Cholecalciferol plus diphacinone baits for vole control: a novel approach to a historic problem

Combination baits containing cholecalciferol plus an anticoagulant are effective against commensal rodents resistant to anticoagulants, and they likely pose less risk than anticoagulant-only rodenticides due to lower concentrations of active ingredients and shorter time to death. However, these combination baits have not been tested for agricultural rodent pests. Therefore, we established a study to test the efficacy of cholecalciferol plus diphacinone artichoke bract and pellet baits to determine their ability to manage California voles Microtus californicus in artichokes, where resistance to anticoagulants is known to occur. Field tests using radiocollared voles indicated that bract baits were highly efficacious (85 %), although pellet baits were less effective (60 %). Low observed efficacy of pellet baits may have resulted from poor weather following application during the second sampling period; further testing may yield more positive results. We observed a bimodal distribution in timing of death, with one group of voles dying between 4.3 and 5.8 days post-consumption; the other group died between 9.0 and 14.5 days post-consumption. Deaths in the first group were attributed to cholecalciferol, while deaths in the second group were likely due to chronic anticoagulant exposure. Almost double the proportion of voles that died from bract consumption did so during the early period when compared to their pellet plot counterparts. This suggests that voles were consuming greater quantities of bract baits over a shorter period of time when compared to the pellet bait. Collectively, these findings indicate that baiting with cholecalciferol plus diphacinone coated bracts is an effective method for controlling vole populations in artichokes.     

Verdeckte Ausbringung von Rodentiziden in Köderstationen zur Abwehr von Mäuseschäden in Forstkulturen

The Common Vole (Microtus agrestis) and the Redbacked Vole (Clethrionomys glareolus) can cause severe damages in forest plantations. Different application techniques of rodenticides to control these harmful rodents were tested by several institutions of plant protection in the Federal Republic of Germany. The following registered baits were used: A bluestained pectin-wax pellet containing 0.0075% Chlorphacinon (Lepit^®-Forstpellet), small flour-plates (Arrex^®-M-Köder klein) and sunflower kernels coated with plastique-foil (Arrex^®-E-Köder) both incorporated with 2% resp. 3.75% zinc-phosphide. In 1985 disperse spraying versus concentrated offering of the baits in 12 earthenware pipes/ha was tested. The density of mice and voles could be reduced nearly to the same level with both methods. However, the amount of baits needed was much less when bait stations were used. In 1986 a new and save type of bait station (Theyson-Köder-station) was tested, from which non-target animals cannot get baits. The acceptance of the bait station could be improved by aromatic compounds from apples. According to the obtained first results forest plantations can be protected during the whole wintertime against vole-damages by means of bait stations.     

Bekämpfungsversuche gegen die KleinwühlmäuseMicrotus lusitanicus (Gerbe) undM. duodecimcostatus (Sel.-Long.) in Obstkulturen

Tests with different rodenticides against the Iberian Vole (Microtus lusitanicus) and the Mediterranean Vole (M. duodecimcostatus) were carried out in highly infested orchards in Portugal. Best results were obtained with baits containing 0.005% Bromadiolon. Broken carob was a suitable bait material. Apple slices and granulats of lab chow were also accepted, but were destructed very fast by fungi. Cultivation techniques had a great influence on the results. The density of Iberian Voles could be diminished drastically with a combined method of removing the ground cover and subsequent application of poisoned baits. Blowing anticoagulant dusts directly into the galleries of the voles was not very successful until now.     

Empfindlichkeit von Hausmäusen verschiedener Herkunft gegen Antikoagulantien

Various subspecies ofMus musculus and related species are worldwide in distribution. In the temperate regions this rodent lives in the field throughout the year. it can cause severe damages to various crops, i. e. in Egypt the new reclaimed areas within the desert are heavily infested, and in Portugal seeds in greenhouses are often destroyed.The control of the house mouse is increasingly difficult because this pest rodent has become resistant to many rodenticides in some regions. The house mouse also inspects and is cautious when selecting its food, especially poisoned baits, and develops bait-shyness rapidly.The efficacy of several anticoagulants against house mice of different origins was tested. The animals were caught in the surrounding areas of Munich, Lisbon, and Cairo. An albino laboratory strain served as a standard. The rodenticides were diluted with olive oil and administered in varying doses to the animals. Before and after treatment the mortality and the prothrombin times of the test animals were observed. The following anticoagulants are ordered according to their increasing efficiency: Coumarin, Coumatetralyl, Chlorphacinon + Sulfachinoxalin, Difenacoum, Bromadiolon, and Fluocoumaphen.The susceptibility of different subspecies of the house mouse to the anticoagulants varied remarkably.M. m. spretus from Portugal was very resistant to all the tested rodenticides whereasM. m. praetextus in Egypt was highly susceptible.In Egypt bait preference tests and some experiments with ready made baits containing Difenacoum (RS 2®), Chlorphacinone + Sulfachinoxalin (Raviac®), and Warfarin (Coumafene®) were conducted in the field. Wheat was the preferred bait as compared to sunflower kernels, maize, and chicken pellets. The acceptance was slightly improved by adding a small quantity (5–15%) if sesame to the bait but not in combination with oliveoil, maizeoil or cottonoil. In small testplots in 0,5 ha of straw heaps and in 1 ha of maize fields the bait consumed was reduced on the seventh day by more than 70% after application of anticoagulants, but increased very rapidly when the treatment was interrupted because of reinfestation.

