Climatic signal in annual growth variation of silver fir (Abies alba Mill.) and spruce (Picea abies Karst.) from the French Permanent Plot Network (RENECOFOR)

This paper explores the growth/climate relationships in earlywood, latewood and total ring-width chronologies of five Norway spruce (Picea abies) and six silver fir (Abies alba) stands sampled in the French permanent plot network (RENECOFOR) (327 trees). The relationships between climate and ring widths were analyzed using extreme growth years, simple correlations and response functions analysis (bootstrapped coefficients). Monthly climatic regressors were derived by a physiological water balance model that used daily climatic data and stand parameters to estimate soil water deficits. Pointer years underline the high sensitivity to winter frosts (1956, 1986) and exceptional annual droughts (1962, 1976, 1991) for both species. For those years, growth variations were higher for Abies alba than for Picea abies. For each species, the climate information of tree ring series is not modified by local site characteristics (altitude, slope, aspect, soil water reserve). Moreover, strong specific differences appear among species. Earlywood and latewood spruce growth mainly depends on current summer soil water deficit conditions. For silver fir, winter and early summer temperatures, as well as the water supply of the previous year (August to October) play a major role for the production of earlywood, after which the current early summer water supply influences mainly latewood width.     

Die Verjüngung gemischter Bergwälder—Praktische Konsequenzen aus 10jähriger Untersuchungsarbeit

Zusammenfassung Seit zehn Jahren betreibt der Lel-irstuhl für Waldbau and Forsternrichtung der Universit?t M?nchen intensive Verjüngungsstudien auf 25 Dauerversuchsfl?chen im Bergmischwald der ostbayerischen Kalkalpen. Am Bei-spiel der Aufnahmedaten yon fünf ausgew?hlten Versuchsfl?chen werden grundlegende Prinzipien des Ver-jüngungsprozesses im Bergmischwald aufgezeigt and daraus praktische Konsequznzen abgeleitet. Alle am Autbau der Altbest?nde des Bergmischwaldes beteiligten Baumarten bilden bislang trotz d utli-cher Waldschadenssvmptome reichlich Samen von hochwertiger Qualit?t aus. Damit aus diesem Verjüngungspotential Naturverjüngung entstchen kann, müssen die en tsprechenden überschirmungsverh?ltnisse lurch den Altbestand gegeben sein. Für die Dichte, Baumartenztusammenset zung and H?henentwicklung der Naturverjüngungspflanzen ist n?mlich die Uberschirrnung von ganz ent-scheidender Bedeutung. In einem sehr dichten Altbestand, in derv der überschirmungsgrad fiber 75% liegt , haben Verjüngungspflanzen Schwierigkeiten, sick zu etablieren. Eine Ieichte Auflichtung auf einen über-schirmungsgrad von 60 (der dann gegeben ist, wenn die rich unter dem Schirm entwickelnde Bodenvege cation Bedeckungsgrade zwischen 20 and 3C einstellt) erm?glicht den Naturverjüngungsflanzen ein überleben. Diese Uberschirmung kann durch einen schwachen Schirmhieb (Entnahme von etwa einem Vier-tel der Grundtl?che eines geschlossenen Bestandes) erreicht werden. Diese Eingriffsst?rke dürfte auch unter den Gesichtspunkten der Stabilit?it and des Zuwachsverlustes dill Altbestand zu vertreten sein. Vor einer st?rkeren Auflichtung des Altbestandes müsses genügend Naturverjüingungspflanztn ant Bo den vorhanden sein. Nur so is[ gew?hrleistet, daβ these einen Vorsprung vor der Bodenvegatation bekom Men. Die Pflanzung ist immer dann, wenn sich Schwierrigkeiten mit der Naturverjüngung ergeben, ein geeigne-tes Mittel, um einen neuen Bergmischwald zu begründen. Derzeit ist für das Entstehen tines neuen Bergmischwaldes - sei es durch Naturverjüngung odor lurch Pflanzung - Zaunschutz erforderlich. Summary In 1976, a research project entitled ’Natural Regeneration of Mixed Mountain Forests ’ was etablished in the Calcareous Alps of eastern Bavaria, by the Chair of Silviculture and Forest Management of the University Of Munich. Over the past ten years, the multi-variate aspects of regenaration have bean intensively investigated on 25 permanent research plots. The data from 5 selected plats were extracted and processed. from these data, it will be possible to present some fundamental principles of natural regenaration processes. From these prin-ciples, it is hoped that some practical applications can be derived. The mature stands of mixed mountain forests are still able to produce high quantities and good quality of seed, although distinct symptoms of forest decline are present. In order to utilize this potential for natural regeneration, an adequate canopy density is necessary. Canopy density is the crucial factor which regulates the density, species composition and height development of regeneration. In a very heavily, stocked mature stand with a canopy density of over 75 establishment of regenerations is difficult. When canopy density is reduced to, for example, 60% (this percentage can be estimated from a ground vegetation covering approximately 20–30 of the soil), the naturally regenerated, plants have a better opportunity to survive. A 60% canopy density can be achieved by light shelterwood cutting (removal of approximately 25% of basal area of a closed stand). This type of cutting can maintain the stability and prevent increment loss of forest stands. It is important that regeneration is established before opening up the stand, only, then these plants are capable to compete with the other ground vegetation. Planting is always appropriate when natural regeneration fails. Fencing is necessary for undisturbed development of natural and artificial regeneration.

