual height (HI) increment of saplings. To obtain the growth characteristics for individual trees and saplings, their social status and crown parameters were assessed by rank. In the multivariate general linear model for BAI, social status, crown size and crown coverage of individuals as the predictors, and dbh² as the covariate, explained 70% of total variability. Similarly, social status, crown size, crown coverage and crown shading had a significant impact on the HI of saplings, explaining 70% of total variability. Among the observed variables, social status determined according to the individual’s position in vertical stand structure was, in addition to dbh, the most important predictor for both BAI and HI. Significant differences were observed between the BAI and HI models for the main tree species (European beech and silver fir), indicating their different growth characteristics. The applied method could be used as a supplement to the more widely used approaches for studying basal area and height growth of individual trees in selection forest stands.     

黑果枸杞栽培株行距研究

为确定黑果枸杞栽植的株行距,以黑果枸杞为试验材料,采用实生苗进行田间栽植,分别设置3个不同株距1、1.2、1.5 m,以及3个栽植株行距1.5 m×2 m、1.5 m×3 m和2 m×2.5 m,通过测定株高、冠幅、分枝数、侧枝数、侧枝长、尖削度、坐果率、果实参数、产量等,比较不同株距和栽植株行距对黑果枸杞生长发育及果实表型性状的影响。结果表明,黑果枸杞人工栽培的合适株距为1.5 m,行距2~3 m,在保持单株占地面积相近的情况下,可根据需要适当地调整株行距;栽植株行距为1.5 m×3 m时,果型变异小,果实纵径、横径、果型指数等表型特征较稳定。以期为人工栽培管理提供技术参考。     

Individual-based measurement and analysis of root system development: case studies for <Emphasis Type="Italic">Larix gmelinii</Emphasis> trees growing on the permafrost region in Siberia

We present results of individual-based root system measurement and analysis applied for Larix gmelinii trees growing on the continuous permafrost region of central Siberia. The data of root excavation taken from the three stands were used for the analyses; young (26 years old), mature (105 years old), and uneven-aged over-mature stand (220 years old). In this article, we highlight two topics: (1) factors affecting spatio-temporal pattern of root system development, and (2) interactions between aboveground (i.e., crown) and belowground (i.e., root) competition. For the first topic, the detailed observation of lateral roots was applied to one sample tree of the overmature stand. The tree constructed a superficial (<30 cm in depth) and rather asymmetric root system, and each lateral root expanded mainly into elevated mounds rather than depressed troughs. This indicated that spatial development of an individual root system was largely affected by microtopography (i.e., earth hummocks). For these lateral roots, elongation growth curves were reconstructed using annual-ring data, and annual growth rates and patterns were compared among them. The comparison suggested that temporal root system development is associated with differences in carbon allocation among the lateral roots. For the second topic, we examined relationships between individual crown projection area (CA) and horizontal rooting area (RA) for the sample trees of each stand. RA was almost equal to CA in the young stand, while RA was much larger (three or four times) than CA in the mature and overmature stands. Two measures of stand-level space occupation, crown area index (aboveground: CAI; sum of CAs per unit land area) and rooting area index (belowground: RAI; sum of RAs), were estimated in each stand. The estimates of RAI (1.3–1.8 m² m₋₂) exceeded unity in all stands. In contrast, CAI exceeded unity (1.3 m² m₋₂) only in the young stand, and was much smaller (<0.3 m² m₋₂) in the two older stands. These between-stand differences in RAI–CAI relationships suggest that intertree competition for both aboveground and belowground spaces occurred in the young stand, but only belowground competition still occurred in the two older stands. Based on this finding, we hypothesized that competition below the ground may become predominant as a stand ages in L. gmelinii forests. Methodological limitations of our analysis are also discussed, especially for the analysis using the two indices of space occupation (CAI, RAI).     

Removing aboveground vegetation facilitates survival but slows height growth of spruce saplings in a fenced, degraded sub-alpine forest in central Japan

The effects of removing aboveground vegetation on survival and growth of Hondo spruce (Picea jezoensis var. hondoensis) saplings were examined in a dense dwarf bamboo (Sasa nipponica) field inside a deer-proof fence built in a degraded sub-alpine forest on Mt Ohdaigahara, central Japan. All bamboo culms were removed within a radius of 1 m from each sapling in a plot of 0.6 ha (removal plot), whereas no culms were removed in two control plots of 0.1 ha. We measured the height, crown depth, and main shoot elongation over 1 year for all spruce saplings, culm height and cover ratios of dwarf bamboo growing around each spruce sapling, and the light levels above each sapling. Removal of dwarf bamboo regulated the culm height and bamboo coverage until the following summer such that light conditions improved. The mortality of saplings smaller than the average culm height was lower in the removal plot (0.89%) than in a control plot (5.9%). After bamboo removal, sapling height growth was reduced with increasing bamboo cover in the previous year. Complete removal of the aboveground portions of covering bamboo improved sapling survival while regulating elongation growth, possibly because of the sudden increase in light intensity. Thus, controlling the extent of dwarf bamboo removal might be necessary to facilitate the growth of spruce saplings to restore the forest.     

Effective period of volatiles from softwood veneers embedded in tatami mats on the activity of house dust mites

To suppress the activity of house dust mites in tatami mats, where they tend to breed, tatami mats were prepared with embedded softwood veneers. The effective period of the volatiles from the veneers on the mites was then measured. To investigate the effective period of volatiles from hiba (Thujopsis dolabrata var. hondai) and hinoki (Chamaecyparis obtusa) veneers on house dust mites (Dermatophagoides pteronyssinus), 5-day exposure tests were conducted every few weeks for 54 weeks. In the exposure tests, the activity of the mites was observed after 5 days of exposure to the volatiles. Volatiles from hiba veneers strongly suppressed the activity of the mites for 15 weeks. The suppressive effect decreased gradually after that, but it was maintained for 54 weeks. Volatiles from hinoki veneers showed moderate to high suppression of mite activity for 11 weeks, but no suppressive effect was observed after that. In conclusion, embedding hiba or hinoki veneers in tatami mats is an effective method of suppressing the activity of mites for about a year or for slightly less than 3 months, respectively.Part of this paper was presented at the 51st Annual Meeting of the Japan Wood Research Society in Tokyo, April 2001     

马尾松实生种子园五年生的植株生长与分枝

本文研究了马尾松实生种子园建立第五年时植株的生长与分枝状况,研究的性状包括树高、胸径、枝条总数、年高生长、 年枝条生长量、年分枝数、不同分枝处树干直径等。对总的生长与分枝性状(含树高、胸径、枝条总数)分析表明:家系间只在胸径方面存在显著差异。对分年度的生长与分枝性状的研究表明:家系间在年高生长、年枝条生长量、年枝条直径方面无显著差异;年分枝数在刚建立的前两年家系间没有显著差异,后两年则差异显著;不同分枝处树干直径在连续的四年内,家系间均存在显著差异。不同年度的生长与分枝的趋势分析结果发现,大部分家系的年高生长与年枝条生长呈递增型,而大部分家系每年的分枝数却为波动型。这些研究结果表明,该马尾松实生种子园到建立的第五年时,家系间的差异大部分都不显著。究其原因,一方面可能是马尾松初期生长节律;另一方面可能是因为建园家系复杂的父本构成。因此,这个时期进行家系选择不太有效,建议在利用优树自由授粉子代建立实生种子园时,对他们先期进行苗期选择,而不是采用所有的子代。图1表4参20。