Dead Trees Research Articles

Replace me if you can: Abundance of advance regeneration under canopy trees in a primeval beech forest

Tree replacement patterns strongly shape species coexistence and dominance in forest ecosystems. In mixed forests subject to a small-scale disturbance regime, dead canopy trees are often replaced by advance regeneration. We studied the abundance of saplings (6–10 cm dbh) and poles (10–25 cm dbh) under canopy trees based on four inventories on a 10-ha permanent plot in a large primary forest dominated by Fagus sylvatica in Ukraine. Saplings and poles of Fagus sylvatica, Acer platanoides, A. pseudoplatanus and Ulmus glabra were spatially linked to canopy trees (‘hosts’, dbh > 25 cm) based on their crown radius, and the hosts’ neighborhood was classified according to the presence of dead trees. The number of saplings and poles under hosts was modelled with a Bayesian approach. There was a higher number of advance regeneration under hosts with increasing host diameter. The abundance of advance regeneration was the lowest under hosts in the canopy (i.e., under shaded conditions) and highest for hosts growing in gaps. 1) Under the canopy, only F. sylvatica poles can replace heterospecific hosts > 80 cm dbh, while other pole species are clearly below the replacement threshold. 2) Near dead lying trees, Acer pseudoplatanus rarely achieved an abundance of one pole at a host dbh > 80 cm. 3) In gaps, Acer spp. poles were able to replace F. sylvatica hosts. The proximity to dead lying trees and gaps is crucial for Acer spp. and U. glabra saplings for recruitment to the pole stage. The higher rate of recruitment under hosts adjacent to dead lying trees suggests that the total length of gap edges may be as important as gap size or disturbance frequency. In gaps > 550 m2, advance regeneration without hosts (growing in gaps) of Acer spp. can recruit higher number of saplings than F. sylvatica, but not poles. We conclude that almost all canopy trees of Acer spp. and U. glabra are likely to be replaced by Fagus sylvatica if the current small-scale disturbance regime and single-tree mortality continue to prevail.

Seed dispersal and tree legacies influence spatial patterns of plant invasion dynamics

Invasive plant species alter community dynamics and ecosystem properties, potentially leading to regime shifts. Here, the invasion of a non-native tree species into a stand of native tree species is simulated using an agent-based model. The model describes an invasive tree with fast growth and high seed production that produces litter with a suppressive effect on native seedlings, based loosely on Melaleuca quinquenervia, invasive to southern Florida. The effect of a biocontrol agent, which reduces the invasive tree's growth and reproductive rates, is included to study how effective biocontrol is in facilitating the recovery of native trees. Even under biocontrol, the invader has some advantages over native tree species, such as the ability to tolerate higher stem densities than the invaded species and its litter's seedling suppression effect. We also include a standing dead component of both species, where light interception from dead canopy trees influences neighboring tree demographics. The model is applied to two questions. The first is how the mean seedling dispersal rate affects the spread of the invading species into a pure stand of natives, assuming the same mean dispersal distance for both species. For assumed litter seedling suppression that roughly balances the fitness levels of the two species, which species dominates depends on the mean dispersal distance. The invader dominates at both very high and very low mean seedling dispersal distances, while the native tree dominates for dispersal distances in the intermediate range. The second question is how standing dead trees affect either the rate of spread of the invader or the rate of recovery of the native species. The legacy of standing dead invasive trees may delay the recovery of native vegetation. The results here are novel and show that agent-based modeling is essential in illustrating how the fine-scale modeling of local interactions of trees leads to effects at the population level.

