Tree Bark Research Articles

Vertical variation in swelling properties of Norway spruce bark depending on tree age and bark moisture content

AbstractIn forest ecosystems, interception of rainwater on foliar and woody surfaces and the subsequent partitioning into stemflow is largely controlled by physical and hydrological properties of bark. Few forest ecohydrology studies have explored the role of bark properties (e.g., thickness, density) on bark water storage capacity and stemflow production. Even fewer have explored how different phases of water (e.g., liquid, vapor) may affect bark through bark swelling properties across the stem and how the degree of swelling affects tradeoffs between bark water storage and stemflow generation. Thus, the objective of this study was to analyze changes in a bark swelling index (BSI) vertically along stems of Picea abies (Norway spruce) after exposure to both water vapor and liquid water, as a function of tree age and bark moisture content. We found that tree age influenced BSI and bark moisture content, wherein BSI was ∼ 6.5% lower in older trees (70 years) compared to younger trees (35 and 50 years), and average moisture content was 10.4–13.2% lower. BSI increased when bark was exposed to hygroscopic water vapor and reached maximum swelling after 1 day of water saturation. BSI also increased from the base of the tree to 20–30% of total tree height, beyond which BSI remained relatively stable across all age classes. Enhanced understanding of bark swelling mechanisms as a result of stem position, age, and moisture content and exposure provide stronger foundations for understanding canopy hydrologic partitioning and the fate of rainwater moving through forest canopies.

Trunk injection of oxytetracycline improves plant performance and alters the active bark and rhizosphere microbiomes in huanglongbing-affected citrus trees

Trunk injection of oxytetracycline improves plant performance and alters the active bark and rhizosphere microbiomes in huanglongbing-affected citrus trees

Severe and Short Interval Fires Rearrange Dry Forest Fuel Arrays in South-Eastern Australia

Fire regimes have shaped extant vegetation communities, and subsequently fuel arrays, in fire-prone landscapes. Understanding how resilient fuel arrays are to fire regime attributes will be key for future fire management actions, given global fire regime shifts. We use a network of 63-field sites across the Sydney Basin Bioregion (Australia) to quantify how fire interval (short: last three fires <10 years apart, long: last two fires >10 years apart) and severity (low: understorey canopy scorched, high: understorey and overstorey canopy scorched), impacted fuel attribute values 2.5 years after Australia’s 2019–2020 Black Summer fires. Tree bark fuel hazard, herbaceous (near-surface fuels; grasses, sedges <50 cm height) fuel hazard, and ground litter (surface fuels) fuel cover and load were higher in areas burned by low- rather than high-severity fire. Conversely, midstorey (elevated fuels: shrubs, trees 50 cm–200 m in height) fuel cover and hazard were higher in areas burned by high- rather than low-severity fire. Elevated fuel cover, vertical connectivity, height and fuel hazard were also higher at long rather than short fire intervals. Our results provide strong evidence that fire regimes rearrange fuel arrays in the years following fire, which suggests that future fire regime shifts may alter fuel states, with important implications for fuel and fire management.

Characterizing diurnal roosts of male Little Brown Myotis (Myotis lucifugus) during summer

