Characterizing the setting of cement when mixed with cork, blue gum, or maritime pine, grown in Portugal I: temperature profiles and compatibility indices

Data are presented on the effects that cork, blue gum, or maritime pine, all grown in Portugal, have on cement setting. These materials were mixed with cement either without any treatment or after being extracted previously with a range of solvents (ranging from nonpolar to very polar). Other experiments were carried out in which extractives or calcium chloride were added to the cement paste. All lignocellulosic substrates have detrimental effects on cement setting, which is mostly seen by a delay in attaining the maximum temperature in the process. However, the addition of calcium chloride was able to overcome this disadvantage. Extraction of the substrates with some polar extraction agents before addition to the cement paste only slightly improved compatibility, and the addition of water-based extractives to a cement paste affects the setting much less than the lignocellulosic material by itself. Several thermal compatibility indices, including a new index proposed in this article, were calculated from data taken from temperature profiles, and conclusions are presented on the performance of the setting systems, as compared with a neat cement paste. In addition, comments are expressed on the level of accuracy offered by the indices applied in this study, and how such accuracy can be checked or improved by matching them to the physical properties of the wood-cement composites.     

Response of Japanese red pine to inoculation with a blue stain fungus,Ceratocystis piceae

To confirm the pathogenicity of a blue stain fungus,Ceratocystis piceae (Münch) Bakshi to the Japanese red pine (Pinus densiflora Sieb. et Zucc.), the responses of healthy young pine trees and stressed trees which were girdled by the half-circumferential girdling technique were investigated by the fungal inoculation test. Although neither of the pine trees inoculated withC. piceae in the non-girdled treatment nor the controls died, mortality of the trees girdled and inoculated withC. piceae was 28.6%. In the pine trees inoculated withC. piceae, the mean area of the necrotic lesion of the sapwood was significantly larger than that of the controls, and the mean of the water pressure potential of the xylem decreased, regardless of the girdling treatment. TheC. piceae was reisolated from the wood pieces near the inoculation points on the inoculated trees, but not from the controls. These results suggest that under strongly stressed conditions, the Japanese red pine trees might have been killed by heavy infestations ofC. piceae carried by bark beetles. A part of this paper was presented at the 103rd Annual Meeting of the Japanese Forestry Society (1992).     

Study of hydration behavior of wood cement-based composite II: effect of chemical additives on the hydration characteristics and strengths of wood-cement composites

The influence of the 30 chemical additives on the hydration characteristics of birch wood-cement-water mixture was determined by measuring the maximum hydration temperature (T _max) and the time (t _max) required to reach the temperature. The chemical additives were tested and divided into two types depending on the pattern of exothermic reaction peak within the 24-h observation period. The wood-cement-water mixtures with additions of each of the 11 type I chemical additives showed a two-peak temperature-time curve similar to that for neat cement. CaCl₂, FeCl₃, and SnCl₂ reached the highestT _max above 50°C. When the 19 type II chemical additives were included, the mixtures offered only one peak hydration temperature-time curve. Among them, the 10 chemical additives caused an obvious temperature increase at the beginning of the hydration reaction. The most significant effect was with the addition of diethanolamine, where the mixture produced aT _max above 50°C. The strength values (modulus of rupture, internal bond strength) of word-cement board were tested with separate additions of the 10 chemical additives arranged by the highestT _max. There was a good positive correlation betweenT _max and the strength values. In addition, the composite chemical additives were preliminarily examined to determine if they accelerated the hydration reaction of blast-furnace slag cement. The results revealed that composite chemical additives evidently accelerated the hydration reaction and the setting of blast-furnace slag cement mixed with wood. Blast-furnace slag cement can thus be considered for use as an acceptable inorganic bonding material for wood-cement panel manufacture.Part of this report was presented at the 49th Annual Meeting of the Japan Wood Research Society, Tokyo, April 1999     

Compatible volume and taper models for economically important tree species of Turkey

• Introduction  

The accurate estimation of stem taper and volume are crucial for the efficient management of the forest resources. Compatible segmented polynomial taper and volume equations were developed for Brutian pine (Pinus brutia Ten.), Lebanon cedar (Cedrus libani A. Rich.), Cilicica fir (Abies cilicica Carr.), Scots pine (Pinus sylvestris L.), and Black pine (Pinus nigra Arnold.).     