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Mit 4 Tabellen     

Stiffness of normal, opposite, and tension poplar wood determined using micro-samples in the three material directions

Mechanical tests on micro-samples were performed in the three material directions in normal, opposite, and tension wood collected from a poplar tree. Two custom micro-devices were designed and built in the laboratory to test samples under pure tension in the transverse direction and under 4-point bending conditions in the longitudinal direction. Both devices were designed to handle samples with a small transverse section (a few square mm), which allowed to select zones with homogenous anatomical features. The results indicate a very high longitudinal stiffness in tension wood (up to 35 GPa compared to an average of 18 GPa for normal wood). Considering wood density, the value represents a specific modulus that is nearly 70 % crystalline cellulose. However, tension wood is slightly less stiff in the tangential and radial directions (1,150 vs. 1,500 MPa for normal wood in the radial direction and 430 vs. 530 MPa in the tangential direction).     

Quantifying lignin and holocellulose content in coniferous decayed wood using near-infrared reflectance spectroscopy

To determine the independent decomposition rates of lignin and cellulose of decayed woody debris, a technique for the rapid analysis of lignin and cellulose is required. We applied a near-infrared spectroscopy (NIRS) technique to measure the lignin and holocellulose content in decayed wood. We succeeded in creating partial least-squares (PLS) models to estimate the lignin and holocellulose content in the decayed wood of five species using NIR spectra. Although the accuracy was acceptable for the estimation of a five-species mixed model (R ² = 0.970 for lignin and R ² = 0.962 for holocellulose), it was further improved when the model was applied to each species independently. This combination of NIRS and a PLS model is a valuable tool for the determination of the lignin and holocellulose content in decayed wood. The technique is time efficient (3 min per sample) and non-hazardous (no acid treatment is required).     

Development and activity of early saproxylic fungal communities in harvested and unmanaged boreal mixedwood stands

Limited scientific information is currently available regarding saproxylic fungal communities in the boreal forest of North America. We aimed to characterize the community development, richness and activity of saproxylic fungi on fresh wood in harvested and unmanaged boreal mixedwood stands of northwestern Québec (Canada). Fresh wood blocks (n = 480) of balsam fir (Abies balsamea (L.) Mill.) and trembling aspen (Populus tremuloides Michx.) were placed on the forest floor in a range of stand conditions (n = 24). Blocks were harvested every 6 months for up to 30 months and characterized for species composition and richness (PCR–DGGE, DNA sequencing), respiration, wood density and lignin and cellulose content. Colonization by a wide range of functional groups proceeded rapidly under different stand conditions. We detected a total of 35 different fungal operational taxonomic units, with the highest species richness at the wood block level being observed within the first 12 months. No differences in community composition were found between wood host species or among stand conditions. However, the variability in fungal communities among blocks (β diversity) was lower on trembling aspen wood compared with balsam fir and decreased over time on trembling aspen wood. Also, fungal activity (respiration and wood decomposition) increased on trembling aspen wood blocks and species richness decreased on balsam fir wood over time in partial-cut sites. The overlap in tree composition among stands, the high volume of logs and the recent management history of these stands may have contributed to the similarity of the saproxylic fungal community among stand types and disturbances.     

