Coniferous Wood Research Articles

To epiphytotic process at bursaphelenchosis (Bursaphelenchus mucronatus) of common pine

The purpose of the research is to study pine bursaphelenchosis foci identified in Vladimir Region and to describe the epiphytotic process at bursaphelenchosis of common pine Pinus sylvestris caused by the coniferous wood nematode Bursaphelenchus mucronatus Mamiya, Enda, 1979.Materials and methods. Research was conducted on the wilt of pine P. sylvestris L. in July 1998 in the Gus-Khrustalniy district of Vladimir Region. The symptoms of the lesion are similar to wilt caused by the nematode B. xylophilus. Selected large branches with yellow or red needles from 4 wilt centers. Rotten wood with bark beetle tracks was taken from windbroken trees. Externally uninfected trees were stripped of their bark and pieces of wood were cut. In the lab, the samples were pulverized, cut and placed in water. Nematodes were counted under binoculars. Nematodes were identified using methods generally accepted in phytohelminthology.Results and discussion. Foci of phytohelminthosis were found in pine plantations of Gus-Khrustalny District. The symptoms are similar to pine stem nematode infection, including yellow or red needles and tree death. B. mucronatus nematodes were found in small and large branches, trunks with bark beetle passages and in tree wood with alternating light and dark bluish layers. Capricorn beetles Monochamus spp. are vectors of the pathogen. B. mucronatus, phytopathogenic fungi, and symbiont bacteria contribute to pine death. Capricorn beetles lay eggs the larvae of which eat wood and complete the epiphytotic process. Transportation of contaminated materials facilitates the spread of bursaphelenchosis over long distances. Increasing air temperature increases the symptoms of bursaphelenchosis.

First record of Brachyoxylon wood from Upper Jurassic of Sichuan Basin, Southwest China and its paleoenvironmental significance

Diverse and abundant foliage fossils are well known and well documented from the Upper Triassic to the Lower and Middle Jurassic of Sichuan Basin in Southwest China. Yet, the fossil record of Upper Jurassic plants in this region is sparse. Decades ago, hundreds of fossil wood specimens were unearthed from the Upper Jurassic in the central part of the Sichuan Basin, offering important insights into region’s past terrestrial ecosystems and paleoclimate. Despite their significance, systematic studies of these fossils have been limited. Here, we describe the anatomy of a fossil wood specimen from the Upper Jurassic Penglaizhen Formation in Shehong City, Sichuan Province. The specimen displays key Brachyoxylon features, including mixed radial tracheid pitting in conjunction with araucarioid cross-field pitting. This is the first record of the coniferous wood Brachyoxylon in the central Sichuan Basin. Paleoclimatic evidence from associated leaves, pollen, and sediments, suggests that these trees thrived under generally warm and semi-arid to arid conditions, likely in riparian and lacustrine environments with local water abundance, as indicated by the growth rings with narrow latewood bands.

Investigation of the Fiberboard Production Process with the Addition of Coniferous Wood Greenery

Investigation of the Fiberboard Production Process with the Addition of Coniferous Wood Greenery