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Dieses Heft enth?lt waldbauliche Beitr?g zu den Forschungsschwerpunkten Bergwald, Waldschaden und Kiefer. Sie sind überwiegen als Vortr?ge auf der Hochschulwoche der Forstwissenschaftlichen Fakult?t München im Oktober 1987 gehalten worden. Ihre Autoren widmen sie Herrn Professor Dr. Peter Burschel zum 60. Geburtstag.

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Auf der Forstlichen Hochschulwoche 1987 in München gehaltener Vortrag.     

Application of cationic polymer prepared from sulfuric acid lignin as a retention aid for usual rosin sizes to neutral papermaking

Cationic polymers that acted as the retention aids for usual rosin sizes in neutral papermaking were prepared from sulfuric acid lignin (SAL), one type of acid lignin. To convert SAL to the cationic polymer (MP-SAL), SAL was phenolated and then treated by the Mannich reaction to introduce the amino groups. In the MP-SAL single system, MP-SAL exhibited high sizing effectiveness in neutral papermaking with the rosin emulsion size. However, MP-SAL showed no sizing effectiveness when soap rosin size was used. MP-SAL showed increased sizing effectiveness as the pK _a of the introduced amino group increased. From this and comparison of the sizing degrees of MP-SAL and polyethylenimine, which possesses a linear structure, it was suggested that the sizing effectiveness was not only affected by the charge density and molecular weight, but also by the basicity of the introduced amino groups and the molecular structure of the retention aid. In the alum–MP-SAL dual system, alum and MP-SAL synergistically enhanced the sizing effectiveness in the rosin emulsion sizing at neutral pH. In turn, this allowed a decrease in the MP-SAL dosage and resulted in a small decrease in brightness.Part of this report was presented at the 48th Lignin Symposium, October 2003, Fukui     

Content changes of several endogenous plant hormones in female-sterile <Emphasis Type="Italic">Pinus tabulaeformis</Emphasis> Carr

To determine the relationship between female sterility of Pinus tabulaeformis Carr. and plant hormones, content changes of several endogenous plant hormones in a female-sterile clone and a normal clone were analyzed during the key period of female gametophyte abortion in mutant clones. The change of ABA content showed a similar pattern between normal and mutant clones, but the ABA content of the mutant clone was always much higher than that of the normal clone. In the normal clone, the IAA content decreased significantly at the early stage of the period and reached its minimum during the first ten days of April and stabilized thereafter. The endogenous ZR levels increased sharply at the early stages and reached a maximum in the middle of April, then decreased dramatically. The IAA and ZR contents of the mutant clone did not change perceptively through the entire period. We conclude that the high levels of ABA and the deficit of IAA and ZR may be the reasons of female gametophyte abortion in the female-sterile clones of P. tabulaeformis.     