Antifungal and antitermitic activities of wood vinegar from Vitex pubescens Vahl

Antifungal and antitermitic activities of wood vinegar produced from Vitex pubescens were evaluated. Three kinds of wood vinegar were produced at three different pyrolysis temperatures, i.e. at 350, 400 and 450 °C. A PDA dilution method was employed to assay antifungal activity of the vinegars with a white-rot fungus Trametes versicolor and a brown-rot fungus Fomitopsis palustris. Termiticidal activity and repellent effect were evaluated by a no-choice test and a choice test with Reticulitermes speratus and Coptotermes formosanus. All wood vinegars exhibited antifungal activity against both fungi. Wood vinegar of 450 °C had the higher activity than those of 400 and 350 °C. It was assumed that acid component contributed to the increase in controlling the growth of fungal. The wood vinegar exhibited antitermite activity to both R. speratus and C. formosanus workers in the no-choice experiment. However, it needed relatively high concentration to obtain the perfect mortality. For instance, the wood vinegar of 10 % concentration was needed to achieve 100 % mortality against C. formosanus, whereas for R. speratus only 3 % of wood vinegar was required. In the direct-choice experiment, wood vinegar had a significantly repellent effect to both termites at the lowest treating concentration of 10 %.     

A meta-analysis of the effects of wildfire,clearcutting, and partial harvest on the abundance of North American small mammals

Wildfires and timber harvest are two of the most prevalent disturbances in North American forests. To evaluate and compare their impact on small mammals, I conducted meta-analyses on (1) the effect of stand-replacement wildfires and several types of forest harvest (clearcutting followed by burning, clearcutting, and uniform partial harvest) on the abundance of deer mice (Peromyscus maniculatus) and red-backed voles (Myodes gapperi), (2) the impact of clearcutting and partial harvest on a broader array of small mammal species, and (3) the responses of small mammals to recent and older clearcuts (i.e. less than 10 years vs. 10–20 years after harvest). In coniferous and mixed forest, all disturbances except for partial harvest triggered significant increases in the abundance of deer mice and declines in red-backed voles. The increase in deer mice after wildfire was stronger than after clearcutting and marginally stronger than after clearcutting and burning. The abundance of red-backed voles was greatest in undisturbed or partially harvested stands, intermediate after clearcutting, and lowest after wildfire or clearcutting and burning. While the positive effect of clearcutting on deer mice did not persist beyond 10 years after disturbance, the negative effect on red-backed voles was similar between recent and older clearcuts. In deciduous forest, clearcutting did not result in a consistent change in abundance of deer mice and red-backed voles. For other small mammals, recent clearcutting tended to increase the abundance of yellow-pine chipmunks (Tamias amoenus), and meadow and long-tailed voles (Microtus pennsylvanicus and Microtus longicaudus). Woodland jumping mouse (Neozapus insignis), masked shrew (Sorex cinereus), and short-tailed shrew (Blarina brevicauda) did not show consistent response to timber harvest. Overall, the impact of different disturbances on the abundance of small mammals (i.e. positive or negative) appears to be species-specific, but disturbance type may influence the magnitude of this effect. Disturbance types can be ranked from severe to mild in terms of small mammal responses. The effects of forest harvest on small mammals are not equivalent to those of wildfire.     

Sorption and thermodynamic properties of buried juvenile <Emphasis Type="Italic">Pinus sylvestris</Emphasis> L. wood aged 1,170 ± 40 BP

The hygroscopicity and thermodynamic properties of buried juvenile Pinus sylvestris L. wood with an age of 1,170 ± 40 BP were compared with the corresponding values of juvenile wood of the same species from recently cut trees. The 35 and 50°C isotherms were plotted following the saturated salts method and subsequently fitted in accordance with the GAB model. The isotherms were then compared by means of the hysteresis coefficients. X-ray diffractograms were used to analyse the crystal structure of the cellulose. The effect of time on the buried wood caused hemicelluloses degradation and a decrease in the crystallinity index and the crystallite length, resulting in an increase in the proportion of amorphous zones. Because of this, the equilibrium moisture contents of the buried wood are higher than of the recent wood, both in adsorption and desorption. In terms of the thermodynamic properties, the heat involved is greater in the buried wood than in the recent wood.     

Provenance variation in growth and wood properties of juvenile Cyclocarya paliurus

Cyclocarya paliurus is a highly valued and multiple function tree species. There has been increasing interest in planting and managing C. paliurus for timber production and medical use owing to loss of harvestable acreage. Seed from six provenances was collected from the main natural range of this species. Significant variation in growth and wood properties was measured among the six provenances at age 7 years. Provenance mean height and DBH varied significantly from 730–991 and 6.7–10.0 cm, whereas provenance means of wood basic density and crystallinity ranged from 463–554 kg m^?3 and 51.4–74.1 %, respectively. Mean provenance microfibril angle (MFA) at breast height ranged from 18.1° to 23.2°, while MFA at breast height varied from 11.0° to 34.5° among growth rings which showed a consistent pith-to-bark trend of declining angles. There was no significant relationship of growth rate with latitude or longitude of seed sources, however, provenances from low latitude and longitude grew faster at the trial site. Wood quality was significantly related to latitude of seed sources, showing a positive correlation for both wood basic density and wood crystallinity, but a highly negative association with MFA. Significant correlations between wood properties measured indicated that there exists a great opportunity to improve wood quality of C. paliurus through selection of juvenile trees with low MFA.     