Thermal engineering and chemical kinetics of wood pellets torrefication

Relevance. The widespread distribution and availability of biomass in the regions of Russian Federation make it possible to consider it as a renewable energy source with a lower negative impact on the environment compared to fossil fuels, since biomass is recognized as a carbon-neutral fuel. The use of biomass as a fuel in the form of pellets is increasing, which provides increased density and heat value. At the same time, pellets as a fuel or as a technological raw material have a significant disadvantage – low hydrophobicity. This problem is solved by torrefaction – low-temperature pyrolysis at a temperature of 200–300°C to produce bio-carbon. The study of the wood pellets torrefaction in order to improve it is an urgent task. Aim. To identify the impact of the parameters of the torrefaction of wood pellets on the thermal characteristics of the product (the highest heat value of bio-coal) and the regime parameters of the process (mass and energy yields), as well as to determine the parameters of the chemical kinetics of low-temperature pyrolysis as the basis for mathematical modeling and development of efficient torrefaction reactors. Object. Torrefied coniferous wood pellets of domestic production (Moscow region). Methods. Experimental study of the low-temperature pyrolysis thermal characteristics; synchronous thermal analysis in an inert atmosphere. Results. It was found that during the torrefaction of wood pellets in an inert atmosphere, a change in the holding time in the range of 30–60 minutes does not significantly affect the higher heat value, mass and energy yield of bio-coal, while an increase in temperature from 250 to 300°C reduces mass and energy yield, and the higher heat value increases by 26%. The dynamics of mass loss and thermal effects when heated to 600°C at a rate of 10 K/min are determined by means of the synchronous thermal analysis. It is established that the chemical kinetics of the process is described by a generalized reaction of the order n=1.507, in the Arrhenius equation the activation energy E=71.25 kJ/mol, the pre-exponential factor A=4772 s–1.

Thermogravimetric Analysis of Combustion of Semi-Coke Obtained from Coniferous Wood and Mixtures on Their Basis

Coal remains one of the most used solid fuels for heat and electricity generation but burning coal releases large amounts of CO2 into the urban atmosphere in addition to harmful substances. In order to reduce the consumption of solid fossil fuels, it is necessary to search for fuels capable of replacing coal in terms of its thermal and environmental characteristics. One of the best alternative fuels is biomass, which is considered carbon neutral, but its thermal characteristics are worse than those of solid fossil fuels. In this work, an alternative to coal was studied for the first time, which was semi-coke, obtained by gasification at a temperature of 700–900 °C, the heat of combustion of which turned out to be higher than that of biomass before thermal treatment by 75%. We also studied fuel mixtures based on the resulting semi-coke. The aim of the work is to determine the main characteristics of combustion of semi-coke obtained from coniferous wood and mixtures based on them. The method of thermogravimetric analysis in oxidising medium at a heating rate of 20 °C/min was applied for the research. According to the results of this analysis, the ignition and burnout temperatures were determined, the combustion index was determined, the duration of coke residue combustion was determined, and synergetic interactions between the mixture components influencing the combustion characteristics were established. It was found that the ignition temperature of semi-coke is more than 50% higher than that of biomass and the burnout temperature is 10% higher. Adding 50% of biomass to semi-coke increases the combustion index by more than 30% and decreases the ignition temperature and burnout temperature. The mixture components synergistically interact with each other during combustion to reduce the value of maximum mass loss rate. It was found that the atomic ratios of O/C and H/C in semi-coke are lower than in biomass before gasification.

Structural characterization of wild edible Pleurotuscollected from Punjab, India

Oyster mushroom (Pleurotus spp.) belongs to the class Basidiomycetes, family Agaricaceae, commonly known as ‘dhingri’ in India and proliferates naturally on dead, decay wooden logs or trunks of deciduous or coniferous woods in tropical and temperate forests. Although Pleurotus mushrooms are commercially important mushrooms but wild Pleurotus still require public recognition. Hence, the present study aimed to conduct a field survey for collection of Pleurotus mushrooms from wild regions of of Punjab Two wild Pleurotus were collected and domesticated at Mushroom Research Complex, Punjab Agricultural University, Ludhiana, Punjab which were further analyzed at molecular and biochemical levels. These mushrooms were identified at species level through ITS (Internal transcribed spacer region) based method (18S ribosomal RNA gene, internal transcribed spacer, 5.8S ribosomal RNA gene, complete sequence; and 28S ribosomal RNA gene) was carried out. The gene bank accessioned Pleurotus sapidus as MK 281339 and Pleurotus floridanus as MK 281340. Hyphae of Pleurotus sapidus was observed to be packed tightly to a greater extent as compared to Pleurotus floridanus according to the ultra-structure recorded by scanning electron microscope. Both species of Pleurotus share two different proteins of same molecular weight 24.81 KDa and 28.43 KDa. Collecting and identifying wild species is crucial to preserve the wild fruits and fathom out the benefits of wild edible Pleurotus spp.