Abstract Shelter is one critical aspect of an animal’s habitat, providing refuge from predators and weather, protection for offspring, and aiding in physiological homeostasis. During the day, bats find shelter in roosts—spaces created under tree bark, in tree cavities, or between rocks—after spending the night searching for food. Finding a roost with a microclimate that enables bats to remain in their thermoneutral zone could reduce energetic demands or allow bats to allocate energy to other activities such as reproduction and fighting disease. We aimed to characterize the structural features and microclimate (i.e., temperature) of roosts used by male Little Brown Myotis (Myotis lucifugus) during the summer and determine whether bats select certain characteristics disproportionally to what is available at different spatial scales. During the summers of 2017 and 2018, we radio-tracked 34 male M. lucifugus in Lodgepole Pine-dominated forests. We located at least 1 roost for 20 individuals (average = 2.85 roosts/bat, range = 1 to 6). Although snags were available, most of the roosts were in rock features (86% in rocks, 14% in trees or snags). Male M. lucifugus were more likely to select rock roosts with less canopy closure that were closer to water compared to available roosts on the landscape. They also selected roosts in rock features occurring within larger areas of rock cover that had wider entrances and access to crevices that faced the sky; these roosts also had warmer microclimates relative to other locations available on the landscape. Crevices that allow the bat to bask in the sun and change locations within a roost, minimizing energy needed for active thermoregulation, could be very beneficial for individuals recovering from diseases such as white-nose syndrome. Our work indicates that rock features provide habitat for male M. lucifugus during summer; other studies have shown that bats roost in these features during autumn and winter, further supporting their importance. By protecting these important rock structures, managers can help bats meet their habitat needs throughout the year.

Phorophyte preference of an epiphytic orchid (Dendrobium wangliangii) is independent of orchid mycorrhizal fungi that promote seed germination

Abstract Epiphytism is an example of an obligate interspecific interaction between plants, where a plant species grows on another plant species for physical support. In epiphytic orchids that rely on suitable host tree species (phorophytes) and mycorrhizal fungi for germination and growth, a distinct preference has been observed for particular host tree species. However, the factors driving this host preference remain unclear. In this study, we investigated whether mycorrhizal fungi that promote seedling development determine the preference of phorophytes in the epiphytic orchid Dendrobium wangliangii. First, we identified the preferred host tree species for this orchid. Next, in vitro and in situ germination experiments were conducted to identify potential fungi that promote seed germination. Finally, high‐throughput sequencing was used to assess the distribution of these fungi on both colonized host trees and potential host trees, including individual trees of the host species not yet colonized by the orchid and trees of another species growing in the vicinity of a colonized tree. Dendrobium wangliangii exhibited a preference for trees within the Fagaceae family. Two Fusarium species from the bark of host trees were identified as the primary fungi that promote seed germination. Successful protocorm formation and seedling development were observed exclusively on preferred phorophytes. Fungal community analyses further indicated that both Fusarium spp. occurred on all potential host trees, suggesting that the host preference of this epiphytic orchid is not constrained by the distribution of suitable mycorrhizal fungi. Synthesis: Regarding the epiphytes that depend on mycorrhizal fungi for successful seedling recruitment, we conclude that strong epiphyte–phorophyte associations do not arise from the limited distribution of mycorrhizal fungi but are more likely the result of other factors inherent in the phorophyte environment.

Soil fungal composition under decomposing deadwood is largely affected by tree bark density rather than soil properties

Deadwood is an important structural and biological component of forest ecosystems habitating for a variety of soil fungal communities. However, it is unknown how decomposition of deadwood impacts fungal communities in the soil underneath functionally different tree species in forests. This study compared the effects of the barks of seven tree species, differing in physicochemical characteristics, on soil fungal communities during the early stages of deadwood decomposition in a subtropical forest. A field experiment consisting of 3 evergreen broadleaf, 3 deciduous broadleaf and 1 coniferous tree species, was conducted for 18 months to examine the impact of deadwood decomposition on soil fungal community using real-time PCR and high-throughput sequencing. Our results demonstrated that wood decomposition led to significant declines in soil pH. Functionally distinct tree species significantly shaped the distinct soil fungal composition and abundances underneath the deadwood of both broadleaf and coniferous trees after 18 months of decomposition. The fungal ecological guilds underneath the deadwood were altered, with symbiotrophs being more prominent, and a higher proportion of pathogens were observed under certain broadleaf tree species. Out of the soil fungal ASVs detected, only 51 (3 %) were generalists, while 1053 ASVs (52 %) exhibited traits indicating potential fungal specialists. There were stronger coniferous tree species preferences in soil fungal composition, compared to broadleaf trees. The initial bark density from broadleaf and coniferous species illustrated the most obvious difference. Interestingly, tree bark density, rather than soil chemistry, was the key driver causing the fluctuations in fungal composition during deadwood decomposition. Tree species traits notably affected soil fungal community during early wood decomposition. These findings highlight the importance of considering the bark traits in understanding the dynamics of soil fungal communities and its implications for forest health and ecosystem management.

