Tree Wood Research Articles

Fungi associated with dieback of apple trees to be excavated and the assessment of Diplodia seriata fruiting structures on chipped apple wood used for mulch

Excavated apple trees as part of orchard renewal are often chipped and used as mulch in younger orchards. Therefore, the extent of fungal pathogens associated with dieback in old apple orchards to be excavated was investigated, with an emphasis on Diplodia seriata, an important canker pathogen of Malus domestica in South Africa. Trees showing symptoms of dieback were sampled from 14 orchards in the Grabouw, Vyeboom and Kouebokkeveld apple-producing areas in South Africa. Isolations were made from surface sterilised internal tissue of dieback samples. For the detection of D. seriata inoculum from chipped apple wood pieces, samples were collected in October 2020 and from February to April 2021 of orchards in the Grabouw (2 orchards) and Vyeboom (1 orchard) production regions. Fungi associated with canker and wood rot symptoms were isolated from 118 of the 144 trees showing symptoms of dieback. Eutypa lata was most often isolated (from 18.6 % of trees) followed by D. seriata (9.3 %). The predominant wood rot pathogen associated with the dieback of apple trees was Trametes versicolor (from 33.1 % of trees). Visual inspections of mulch wood pieces indicated the presence of D. seriata pycnidia and or conidia from material assessed between October 2020 and April 2021. Viable D. seriata cultures were obtained from 87 % of the mulch wood pieces investigated. Diplodia seriata remained present and viable for a period of 20 months on the wood chips. This study showed that apple trees to be excavated and used for mulch, harbor important canker and wood rot pathogens. The presence of viable D. seriata inoculum on apple tree wood chips used for mulch in younger orchards illustrates that there is a risk involved in using wood chips made from old fruit trees. Infected tree parts and entire dead trees should thus be removed before the chipping of older apple trees to be used for mulch.

Recent Advancement in Agarwood Induction Technology: A Comprehensive Review for the Transformation of Artificial Agar Resin Induction Methods

Agarwood is a high valued resinous wood containing aromatic constituents of sesquiterpenes and phenyl-ethylchromones. They are typically found in the wood tissue of Thymalaeaceae family trees such as Aquilaria and Gyrinops species once they have been physically or chemically damaged or diseased by microbial pathogens. However, the natural occurrence based agarwood production is inadequate to fulfill the worldwide market demand as it never reach to the potential yield. As a result, recent advancements in artificial agarwood induction technology have led to the efficient production of agarwood resin, surpassing conventional methods. These technologies include mechanical, biological, and chemical methods, as well as combinations of these techniques such as fungal inoculation, nailing, drilling, partly trunk pruning, aeration method, agar-wit, C-A kits, Agar-sit, Bottle dipping, ChemJet, Pinhole infusion, Automated transfusion, Agar-Bit and Bamboo stick method. While interdisciplinary approaches have pros and cons, chemical inducers have shown rapid invasion inside particular tree species trunks to produce superior agarwood resin at consistent rate. Therefore, diverse forms of inducers can be utilized to develop this finest fragrance resinous wood in cultivated trees within a short period of time compared to the natural approach and almost similar in the quality compared to the natural agarwood formations. The objective of this review paper was to presents a comprehensive collection of agarwood resin inducing methods and their potential to enhance the total production and the quality of agarwood in the final harvest. The application of these techniques has significant implications to the agarwood industry as it seeks to meet the growing global demand for this highly sought-after and valuable product leading to a high profitable business. Therefore, this review article serves as a valuable collection of resource for the researchers and industry professionals who are ambitious to develop their agarwood industry to a new level.