Improving the equation of nonlinear relationships between cell anatomical parameters of conifer wood

Improving the equation of nonlinear relationships between cell anatomical parameters of conifer wood

Enzyme-Mediated Duplex Exponential Amplification: A New Platform for Rapid Screening of <i>Hylurgus ligniperda</i>

As the world's second largest timber importer, wood demand in China has been growing extremely rapidly, leading to an increase of 163% from 2009 to 2018. The plant quarantine pest <i>H. ligniperda Fabricius, 1787</i> is an invasive species frequently intercepted at ports. <i>H. ligniperda</i> causes damage mainly to pine and spruce. To improve the efficiency of on-site inspection and the efficacy of early detection, tight quarantine in ports, time-effective identification, and a national surveillance program for high-risk invasive bark beetles are in urgent need. In this study, a simple, fast and accurate classification method for <i>H. ligniperda </i>is established based on the enzyme-mediated duplex exponential amplification (EmDEA) technique. Partial region from <i>inhibitor of apoptosis 2</i> (<I>IAP2)</I> gene was selected as the target and 6 primer/probe combinations were designed. Through selection, the combination of 3-HY-F3, 3-HY-R2 and 3-HY-RNA5 was chosen as the final primer-probe set, as it showed the lowest Ct with highest final fluorescence signal. Method validation and specificity test using 6 other beetle species living on coniferous wood showed that this method is result reliable and specific. Through parameter analysis with positive plasmid, the detection limit was calculated to be 13.6 copies/μL (9×10<sup>-7</sup> ng DNA/ reaction), much higher than conventional molecular methods such as PCR. The whole process including isothermal amplification, data analysis, and result output can be finished in 30 min, which is highly time-effective. Besides, the operation is simple and little training is needed for non-professionals. The application prospects of this rapid screening system include customs screening in ports, wild survey in non-lab situations and early warning system development. The new analysis platform EmDEA, can also be implemented in rapid detection and identification of other forestry pests.

In situ self-assembly of pulp microfibers and nanofibers into a transparent, high-performance and degradable film

Despite the significant properties of fossil plastics, the current unsustainable methods employed in production, usage and disposal present a grave threat to both energy and environment. The development of degradable biomass materials as substitutes for fossil plastics can effectively address the energy-environment paradox at the source. Here, we prepared novel micro-nano multiscale composite films through assembling and crosslinking nanocellulose with coniferous wood pulp microfibers. The composite film combines the advantages of microfibers and nanocellulose, achieving a maximum transmittance of 91 %, foldability, excellent mechanical properties (tensile strength: 51.3 MPa, elongation at break: 4 %, young's modulus: 3.4 GPa), high thermal stability and complete degradation within 40 days. The composite film exhibits mechanochemical self-healing and retains properties even after fracture. Such exceptional performance fully meets the requirements for substituting petroleum plastics. By incorporating CaAlSiN3:Eu2+ into the composite film, it enables dual emission of red and blue light, thereby being able to promote plant growth and presenting potential as a novel sustainable alternative for agricultural films. By assembling microfiber and nanocellulose, such novel strategy is presented for the fabrication of high-quality biomass materials, thereby offering a promising avenue towards environment-friendly resource-sustainable new materials.