DNA EXTRACTION FROM LOCAL SOUVENIR OF SUKU ANAK DALAM JAMBI WITHOUT LIQUID NITROGEN USING CTAB METHOD

One of the local souvenirs from Jambi is accessories made from the seed bark of the sebalik sumpah tree. The sebalik sumpah tree is currently quite rare. Through DNA isolation, sebalik sumpah is one of the efforts of genetic conservation and as a first step in cultivating sebalik sumpah trees. DNA isolation is the initial stage in molecular analysis. The purpose of DNA isolation is to obtain genomic DNA from a sample. Plant DNA isolation generally uses fresh plant samples, with young and soft plant parts. This is recommended to obtain good quality genomic DNA. However, with the limitations of fresh samples, a method is needed that is able to extract DNA from plants that have changed shape and have undergone processing. Each plant requires a different method to obtain DNA. The CTAB (Cethyl Trimethyl Ammonium Bromide) buffer method is a method commonly used in plants because it is able to extract DNA with high polysaccharide and phenol content, so many have modified the method. This study aims to determine the success of the CTAB method without nitrogen in extracting processed materials and the length of incubation time at the precipitation stage. Extraction was carried out by liquid nitrogenless CTAB method with the addition of PVP (Polyvinylpolypyrrolidone). The results show that the CTAB method without liquid nitrogen is able to extract plant samples that have undergone processing and the length of incubation time at the precipitation stage affects the DNA produced.
  

Chloride leaching of eucalyptus wood particles by water for pellets production

The impacts of climate change caused by the consumption of fossil fuels have encouraged the reduction of greenhouse gas emissions. The use of forest biomass for the pellets production is an alternative for energy generation. However, the high chloride content present in this forest biomass has caused human health and economic problems, which are factors that restrict the export of pellets. The main objective of this work was to reduce the chloride content in eucalyptus wood intended to produce pellets, by leaching the particles with water. Different parts of the eucalyptus tree (bark, branches, leaves, heartwood and sapwood) were characterized, and the biomass stock was determined. The chloride content determination was carried out using the selective chloride electrode and ion chromatography methods. Leaching was performed using a water/wood ratio of 25, 50, 75 or 100 L kg−1. The higher heating value (HHV) of the bark (18.47 MJ/kg), branches (20.01 MJ/kg) and leaves (22.04 MJ/kg) met the requirements of ISO 17225–2. However, their ash (1.91–4.32 %) and chloride content (0.120–0.627 %) were above what is allowed by the standard. The sapwood showed a higher content of volatile matter, ash and holocellulose, while higher values of HHV, fixed carbon, lignin and extractives content were observed for the heartwood. The chloride content present in heartwood was lower than that of sapwood and did not meet the requirements for ISO 17225–2 (≤0.03 % for B and ≤ 0.02 % for A pellets). In general, particle leaching did not significantly affect the energetic properties of wood. Leaching the particles with the lowest water/wood ratio (25 L/kg) was sufficient to remove chloride ions and meet the requirements of ISO 17225–2.

Unlocking the effective alliance of β-lapachone and hydroxytyrosol against triple-negative breast cancer cells

