Search

Via sheltering, decoupling and buffering mechanisms, tree canopies have the capacity to mitigate impacts of multiple global‐change drivers on below‐canopy processes and organisms in forests. As a result, canopies have an important potential as nature‐based solution. The optimal combinations of forest canopy structural attributes to jointly mitigate the impacts of multiple global‐change drivers on below‐canopy organisms and processes have received little attention to date. To help solving this research gap, here we review how forest canopies modulate the effects of four important global‐change drivers—climate warming, drought, air pollution and biological invasions—on below‐canopy conditions. Particular attention is paid to mitigating canopy attributes that can be influenced by forest management, including canopy cover, tree species composition and vertical and horizontal structure. Synthesis. We show that the potential of forest canopies to mitigate global‐change effects is highly context‐dependent and that optimal canopy‐based solutions strongly depend on the environmental context and the targeted subcanopy organisms. Hence, holistic approaches, which maximize synergies and minimize trade‐offs, are needed to optimize the solution potential of forest canopies. [ABSTRACT FROM AUTHOR]

Mounting evidence suggests that reciprocal interactions between plants and the soil microbiota can be a primary force that generates key macroscopic patterns of plant communities (coexistence, dominance, and succession) in forest ecosystems. The aim of this article is to review empirical and theoretical perspectives of plant–soil feedback research in the context of forest community ecology. I first use a simple theoretical model to get insights into an array of the dynamics generated by plant–soil feedback: negative plant–soil feedback maintains plant species diversity and reduces plant growth, while positive plant–soil feedback drives plant growth of certain species and hence their dominance. I then describe how ecologists have unveiled the enormously complex plant‐microbiota interaction (i.e., the soil conditioning experiment) and review the linkage of plant–soil feedback with three key plant community patterns: (i) dominance, (ii) spatial structure and (iii) succession. I highlight one belowground plant trait (mycorrhizal type) that can mediate these linkages: arbuscular mycorrhizal species tend to exhibit negative plant–soil feedback while ectomycorrhizal species tend to exhibit positive plant–soil feedback. Although mycorrhizal plant–soil feedback potentially explains the patterns of tree diversity from local to global scales, many questions remain. Future studies should expand plant–soil feedback theory to incorporate numerous other feedback mechanisms and test how mycorrhizal types mediate the net feedback effects that could propagate to shape large‐scale forest structures and dynamics. [ABSTRACT FROM AUTHOR]

Climatic drivers alone do not adequately explain the regional variation in budburst timing in deciduous forests across Europe. Stand‐level factors, such as tree species richness, might affect budburst timing by creating different microclimates under the same site macroclimate. We assessed different phases of the spring phenology (start, midpoint, end, and overall duration of the budburst period) of four important European tree species (Betula pendula, Fagus sylvatica, Quercus robur and Tilia cordata) in monocultures and four‐species mixture stands of a common garden tree biodiversity experiment in Belgium (FORBIO) in 2021 and 2022. Microclimatic differences between the stands in terms of bud chilling, temperature forcing, and soil temperature were considerable, with four‐species mixtures being generally colder than monocultures in spring, but not in winter. In the colder spring of 2021, at the stand level, the end of the budburst period was advanced, and its overall duration shortened, in the four‐species mixtures. At species level, this response was significant for F. sylvatica. In the warmer spring of 2022, advances in spring phenology in four‐species stands were observed again in F. sylvatica and, less markedly, in B. pendula but without a general response at the stand level. Q. robur showed specific patterns with delayed budburst start in 2021 in the four‐species mixtures and very short budburst duration for all stands in 2022. Phenological differences between monocultures and four‐species mixtures were linked to microclimatic differences in light availability rather than in temperature as even comparatively colder microclimates showed an advanced phenology. Compared to weather conditions, tree species richness had a lower impact on budburst timing, but this impact can be of importance for key species like F. sylvatica and colder springs. These results indicate that forest biodiversity can affect budburst phenology, with wider implications, especially for forest‐ and land surface models. [ABSTRACT FROM AUTHOR]