Mammalian browsing damage in the Mt. Cole State forest,southeastern Australia: analysis of browsing patterns,spatial relationships and browse selection

Browsing by mammals can have a substantial impact on the survival, growth and form of regenerating forest trees. This study investigated the severity and distribution of mammalian browsing damage, and the degree to which eucalypt seedlings (Eucalyptus spp.) were selected for browsing on three regenerating native forest coupes in southeastern Australia. Damage was greatest 6 months after eucalypt germination and at this time, both messmate (Eucalyptus obliqua) and blue gum (E. globulus) seedlings were browsed at similar intensity. Nine and 12 months after germination, messmate was browsed more heavily than blue gum. Consistent relationships between browsing damage and both distance from the forest edge and wallaby density were not observed. Analysis of use and availability data for messmate, blue gum and manna gum (E. viminalis) seedlings showed that messmate was selected for browsing more than expected by chance while manna gum was browsed less than expected. Mammalian browsing affects a substantial portion of Victorias native forest estate, and could alter the species composition of future forests. Research into the ecology of browsing species and the development of non-lethal browsing reduction strategies is seen as a priority for the management of mammalian browsing in Victoria.     

Hydration behavior of wood cement-based composite I: evaluation of wood species effects on compatibility and strength with ordinary portland cement

As an essential preliminary evaluation for understanding the hydration behavior of wood-cement-water mixtures, an isothermal calorimetry and experimental method were used to measure the hydration heat of woodcement-water mixtures. The compatibility of 38 wood species with ordinary portland cement was studied using this procedure. Based on the results, all the wood species tested were classified into two groups. The 24 species included in the first group showed a moderating influence on the hydration reaction of cement, and a maximum temperature (T _max) peak during the exothermic reaction while the cement set appeared within 24h for each species. The other 14 species inhibited cement hydration completely. According to the maximum hydration temperature (T _max) and the time (T _max) required to reach the maximum temperature of the mixture, the suitability of each species in the first group was estimated when used as a raw material during production of cement-bonded particleboard. By testing mechanical properties [modulus of rupture (MOR) and internal bonding strength (IB)] during the board-making experiment using the same composition of wood-cement-water, a positive correlation was found betweenT _max andt _max and MOR and IB. The results imply that the method can be used as a predictor of the general inhibitory properties and feasibility of using wood species as raw materials prior to manufacture of cement-bonded particleboard.Part of this report was presented at the 49th annual meeting of the Japan Wood Research Society, Tokyo, April 1999     

Manufacture and properties of oil palm frond cement-bonded board

This study was designed to reveal the role of the cement/wood ratio in a hydration test of wood-cement mixtures. The compatibility of oil palm (Elaeis guineensis Jacq) fronds-cement mixtures was tested in the hydration test, with the addition of magnesium chloride as an accelerator at different water/cement ratios. To prove the findings on the hydration behavior of components, the cement-bonded boards were manufactured using a conventional cold-pressing method at different cement/wood ratios. Results indicated that the optimum weight ration of cement/wood increased with decreasing wood powder size based on the equal specific surface area ratio of cement/wood in the hydration test and board manufacturing. The addition of magnesium chloride improved the compatibility of oil palm fronds with cement; the compatibility factor (C _A) increased by more than 90% with the addition of 5% magnesium chloride. TheC _A factor increased proportionally with a higher magnesium chloride content and a higher water/ cement ratio. The addition of magnesium chloride also enhanced the cement hydration and ultimate board strength properties. However, the addition of 5% magnesium chloride did not improve the properties of boards sufficiently at a cement/wood ratio of 2.21.0.     