Triple-negative breast cancer (TNBC) is characterised by its aggressiveness and resistance to chemotherapy, demanding the development of effective strategies against its unique characteristics. Derived from lapacho tree bark, β-lapachone (β-LP) selectively targets cancer cells with elevated levels of the detoxifying enzyme NQO1. Hydroxytyrosol (HT) is a phenolic compound derived from olive trees with important anticancer properties that include the inhibition of cancer stem cells (CSCs) and metastatic features in TNBC, as well as relevant antioxidant activities by mechanisms such as the induction of NQO1. We aimed to study whether these compounds could have synergistic anticancer activity in TNBC cells and the possible role of NQO1. For this pourpose, we assessed the impact of β-LP (0.5 or 1.5 μM) and HT (50 and 100 μM) on five TNBC cell lines. We demonstrated that the combination of β-LP and HT exhibits anti-proliferative, pro-apoptotic, and cell cycle arrest effects in several TNBC cells, including docetaxel-resistant TNBC cells. Additionally, it effectively inhibits the self-renewal and clonogenicity of CSCs, modifying their aggressive phenotype. However, the notable impact of the β-LP-HT combination does not appear to be solely associated with the levels of the NQO1 protein and ROS. RNA-Seq analysis revealed that the combination's anticancer activity is linked to a strong induction of endoplasmic reticulum stress and apoptosis through the unfolded protein response. In conclusion, in this study, we demonstrated how the combination of β-LP and HT could offer an affordable, safe, and effective approach against TNBC.

Contributions and limitations of environmental magnetism to characterize traffic-related particulate matter sources

Summary The chronic exposure to particulate matter (PM) pollution causes societal and environmental issues, in particular in urban areas where most citizen are regularly exposed to vehicular traffic. Since almost two decades, environmental magnetic monitoring has demonstrated its efficiency to successfully map relative concentrations of airborne particle deposition on accumulative surfaces. A better understanding of the magnetic results requires discriminating the main traffic-related sources of the observed signal on particle collectors. To meet this objective, we investigated a sample set of exhaust and non-exhaust sources with respect to their magnetic fingerprints inferred from hysteresis loops, first order reversal curve (FORC) diagrams, temperature dependency of initial susceptibility, and unmixing of IRM acquisition curves. The source sample set comprises 14 diesel and gasoline exhaust smoke residues, 12 abrasive-fatigue wear test pieces from worn brake-pads, brake powders, worn tire-tread, and three resuspension products: asphalt concrete, street dust, and Saharan mineral dust deposited by precipitation after long-range eolian transport. Magnetic properties of the source samples were compared to those from various accumulative surfaces exposed to urban traffic (passive collectors, filters of facemasks for cycling, plant leaves, and tree barks). We found some fingerprints of exhaust pipes and brake wear products on these collectors. The findings highlight the relevance of environmental magnetism tools to characterize different traffic-related source signals in accumulative surfaces in urban environment.

Potential of Pinus eldarica Medw. tree bark for biomonitoring polycyclic aromatic hydrocarbons in ambient air

Urban trees' biomonitoring of pollutants such as polycyclic aromatic hydrocarbons (PAHs) yields pertinent and useful data for air pollution management. The aim of this study was to biomonitor PAHs in pine (Pinus eldarica Medw.) trees in the city of Isfahan and identify their sources. In total, 34 samples of outer bark of the trees were collected and their contents of 16 EPA PAHs were analyzed. With a median value of 136.3 ng/g, the total PAH contents in tree barks varied from 53.4 to 705.2 ng/g. The average values of the diagnostic ratios for Ant/(Ant + Phe), Flu/(Flu + Py), BaA/(BaA + Chr) and IP/(IP + BP) were 0.19, 0.49, 0.45 and 0.49, respectively, revealing the PAHs majority source of pyrogenic. Meanwhile, principal component analysis showed two major types of PAHs sources including pyrogenic (fossil fuel combustion and industrial activities) and petrogenic (uncombusted) sources. The average ratio An/(An + Phe) and Flu/(Flu + Py) in bark samples was close to their relevant ratios in ambient air which demonstrated the potential use of this approach for biomonitoring of PAHs.

Comparative metabarcoding and biodiversity of gut-associated fungal assemblages of Dendroctonus species (Curculionidae: Scolytinae).