Differentiating effects of salvage logging and recovery patterns on post-fire boreal forests in Northeast China using a modified forest disturbance index

ABSTRACT Forests are resilient to a range of disturbances, but combinations of severe natural and anthropogenic disturbances (e.g. wildfire and logging) may inhibit forest recovery and lead to forest degradation. Recent studies have explored long-term forest-disturbance detection and forest-recovery dynamics by using free and open-access remote-sensing images. However, mapping consecutive multiple disturbance agents is challenging using existing automated change-detection algorithms because the reduced canopy reflectance and the smoothing of consecutive disturbance signals mean that the initial disturbance cannot be spectrally separated from the second disturbance. Furthermore, uncertainty remains about post-disturbance vegetation dynamics and the effects of forest recovery under the interaction of burn severity, biological-legacy management, and active forest restoration (i.e. artificial regeneration and assisted natural regeneration). This contributes to biases in long-term forest-recovery monitoring, which are not conducive to the guidance of post-fire vegetation recovery. Here, we propose a modified disturbance index to separate the spectral characteristics of fire and forest logging using normalized tasseled-cap components (brightness and wetness) and detect the spatiotemporal distribution of post-fire logging by means of an index threshold and image differencing. On this basis, the recovery patterns of the post-fire forest are differentiated by considering the cumulative effect of fire, post-fire logging, and recovery approaches. The method is tested in the burn areas of the 5.6 Fire in the Greater Hinggan Mountain area (the largest forest fire in recorded history in China), giving an overall accuracy of 85% in post-fire forest logging mapping. Our results confirm that biological legacies (i.e. trees, logs, and snags) were removed across many areas in the fire, with activities peaking in the second year after the fire and located chiefly in areas of moderate and high burn severity. By identifying post-fire logging, the fluctuation and high disturbance index of the conventional temporal trajectory in the early stage of forest recovery are explained. The large-scale salvage logging slowed the recovery of the post-fire forest ecosystem and influenced the recovery process through the interaction of burn severity and active forest restoration. In areas of high burn severity, assisted natural regeneration (i.e. natural regeneration with artificial aids such as clearing the snags, weeding, digging pits, and supplemental planting) preserved biological legacies and achieved a higher proportion of forest recovery, second only to non-logged areas where natural regeneration (i.e. forestry recovering naturally without any artificial intervention) occurred. By contrast, salvage logging followed by artificial regeneration (i.e. clear-cutting all dead or damaged trees followed by tree planting or artificial seeding) hindered vegetation recovery in the early stage, but it improved the recovery rate in years 10–20 and approached the recovery proportion of non-logged areas where natural regeneration occurred as the recovery progressed and habitat conditions improved. The proposed method is shown to offer important advantages in detecting post-fire salvage logging, and it provides improved guidance for forest managers in developing strategies for forest recovery.

Environmental forensics evaluation of residual soybean sludge using trees of Brazilian savannah

Truck and train are the primary transport means for soybean shipments to national or international markets from Brazil. Substantial amounts of grain residues are dispersed throughout the transport and may accumulate in various places by the runoff. The objective of this study was to evaluate the contamination and mortality of Brazilian savannah trees due to the accumulation of soybean runoff that comes from a grain storage yard. Xylem samples were collected from 28 dead trees in a forest where residues severely polluted the natural environment. Increment cores at breast height were also taken from 25 living trees for control procedure. All samples were analyzed by X-ray densitometry and microfluorescence (XRF) techniques. No differences were observed in the xylem densitometry profile from bark to pith between dead and living trees, indicating that the stagnation in cell production and tree growth occurred drastically after the accumulation of soybean residual sludge, which was confirmed by temporal analysis of satellite images. Significantly higher S, P, Ca and Fe concentrations were observed close to the bark in dead trees. The roots of dead trees accumulated higher amounts of Al, Si, S, Ca and Mn. Higher K, Ca and Si concentrations and lower Mn concentrations were observed in trees closer to the polluted area, and it indicates the need for soil remediation. However, As, Pb and Cd, markers of fertilizers and pesticides in soybean production, were not detected by the analyses performed. It is likely that the residual soybean sludge and its fermentation process during the rainy season (tree - growing season) have generated toxic concentrations of inorganic constituents, that together with warmer soil conditions caused the death of many trees. This study provides tools for the assessment of the environmental impact of soybean production through a novel protocol for monitoring the physical and chemical patterns of tree growth using rapid microscopic scale X-ray techniques.