Changes in strontium levels in bark and over the past 40 years in the wood of trees exposed to high levels of air pollution

The present study aims to identify the most suitable tree species for monitoring and reducing strontium (Sr) pollution. Strontium is a heavy metal that is extremely harmful to human and environmental health even at low concentrations and is listed as a priority pollutant by the Agency for Toxic Substances and Disease Registry due to its potential harm. Samples were taken from Pinus pinaster, Cupressus arizonica, Picea orientalis, Cedrus atlantica, and Pseudotsuga menziesii species grown in Düzce, a location reported as one of the top 5 cities having the most polluted air in Europe by the World Air Pollution Report. The changes in Sr concentration over the last 40 years were evaluated by species, organ, direction, and age range. The results indicate that Sr pollution significantly increased due to traffic sources. This study also showed that the transfer of Sr within the wood is limited in all the species under consideration; hence, all these species can be used in monitoring the changes in Sr pollution. The most suitable species for reducing Sr pollution were Cupressus arizonica and Picea orientalis, which have the highest capacity to accumulate the most Sr in their wood.

AVALIAÇÃO DO DESEMPENHO DE ALGUNS CLONES DE SERINGUEIRA PARA PRODUÇÃO DE MADEIRA

The rubber tree was originally introduced in the State of São Paulo, Brazil, with a view to exploiting natural latex as the main source of income. However, there are some alternatives that may be viable for properties looking to diversify agricultural production. In some Asian countries, timber extraction, seed production for vegetable oil extraction and honey production have been commercially exploited. The exploration of wood has been the most important alternative, extracted when the productive period of the trees ends (25 - 30 years). Rubber tree wood can be used in the furniture industry and in the manufacture of doors, windows and other household items. At the end of their productive life, when it is necessary to replant the area, as the exploitation of latex is no longer viable, the trees have a circumference of 100 - 110 cm (at 125 cm above the ground), being suitable for cutting approximately 300 to 400 trees/ha, with a production of 1 m3 of wood/tree. However, there are some peculiarities in rubber tree wood that should be known. The main objective of this work was to evaluate the wood productive potential of rubber tree clones, as well as the relationship between the rootstocks and the clones in characteristics such as total height, marketable height, DBH (diameter at breast height) and marketable volume of wood. The experiment was carried out at APTA Regional in Pindorama, State of São Paulo, Brazil and the experimental design used was randomized blocks with split plots, with 6 treatments (rootstocks), 6 subtreatments (clones), four replications and 20 plants/plot, with 6 plants useful. The results show that the clone PB 235 is the best for the characteristic total height and commercial height and that the rootstocks RRIM 701, GT-1, PB235 and IAN 873 are the best for the characteristic total height. There was interaction between the different clones and rootstocks tested in terms of total height. Clones PB 235, RRIM 600 and PR 107 are the best for the DAP trait. The rootstocks PB 235, GT-1, IAN 873 and RRIM 701 are the best for the DAP characteristic. Keywords: Hevea brasiliensis. Diameter. Height.

First Report of Infestation of the Agar Defoliator <i>Heortia vitessoides</i> (Moore) on the Agar Wood Tree <i>Aquilaria malaccensis</i> Benth. in South India

Massive infestation of the agar defoliator Heortia vitessoides (Moore) (Lepidoptera, Pyraloidea, Crambidae) was observed in Thiruvananthapuram and Kollam districts in Kerala on agar wood tree Aquilaria malaccensis Benth. (Thymelaeaceae), during February – December, 2022. Of the 119 trees observed in Thiruvananthapuram and Kollam districts, 115 were infested and six of them died due to the pest attack.