Forest canopy height data are crucial for estimating forest carbon storage and assessing forest ecology. By utilizing satellite imagery, canopy height data obtained from airborne or spaceborne LiDAR have been expanded from footprint and plot levels to spatially continuous elevation mapping of forests. However, current research suggests that estimating forest canopy height without forest type data presents a challenge in how to effectively integrate multi-source LiDAR data and ensure the samples adequately represent various forest types for higher estimation accuracy. Therefore, this study proposes a forest canopy height estimation method that considers forest structure and integrates multi-source LiDAR data to overcome the challenge. First, a stratified sampling method based on forest structure (SSMFS) was proposed to select training samples and enhance their representativeness. Second, we combined GEDI and ATL08 data to create a multi-source spaceborne LiDAR dataset, enhancing geographic coverage and increasing canopy height samples. Third, the spaceborne LiDAR-based canopy height estimation model incorporates previously unconsidered canopy openness features and uses SSMFS to select training samples. Finally, we improved spaceborne LiDAR canopy height accuracy by creating a residual correction model that adjusts for differences between airborne scanner (ALS) and spaceborne LiDAR estimates. This study, conducted in Zhangwu County, achieved an accuracy of R2 = 0.71, MAE = 1.20 m, and RMSE = 1.71 m. These results show a 51.06% increase in R2, a 26.38% decrease in MAE, and a 24.00% decrease in RMSE compared to recent research. In summary, this study profoundly amplifies predictive accuracy, providing a clear advantage in the delineation of regional forest canopy maps. [ABSTRACT FROM AUTHOR]

Climate change will likely increase habitat loss of endemic tree species and drives forest conversion in mountainous forests. Elevation gradients provide the opportunity to predict possible consequences of such changes. While species compositions of various taxa have been investigated along elevation gradients, data on trophic changes in soil-dwelling organisms are scarce. Here, we investigated trophic changes of the Collembola communities along the northern slope of Changbai Mountain, China. We sampled Collembola in primary forests at seven elevations (800–1700 m asl). We measured individual body lengths and bulk stable isotopes on species level. We further categorized Collembola species into life forms. The community-weighted means of Δ15N and Δ13C values as well as minimum Δ15N values and isotopic uniqueness of Collembola communities increased with increasing elevation, while the range of Δ15N values decreased. Maximum and minimum of Δ13C values differed between elevations but showed no linear trend. Further, Δ15N values of Collembola species occurring across all elevations increased with elevation. Changes in Δ15N values with elevation were most pronounced in hemiedaphic species, while Δ13C values increased strongest with elevation in euedaphic species. Δ15N values increased with decreasing body size in hemiedaphic and euedaphic species. Overall, the results suggest that Collembola species functioning as primary decomposers at lower elevations shift towards functioning as secondary decomposers or even predators or scavengers at higher elevation forests. The results further indicate that access to alternative food resources depends on Collembola life form as well as body size and varies between ecosystems. [ABSTRACT FROM AUTHOR]

Mycorrhization has been an integral part of plants since colonization by the early land plants. Over decades, substantial research has highlighted its potential role in improving nutritional efficiency and growth, development and survival of crop plants. However, the focus of this review is trees. Evidence have been provided to explain ecological and physiological significance of mycorrhization in trees. Advances in recent technologies (e.g., metagenomics, artificial intelligence, machine learning, agricultural drones) may open new windows to apply this knowledge in promoting tree growth in forest ecosystems. Dual mycorrhization relationships in trees and even triple relationships among trees, mycorrhizal fungi and bacteria offer an interesting physiological system to understand how plants interact with other organisms for better survival. Besides, studies indicate additional roles of mycorrhization in learning, memorizing and communication between host trees through a common mycorrhizal network (CMN). Recent observations in trees suggest that mycorrhization may even promote tolerance to multiple abiotic (e.g., drought, salt, heavy metal stress) and biotic (e.g. fungi) stresses. Due to the extent of physiological reliance, local adaptation of trees is heavily impacted by the mycorrhizal community. This knowledge opens the possibility of a non‐GMO avenue to promote tree growth and development. Indeed, mycorrhization could impact growth of trees in nurserys and subsequent survival of the inoculated trees in field conditions. Future studies might integrate hyperspectral imaging and drone technologies to identify tree communities that are deficient in nitrogen and spray mycorrhizal spore formulations on them. [ABSTRACT FROM AUTHOR]