The genus Dendroctonus is a Holarctic taxon composed of 21 nominal species; some of these species are well known in the world as disturbance agents of forest ecosystems. Under the bark of the host tree, these insects are involved in complex and dynamic associations with phoretic ectosymbiotic and endosymbiotic communities. Unlike filamentous fungi and bacteria, the ecological role of yeasts in the bark beetle holobiont is poorly understood, though yeasts were the first group to be recorded as microbial symbionts of these beetles. Our aim was characterize and compare the gut fungal assemblages associated to 14 species of Dendroctonus using the internal transcribed spacer 2 (ITS2) region. A total of 615,542 sequences were recovered yielding 248 fungal amplicon sequence variants (ASVs). The fungal diversity was represented by 4 phyla, 16 classes, 34 orders, 54 families, and 71 genera with different relative abundances among Dendroctonus species. The α-diversity consisted of 32 genera of yeasts and 39 genera of filamentous fungi. An analysis of β-diversity indicated differences in the composition of the gut fungal assemblages among bark beetle species, with differences in species and phylogenetic diversity. A common core mycobiome was recognized at the genus level, integrated mainly by Candida present in all bark beetles, Nakazawaea, Cladosporium, Ogataea, and Yamadazyma. The bipartite networks confirmed that these fungal genera showed a strong association between beetle species and dominant fungi, which are key to maintaining the structure and stability of the fungal community. The functional variation in the trophic structure was identified among libraries and species, with pathotroph-saprotroph-symbiotroph represented at the highest frequency, followed by saprotroph-symbiotroph, and saprotroph only. The overall network suggested that yeast and fungal ASVs in the gut of these beetles showed positive and negative associations among them. This study outlines a mycobiome associated with Dendroctonus nutrition and provides a starting point for future in vitro and omics approaches addressing potential ecological functions and interactions among fungal assemblages and beetle hosts.

Change of carbon mass after timber harvesting in a natural forest, West Sumatra Indonesia

Forests have an important role in the carbon cycle and in the dynamics of storing and releasing carbon in growth, decay, and disturbance processes. Timber harvesting initially reduces the amount of carbon in the forest. This study aims to analyze the magnitude of changes in carbon mass due to timber harvesting. It was conducted in a forest concessionaire located at Siberut of West Sumatra on a natural forest covering about 48,000 hectares. Selective cutting was implemented for logging where the harvestable trees were over 50 cm in diameter. The amount of carbon mass was obtained based on laboratory tests on tree parts, including trunk, branches, twigs, and bark. The average carbon content in each part of the tree is different. The trunk contains 53.86% of carbon mass, the branches are 51.98%, the twigs are 31.58%, the leaves are 27.91%, and the bark is 32.01%. Timber harvesting was conducted at the forest compartment with an average forest stand density of 71.5 trees ha−1 and a felling intensity of 8.8 trees ha−1, causing damage to 16.17 trees ha−1 stands. Timber harvesting causes a decrease in carbon mass reserves of 43.26% from forest carbon mass of 141.89 tons C ha−1 before harvesting to 80.00 tons C ha−1 after harvesting.

Biomonitoring with Lichens: Evaluating Heavy Metal Concentrations, Environmental Factors, and Lichen Diversity in Bengaluru, Karnataka, India

Lichens are commonly used in biomonitoring due to their unique characteristics that make them a cost-effective option. Unlike chemical analysis, sampling lichen diversity is less expensive, enabling a more extensive sampling coverage while reducing costs. This diverse group of organisms can be used to detect areas that are affected by pollution, land use changes, and ecological imbalances. In recent years, researchers have been working to establish a reliable protocol for lichen sampling in biomonitoring to enhance its utility and minimize any variations caused by extraneous environmental factors. In this article concentrations of heavy metals s (Cd, Cr, Cu, Fe, Ni, Pb and Zn), acidity and electrical conductance of few flowering trees bark (Albizialebbeck, Delonixregia, Pongamiaglabra, Callistemon Lanceolatus, Cassia Fistula, Cassia Javanica) were evaluated to determine the impact the lichen value diversity in six different places based on different environmental factors. It has been stated that the correlation between acidity level and lichen species exists in all investigated tree species. Six lichen species (Chrysothrixcandelaris (L.) Laundon, Graphisscripta (L.) Ach, G. scripta (L.) Ach., leucosorodes Nyl, D. consimilis (Stirton) Awasthi, D. aegialita (Afz. in Ach.) Moore and L.(perplexa Brodo) were registered, among them three were foliose and three were crutose. Lichen leucosorode Nyl was predominant in Albizialebbeck, Delonixregia, Pongamiaglabra trees. It was observed that the lichen diversity was less near heavy traffic location, industrial areas and also rougher bark of trees provided a better habitat of wider variety of lichen species.

