What is new about new forest owners? A typology of private forest ownership in Austria

With structural changes in agriculture, new types of forest owners have become increasingly important. This article develops an empirically-based typology of forest owners in Austria. Based on a representative survey and by means of cluster analysis, seven types of forest owners are identified. These types form a sequence, ranging from forest owners with a strong agricultural background to forest owners with no agricultural background at all. The latter exhibit markedly different behaviour in various respects, e.g. in their interest in forest-related information. The increasing number of ‘new’ forest owners raises important questions for forest policy, especially how policy instruments can reach these owners and how extension services can address them.     

Effects of acorn attack by curculio weevils on the germination and early growth of <Emphasis Type="Italic">Pasania edulis</Emphasis> (Makino) seedlings

We conducted field studies to evaluate the impact that curculio weevil attacks on Pasania edulis (Fagacea) acorns have on the regeneration of this tree. The germination ratio of weevil-attacked acorns was significantly lower than that of sound acorns. The number and position of the attacks on acorns affected the germination ratio. The seedlings from weevil-attacked acorns were shorter and had a smaller leaf area than those from sound acorns. The negative effects on seedling height lasted for at least three years after germination. We also studied the handling of the two types of acorns by granivorous Apodemus mice in a broad-leaved forest dominated by P. edulis. The mice picked up, transported, hoarded, and recovered sound and weevil-attacked acorns similarly. In the study site, the seedlings from weevil-attacked acorns were estimated to account for 1.5–20.4 % of the total seedlings for cohorts of mast years and 0–3.7 % for those of poor or medium acorn production. From these results, we conclude that acorns with the lower part of their cotyledons slightly damaged by weevil larvae might still be able to contribute to the regeneration of P. edulis in the field but that their contribution would be negligible or small even in mast years in this study site.     

影响高脂马尾松扦插成活率的主要因子研究

通过多年的高脂马尾松扦插育苗试验,结果表明:采用半木质化且幼化程度高的枝条,在适宜的水分、光照、温度的条件下,采用适宜浓度(含IBA1500 mg/kg)的生根粉,不但可以加快生根,而且可大大地提高生根率,全年扦插,成活率都可达90%以上。     

Fine roots refilling process in an artificial gap in a Picea mongolica forest

Picea mongolica is an endemic but endangered species in China. The spruce forest is only found in sandy forest-steppe ecotones. In this study, we examined the initial response of the quantity and refilling process of fine roots in an artificial canopy gap with a diameter of 36 m in a P. mongolica forest. Under the canopy, the fine root length densities of trees, shrubs and herbs were 2,622, 864 and 3,086 m·m–2, respectively. The fine root biomass of trees, shrubs and herbs were 148, 62 and 65 g·m–2, respect...     

Bending characteristics of bamboo (<Emphasis Type="Italic">Phyllostachys pubescens</Emphasis>) with respect to its fiber–foam composite structure

The bending properties of split bamboo culm were compared with those of spruce and beech wood specimens. The bamboo allowed large flexural deformation since its outer layer retains the tensile stress while the softer inner layer undergoes large compressive deformation. The results suggested that the combination of the fiber-rich outer part and the compressible inner part was responsible for the flexural ductility of split bamboo. To clarify the compressible nature of the inner part of bamboo, the longitudinal surfaces of the bamboo and wood specimens were microscopically observed before and after a large longitudinal compression. Although the wood specimens showed serious and localized buckling, the inner part of the bamboo specimens showed no such visible buckling. In the latter case, the foam-like parenchyma cells absorbed the large compressive deformation by their microscopic buckling and simultaneously, the alignment of sclerenchyma fibers was maintained by the surrounding parenchyma matrix. The flexural elasticity of the bamboo was compared to that of the wood in respect of remaining strain during cyclic bending tests. No clear difference was recognized between their remaining strains. This fact indicated that the bamboo was not so flexible elastically, although its fiber–foam combination and intelligent fiber distribution improve flexural ductility.     

Effects of heat treatment on brittleness of <Emphasis Type="Italic">Styrax tonkinensis</Emphasis> wood

A new approach is proposed for the evaluation of the brittleness of heat-treated Styrax tonkinensis wood. Heat treatment made wood more brittle when wood was heated at a higher temperature or for a longer time. The brittleness increased to four times that of the control when wood was heated at 200°C for 12 h. For treatment at 160°C, the increase in brittleness without any change in weight is thought to be possibly caused by the relocation of lignin molecules. At higher temperatures, loss of amorphous polysaccharides due to degradation is thought to become the main factor affecting brittleness. The crystallites that were newly formed after 2 h of treatment showed brittleness that was different from that of the inherent crystallites remaining after 12 h of heat treatment. This inherent crystalline cellulose possibly plays a role in brittleness. There is also the possibility of using color to predict the brittleness of heat-treated wood.     