Study of the resilience parameters of cork oak after fire in north-western Algeria

ABSTRACT The periodic exploitation of the cork coinciding with the wildfire reinforces the vulnerability of the trees by affecting their vigour and their productive potential. Results showed that trees lightly affected by fire (recoverable) manage to overcome the disturbance without major impact on regeneration and growth variables (IR = 3.80, growth = 2.04mm/year; thickness = 14.81mm; volumetric density = 283,59 kg/m3; IQ = 8,56). Paradoxically, standing dead trees record a very low resilience (IR = 1.23; growth = 0.26mm/year; thickness = 1.99mm; volumetric density = 347.02 kg/m3 and IQ = 1.50).

Earthworms from natural and managed ecosystems in Southern Bahia, Brazil.

The earthworms (Crassiclitellata) of the Northern Atlantic Forest region are poorly known, and many new species are expected to be found in the region. Hence, quantitative and qualitative samples were taken in the Atlantic Forest region of southern Bahia State, Brazil, at eight sites to assess species presence and abundance in different land uses (forests, pastures, plantations). Earthworms were also qualitatively collected at an additional eight sites. Only one to two species per site were found in quantitative samples, while qualitative samples generally resulted in higher species recoveries, with highest richness observed at the native Atlantic Forest of Veracel in Porto Seguro. Pontoscolex corethrurus (Müller, 1857) was the dominant species at all sites and in most land use systems, probably favored by human migration and agricultural activities; it was only absent in one primary forest site where native Ocnerodrilidae species predominated. In total at least 14 species were found of which eight were new, belonging to the genus Rhinodrilus and three new genera in the Ocnerodrilidae family (Pauqueba, Parabauba and Diplomoela). Contrary to sites in Southern and Southeastern Brazil, where many native species belong to the Glossoscolecidae family, in southern Bahia, Ocnerodrilidae species tend to be more prevalent, occupying various habitats. More intensive sampling of these habitats, including surface litter, in and under fallen logs and dead tree trunks, under rocks, in bromeliad leaf tanks and deeper soil layers is essential in order to properly characterize earthworm communities in Brazilian Atlantic Forests.

Carbon stored in live ponderosa pines in the Sierra Nevada will not return to pre-drought (2012) levels during the 21st century due to bark beetle outbreaks

Outbreaks of several bark beetle species can develop rapidly in response to drought and may result in large transfers of carbon (C) stored in live trees to C stored in dead trees (10s of Tg C yr-1 in the western U.S. alone), which over time will be released back to the atmosphere. The western pine beetle (WPB) outbreak incited by the 2012–2015 mega-drought in the Sierra Nevada, California, U.S., could portend more frequent and/or severe bark beetle outbreaks as the temperature warms and drought frequency and intensity increase in the future. However, changes in the frequency and/or severity (resultant levels of host tree mortality) of beetle outbreaks are difficult to predict as outbreaks are complex with non-linear and eruptive processes primarily driven by interactions among beetle populations, the demography of hosts and other tree species, and climate and weather. Using an insect phenology and tree defense model, we projected the future likelihood of WPB outbreaks in the Sierra Nevada with climate drivers from different Earth System Models. Our goal was to understand how host (ponderosa pine, PIPO) recovery and future warming and drought affect the frequency and severity of WPB outbreaks and their C consequences. Our projections suggested that by 2100 the C stored in live PIPO (mean: 1.98 kg C m-2, 95% CI: 1.74–2.21 kg C m-2) will not return to levels that occurred before the 2012–2015 drought (2012: ∼2.30 kg C m-2) due to future WPB outbreaks. However, differences in climate models indicate a wide range of possible WPB outbreak frequencies and severities. Our results suggest that total plot basal area is the most significant factor in the mortality rate of PIPO by WPB in any given year, followed by drought severity and temperature. High levels of host basal area, higher temperature, and extreme drought all contribute to the frequency and severity of future WPB outbreaks. While PIPO basal area may decline under increased drought and warming, limiting high-stand basal area (>60 m2 ha-1) may reduce the severity of future WPB outbreaks in the Sierra Nevada.