Enzymatic hydrolysis of wood with alkaline treatment

Pulverized samples of wood, cedar and eucalyptus were treated with 5 N NaOH solutions at 25–150 °C. Hemicellulose and lignin content in the samples decreased with increasing treatment temperatures, while the recovery of glucose was maintained at nearly 90 %. X-ray diffraction analysis showed that the content of the original cellulose I structure in the samples decreased with increasing temperature, and most of the cellulose in the sample treated at 150 °C was converted to cellulose II by mercerization. Enzymatic hydrolysis of the alkaline-treated samples was carried out at 37 °C using solutions comprising a mixture of cellulase and β-glucosidase. The samples treated at higher temperatures showed better enzymatic degradability. Treatment with an alkaline solution of lower concentration (1 N NaOH) at 150 °C was also used. Despite significant quantities of hemicellulose and lignin being removed, mercerization was not induced. The enzymatic degradability was much lower than that of the sample treated with a 5 N NaOH solution at 150 °C. Thus, treatment with concentrated alkaline solution at high temperature led to not only the removal of hemicellulose and lignin, but also to modification of the cellulose structure, which resulted in high efficiency of enzymatic saccharification of the wood samples.     

Comparative studies on microstructures and chemical compositions of cell walls of two solid wood floorings

Two common wood flooring materials, taun (Pometia spp.) and cumaru (Dipteryx odorata), were used as investigated objects and comparison was made between the two wood species for their density, microstructure, microfibril angle (MFA), cellulose crystallinity and the main chemical composition. Results showed that the density of cumaru was 0.941 g·cm^?3, significantly larger than that of taun, 0.737 g·cm^?3. The biggest difference of two wood species in microstructures was fiber cells. Fiber cells of cumaru had dense cell walls, almost no cell lumens; while fiber cells of taun had relatively thin cell walls, with apparent cell lumens. The thickness of fiber cell wall of cumaru and taun were 6.80 and 2.82 µm, respectively, and the former is about 2.5 times thicker than the latter. Measured data of MFA indicated that the average MFA of cumaru was 11.7°, smaller than that of taun, 13.4°. The relative crystallinity of cumaru and taun were 54.0 and 50.8%, respectively. The two wood species had the similar holocellulose contents, but the lignin content of cumaru was higher than that of taun, especially that the content of extractive of cumaru was as twice as that of taun.     

Influence of provenance,silvicultural regime and tree shape on the quality of maritime pine (Pinus pinaster) timber

The aim of this study was to establish the sources of variation in maritime pine wood properties related to appearance and strength, because of the importance of this wood in the sawing industry in Galicia (NW Spain). Ten trees from each of ten plots of the species (i.e., 100 trees) growing in Galicia were felled and sawn to produce the structural planks required for studying the presence of external strength-reducing characteristics. The planks were sampled from the basal logs to 16 m height in the stems, yielding cross sections of target dimensions 100 × 40 mm to 200 × 200 mm. We propose a model in which individual tree height and dominant height are used to predict the knottiness of planks from trees in mature stands. The abundance of externally visible knots on faces and edges of sawn planks is therefore more dependent on the stand location than on the prior silvicultural treatment of the stand.     

三种阔叶树树瘤化学成分的研究

利用自然生长的、带有树瘤的毛白杨、旱柳、洋槐为研究材料,对各树种的正常材、瘤材的化学成分进行对比研究.结果表明:瘤材中的水抽提物含量、1%氢氧化钠抽提物含量、苯醇抽提物含量、木素、聚戊糖的含量有所增加,但纤维素含量却有所减少.     