Design of wood/montmorillonite (MMT) intercalation nanocomposite

Studying new wood composites through nano science and technology (NSC) will develop new compounding theory of wood, and accelerate the combination of new technology, wood science, material science and other disciplines. The compounding of wood and inorganic MMT on nanoscale molecular level has high potential to greatly improve the mechanical properties, fire retardance, abrasion resistance, decay resistance, dimensional stability and other properties of wood. Based on the great achievements of polymer/montmorillonite (MMT) nanocomposites, this paper reviewed nano intercalation compounding methods (i.e. in-situ intercalative polymerization and direct polymer intercalation), and discussed the structure, properties and modification of montmorillonite (MMT). According to the main chemical components and particular structure of wood, the authors discussed the liquefaction and plasticization of wood, compared the dissolvability and meltability between wood and polymer, and then systematically put forward the basic idea, technological processes and schematic diagram to prepare wood/MMT nanocomposites (WMNC). The key technology to prepare WMNC is either to introduce delaminated MMT nanolayers into wood with the help of some intermediate polymers, or to obtain liquefied wood or plasticized wood from the complicated natural composite. It is applicable and effective to realize wood/MMT nanoscale compounding with the help of proper intercalation agent and medium polymer through the proposed “one-step” or “two-step” impregnating processes.     

健康黑松幼苗中的电波传递

以健康黑松(Pinus thunbergii)幼苗为材料,用非伤害性刺激,如冷冻和伤害性刺激,如：烧伤、刺伤、化学伤害等引发了植物体内的波形的变化,研究表明,非伤害性刺激能在幼苗体内引起动作电波的传递,伤害性刺激除了能引起动作电波的传递外,还能引起较为复杂的变异电波的传递并对这种现象进行了讨论。图4参28。     

Regeneration of Psychotria umbellata and production of the analgesic indole alkaloid umbellatine

Psychotria umbellata Vell. (Rubiaceae), a Brazilian coastal woody species, produces umbellatine (also known as psychollatine), an analgesic indole alkaloid. An in vitro embryogenic regeneration protocol capable of yielding alkaloid-accumulating plants was developed. Rhizogenic calli, which were obtained from stem segments derived from rooted apical cuttings, were cultured on Murashige and Skoog's (MS) medium containing either 1 mg l(-1) NAA (naphthalene acetic acid) and no kinetin, or 5 mg l(-1) NAA + 1 mg l(-1) kinetin. Calli did not accumulate umbellatine. Segments of rhizogenic callus were cultured on complete MS medium with various concentrations of kinetin and sucrose. Plant regeneration was best in the light with 0.25 mg l(-1) of kinetin and 1.5% sucrose. After 3 months of acclimatization in soil mixture, plant survival was 81%. Leaves of 10-month-old regenerated plants yielded umbellatine concentrations equivalent to those of adult forest-grown plants.     

Crystallinity of wood and the size of cellulose crystallites in Norway spruce (<Emphasis Type="Italic">Picea abies</Emphasis>)

X-ray diffraction was used to study variations in the crystallinity of wood and the average thickness and length of the crystallites of cellulose as a function of the number of the year ring in Norway spruce [Picea abies (L.) Karst.]. The crystallinity increased from ring 4 to ring 10 from the pith and was constant after ring 10. The crystallinity of mature wood was about 30% ± 5%. The average thickness and average length of the crystallites were 3.2 ± 0.1nm and 28 ± 2nm, respectively; and no systematic variation of these values with the number of the year ring was observed. The mean microfibril angle decreased near the pith but was constant in the mature wood.     

Effect of board density on bending properties and dimensional stabilities of MDF-reinforced corrugated particleboard

We investigated the bending properties of composite boards produced by reinforcing both sides of corrugated particleboard with medium-density fiberboard (MDF). Thickness swelling and linear expansion (LE) were measured to assess the dimensional stabilities of the composite board. Although the apparent density of the composite board was 0.48g/cm³, its strength was found to be equivalent to that of 18-type particleboard as described in JIS A 5908. The boards parallel/perpendicular anisotropy in strength was 0.9. The modulus of rupture (MOR) of the composite board increased with board density only up to a certain density, beyond which the MOR was constant. On the other hand, the thickness swelling of both corrugated particleboard and the composite board was smaller than that of flat-type particleboard, satisfying the JIS A 5908 standard of 12%. Linear expansion (soaking in water of ordinary temperature for 24h) of corrugated particleboard was 0.7%–0.9% in the parallel direction and 2.1%–3.1% in the perpendicular direction; hence, anisotropy in linear expansion existed in the corrugated particleboard. The linear expansion of the composite board was 0.6%–0.9% in the parallel direction and 1.8%–2.5% in the perpendicular direction. Although the LE of the composite board was lower than that of corrugated particleboard, it is necessary to improve the LE of composite board for practical use.