Effects of woodchip biochar on temperature sensitivity of greenhouse gas emissions in amended soils within a mountain vineyard

The utilization of biochar as a soil amendment holds promise for long-term carbon sequestration due to its elevated carbon content and persistent chemical structure. This characteristic has positioned biochar as a proposed nature-based solution for climate change mitigation. Nevertheless, the impact of biochar on soil greenhouse gas (GHG) emissions remains a subject of ongoing debate. In the present investigation, we evaluated the influence of conifer wood biochar on the fluxes of three GHGs, namely carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4), in a vineyard soil subjected to biochar-alone treatments (at rates of 25 and 50 t ha−1) and in combination with green waste compost (at a rate of 45 t ha−1). The experimental field was situated in northern Italy and was organized in a randomized block design. Soil GHG fluxes were monitored for two and a half years. Monthly flux measurements were conducted using a high-resolution multi-gas analyzer for 24 hours. Fluxes were, therefore, correlated with soil temperature to assess the influence of treatments on the sensitivity of GHG emissions to this pivotal environmental parameter. The findings demonstrated diminished temperature sensitivity in the initial experimental year across all GHG fluxes in soils amended with biochar and biochar-compost combination, in contrast to treatments lacking biochar (i.e., control and compost-alone treatments). Notably, the attenuation was most pronounced for N2O emissions, suggesting a potential role of biochar in mitigating the release of this gas. However, this effect did not persist in the second and third years of the experiment. Overall, biochar significantly contributed to a reduction in N2O fluxes and an increase in CO2 fluxes, but the effect was limited and temporary. Furthermore, biochar had no impact on CH4 fluxes. The discerned fluctuation in the impact of biochar over time can be attributed to the processes of biochar aging and/or the interannual variability in soil moisture.

Elucidation of the life cycle of a saprotrophic inoperculate discomycete that is associated with pinesap using a polyphasic taxonomic approach

This study deals with the elucidation of the life cycle of an inoperculate discomycete that was eventually collected from conifer wood in South Germany and has become famous for the extraordinary diversity of its secondary metabolites when it was studied extensively during the 1990s. It had then been identified as Lachnum papyraceum (Lachnaceae, Helotiales) based on morphological traits, and extracts from its mycelial cultures were found to possess extraordinary nematicidal and antibiotic activities. Over 60 different secondary metabolites were finally identified from this fungus after extensive variation of culture media and scale-up of production up to 100-L scale. Among the main active principles were mycorrhizin A and chloromycorrhizin A, which had first been reported in 1977 from an unnamed “mycorrhizal” fungus of the hemiparasitic plant, Monotropa hypopitys (pinesap), that was isolated in Sweden. We noted that both the Lachnum strain and the original mycorrhizin producer were still available in the public domain and decided to study them for comparison using a multilocus phylogeny and also generated secondary metabolite profiles of both strains using analytical high performance liquid chromatography coupled to diode array and mass spectrometric detection (HPLC–DAD/MS). Surprisingly, the sequence data as well as the secondary metabolite profiles of both strains were highly similar, and it was also confirmed by phylogenetic methods that the strains are indeed nested within the genus Lachnum by comparison of their ITS, LSU, and RPB2 sequences. The specimen called L. papyraceum in the old publications was tentatively re-identified by Hans-Otto Baral as L. cf. subvirgineum, but substantial further work on the taxonomy of the genus remains to be done, anyway. We conclude that some Lachnum species have a highly complex but all the more interesting life cycle, and the mycorrhizal symbiont partner may invade the host plant, where it may persist as an endophyte and finally turn saprotrophic on the wood of the senescent pine tree. The taxonomy of these fungi should also be further resolved in the future, using a polythetic concept that includes chemotaxonomic data and a multi-locus genealogy.

The influence of nanocellulose from different plant raw materials on the quality indicators of electrical insulation paper