Prioritization of the Forest Species Most Exploited by the Communities Bordering the Natural Forests of Pobè and Dogo-Kétou in Southeastern Benin, West Africa: An Ethnobotanical Approach

Benin is not a big forest country, and the sustainable management of forest relics and their resources is a priority for the managers. This study was conducted in the forest regions of Pobè and Kétou located in Southeast Benin with the objective of characterizing the ethnobotanical forest species prioritized by the local populations for their different uses. Specifically, it aimed to identify the ethnobotanical priority species for conservation, characterize the ethnobotanical value of these priority species, and analyze the tree organ harvesting methods used for the sustainable management of the forest species. Data have been collected from 287 local populations investigated and on the specimens collected on the field, which allowed to identify the scientific name. The combination of the citation frequencies, the method of reproduction, the vulnerability scores, and the IUCN status of the species has allowed to identify five priority ethnobotanical species per forest. The software Ri386_3.5.1 has been used for the different analysis such as the calculation of the various frequencies and the correspondence factor analysis to show the relationships between socioethnic groups, organs used, and the categories of use. The priority species identified in the forest of Pobè are Milicia excelsa, Khaya senegalensis, Anogeissus leiocarpa, Ceiba pentandra, and Adansonia digitata. The priority species identified in the forest of Dogo-Kétou are Vitellaria paradoxa, Prosopis africana, Pterocarpus erinaceus, Khaya senegalensis, and Anogeissus leiocarpa. This study has revealed 54 tree species gathered into 47 genera and 25 botanical families. Their different parts have been harvested for many kinds of utilization such as medicinal, commercial, feeding, medico-magic, and artisanal. The most commonly used organs were leaves, fruits, seeds, barks, roots, and wood. The harvesting methods include cutting poles, cutting twigs and branches to harvest leaves, debarking the trunk, felling trees for wood, cutting roots, picking and harvesting fruits and seeds, and harvesting of flowers. Cutting down trees and picking flowers, fruits, and seeds have been the methods of harvesting, which affect negatively regeneration of the tree populations. It is then important to sensitize the local people on the sustainable management of their forest resources through the conception and implementation of a project program focused on forest conservation.

Study of antioxidant enzymes’ activity in reaction wood of poplar tree (Populus alba L.)

Summary Studying biochemical variation in reaction wood is needed to understand the nature of reaction wood formation and the physiology of trees. The activity of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and guaiacol peroxidase (GPX)) was studied in normal wood (NW) and reaction wood (RW) (opposite wood (OW) and tension wood (TW)) in the bole of poplar trees (Populus alba L.). Four-year-old trees were induced to produce reaction wood by forced bending. The activity of antioxidant enzymes was studied with repeated sampling during a growing season. The results showed that total protein content and antioxidant enzymes are sensitive to mechanically induced stress. TW and OW showed higher activity of enzymes than NW as well as higher amounts of total protein. OW showed a higher concentration of CAT and SOD than TW. APX was more active than GPX in both TW and OW. In addition to mechanical stress, the effect of other climate factors was observed in the reactive oxygen species accumulation.

Biotechnological Potential of the Stress Response and Plant Cell Death Regulators Proteins in the Biofuel Industry.

Production of biofuel from lignocellulosic biomass is relatively low due to the limited knowledge about natural cell wall loosening and cellulolytic processes in plants. Industrial separation of cellulose fiber mass from lignin, its saccharification and alcoholic fermentation is still cost-ineffective and environmentally unfriendly. Assuming that the green transformation is inevitable and that new sources of raw materials for biofuels are needed, we decided to study cell death-a natural process occurring in plants in the context of reducing the recalcitrance of lignocellulose for the production of second-generation bioethanol. "Members of the enzyme families responsible for lysigenous aerenchyma formation were identified during the root hypoxia stress in Arabidopsis thaliana cell death mutants. The cell death regulatory genes, LESION SIMULATING DISEASE 1 (LSD1), PHYTOALEXIN DEFICIENT 4 (PAD4) and ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1) conditionally regulate the cell wall when suppressed in transgenic aspen. During four years of growth in the field, the following effects were observed: lignin content was reduced, the cellulose fiber polymerization degree increased and the growth itself was unaffected. The wood of transgenic trees was more efficient as a substrate for saccharification, alcoholic fermentation and bioethanol production. The presented results may trigger the development of novel biotechnologies in the biofuel industry.