Morphological characteristics associated with tolerance to competition from herbaceous vegetation for seedlings of jack pine,black spruce,and white pine

Tolerance of bareroot and container-grown seedlings of black spruce (Picea mariana (Mill.) B.S.P.), jack pine (Pinus banksiana Lamb.), and eastern white pine (Pinus strobus L.) to competition from herbaceous vegetation was examined in the first five years after planting on a site in the Great Lakes/St. Lawrence forest of Ontario, Canada. Shoot and root morphological characteristics of various stocktypes were measured before planting and correlated with 5-year survival and growth following control and no control of herbaceous vegetation. For black spruce and jack pine, medium-sized bareroot stocktypes had greater relative 5-year stem volume growth in the presence of herbaceous vegetation than did container stock of either species or large bareroot stock of spruce. Relative volume growth was measured as the ratio of the cumulative stem volume increment in the presence of vegetation (Veg) to that in the absence of vegetation (NoVeg), i.e., the Veg:NoVeg ratio. In white pine, the Veg:NoVeg ratio of volume increment of medium container and large bareroot stocktypes exceeded that of small container and medium bareroot stocktypes. In jack pine, root collar diameter at planting and number of first-order lateral roots were positively correlated with 5-year Veg:NoVeg ratio of volume increment. In white pine, the Veg:NoVeg ratio was also positively correlated with root collar diameter at planting and with root volume. In black spruce, the ratio was not related to pre-plant morphology. Thus, for white pine and jack pine, certain pre-plant morphological features may be useful in forecasting the relative ability of different stocktypes to grow under herbaceous competition conditions in the field.     

Influences of Thinning,Chipping, and Fire on Understory Vegetation in a Sierran Mixed Conifer Stand

Thinning implemented with a cut-to-length harvesting system coupled with on-site slash chipping and redistribution and followed by prescribed underburning were assessed for their impacts on a shrub understory in an uneven-aged Sierra Nevada mixed conifer stand. Overstory species consisted of California white fir (Abies concolor var. lowiana [Gord.] Lemm.), Jeffrey pine (Pinus jeffreyi Grev. & Balf.), sugar pine (Pinus lambertiana Dougl.), incense-cedar (Libocedrus decurrens Torr.), and red fir (Abies magnifica A. Murr.), while huckleberry oak (Quercus vacciniifolia Kellogg) was predominant among 10 understory shrubs. Herbaceous species were entirely absent from the site for the 4-yr duration of the study. The mechanized treatments exerted minimal detriment effects on overall understory cover and weight, and for prostrate ceanothus (Ceanothus prostratus Benth.) and creeping snowberry (Symphoricarpos mollis Nutt.)—two of the lesser shrubs—were stimulatory. In contrast, losses to the total understory from the underburn amounted to two-thirds of cover and weight in the absence of the mechanized treatments and more than three-quarters where they had been implemented, with huckleberry oak prevalence especially diminished. For almost all of the understory species individually as well as for the total, greater pretreatment abundance predisposed greater posttreatment prevalence. Results of this study provide insight into the understory impacts of restoration treatments that are deemed especially appropriate for sensitive sites in western U.S. forests.     

Modeling stem profile of Lebanon cedar,Brutian pine,and Cilicica fir in Southern Turkey using nonlinear mixed-effects models

The Max and Burkhart segmented taper model was fitted using nonlinear mixed-effects modeling techniques to account for within- and between-individual stem profile variation for Lebanon cedar (Cedrus libani A. Rich.), brutian pine (Pinus brutia Ten.), and cilicica fir (Abies cilicica Carr.) in Turkey. About 75% of the trees were randomly selected for model development, with the remainder used for model validation. Diameter measurements from various heights were evaluated for tree-specific calibrations by predicting random-effects parameters using an approximate Bayesian estimator. The procedure was tested with a validation dataset. Predictive accuracy of the model was improved by including random-effects parameters for a new tree based on upper stem diameter measurements. Prediction in stem diameter was less biased and more precise across the all sections of bole when compared to predictions based only on fixed-effects parameters. In the future, the proposed mixed models can be applied to region wide three species stands by fitting the model to a larger data set that more closely represents regional variation.     