Fire blight rootstock infections causing apple tree death: A case study in high-density apple orchards with Erwinia amylovora strain characterization

A devastating outcome of fire blight in apple trees is the infection of rootstock, which leads to canker development. Fire blight cankers are infected zones of dead bark on perennial branches, trunk, or rootstock that develop after fire blight pathogen Erwinia amylovora invades wood. Cankers can girdle the trunk, branches and rootstock leading to tree death and production losses, especially significant in high-density orchards. An accurate diagnosis of trunk and rootstock blight is a top challenge for apple growers because fire blight cankers can be visually misdiagnosed with cankers caused by less frequent Oomycete and fungal pathogens (e.g., Phytophthora spp., Botryosphaeria dothidea, B. obtusa, Valsa mali). In addition, detecting E. amylovora in apple rootstocks is essential because this pathogen also causes asymptomatic infections. Accurate fire blight diagnosis is necessary to inform the complete removal of infected trees from the orchard and help replanting efforts while preventing further pathogen dissemination. To determine apple tree losses caused by fire blight rootstock infections, PCR was used to detect E. amylovora in symptomatic and asymptomatic rootstocks for two years. Rootstock canker incidence and tree death were rated in selected infection foci on seven commercial apple orchards in New York. Each infection focus consisted of central rootstock-blighted tree and the nearest surrounding edge trees showing no rootstock blight. E. amylovora strains collected from these seven orchards and other orchards in New York were characterized. In the first year, most of the orchards showed E. amylovora detection rates of 10.7 – 45.3% in asymptomatic rootstocks on the edge trees immediately surrounding visibly infected i.e. rootstock-blighted central trees. One year later, 20.8 – 56.3% cankered rootstocks were detected on the edge trees and from zero to 35.4% dead edge trees were recorded. However, the PCR from sampled edge rootstocks one year later showed no pathogen detections. E. amylovora rootstock strains showed slight variability in enzymatic activity, copper sensitivity, virulence, and exopolysaccharide production. These results elucidate the role and importance of rootstock infections for apple tree survival, the presence of latent fire blight infections, and the valuable utility of molecular detection methods to assist apple tree removal after epidemics.

Forgotten forest relics: Apple trees (Malus spp.) in eastern U.S. forests

One potential legacy of the widespread deforestation of the 1700-1800s and subsequent agricultural abandonment and reforestation across the eastern United States (U.S.) during the 1900s is the establishment of introduced apple trees (Malus domestica) exclusive of naturally occurring native crab apple species. As these apple trees might provide ecological services and a genetic reserve of long-forgotten apple cultivars, a region-wide forest inventory was used to estimate the current extent, condition, and changes in the population of apple trees across eastern forests of the U.S. It was found that hundreds of millions of apple trees currently exist in the forests of the northern U.S. with indications of population senescence as the abundance of seedlings and saplings decline while the abundance of the largest-sized trees and standing dead trees increase. The distribution of forest apple trees is only aligned with native crab apple distributions in limited areas, suggesting distinct feral apple populations derived from agricultural abandonment decades ago. As these extant apple trees are likely relics of former orchards and/or their naturally dispersed progeny, these populations may serve as an in-situ gene bank representing hundreds, if not thousands, of apple cultivars forgotten long ago but adapted to local conditions and perhaps of importance to ensuring the future resilience of domestic apple production in the context of global change.

Material legacies can degrade resilience: Structure-retaining disturbances promote regime shifts on coral reefs.