Alteration of Organic Matter during Wildfires in the Forests of Southern Siberia

Large areas of forests burn annually in Siberia. Pyrogenic organic matter (PyOM) generated by wildfires acts as a stable carbon deposit and plays an important role in the global carbon cycle. Little is known about the properties of PyOM formed during fires in Siberian forests. In this work, we report the results of thermogravimetry (TG), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy applied to the study of the chemical composition, structure, and thermal stability of PyOM formed during surface and crown fires of moderate to high severity in southern Siberia. We studied the PyOM produced from the forest floor, down wood, cones, and outer bark of tree stems in Scots pine, larch, spruce, and birch forests. We calculated the thermal recalcitrance indexes (R50, Q3) based on TG/DSC data. We found that wildfires resulted in a strong decrease in thermolabile components in burned fuels, enrichment by aromatic structures, and a significant increase in thermal stability (T50) compared to unburned samples. In all the studied forests, bark PyOM revealed the highest value of T50 while forest floor PyOM had the lowest one. At the same time, our results indicated that the properties of PyOM were more strongly driven by wildfire severity than by fuel type. Overall, the thermal recalcitrance R50 index for PyOM samples increased by 9–29% compared to unburned plant residues, indicating a shift from low to intermediate carbon sequestration potential class in the majority of cases and hence less susceptibility of PyOM to biodegradation.

Functional trade-offs are driven by coordinated changes among cell types in the wood of angiosperm trees from different climates.

Wood performs several functions to ensure tree survival and carbon allocation to a finite stem volume leads to trade-offs among cell types. It is not known to what extent these trade-offs modify functional trade-offs and if they are consistent across climates and evolutionary lineages. Twelve wood traits were measured in stems and coarse roots across 60 adult angiosperm tree species from temperate, Mediterranean and tropical climates. Regardless of climate, clear trade-offs occurred among cellular fractions, but did not translate into specific functional trade-offs. Wood density was negatively related to hydraulic conductivity (Kth ) in stems and roots, but was not linked to nonstructural carbohydrates (NSC), implying a functional trade-off between mechanical integrity and transport but not with storage. NSC storage capacity was positively associated with Kth in stems and negatively in roots, reflecting a potential role for NSC in the maintenance of hydraulic integrity in stems but not in roots. Results of phylogenetic analyses suggest that evolutionary histories cannot explain covariations among traits. Trade-offs occur among cellular fractions, without necessarily modifying trade-offs in function. However, functional trade-offs are driven by coordinated changes among xylem cell types depending on the dominant role of each cell type in stems and roots.

Experimental study on optimized using activated agricultural wastes at hemispherical solar still for different types of water

The subsequent work aims to improve freshwater production and reduce the cost of generated water with little energy expenditure. Thermo-economic performance, hourly and daily production were evaluated by the experimental study on a hemispherical solar still in several configurations. The two floating agricultural waste materials utilized in the experiment were charcoal derived from guava tree wood (CHL) and carbonized corncobs (CCC). To enhance photothermal properties of the utilized primary materials, both have undergone physical and chemical activation by HCL or NaOH under specific conditions. In addition, the experiment was conducted using both seawater and lake water. Each modified distiller's performance was compared to that of a conventional unit in terms of thermal efficiency, exergy efficiency, daily output, and cost of freshwater in the climate of Kafrelsheikh, Egypt (31.09679°N, 30.94945°E) from 9:00 A.M. to 5:00 P.M. Therefore, this study aims to enhance the photothermal properties of charcoal and corn cobs by chemical and physical activation, which lead to enhance the efficiency of the hemispherical solar still by using this modified agricultural waste in its base compared to the traditional way. The daily productivity, thermal, and exergy efficiencies for H.CCC.LW were 4455 mL/m2,41.19%, and 3.85% showing improvement compared to a conventional hemispherical solar still by 41.2%, 40.72%, and 59.09%, respectively. At approximately 0.014 $/L (a savings of 26.70%), H.CCC.LW was shown to be the most cost-effective source of freshwater.