An urgent scientific and practical task for electrical engineering enterprises is to improve the specific characteristics of component transformers and capacitors that use electrical insulating paper. Electrical insulating paper is characterized by a wide list of special quality indicators, the necessary values ​​of which are achieved due to the use of cellulose with special properties and various chemical auxiliary substances. There are known attempts to use nanocellulose (NC) from wood to reduce the consumption of harmful synthetic chemical auxiliaries, but there are practically no research results on the impact of consumption of NC from non-wood plant materials. Therefore, in the work, a comparative study of the effect of NC from hemp fibers and coniferous wood on the target indicators of the quality of electrical insulating paper was carried out. For this, cellulose, suitable for extracting NC from hemp fibers, was obtained by an environmentally safe organosolv method. NC is obtained as a result of acid hydrolysis of organosolv hemp and sulfate unbleached coniferous cellulose, which is traditionally used in the production of electrical insulating paper. Laboratory samples of electrical insulating paper were made with a weight of 65±3 g/m2 from sulfated unbleached coniferous cellulose with the addition from 1% to 5% NC by weight of paper. The research results confirmed the hypothesis that the addition of NC paper pulp from various plant raw materials leads to an increase in the mechanical and electrical strength of the paper. It has been established that the effect of NC from hemp fibers on the quality indicators of electrical insulation paper is not inferior to the effect on them of NC from coniferous wood, and in some cases even a better result is observed. It was established that the introduction of NC into the composition of paper practically does not reduce its degree of polymerization, which is of great importance for maintaining high reliability and a long duration of work of paper insulation. The obtained results have scientific and practical significance for other types of insulating papers: capacitor, cable, telephone, impregnation, transformer, etc.

Комплексная утилизация лигносодержащих древесных отходов

The recycling of wood processing waste generated at pulp and paper and woodworking enterprises by reusing it in obtaining a high-yield semi-finished product for the production of paper and cardboard has been studied. The economic and environmental feasibility of wood waste recovery is beyond doubt. The aim has been to develop technology and modes for recycling wood waste from the production of high-yield pulp (birch sawdust) and woodworking (coniferous and the mix of coniferous and deciduous chips). In the course of the study, high-yield pulp has been obtained from birch sawdust using continuous technology (at Perm Pulp and Paper Company) and batch technology (at most pulp and paper industry enterprises). Cooking of wood chips has been carried out only using batch technology. It is shown that the recycling of birch sawdust to produce a fibrous semi-finished product for use in the production of paper and cardboard solves an important economic problem of the pulp and paper industry, which is the need to reduce the consumption of pulpwood and preserve forest resources. The process of recycling wood waste does not require changes to current technology. This produces high-yield pulp, which in terms of quality is not inferior to a similar semi-finished product made from birch technological chips and meets the enterprise standards. It has been revealed that wood chips from coniferous and deciduous wood from woodworking enterprises can also be used as a raw material for the production of high-yield pulp, but only together with sawdust from birch wood. High-yield pulp from the chips of coniferous and the mix of coniferous and deciduous wood is obtained with increased yield, but with low mechanical strength, since the neutral-sulfite method is intended for the production of a fibrous semi-finished product only from deciduous wood; coniferous wood is not boiled using this method. High-yield pulp with quality indicators corresponding to the enterprise standards from technological chips is produced by the ratios of chips and sawdust of 50:50 and 70:30. The yield of the semi-finished product from the raw materials of all used compositions is high – 75…82 %. Tests of high-yield pulp obtained from birch sawdust have shown that the fibrous semi-finished product can replace 20 % of the MS-5B waste paper mass in production in the production of paper and cardboard compositions.

Seeing the wood for the trees: active human–environmental interactions in arid northwestern China

Abstract. Due largely to demographic growth, agricultural populations during the Holocene became increasingly more impactful ecosystem engineers. Multidisciplinary research has revealed a deep history of human–environmental dynamics; however, these pre-modern anthropogenic ecosystem transformations and cultural adaptions are still poorly understood. Here, we synthesis anthracological data to explore the complex array of human–environmental interactions in the regions of the prehistoric Silk Road. Our results suggest that these ancient humans were not passively impacted by environmental change; rather, they culturally adapted to, and in turn altered, arid ecosystems. Underpinned by the establishment of complex agricultural systems on the western Loess Plateau, people may have started to manage chestnut trees, likely through conservation of economically significant species, as early as 4600 BP. Since ca. 3500 BP, with the appearance of high-yielding wheat and barley farming in Xinjiang and the Hexi Corridor, people appear to have been cultivating Prunus and Morus trees. We also argue that people were transporting preferred coniferous woods over long distances to meet the need for fuel and timber. After 2500 BP, people in our study area were making conscious selections between wood types for craft production and were also clearly cultivating a wide range of long-generation perennials, showing a remarkable traditional knowledge tied into the arid environment. At the same time, the data suggest that there was significant deforestation throughout the chronology of occupation, including a rapid decline of slow-growing spruce forests and riparian woodlands across northwestern China. The wood charcoal dataset is publicly available at https://doi.org/10.5281/zenodo.8158277 (Shen et al., 2023).