Standing dead structures of habitat-forming organisms (e.g., dead trees, coral skeletons, oyster shells) killed by a disturbance are material legacies that can affect ecosystem recovery processes. Many ecosystems are subject to different types of disturbance that either remove biogenic structures or leave them intact. Here we used a mathematical model to quantify how the resilience of coral reef ecosystems may be differentially affected following structure-removing and structure-retaining disturbance events, focusing in particular on the potential for regime shifts from coral to macroalgae. We found that dead coral skeletons could substantially diminish coral resilience if they provided macroalgae refuge from herbivory, a key feedback associated with the recovery of coral populations. Our model shows that the material legacy of dead skeletons broadens the range of herbivore biomass over which coral and macroalgae states are bistable. Hence, material legacies can alter resilience by modifying the underlying relationship between a system driver (herbivory) and a state variable (coral cover).

UAV-based reference data for the prediction of fractional cover of standing deadwood from Sentinel time series

Increasing tree mortality due to climate change has been observed globally. Remote sensing is a suitable means for detecting tree mortality and has been proven effective for the assessment of abrupt and large-scale stand-replacing disturbances, such as those caused by windthrow, clear-cut harvesting, or wildfire. Non-stand replacing tree mortality events (e.g., due to drought) are more difficult to detect with satellite data – especially across regions and forest types. A common limitation for this is the availability of spatially explicit reference data. To address this issue, we propose an automated generation of reference data using uncrewed aerial vehicles (UAV) and deep learning-based pattern recognition. In this study, we used convolutional neural networks (CNN) to semantically segment crowns of standing dead trees from 176 UAV-based very high-resolution (<4 cm) RGB-orthomosaics that we acquired over six regions in Germany and Finland between 2017 and 2021. The local-level CNN-predictions were then extrapolated to landscape-level using Sentinel-1 (i.e., backscatter and interferometric coherence), Sentinel-2 time series, and long short term memory networks (LSTM) to predict the cover fraction of standing deadwood per Sentinel-pixel. The CNN-based segmentation of standing deadwood from UAV imagery was accurate (F1-score = 0.85) and consistent across the different study sites and years. Best results for the LSTM-based extrapolation of fractional cover of standing deadwood using Sentinel-1 and -2 time series were achieved using all available Sentinel-1 and --2 bands, kernel normalized difference vegetation index (kNDVI), and normalized difference water index (NDWI) (Pearson’s r = 0.66, total least squares regression slope = 1.58). The landscape-level predictions showed high spatial detail and were transferable across regions and years. Our results highlight the effectiveness of deep learning-based algorithms for an automated and rapid generation of reference data for large areas using UAV imagery. Potential for improving the presented upscaling approach was found particularly in ensuring the spatial and temporal consistency of the two data sources (e.g., co-registration of very high-resolution UAV data and medium resolution satellite data). The increasing availability of publicly available UAV imagery on sharing platforms combined with automated and transferable deep learning-based mapping algorithms will further increase the potential of such multi-scale approaches.

Discovery of the termitophilous genus Trichopsenius Horn, 1877 (Coleoptera, Staphylinidae, Aleocharinae) from China with description of a new species.

The termitophilous genus Trichopsenius Horn, 1877 is recorded from China for the first time. A new species, Trichopseniushuaxiensissp. nov. is described; it was collected in a nest of the termite genus Reticulitermes Holmgren from a dead and flattened pine tree.

Tree mortality in mature temperate forests of central Mexico: a spatial approach

Tree mortality is an important process of forest stand dynamics and knowledge of it is fundamental to implement adequate management strategies. Subject to several factors, tree mortality can induce different spatial patterns on the remaining live and dead trees. While spatially clustered tree mortality in young forests is often driven by competition, in old-growth forests, spatially clustered tree mortality is often caused by disturbance agents. This study is focused on a spatiotemporal analysis of tree mortality in a mature temperate forest located in central Mexico dominated by Pinus montezumae and Alnus firmifolia. We used tree locations from a permanent plot (300 × 300 m) measured over a 20-year period. The results, from applying point pattern analysis, showed that the spatial pattern of all dead trees was clustered at short to medium distances, but showed no clear deviation from complete spatial randomness at longer distances. Similar results were found for P. montezumae and A. firmifolia. Using the bivariate mark-connection function (alive and dead trees), no tree mortality caused by competition was discernable, only A. firmifolia showed a tendency toward competition-introduced mortality around 15 m. Regarding forest structure, alive trees retained a clustered distribution and size heterogeneity at different distances during the measurement period. Thus, there was evidence that the resulting spatial pattern of tree mortality could be explained by disturbance agents such as droughts rather than tree competition. Therefore, the results of this study can contribute to implement management strategies based on the principles of continuous cover forestry and provide novel information regarding tree mortality in Mexican montane forests.