Beetles (Coleoptera) in deciduous dead wood tree species trunks in Lithuania.

We present a list of beetles that emerged from wind-felled tree trunks of several tree species, including European ash (Fraxinusexcelsior), aspen (Populustremula), common oak (Quercusrobur), birch (Betula sp.), small-leaved linden (Tiliacordata) and black alder (Alnusglutinosa). Four hundred and ninety species and 60 families of beetles were collected using trunk-emergence type traps. We found 440 beetle species that had previously been recorded from dead wood; the remaining 50 were newly discovered and all were considered as not directly associated with dead wood. Common oak trunks had the highest diversity of beetles, with approximately 42% of the identified beetle species found in our research. Of all the beetle species identified in the study, about half are saproxylic, while the remaining are considered as not having direct association with dead wood. The results of the study emphasise the importance of dead wood in maintaining beetle diversity in Lithuanian forests. This study provides a valuable baseline for future research on beetles in dead wood in Lithuania and may help to provide information for conservation efforts to protect these important habitats.

Fungal Community Taxa Differ in Diversity and Number between Live and Dead Prunus serotina Ehrh. Wood in a Protected Forest within Its Secondary Range of Distribution

Prunus serotina is an important invasive plant species in Poland. It was introduced to European forests, even in places currently protected by law, such as national parks. One major factor contributing to the spread of this species is the lack of infecting pathogens and incomplete knowledge about the relationship between the plant and microorganisms. This study aimed to identify fungal communities collected from freshly cut stumps of live and dead black cherry tree specimens growing in a protected forest. The main working hypotheses were as follows: (i) fungal communities inhabiting the wood of dead and living trees will differ in diversity and the number of taxa; and (ii) saprotrophic fungi will dominate in the wood of dead tree stumps. This study applied Illumina sequencing based on the amplification of the fungal ribosomal ITSI region. The average number of sequences (OTU) obtained from the analysis of dead tree wood was 101,758, while that of living trees was 94,150. These sequences belonged to 312 taxa, among which 254 were isolated from the wood of dead trees and 171 from that of living trees. Among the saprotrophs on dead trees, the following species were identified: Stereum rugosum, Ganoderma adspersum, G. applanatum, Peniophora cinerea, and Ascocoryne cylichnium. On the other hand, in the wood of living trees, Cytospora leucostoma and Botrytis cinerea were the most abundant saprotrophic species. The fungal communities inhabiting the wood of dead and living trees differed in the diversity and abundance of taxa, thus confirming our hypothesis. The results of our research conducted in a protected area indicate that black cherry wood can be naturally colonized by many pathogen species that can further limit its expansion.

LWSNet: A Point-Based Segmentation Network for Leaf-Wood Separation of Individual Trees

The accurate leaf-wood separation of individual trees from point clouds is an important yet challenging task. Many existing methods rely on manual features that are time-consuming and labor-intensive to distinguish between leaf and wood points. However, due to the complex interlocking structure of leaves and wood in the canopy, these methods have not yielded satisfactory results. Therefore, this paper proposes an end-to-end LWSNet to separate leaf and wood points within the canopy. First, we consider the linear and scattering distribution characteristics of leaf and wood points and calculate local geometric features with distinguishing properties to enrich the original point cloud information. Then, we fuse the local contextual information for feature enhancement and select more representative features through a rearrangement attention mechanism. Finally, we use a residual connection during the decoding stage to improve the robustness of the model and achieve efficient leaf-wood separation. The proposed LWSNet is tested on eight species of trees with different characteristics and sizes. The average F1 score for leaf-wood separation is as high as 97.29%. The results show that this method outperforms the state-of-the-art leaf-wood separation methods in previous studies, and can accurately and robustly separate leaves and wood in trees of different species, sizes, and structures. This study extends the leaf-wood separation of tree point clouds in an end-to-end manner and demonstrates that the deep-learning segmentation algorithm has a great potential for processing tree and plant point clouds with complex morphological traits.