DEVELOPMENT OF MYCROCRYSTALLINE CELLULOSE ORIGINATE FROM SAGO (METROXYLON SAGU) STEM BARK BY HYDROLISIS METHODE USING NITRIC ACID

Objective: Microcrystalline cellulose (MCC) is an essential excipient in tablet formulation. Mostly MCC was obtained from wooden conifer stem fiber, therefore environment issues had been came up. Alternative sources for MCC which offer friendly conifer wood need to be explored. This study aimed to isolate and determine the characteristics of MCC originated from Sago (Metroxylon sago Rottb.) stem fibers as an promising alternative of MCC. Methods: MCC was prepared through pre-hydrolysis using an acetic acid solution, alkali heating using NaOH solution, and acid hydrolysis using nitric acid 0.3 N using three variations of heating temperature, namely 90, 95 and 100 °C. The characterization carried out were pharmaceutical grade, powder properties, FTIR analysis and powder morphology by SEM. Results: The yields obtained were 66.02; 65.53 and 65.08%, respectively. The characteristics of the MCC sample based on pharmaceutical grade quality were white to yellowish white powder, odorless, tasteless, insoluble in: ether, 96% alcohol, HCl 2N and NaOH 1N. The pH of the MCC suspension were 5.07-5.12, while moisture content were 3.67-4.17%, with loss on drying value as much as 0.37-0.4%, and ash content 1-2.17%. The value of permanganate number were 0.09-0.11, Hausner factor was between 1.05-1.25, and angle of repose were between 11.4-24.8°. Conclusion: Based on the results, it can be concluded that Sago is potent natural resource for MCC. The resulting MCC revealed physicochemical and characteristic of MCC, which almost similar to Avicel PH 102 as standard.

Gluing parameters optimization and failure mechanism of cross-laminated timber prepared with Chinese fir

Cross-laminated timber (CLT) has become a popular engineered wood product, mainly prepared from imported wood in China. More extensive research is needed to improve the local production of cross-laminated timber with fast-growing coniferous wood species. Chinese fir (Cunninghamia lanceolata) and one component polyurethane (1C-PUR) adhesive were selected to prepare CLT under different process parameters. International standard methods, scanning electron microscopy (SEM), optical microscopy (LM), confocal laser scanning microscopy (CLSM), and nanoindentation (NI) were applied. The bonding performance and failure mechanism of Chinese fir CLT were investigated and clarified. The results showed that the optimal gluing parameters for preparing CLT from Chinese fir wood were 160 g/m2 of glue, 0.9 MPa of pressure, and 180 minutes of pressing time. Failure of CLT made from Chinese fir lumber was mainly due to the shear failure of the vertical layer board. Cracks often appeared in the earlywood cells near the boundary between earlywood and latewood. The impact of adhesive penetration on the mechanical properties of the wood cell wall showed that adhesive penetration increased the elastic modulus of the cell wall at earlywood and latewood cells.