Detection and description of four Vespa mandarinia (Hymenoptera, Vespidae) nests in western North America

Vespa mandarinia Smith 1852 is a semi-specialized predator of other social Hymenoptera and one of the two largest species of Vespa. Several individuals of this predatory wasp were detected in Canada and the United States in 2019, including an entire nest that was located and destroyed on Vancouver Island, British Columbia. The Washington State Department of Agriculture and the United States Department of Agriculture’s Animal and Plant Health Inspection Service have collaborated to survey Washington State for V. mandarinia since 2020, using traps staffed by agency personnel, collaborators from local governments and nongovernmental organizations, and the general public. Trap data and public reports were used to select sites for live-trapping or net surveys, and live hornets captured in these efforts were subsequently collected and fitted with radio tags to locate nests. The survey ultimately led to the discovery of a V. mandarinia nest in October 2020, and three nests in August and September 2021. All of the nests were located within in red alder trees (Alnus rubra), with one just above the ground in a standing dead tree, and the other three in cavities ~2 to 5 meters above the ground in living trees. The number of combs in each nest varied between four and ten, cells between 418 and 1,329, and total hornets per nest between 449 and 1,474 (including immature and mature stages). Together, the four nests indicate an incipient population of V. mandarinia in the Cascadia region, and ongoing action by local, state, provincial, and federal governments, and residents of both countries is required to avoid the establishment of this exotic species in the region.

A Road Running Southward: Following John Muir's Journey Through an Endangered Land by Dan Chapman