Improvement of Pinus pinaster wood dimensional stability using cork industry wastes

Summary This article relates to a procedure of preparing solutions for wood treatment by dissolving the condensed waste material from the baking steam of expanded cork board production in organic solvents. These solutions were applied by way of different methods inPinus pinaster wood treatment. The use of these products and methods improved the pine wood dimensional stability giving rise to lower water absorption and swelling. This cork industry waste, is mainly constituted by tannins and waxes, and their solutions are easy to obtain at low cost. A patent application was done.The authors would like to thank the collaboration of our fellow Mr. Paulo Cortiço     

Radiata pine plantations in Chile

The landscape of the southcentral part of Chile is dominated by fast-growing plantations of radiata pine (Pinus radiata D. Don), and in lesser extent bluegum eucalyptus (Eucalyptus globulus Labill.), Italian poplar, and willows. Radiata pine was first introduced in 1885 as an ornamental species. During 1940–1960 it was used to control erosion in the Coastal Range. Finally, since the 1960s it has been used for commercial plantations. The present extent of the plantation resource is 1,694,104 ha, of which 80.9 percent is radiata pine. During 1991, 1992, and 1993, this species was planted at rates of 75,416 ha, 81,868 ha, and 71,411 ha, respectively. Even though the soils are eroded to different degrees, exhibit a variety of nutritional disorders, and contain some physical restrictions, the productivity of radiata pine ranges from 18 m³/ha/yr to 35 m³/ha/yr. Additional stress comes from some potentially serious pests; for example, the European pine shoot moth, Rhyacionia buoliana, has presented a real threat to radiata pine. The main products obtained from radiata pine are exported to Japan, Korea, Middle and Far East countries, and Europe. Sawlogs, sawntimber, pulpwood, clearwood, and wood chips are some of the products comprising sales in 1994 of U.S.$1,564 billion. The purpose of this paper is to show how radiata pine silviculture has changed since the last part of the 1980s in Chile. Also we want to show how forestry activities have produced a profound and positive change in the social and economic environment that surrounds the areas where the industry’s main production areas exist. This revised version was published online in June 2006 with corrections to the Cover Date.     

Termite resistance of DMDHEU-treated wood

Four field trials were conducted with wood modified with dimethyloldihydroxy-ethyleneurea (DMDHEU) in contact with subterranean termites. Trials 1 to 3 were conducted with Coptotermes acinaciformis (Froggatt); 1 and 2 in south-east Queensland, and 3 in northern Queensland, Australia. Trial 4 was conducted in northern Queensland with Mastotermes darwiniensis (Froggatt). Four timber species (Scots pine, beech, Slash pine and Spotted gum) and two levels (1.3 M and 2.3 M) of DMDHEU were used. The tests were validated. DMDHEU successfully prevented damage by C. acinaciformis in south-east Queensland, but not in northern Queensland. It also did not protect the wood against M. darwiniensis. Except for beech in trial 4, DMDHEU led to reduced mass losses caused by termite attack compared to the unmodified feeder stakes. Slash pine (in trials 1 and 3) and Spotted gum (in trial 1) presented low mass losses. Modification of Scots pine was more effective against termite damage than the modification of beech.     