Ecophysiological and genetic variation in seedling traits and in first-year field performance of eight <Emphasis Type="Italic">Acacia senegal</Emphasis> provenances in the Blue Nile,Sudan

The genetic variation in seed weight, seed number per kg and seedling traits was compared among eight Acacia senegal provenances originating from the clay plain (east) and sand plains (west) of the gum belt in Sudan. The main objective of this study was to identify germplasm sources of A. senegal that have a good seed germination capacity and seedling traits suitable for reforestation in the clay-soil part of the dryland gum belt in the Blue Nile region in Sudan. A specific objective was to tentatively explore the adaptive strategy of A. senegal populations. Seventeen-week-old seedlings were planted in the field at spacing of 3 m × 3 m, giving 100 trees per plot and replication; within a randomized complete block design with four replications. The experimental site was in the clay plain region. Seed variables showed significant differences. Clay plain provenances showed considerable variation in seed weight and seed number. They had the smallest seed weight but the highest seed number, while the sand (western) provenances had the largest seed weight but lowest seed number. Seedling branch number, root length, root to shoot ratio and shoot dry weight differed significantly among the provenances 12 weeks after germination. Clay provenances had the highest branch number and shoot dry weight but the shortest roots and lowest root to shoot ratio. This was interpreted as showing better adaptation to the site in these local provenances in comparison to those originating from the western sandy soil regions. High positive correlations were observed between seedling variables, such as root nodule and branch numbers; this could be used for early selection. The variation was greater between provenance groups than within them, suggesting that especially selection among groups would yield genetic gain.     

Influence of different forest conversion strategies on ground vegetation and tree regeneration in pine (<Emphasis Type="Italic">Pinus sylvestris</Emphasis> L.) stands: a case study in NE Germany

The conversion of anthropogenic into more natural, self-regenerating forests is one of the major objectives of forestry throughout Europe. In this study, we present investigations on permanent plots with different silvicultural treatment in NE German pine stands. Management of old-growth pine stands on acidic and nutrient-poor sandy sites differs in fencing, thinning, and planting of certain tree species. The investigations were carried out on the community, population, and individual level of the pine forest ecosystems. Thus, vegetation changes, size and height of tree populations, and height increment of tree individuals were observed over a time span of 6 years. Special attention was paid to short-lived tree species such as, e.g., Frangula alnus and Sorbus aucuparia, as well as to Fagus sylvatica as one of the most typical forest tree species of Central Europe. Vegetation changes are interpreted as a consequence of natural regeneration of formerly degraded forest sites, involving an increase in nutrient availability. High browsing pressure can be considered as a key factor for the inhibition of tree seedlings and growth of saplings. Some Sorbus aucuparia individuals, however, succeeded in growing out of the browsing height also in unfenced stands. Few found specimens of Fagus sylvatica proved that this species is able to establish spontaneously on these relatively dry, acidic sites under continental climate influence. Such natural regeneration processes, also including spontaneous rejuvenation of trees, can be integrated into silviculture as passive forest conversion management. An active management like thinning of stands, planting of trees, and fencing can accelerate forest conversion with regard to height growth and species number of trees.     

Nickel-catalyzed carbonization of wood for coproduction of functional carbon and fluid fuels I: production of crystallized mesoporous carbon

Japanese larch wood loaded with nickel (1%–4%) alone or with nickel and calcium (0.25%–1.5%) was carbonized at 800°–900°C for 0–120min with a heating rate of 5°–20°C min⁻¹ in a helium flow of 5.8−46.4 ml STP cm⁻² min⁻¹ to examine the influence of these variables on the crystallization of carbon (the formation of T component) and the development of mesoporosity. From the obtained results, reaction conditions suitable for effective production of carbon with the dual functions of adequate electroconductivity and adsorption capacity in liquid phase were established, thereby explaining the factors that govern the process. It was also confirmed that mesopore having a diameter of about 4 nm was selectively produced at the cost of specific (BET) surface area in parallel with the formation of T component. This result provided good insight into how the simultaneous dual function could be realized.     

Chemical analysis of the product in acid-catalyzed solvolysis of cellulose using polyethylene glycol and ethylene carbonate

Degradation and decomposition of cellulose were studied in an acid-catalyzed solvolysis treatment of biomass using polyethylene glycol (PEG) and ethylene carbonate (EC). The solvolysis reaction was followed by a typical reaction system of wood liquefaction that uses sulfuric acid catalyst at 140° or 150°C at atmospheric pressure. The methods of fractionation and chemical analysis of the degraded cellulose in the solvolyzed product are discussed. The solvolyzed product was separated into several fractions, and they were hydrolyzed to release glucose and levulinic acid to determine the quantity of glucosides and levulinates in the solvolysis product. The data clearly showed that the solvolysis reaction had the same mechanism when using PEG or EC. Degradation of cellulose leads to the formation of glucosides, which then decompose, resulting in a levulinic acid structure, and producing a water-insoluble fraction. The conversion rates of both glucosides and levulinates strongly depend on the reaction conditions of the solvolysis. In particular, EC promotes faster conversion of the reactions. The method discussed here is a chemical analytical technique for characterization of the products of wood liquefaction.