Reviewed by: A Road Running Southward: Following John Muir's Journey Through an Endangered Land by Dan Chapman Joann Mossa A Road Running Southward: Following John Muir's Journey Through an Endangered Land. Dan Chapman. Washington, DC: Island Press, 2022. 256 pp., 2 figs. $26.94 hardcover (ISBN 9780817359997). The southeastern United States is a zone of tremendous biodiversity, but is under duress from changes in land use, climate, industry, invasive species and more. Dan Chapman's first book A Road Running Southward: Following John Muir's Journey Through an Endangered Land reexamines the travels of John Muir, the naturalist and conservationist, best known for his work in Yosemite but also the author of a book A Thousand Mile Walk about travels in the Southeast in 1867. Technically, it was a 900-mile walk and 100-mile boat trip from Louisville, Kentucky to Cedar Key, Florida in the Gulf of Mexico. With limited funds, sleeping in cemeteries, and meeting locals, Muir ends his journey with a three-month convalescence with malaria. Through recounting parts of Muir's journey through mountains, foothills, plains, wetlands, and the coast, and in some cases going beyond it, Chapman weaves Muir's observations about threatened landscapes of the past, with the transformations of today. The key words of Chapman's title are "Endangered Land." Themes like climate change, invasive species, endangered species, pollution, demise of the reefs at Cedar Key, water wars, and other direct and indirect human actions have transformed the Southeast. Through the lens of environmental geography and history, focusing on what has made the South a unique and diverse in its culture, economy, climate, terrain, and biota, the book's goal is to inform the interested layperson about the many past environmental and historical, current, and emerging threats. The table of contents includes a title for each chapter, and a few-sentence synopsis of the topics and major themes. Chapman's graphics include an 1870 photo of John Muir, and a map depicting the 1867 walk through the Southeast and other place names mentioned in the text. The background chapter is an introduction: "Ghosts, Skeeters, and Rye." As Muir did, Chapman stays in a mosquito-rich cemetery named Bonaventure near Savannah where "Tall, dead oak trees resembling the bones of giants rise from the marsh just north of Bonaventure, ghost-forest victims of a rising sea's surge of salt water" (8). Laying the foundation for the interconnectedness of human impacts, Chapman notes: "A billion-dollar river-deepening project for the port of Savannah allows even more salt water to push farther upstream and harm the delicate ecosystem that sustains crustaceans, fish, and shorebirds" (9). In this introduction, he gives an overview and describes the scope of the Southeast's transformation because of human impacts: "Ninety million acres of stately longleaf pine forests and nourishing savannah grasses once filled the coastal plains stretching from Virginia through Georgia and all the way to Texas. Only four million acres remain today, the rest disappearing under the woodsman's ax, the farmer's plow, and the developer's bulldozer" (10). [End Page 123] After the introduction, Chapman begins with background on John Muir, recognizing his flaws and strengths. Some perceived shortcomings and flaws were detailed in the following quote: "Muir remained a Bible-toting prude who blanched at relations with the opposite sex. His encounters with African and Native Americans were less than enlightened, even downright racist. As a boy, he was cruel to animals. Marriage was more of a convenience than an affair of the heart. His all-natural piety grated on less-devoted disciples of wildness" (16). Then, Chapman notes Muir's apparent achievements: "Muir eventually embraced mainstream society, raised a loving family, got rich, and trod the corridors of power. He realized that his articles and books, leadership of the Sierra Club, and lobbying of the mighty served the budding conservation movement better than his musings on flowers and glaciers…Muir's preaching the back-to-nature gospel to an increasingly jaded, yet eager, American audience that would prove to be his most enduring legacy" (16). Chapman uses the biographical information to set the stage in how Muir's long walk began...

Habitat heterogeneity is a good predictor of boreal forest biodiversity

Reliable assessment measures are crucial for tracking changes in biodiversity and for evaluating the state of biodiversity. Two of the main drivers of biodiversity are habitat heterogeneity and resource amount. These drivers are used as proxies of biodiversity but assessing both is costly, limiting their practical use. To test which of the drivers best predicts the number and abundance of sessile species of conservation concern (including macrofungi, lichens, bryophytes, and vascular plants), we assessed forest stand heterogeneity using a method developed in Sweden (‘Habitat Heterogeneity Score HHS’), and quantified the resource amount and quality of ecologically important structural variables (deadwood volume, basal area of living trees, proportion of broadleaved trees, and the age of the oldest tree in the stand). We conducted the assessments in 77 boreal conifer-dominated forest stands in two regions of Sweden. Despite some group-specific organism differences, HHS was the best predictor of both number and abundance of all species of conservation concern, regardless of the region. Further, HHS was the best predictor of red-listed species number and abundance in the southern region, while a model including the volume of deadwood and the age of the oldest tree performed best in the northern region. Deadwood (CWD) volume was the single best resource amount predictor of the number and abundance of species of conservation concern, emphasizing the critical role that dead trees have for biodiversity. In addition, we calculated threshold values for deadwood volume and HHS depicting the level above which the number of red-listed species is significantly higher, and found this value to be higher in the southern region (22.4 m3 ha−1 deadwood and a HSS value of 17) than in the north (20.0 m3 ha−1 and 16). These values can be used as guidance when identifying coniferous forests with high enough qualities to support red-listed species. To conclude, the method of assessing habitat heterogeneity presented in this study is a practical and reliable way to identify forests of high biological diversity, and can therefore be part of the toolbox for sustainable forestry in boreal forests.