Cork oak (<Emphasis Type="Italic">Quercus suber</Emphasis> L.) wood growth and vessel characteristics variations in relation to climate and cork harvesting

Variations in tree ring growth of Quercus suber L. were analysed using dendrochronological techniques on cork oak discs from trees harvested in the cork producing region of Alentejo, Portugal. A tree-ring chronology containing a strong common signal and covering the period from 1970 to 1995 was build for ca. 30-year-old cork oaks never submitted to cork harvesting using 14 trees that crossdated satisfactorily out of 30 sampled trees. The tree ring indices correlated positively with September temperature (r = 0.48, P < 0.05) and very strongly with precipitation totals from previous October until current February (r = 0.82, P < 0.001) showing that the water stored in the soil during the autumn and winter months prior to the growing season has a primordial effect on the growth of the given season. The effects of cork harvesting were analysed by comparing mean ring width, mean annual vessel area, vessel density (n°vessels/mm²), and vessel coverage (percentage of transverse surface occupied by vessels) between three mature cork oak trees and three young trees, for the period from 1987 to 1996, corresponding to the growth between two consecutive cork removals in the case of mature trees. In 1988, 1989 and 1996 (corresponding to the first and second years after cork removal, and 1996 to a year of cork removal), the ratios between ring widths of young versus mature trees was twice that for the rest of the period. However, an effect of cork removal indicated by eventual alterations in vessel size and distribution in the wood rings corresponding to the years 1988, 1989 and 1996 in the mature cork oaks was not observed.     

Evaluation of fungicides for the control of Botryosphaeria corticola on cork oak in Catalonia (NE Spain)

Botryosphaeria canker of cork oak (Quercus suber L.), caused by Botryosphaeria corticola, is a well-known factor contributing to the decline of this forest species and is a serious disease in the main cork-producing countries of the Western Mediterranean basin. In this work, fungicides with the potential for controlling the disease were selected using a combination of in vitro tests and field trials. Fourteen fungicides in different chemical families were tested in vitro to evaluate their effect on inhibition of mycelial growth. The most effective fungicides were benomyl, carbendazim, cyprodinil + fludioxonil, thiabendazol and thiophanate-methyl; these compounds were then further tested under field conditions. In the field trials, carbendazim and thiophanate-methyl were the most effective fungicides, as shown by efficacy indices, in reducing debarked trunk surface affected by cankers (76% and 50–65%, respectively). These results suggest that the occurrence of Botryosphaeria canker on cork oak can be reduced effectively with the application of selected fungicides after cork removal from the trees.     

Gegenwärtige Projekte der biologischen Bekämpfung verschleppter Forstschädlinge

Summary Current projects of biological control of introduced forest insects. (Third report on the activities of the European Station, Commonwealth Institute of Biological Control).The report covers the period of 1965 to 1970 dealing briefly with nine forest pests of European origin introduced into North America or East Africa. Research in Europe on the natural enemies of these pests is described and the present status of biological control operations is dicussed. The pest species dealt with are: the larch sawfly (Pristiphora erichsonii Htg.), the European pine sawfly (Neodiprion sertiferGeoff.), the birch leaf-mining sawfly (Fenusa pusilla Lep.), the birch case-bearer (Coleophora fuscedinella Hb.), the larch case-bearer (Coleophora laricella Zell.), the pine shoot moth (Rhyacionia buoliana Den. & Schiff.), the elm bark beetle (Scolytus multistriatus Marsh.) and the woolly aphidsDreyfusia piceae Ratz. andPineus spp.     

Roads, fire and aggressive competitors: Determinants of bird distribution in subtropical production forests