Feeding activities of Coptotermes formosanus Shiraki and Reticulitermes speratus (Kolbe) as affected by moisture content of wood

The relationship between the moisture content (MC) of wood blocks and the feeding activities of two Japanese subterranean termites, Coptotermes formosanus Shiraki and Reticulitermes speratus (Kolbe), was investigated with two choice tests. When three wood blocks with low MC (6%–12%), middle MC (79%–103%), and high MC (140%–182%) were exposed to workers of C. formosanus and R. speratus in a choice test, the feeding preferences were found in the middle MC blocks for C. formosanus, and the middle and high MC blocks for R. speratus, although wood blocks of low MC were also attacked. In a second choice test, wood blocks consisting of five pieces with water-impregnated (MC: 133%–191%) top, middle, or bottom piece were exposed to workers of both species. Higher consumptions were generally obtained in water-impregnated wood pieces and bottom pieces.     

Landscape context and small-mammal abundance in a managed forest

We assessed whether small-mammal abundance was related to landscape context, when context was considered independently of within-stand vegetation and at different spatial extents. The study took place in an industrial forest in northwestern New Brunswick. Within-stand vegetation models explained 9–32% of the deviance in the abundance of individuals from the four most abundant species: red-backed voles; deer mice; short-tailed shrews; and woodland jumping mice. Landscape context was related to the distributions of two species: red-backed voles were less abundant within contexts of softwood plantations; and jumping mouse abundance was directly related to the amount of softwood forest. Variables measured at the largest radii of landscape context (500 m) were never significantly associated with the abundance of small mammals. Most species appeared robust to forest management with the exception of the negative relationship between red-backed voles and softwood plantations.     

Recycled ionic liquid 1-ethyl-3-methylimidazolium acetate pretreatment for enhancing enzymatic saccharification of softwood without cellulose regeneration

In this work, pretreatment of wood meals using a recycled ionic liquid (IL), 1-ethyl-3-methylimidazolium acetate ([Emim]Ac), enhanced glucose liberation by enzymatic saccharification, without dissolution of cellulose and lignin. In contrast, previous studies on IL pretreatment have mostly focused on lignocellulosic dissolution to regenerate cellulose and removing lignin. Softwood (Cryptomeria japonica) was pretreated with [Emim]Ac at 60–100 °C for 2–8 h without collecting regenerated cellulose. The pretreatment did not have a strong effect on wood component dissolution (weight of residues: 91.7–98.8%). The residues contained relatively high amounts of lignin (26.6–32.6%) with low adsorption of [Emim]Ac (0.9–2.7%). Meanwhile, the crystallinity index (C _r I) of cellulose in the wood was significantly reduced by pretreatment, from 50.9% to 28.4–37.1%. In spite of the high lignin contents in the residues, their glucose liberation values by enzymatic saccharification using a cellulase mixture were 3–16 times greater than that of untreated wood. A good correlation was found between the saccharification effectiveness of pretreated samples and the C _r I. Although lignin dissolved in [Emim]Ac continued to accumulate after repeated use of [Emim]Ac, the pretreatment was found to be effective for three consecutive cycles without the need to remove the dissolved materials.     

Physical properties and termite durability of maritime pine Pinus pinaster Ait., heat-treated under vacuum pressure

An original heat treatment performed under vacuum pressure was investigated. Maritime pine samples were treated at six different temperatures: 140, 160, 180, 200, 230 and 260°C. The physical and mechanical consequences, i.e. bending strength (MOR), modulus of elasticity (MOE), hygroscopic behaviour, equilibrium moisture contents and anti-swelling efficiency (ASE) were studied. A no-choice feeding test according to the NF EN 117 standard was achieved. Temperatures up to 200°C had no significant effect on wood properties. However, at 230 and 260°C, the decrease in MOR was severe, reaching 42.5 and 62.5%, respectively. Whatever the treatment conditions, wood samples were still highly degraded by termites, revealing no increase in their durability.     

A review of wood thermal pretreatments to improve wood composite properties

The objective of this paper is to review the published literature on improving properties of wood composites through thermal pretreatment of wood. Thermal pretreatment has been conducted in moist environments using hot water or steam at temperatures up to 180 and 230 °C, respectively, or in dry environments using inert gases at temperatures up to 240 °C. In these conditions, hemicelluloses are removed, crystallinity index of cellulose is increased, and cellulose degree of polymerization is reduced, while lignin is not considerably affected. Thermally modified wood has been used to manufacture wood–plastic composites, particleboard, oriented strand board, binderless panels, fiberboard, waferboard, and flakeboard. Thermal pretreatment considerably reduced water absorption and thickness swelling of wood composites, which has been attributed mainly to the removal of hemicelluloses. Mechanical properties have been increased or sometimes reduced, depending on the product and the conditions of the pretreatment. Thermal pretreatment has also shown to improve the resistance of composites to decay.