Ice Patch Archaeology in the Teton Mountains

Since 2015, I have investigated 21 ice patches in the Teton Range, Wyoming and located one pre-contact and several post-contact artifacts. The pre-contact artifact is a modified whitebark pine stick that dates to 3158 to 2960 cal BP. The post-contact artifacts are one 1940s wallet, one carved Boy Scout walking stick, and two modified pine sticks that date to the contact/post-contact periods. I also collected paleobiological specimens, including wood samples from dead trees and bison bones that are used to reconstruct past tree line elevations, as proxies for paleoclimate regimes, and to reconstruct the pre-contact lifeways of bison in the higher elevations of the Greater Yellowstone Area. This article presents the combined results of these investigations and their implications for future ice patch research in the Tetons.

The Beauty of Wabi Sabi as the Spirit of Life of the Oldman in Japanese Fairytale

Wabi sabi is one of Philosophy in Japan. It’s about appreciation to the beauty of imperfection. Wabi sabi can be found in so many aspects in Japanese people’s life such as chanoyu, ikebana, haiku, or fairytale of Japanese children. This article aims to know how the oldman gets the spirit of life by wabi sabi to cheer his life. Hanasaka Jiisan is used in this research as a source of data. The result is the beauty of wabi sabi is appeared by the oldman’ house, the falling leaves, the dead trees, and the falling flowers. Furthermore, wabi sabi as the spirit of life can be found in the old man who lives with his wife, the old man who takes care of a dog, the old man who takes the ash of mortar home, and the old man who throws ash all over the dead trees and it makes the lord of local castle so happy.

Thermal Profiles of Chainsaw Hollows and Natural Hollows during Extreme Heat Events.

Loss of hollow-bearing trees threatens many hollow-dependent wildlife. To mitigate this process, artificial chainsaw-carved hollows (CHs) are often created in dead trees, yet little is known about their thermal profiles. We measured temperatures inside 13 natural hollows (8 live and 5 dead trees) and 45 CHs (5 live and 40 dead trees) in the central west of NSW, Australia, over the course of 2 summers. Maximum temperatures and daily temperature ranges within natural hollows and artificial hollows were similar in 2017-2018. Hollow temperatures were lower in thicker-walled hollows than in thinner-walled hollows. During the January 2019 heatwave, temperatures inside CHs in dead trees exceeded 4-35 °C higher than the upper limit of the thermal neutral zone of sugar gliders-for 6.2 consecutive days (range 0-9 days). CHs in dead trees provided little buffering from thermal extremes; when air temperatures peaked at 44.6 °C, CHs in dead trees were on average 2.4 °C cooler than ambient (range: 5.5 °C cooler to 1.0 °C hotter than ambient). These results show that CHs created in dead trees may not provide suitable thermal conditions for hollow-dependent marsupials during summer heatwaves. Retention of large live trees, coupled with revegetation, is crucial for conserving hollow-dependent fauna in agricultural landscapes.

A multi-scale approach to detecting standing dead trees in UAV RGB images based on improved faster R-CNN.

The health of the trees in the forest affects the ecological environment, so timely detection of Standing Dead Trees (SDTs) plays an important role in forest management. However, due to the large spatial scope of forests, it is difficult to find SDTs through conventional approaches such as field inventories. In recent years, the development of deep learning and Unmanned Aerial Vehicle (UAV) has provided technical support for low-cost real-time monitoring of SDTs, but the inability to fully utilize global features and the difficulty of small-scale SDTs detection have brought challenges to the detection of SDTs in visible light images. Therefore, this paper proposes a multi-scale attention mechanism detection method for identifying SDTs in UAV RGB images. This method takes Faster-RCNN as the basic framework and uses Swin-Transformer as the backbone network for feature extraction, which can effectively obtain global information. Then, features of different scales are extracted through the feature pyramid structure and feature balance enhancement module. Finally, dynamic training is used to improve the quality of the model. The experimental results show that the algorithm proposed in this paper can effectively identify the SDTs in the visible light image of the UAV with an accuracy of 95.9%. This method of SDTs identification can not only improve the efficiency of SDTs exploration, but also help relevant departments to explore other forest species in the future.