Forestry practices such as fuel-reduction burning and maintenance of road networks can negatively impact avian assemblages, both directly by changing habitat structure and indirectly by creating conditions favorable for predators or competitors. The Brigalow Belt forests include some of the largest contiguous areas of native forest in the temperate and sub-humid zones of eastern Australia. Over 1 million ha of these forests are proposed to be converted from forestry to conservation tenure, yet the impacts on the avifauna of current and potential future forest management practices are not known. We investigated the influence of road edges and habitat type and structure on the avifauna of a 356 000 ha forest. Survey sites were either <50 m or >300 m from a road, and in either cypress pine Callitris glaucophylla forest, spotted gum Corymbia citriodora forest with a regenerating cypress pine/buloke Allocasuarina luehmannii understorey or spotted gum forest with an open understorey due to fuel-reduction burning. The avifauna differed significantly among vegetation types but not with proximity to a road, with the greatest differences between cypress pine and both types of spotted gum forest. The noisy miner Manorina melanocephala, an aggressive avian competitor, appears to be the factor mediating these assemblage-level differences. Noisy miners were rare in cypress pine forest but were three times more numerous than any other species in spotted gum forest. Spotted gum forest with a regenerating understorey had fewer noisy miners. Although total bird abundance was highest in open spotted gum forest, the species richness and abundance of passerines smaller than noisy miners was significantly lower in this forest type. Abundance of small passerines was eight times higher in sites where <3 noisy miners were recorded. Only one species, the eastern yellow robin, was influenced by proximity to a road edge. Cypress pine forest is potentially an important refuge for smaller birds. The results suggest that burning regimes that reduce regeneration of the cypress pine and buloke subcanopy in spotted gum forest potentially are exacerbating the problem of noisy miner domination of the avifauna.     

Viability of holm and cork oak seedlings from acorns sown in soils naturally infected with Phytophthora cinnamomi

The emergence and survival of pregerminated holm oak (Quercus ilex) and cork oak (Quercus suber) acorns from two ecologically different dehesas (Mediterranean open woodlands) were studied in two soils from these stands naturally infected with Phytophthora cinnamomi, and in the same soils previously sterilized in the autoclave. Phytophthora cinnamomi was consistently isolated from the radicles of all unemerged and all emerged but dead seedlings from the unsterilized substrates. Seedlings of holm oak were more susceptible to P. cinnamomi than those of cork oak. Mortality of holm oak seedlings was significantly different depending only on soil treatment (sterilized or unsterilized), and it was 100% in unsterilized soils, independent of acorn provenance and soil origin. Mortality of cork oak seedlings was significantly different depending on the acorn origin and soil treatment, and on the interactions acorn origin × soil origin and soil origin × soil treatment. The demonstrated high susceptibility of holm and cork oak young seedlings to P. cinnamomi could be a limiting factor in Mediterranean open woodlands (dehesas) not only in natural regeneration processes but also when reforestation by direct sowing is implemented.     

Study of hydration behaviors of wood-cement mixtures: compatibility of cement mixed with wood fiber strand obtained by the water-vapor explosion process

To provide information on the feasibility of using exploded wood fiber strand (WFS) obtained by the water-vapor explosion process in wood-cement mixtures, the compatibility between cement and exploded WFS and its improvement with various additive chemicals were investigated by observation and analysis on hydration behaviors in terms of hydration characteristics: maximum hydration temperature (T _max) and required time (t _max). The three types of cement, six additive chemicals, and exploded WFS (sugi, air-dried and water-soaked) were employed as raw materials in this study. The hydration behaviors of mixtures demonstrated that exploded WFS had strong retarding effects on cement hydration and completely prevented mixtures from setting. The analysis of sugar revealed that the sugar contents of exploded WFS were much higher than those in unexploded wood and increased to about 20-fold (air-dried) and 10-fold (water-soaked), respectively. The degraded polysaccharides became a major factor and played an important role in inhibiting the setting of cement. Moreover, high-performance liquid chromatography analysis proved that the main peaks representing the molecular weight of polysaccharides in extractives of exploded WFS shifted markedly to a lower range of polymerization. MgCl₂ was determined to be an effective additive chemical for restraining the inhibitory influences. Addition contents of 2%–3% and 4%–5% were available and acceptable for quick-curing cement and ordinary Portland cement, respectively. As for the furnace-slag cement, the composite additive chemicals of MgCl₂ (4%) and CaO (2%) were found to have an obvious accelerating effect.Part of this report was presented at the 51th Annual Meeting of the Japan Wood Research Society, Tokyo, April 2001