Facile removal of rhodamine B and metronidazole with mesoporous biochar prepared from palm tree biomass: adsorption studies, reusability, and mechanisms

Abstract Biochar was produced by pyrolysing palm tree bark biomass at 500 °C for the removal of rhodamine B (RhB) and metronidazole (MET). Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller, X-ray diffraction (XRD), scanning electron microscopy, and energy-dispersive X-ray analyses were used to characterize the biochar. The biochar obtained was crystalline, mesoporous (SBET: 189.157 m2 g−1; pore diameter: 2.207 nm), clustered with prominent O–H and C = O functional groups. The pHpzc of the biochar was 7.98, and it adsorbed RhB and MET maximally at pH 3.4 and 7.2, respectively. The Langmuir and Freundlich isotherms described RhB and MET adsorption, respectively, with maximum adsorption capacities (qmax) of 31.81–224.30 mg/g for RhB and 95.44–26.76 mg/g for MET from 303 to 313 K. Both adsorbates exhibit favourable physisorption processes with pseudo-second-order kinetics, as the most appropriate. The thermodynamic parameter (−ΔG°) demonstrates spontaneous adsorption processes for RhB and MET, with spontaneity increasing with temperature for RhB and decreasing with increasing temperature for MET. The adsorption process was endothermic (+ΔH°) for RhB and exothermic (−ΔH°) for MET. Given its reusability of 96 and 95% for RhB and MET, respectively, mesoporous biochar derived from palm trees is a more promising adsorbent.

The Evaluation of Tree Bark as Filler for Wood-Plastic Composites: Experimental Study and Modelling

Tree bark is one of the waste materials produced during harvesting. In this study, tree bark was evaluated for the production of WPCs. Three tree barks (Oak, Calabrian pine, and Cedar) were added to the matrix as an alternative for wood flour (20-80 mesh). Different tree bark content (10, 20, 40%) were also selected. The tree bark-based WPCs were produced with the flat-pressed method. The effect of tree bark on water absorption (WA) and thickness swelling (TS) were investigated during the 14 days. Tree barks have a significant effect on the WA and TS properties of the composites. As the bark content increased, the WA and TS values decreased. While the WA values increased up to 11.27% for control samples, it is only 3.27% for 40% of tree bark. Similar results were also observed for TS values. Also, the prediction models were developed using multiple linear regression (MLR). Correlation coefficient (R2) values of models were determined as 0.882, 0.853, and 0.850 for oak, Calabrian pine, and cedar WA values and 0.889, 0.839, and 0.879 for oak, Calabrian pine, and cedar TS values, respectively. The results showed that tree bark has the potential as an alternative to wood flour for WPC production.

Phloretin Inhibits the Proliferation of Breast Cancer Cells Through the Down-regulation of Estrogen Receptor α.