New species of the march-fl y genus Bibio Geoff roy, 1762 (Diptera, Bibionidae) from the Russian Far East

Three new species of the genus Bibio Geo roy, 1762: B. amurensis sp. n., B. arboricola sp. n. and B. continentalis sp. n. are described from the Russian Far East. The development of the latter two species is discovered under the bark and in decaying wood of deciduous trees. One new to the Russian fauna species, B. medianus Hardy et Takahashi, 1960, is recorded.

The response of lichens inhabiting exposed wood of spruce logs to post-hurricane disturbances in Western Carpathian forests

We investigated which of the following environmental factors: the number of years since the windthrow of the tree (the age of dead wood), the phytocenosis (the type of forest community), altitude, exposure, wood hardness and the spatial scale of forest disturbances (small gaps with a few fallen spruces vs large-area windthrows) contributed to the diversity and abundance of lichens inhabiting the exposed wood of windthrown spruce trees in Polish Western Carpathian forests. Both Shannon H index and sum of coverage coefficients rose with increasing age of the wood, levelling off after 11–14 y (diversity) and 14–17 y (abundance). This factor appeared to be the most important for this group of lichens, but the significant positive impact of large-area windthrows on the lichen abundance was also demonstrated by using a GLM model. The age of the wood we precisely determined on the basis of data on Norway spruce mortality collected annually in permanent plots of the Gorce National Park since 2000. Using the Shore durometer we linked the course of the wood-inhabiting lichen succession with wood decay more precisely than before. The largest number of species was associated with medium hard wood, i.e., 51 < x ≤ 80 on the Shore scale. Based on the NMDS analysis, we distinguished four age groups of logs, differing in lichen abundance and defined by the dominance of distinctive species. A large number of usually corticolous lichen species used the wood of windthrown spruce logs as an optional habitat to survive large-scale, post-hurricane forest disturbances.

Investigation of Natural Composites Matoa Tree Wood as the Base Material for Eco-Friendly House Piles using Ansys

Composite materials, in simple terms, are materials that have a multi-phase system composed of reinforcing materials and matrix materials. Composite materials are divided into two types, namely synthetic composite materials and natural composite materials. Wood is a natural composite material consisting of a reinforcement and a matrix. The wood of the matoa tree (Pometia vinnata) is known for its good mechanical strength. The comparison of compressive mechanical strength in this study was conducted on matoa wood and ironwood tree wood (eusideroxylon zwageri). This was performed as supporting data in the discussion of natural composite materials of matoa tree wood as the foundation for environmentally friendly house piles. FEM (Finite Element Method) is a numerical method that analyzes the compressive strength of retaining walls. In this study, the 2D analysis used to determine the compressive strength of the natural composite material of Matoa tree wood. In this study, Matoa wood and ironwood were analyzed for compressive strength using FEM. In this research, three different finite element numbers are based on the software. The Ansys software is used to simulate compressive strength. The results obtained were matoa wood and ironwood, respectively A1 = 6.07e^(-07) MPa, A2 = 1.11e^(-06) MPa, and A3 = 2.09e^(-06) MPa and B1 = 1.17e ^(-06) MPa, B2 = 2.13e^(-06) MPa, and B3 = 4.02e^(-06) MPa. These results indicated that the resistance to mechanical compression test of ironwood tree was greater than matoa tree. However, when it was seen based on the perspective of the impact on the environment, Matoa tree has environmentally friendly properties that are effective and efficient. This is supported by the nature of the matoa tree which is easy to cultivate and its roots do not damage other plants.