Surface assisted laser desorption/ionization mass spectrometry of lithium cationized lignans – A tool for rapid screening of plant extracts

Lignans are one of the most widespread classes of plant secondary metabolites possessing unique biological activities. The search for new sources of such compounds, their screening and identification in plant biomass is an urgent task, requiring the use of advanced analytical methods. In the present study, matrix-free surface assisted laser desorption/ionization (SALDI) mass spectrometry was proposed for its solution. The combination of carbon nanocoating sputtered on a target plate with lithium cationization allowed obtaining high-quality mass spectra of eight coniferous wood lignans with different bonds between aromatic units (secoisolariciresinol, matairesinol, 7-hydroxymatairesinol, nortrachelogenin, pinoresinol, guaiacylglycerol-β-guaiacyl ether, dehydrodihydrodiisoeugenol, and divanillin). Three types of fragmentation methods (post-source decay, high- and low-energy collision induced dissociation) for the first time were implemented on two types of MALDI instruments. Regardless of tandem mass spectrometry technique, lignans demonstrated the similar fragmentation patterns including the cleavage of bonds between aromatic units with the formation of mostly lithiated product ions. The low-energy collision induced dissociation in quadrupole ion trap provided the most informative tandem mass spectra and multi-stage fragmentation capabilities in structural studies. On this basis, an approach to rapid, high-throughput, and low-cost screening and tentative identification of lignans including isomeric compounds in plant biomass was developed and successfully tested on real samples of pine, fir, spruce, and larch knotwood extracts.

Ecological and geochemical features of mercury accumulation in coniferous wood in the Altai Region

Ecological and geochemical features of mercury accumulation in coniferous wood in the Altai Region

First evidence of Pinaceae and Fagaceae in the fossil wood record of the České středohoří Mts. (Czech Republic): A comprehensive study of fossiliferous sites in pyroclastic rocks surrounding the late Oligocene Milá stratovolcano

A comprehensive anatomical and mineralogical study of fossil wood fragments from fields in the vicinity of Bečov and Břvany villages (NW Bohemia, Czech Republic) indicates that Taxodioxylon gypsaceum (Cupressaceae s.l.) predominates, but also identifies another coniferous wood: Pinuxylon parryoides (Pinaceae) and three angiosperms Quercoxylon böckhianum, Castanoxylon bavaricum and Lithocarpoxylon sp. (all Fagaceae). This paper therefore presents the first occurrence of Pinaceae and Fagaceae fossil wood in the volcanic rocks of the České Středohoří Mts. as well as its youngest palaeobotanical record in general, late Oligocene in age (26.56 ± 0.38 Ma). The samples were buried by alkaline pyroclastic deposits and were mineralized by carbonates. Two distinct depositional processes burying the fossil woods were identified. Closer to the vent, the woods occur in a near-vent pyroclastic fall deposits of the former pyroclastic cone, whereas more distant sites consist of pyroclastic flow deposits. Carbonate mineralization mostly consists of dolomite, but subordinate amounts of magnesite (likely the first time this is documented in fossil wood) as well as calcite and siderite are present. Only one sample collected in the same area, bearing clear signs of riverbed transport (Lithocarpoxylon sp.), was perfectly silicified, but its origin remains unclear.

Apple Growth and Yield in Replant Soils Supplemented by Organic Soil Additives

Repeated apple cultivation in the same area leads to apple replant disease (ARD), which can probably be reduced by the use of organic supplements and selected rootstock/variety combinations. Soils at two conventionally and one organically farmed site in north-eastern Germany were tested for ARD in pot trials. In subsequent field trials, the effects of champost, microbially carbonised compost, and coniferous wood shavings piled up like a dam (‘Müncheberger Damm’ (M)-dam) and of rootstock/variety combinations were tested. On the organic site, only leonardite and champost were tested. The pot trials indicated for all sites that the soil is affected by ARD. After five years, the growth increase in trunks in the M-dam was 20–40% higher than in controls and other treatments, depending on the site. On one site, the yield over four years was a 15.7% increase for M-dam and also for champost compared to controls, on the other site, it was 11.7% and 3.0%, respectively. The M.9 rootstock with the Gala variety had a higher, but insignificant, yield compared to G.11/Gala by 6.7 or 2.6%, depending on the site. No difference in trunk growth or yield with Topaz was observed at the organic farmed site. Further research on M-dam and champost is supported, as both are promising in terms of yield.