Phloretin is a natural flavonoid compound found in some plants, such as apples and pears, as well as in the bark of apple trees. Phloretin has been shown to have inhibitory effects on glucose transporters in cells and can potentially inhibit the growth of cancer cells. However, the mechanism by which phloretin regulates the expression of estrogen receptor alpha (ERα), a key transcription factor in breast cancer, is still unclear. This study investigated how phloretin affects the growth of ERα positive human breast cancer cells. The growth of breast cancer cell lines, including MCF7 and T47D, was examined using cell proliferation and colony formation assays. Western blotting and semi-quantitative RT-PCR were used to examine protein and mRNA levels, respectively. Localization of cellular proteins was analyzed using subcellular fractionation. Transient transfection and reported gene assays were used to elucidate the impact of phloretin on cell proliferation and ERα transactivation. Phloretin decreased ERα expression at the mRNA and protein levels in MCF7 and T47D cells. It also inhibited the binding of ERα to the estrogen response element present in the promoter of target genes. Moreover, treatment with phloretin inhibited the expression of cyclin D1 and breast cancer marker gene pS2, which are known ERα target genes. Consequently, it inhibited the growth of ERα-positive human breast cancer cells. Furthermore, inhibition of breast cancer growth by phloretin was found to be mediated through both the ERα and ERK1/ERK2 pathways. Phloretin, a dihydrochalcone extracted from natural sources, exhibits the ability to regulate ERα function and suppress breast cancer cell proliferation.

DAMAGE TO PINE PLANTATIONS BY THE APICAL BARK BEETLE AND STEM PESTS IN THE BRANCH «KOROSTYSHIV FORESTRY»

The treetop bark beetle (Ips typographus) is the main pest of Scots pine (Pinus sylvestris L.) in Europe in general and in Ukraine in particular. It affects the phloem (inner bark) of trees, disrupting the supply of nutrients, which can lead to the death of pine plantations, especially young or weakened ones [1].

Understanding the Manufacture of Hetian Administration Banknotes from Xinjiang Using Low- and High-resolution Analytical Methods

ABSTRACT Analytical studies of ancient Chinese handmade papers and paper-based materials have long faced challenges, due to the need for high-quality, scientifically sound data that can lead to suitable diagnostic criteria. This study applies Herzberg staining, micro-computed tomography (micro-CT), Raman spectroscopy, pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), and high-resolution mass spectrometry (HRMS) to five Hetian Administration Banknotes (HABs), a particular type of regional banknotes issued by Ma Hu-shan (1910–1954), a Hui warlord, in southern Xinjiang between 1933 and 1937. The results shed important insights into the use of fiber and dyes on HABs, revealing how locally handmade Sangpi (bark of the mulberry tree, Morus alba L.) papers and imported synthetic dyes (Rhodamine B, Methyl Violet 2B, Direct Black 38, and presumably Sudan II) were combined to serve the needs of the regional economy in southern Xinjiang during the 1930s. We conclude the paper by tentatively proposing guidelines for applying low- and high-resolution analytical methods to understand the manufacture and use of ancient Chinese handmade papers and paper-based materials.

The Interacting Influence of Fire and Tree Characteristics on Douglas-Fir Beetle Host-Tree Selection Five Years Post-Fire

Fire injury stresses Douglas-fir trees (Pseudotsuga menziesii) that survive a wildfire event, allowing subsequent Douglas-fir beetle (Dendroctonus pseudotsugae) infection to kill trees that may have otherwise survived. This study aimed to determine how fire injury, stand, and tree characteristics drive Douglas-fir beetle host tree selection five years post-fire. We paired 28 adjacent beetle-infected and uninfected stands (infected N = 14) and 140 Douglas-fir trees (infected N = 70) within the 416 Fire burn area in Southwest Colorado. We found no statistically significant differences between infected and uninfected stand characteristics. Individual tree height, DBH, and bark char severity index were significantly higher in infected versus uninfected trees. We created a regression decision tree model to determine the influence of fire injury and tree characteristics on the probability of infection. Trees with a height ≥ 27 m, bark char height < 2.3 m, and DBH < 80 cm had the greatest probability of attack (100%). Trees with a height < 27 m, bark char severity index < 5.5, and DBH < 49 cm had the lowest probability of attack (3.7%). Understanding the influence of fire on Douglas-fir beetle host selection allows land managers to model potential epidemic outbreaks and guide proactive management actions that may reduce beetle outbreak severity or preserve high-value trees not killed by fire.