Pine root exploration of standing dead tree trunks: a short-cut biocycling process

Aim of study: To characterize the colonization of Pinus herrerae roots in trunks of dead standing trees and to evaluate the composition of roots and decomposing tissues of standing dead trees.&#x0D; Area of study. Jaguariaíva, Paraná state, Southern Brazil.&#x0D; Material and methods: This study evaluated root attributes in the soil, litter, and trunks of dead standing trees and the composition of wood and bark of trees. Root traits (length, mass mycorrhizal colonization, and mean nutrient concentrations), soil and organic layers, and mean nutrient concentrations of wood and bark for were analyzed by non-parametric test.&#x0D; Main results: Approximately 2 to 3.5 years after tree death, roots of adjacent trees in F and H horizon litter migrate into the wood/bark interface. Eight and a half years after tree death, roots of adjacent trees reached up to 3.3 m above the litter surface. At the wood/bark interface, a root mantle formed (length greater than 1 km m-2) with ~5% ectomycorrhizal colonization. Root presence in the wood/bark interface reduced P, K, and Fe concentration of dead wood and Zn concentration in bark.&#x0D; Research highlights: Our results indicate that roots of P. herrerae are capable of colonizing dead tree trunks as a nutrient resource pool. This nutrient acquisition mechanism may function as a shortcut in the biogeochemical cycling of nutrients in forest systems.

IMPACTS OF OPEN DUMPSITE LEACHATE ON SOIL ENZYMATIC ACTIVITY IN KANI-QRZHALA OPEN DUMPSITE – ERBIL CITY

The study was carried out to assess the effect of open dump site leachate on soil enzymes activity. Soil samples were collected in Kani-Qrzhala open dump site in Erbil city in four sites (Site1, Site2, Site3 and Site4) for different depths; surface ,30cm,60cm and 90 cm following the edge drainage pathway of leachate. The results of dehydrogenase, urease and catalase show a significant variation at significant levels (P⩽0.01) and (P⩽0.05) respectively. The highest rates of dehydrogenase, urease and catalase (77.69 µg TPF.g-1, 454.50 µg N.g-1, and 1.927µg H2O2.g-1), were recorded at surface point in all sites, while the lowest rates of all enzymes were recorded at 90 cm respectively, this is indicating that the soil depth adversely affected enzymes activity. Using oak tree wood and walnut shell biochar by 10% as a treatment to polluted soil, significantly increased enzymes activity. Walnut shell biochar was more suitable than oak tree wood biochar to catalase and urease activity, where urease was increased by 133.61% and catalase by 63.40%, while dehydrogenase activity was increased by 95.07% after using oak tree wood biochar which was more suitable than walnut shell biochar. This was related to the feedstock and technology production of biochar that affected on biochar structure and activity, however in this study, biochar application generally had a positive effect on enzymes activity and soil depth had an adverse effect.

High-Throughput DNA Metabarcoding of Stem Sections from Trees with Cavities Describes Fungal Communities Associated with Variable Wood Decay, Position on Stem and Tree Species

The presence of unculturable fungi, variability in timing and frequency of fungal fruiting, hyper-rich fungal communities, and genetic and environmental variability explains the difficulty in adopting ideal sampling schemes and fungal identification approaches in studies of fungal communities in wood at variable stages of decay. Here, we use intensive within-tree sampling of five standing trees with cavities paired with high-throughput DNA metabarcoding, to study fungal communities in decayed and healthy wood of trees from two Populus species in British Columbia, Canada. The amplification of over 3000 fungal DNA sequence variants shows the presence of a hyper-rich wood fungal community that not only varied depending on PCR primers, tree species, tree stem portion and wood decay stage. but also included a large number of taxa unassignable to any known sub-kingdom taxonomic order based on published DNA sequences. Our data show that the use of two different primer sets greatly increases the power of the metabarcoding analysis. By testing three alternative models of fungal community composition, we identify the model that best explains fungal community by considering the position on the stem and distance from the cavity. We suggest this model may be used to design optimal sampling schemes to describe fungal communities in trees experiencing discrete decay pockets or cavities.