Wuchsgesetze von Pinus silvestris

Ohne Zusammenfassung     

Microstructural investigation of UV-laser irradiated pine (Pinus silvestris L.)

Summary Different surfaces of pre-sanded pine (Pinus silvestris L.), namely radial surfaces, tangential surfaces and cross sections, have been subjected to microstructure examination. UV-laser irradiation with a wavelength of 248 nm and an energy of 350 mJ is used to enhance the microstructure exposure. It has been shown that UV-laser irradiation is a useful and practical method for revealing microstructural details. This is more pronounced on the cross section. Sanding with emery paper finer than 800 mesh can reveal microstructure on the radial surface equivalent to that revealed by UV-laser irradiation. On the radial and tangential surfaces, more earlywood is extracted after UV-laser irradiation, resulting in an uneven surface. Some features such as loose fibres and a rack-gearing-like structure on the radial and tangential surfaces, as well as a loss of radially oriented cell walls on the cross section are observed as a result of the UV-laser treatment. The rack-gearing structure is composed mainly of a sawtooth-like pattern. The length of the sawtooth is in most cases approximately 9 and 19 m.This work was carried out in the Department of Wood Technology and Processing, Royal Institute of Technology (KTH). Financial support from KTH is gratefully acknowledged.     

Die GallmückeContarinia baeri (Prell) - ein Schädling der Weibkiefer (Pinus silvestris L.)kiefer (Pinus silvestris L.)

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Control of Lophodermium and Phacidium needle cast and Scleroderris canker in Pinus silvestris

Cycloheximide and a mixture of chlorothalonil and cycloheximide gave acceptable control of Lophodermium pinastri as well as of Phacidium infestans and Scleroderris lagerbergii on Pinus silvestris. The recommended number of sprays per year is one and four respectively.     

Studies on volatile compounds from Pinus silvestris and their effect on wood-decomposing fungi

A headspace pre-concentration technique was used for GC-MS analyses of volatile compounds from fresh and heat-dried wood of Pinus silvestris. α-Pinene and Δ3-carene dominated in the gas phase above both the fresh and heated wood. Low molecular aldehydes and ketones not present above the fresh wood were identified from the heated wood.     

A. Study of Compression Wood in Scots Pine (Pinus silvestris L.): With I Plate

The incidence of compression wood was studied in 24–40-year-oldScots pine plantations. It was found that compression wood distributionin trees depended on type of stem curvature and was associatedwith their attempts to correct stem inclination. Compressionwood volume percentage was not closely related to extent ofstem curvature but was highly correlated with compression woodpercentage in the tree at breast height or 10 feet. There wassignificantly less compression wood near the butt than at higherlevels. In stands examined, compression wood formed 20–40per cent, of the standing volume. The prevailing wind appearedlargely responsible for the initial development of stem inclinationand consequent compression wood formation. Provision of shelterduring establishment should reduce compression wood developmentin second rotation crops.     

Sythèse en culture pure de ľassociation mycorrhizienne Pinus silvestris L. + Rhizopogon rubescens Tul.

Synthesis in pure culture of the mycorrhizal association Pinus sylvestris L. + Rhizopogon rubescens Tul. Ectendomycorrhize obtained by growing Pinus sylvestris and Rhibizopogon rubescens in vitro were compared with ectomycorrhizae of the same association produced in vivo described by Fontana et al. (1976).     

Development of oaks (Quercus petraea (Matt.) Liebl.) emerged from bird-dispersed seeds under old-growth pine (Pinus silvestris L.) stands

In East Germany, there are a lot of areas covered by old pine stands. They are growing on soils, on which under natural conditions without anthropogenic impact mixed stands of oak (Quercus petraea (Matt.) Liebl.) and pine (Pinus silvestris L.), would form a natural forest. An important objective of ecological silviculture in these areas is to convert the pure pine stands into mixed oak–pine stands by using natural regeneration methods. A highly appreciated assistant in this connection is the European jay (Garrulus glandarius L.). The remarkable results of its work have been found by analyzing the natural regeneration in a few old pine stands in the forest district of Weißwasser in Saxony. Although mother trees of oak are very scarce there, natural regeneration of oak was found everywhere in the research area. The oak regeneration, undoubtedly created by the jay, amounted to at least 2000 oaks/ha. They were mainly distributed at random, while pine regeneration was aggregated in places where gaps in the pine canopy occurred. Oak regeneration was established much earlier than pine regeneration. Thus, oaks exceeded pines in age, height and diameter. The oaks were also superior to pines concerning height increment for the last three years. Thus, there is a good chance for oak to defend its prevailing role in the regeneration in the future. Probably, the next forest generation will be composed of oak and pine trees. The analysis of the quality of the oak regeneration shows that there is no substantial difference to artificially sown oak stands. This indicates that the European jay creates oak stands sufficiently both in number and quality.     

The colour of Pinus silvestris L. seeds and their susceptibility to damping-off. II. Colour of seed coats and their chemical composition

Black seed of Scots pine are more resistant to damping-off. The content of certain elements and chemical compounds in the seed coats differs widely depending on seed colour and physiological state (resting, germinating and infected seeds). The quantitative and qualitative differences in fatty acids content, total nitrogen, amino acids, some metals and nonmetals, chlorogenic acid, phenol and a number of its derivatives seem to be some of the factors conditioning differences in resistance to damping-off.     

Das Wachstum von Pinus pinaster (Aiton) in Abhängigkeit vom Standraum

Summary Spacing trials were established inPinus pinaster, in plantations in the Southern and South-Western Cape Province in South Africa. Eight spacings, with nominal initial stem numbers between 125 and 3000 were tested in each of the two trials, with a single replicate in each experiment. The Chapman-Richards growth model was applied to mean diameter, mean height and basal area/ha. For diameter and height, the assumption m=0 holds true, but for basal area/ha, this parameter is related to initial stem number. The volume growth of each sample plot was estimated from equations with basal area and mean height and their interaction as predictor-variables. The regression model also included constraints for basal area and height, to prevent anomalies for the estimated volume per hectare at young age. Each of the trials contained a number of plots, thinned after the onset of competition. The growth rates in these plots was statistically significantly greater than that of the same stand density in the unthinned plots.      

Physiologische Untersuchungen über die unterschiedliche Resistenz von Pinus sylvestris gegen Lophodermium pinastri

Physiological studies on variation in resistance of Pinus sylvestris to Lophodermium pinastri. I. Buffer capacity in needles. Studies on the buffering of hydrogen-ion concentration in needles of resistant and susceptible pines showed that the pH-value was changed by the growing fungus from about pH 3.7 to 5, The buffer capacity of homogenized needles varied greatly between clones, The change of pH-value as well as the buffer capacity were significantly different between resistant and susceptible clones.