Aim: Climate change challenges temperate forest trees by increasingly irregular precipitation and rising temperatures. Due to long generation cycles, trees cannot quickly adapt genetically. Hence, the persistence of tree populations in the face of ongoing climate change depends largely on phenotypic variation, that is the capability of a genotype to express variable phenotypes under different environmental conditions, known as plasticity. We aimed to quantify phenotypic variation of central Europe's naturally dominant forest tree across various intraspecific scales (individuals, mother trees (families), populations) to evaluate its potential to respond to changing climatic conditions. Location: Europe. Time Period: 2016–2019. Major Taxa Studied: European beech (Fagus sylvatica L.). Methods: We conducted a fully reciprocal transplantation experiment with more than 9000 beech seeds from seven populations across a Europe‐wide gradient. We compared morphological (Specific Leaf Area), phenological (leaf unfolding) and fitness‐related (growth, survival) traits across various biological scales: within single mother trees, within populations and across different populations under the contrasting climates of the translocation sites. Results: The experiment revealed significant phenotypic variation within the offspring of each mother tree, regardless of geographic origin. Initially, seedling height growth varied among mother trees and populations, likely due to maternal effects. However, the growth performance successively aligned after the first year. In summary, we observed a consistent growth response in different beech populations to diverse environments after initial maternal effects. Main Conclusions: The study strikingly demonstrates the importance of considering intraspecific variation. Given the surprisingly broad spectrum of phenotypes each mother tree holds within its juvenile offspring, we conclude that Fagus sylvatica might have the potential for medium‐term population persistence in face of climate change, provided that this pattern persists into later life stages. Hence, we also suggest further investigating the inclusion of passive adaptation and natural dynamics in the adaptive management of forests. [ABSTRACT FROM AUTHOR]

The study considers the issues of introduction and reintroduction of the Red Book species of checker tree in the system of decorative gardening, forest protection, and forest ecosystems. That is why the purpose of the study was to monitor the green corridors of rural and urban ecosystems of the forest-steppe zone of Ukraine, to investigate and select the best forms of checker tree in terms of morphological characteristics and physiological properties for promising areas of distribution and conservation in the form of pure and mixed plantings. The following methods were used in the research: route, field, biometric, laboratory, comparative analysis, mathematical and statistical. New forms of checker tree were introduced, studied in in situ and ex situ conditions, and selected for the prospects of their further introduction and reintroduction into the ecological network of Ukraine and conservation to activate trophic, phoric, and other types of biotic interactions in a single territorial ecosystem. Sparsely distributed biotypes of Torminalis glaberrima (Gand.) Sennikov & Kurtto f. Intermedia Kossetz were found in the zone of green corridors of rural and urban ecosystems of the forest-steppe zone of Ukraine. Some specimens of these biotypes were identified as valuable material for introduction into the system of fruit and ornamental gardening, including parks and monuments of landscape art, as well as natural monuments, protected tracts, sanctuaries and reserves of pure and mixed plantings, alleys, forest reclamation strips, etc. It was established that the elements of originality of the selected forms of checker tree - Eva, Podolianochka and Slavka - are the specificity of the crown shape, which determines the level of productivity, small and medium growth force, normal reaction to pruning (which affects the size and yield of fruits), high degree of flowering (60-80%), increased fruit size (diameter of more than 2 cm), increased fruit weight (1.8-2.1 g), increased number of fruits on the stem (≥20 units), a pleasant and harmonious taste of fruits, high quality of fruits, lack of periodicity in fruiting in nature and in culture, high xenogamy (69-75%), high yield of fruits from the plant, increased winter hardiness (7.5 pt.), high drought resistance (8 pt.) and resistance to pests, including pear leaf blister mite (7-9 pt.). The findings can be used in the future to replenish pure and mixed plantings in the ecological network of Ukraine. [ABSTRACT FROM AUTHOR]

The functional load of forests necessitates the activation of meliorative measures to optimize the functioning of agrolandscape complexes. These measures contribute to improving the environmental situation and advancing towards sustainable functioning of forest ecosystems. Therefore, the study of the structural and species formation of forest ecosystems is of significant scientific interest. The aim of the article was to analyse the impact of agroforestry measures on the process of forming the structure of forest ecosystems through a comprehensive examination of interrelationships. The research utilized general scientific methods, including specification, deduction, systemic analysis, synthesis, and abstraction, as well as formalization. During the study, vectors of organizing optimized systems of protective forest plantations were analysed, and environmental protection priorities for the development of agroforestry ecosystems were substantiated. Basic principles of managing the agroforestry complex based on sustainable land use were identified, including a comprehensive approach, ecologization of the process, and continuous monitoring. The study revealed current ecological consequences of irrational melioration for forest plantations, such as increased erosion processes and land resource degradation. Risks and challenges requiring preventive solutions were identified. It was proven that increasing the share of agroforestry plantations would allow optimizing the environmental situation in Ukraine, promoting the regeneration of the natural resource base, restoring landscapes, and minimizing land resource degradation processes. The article proposed key measures to optimize the environmental situation at the local level of forest ecosystems, as well as preventive measures to prevent destructive impacts, including the improvement of legal support and the implementation of strict measures of responsibility for irrational resource use. The value of the conclusions lies in their practical application for monitoring the state and the process of forming the structure of forest ecosystems under the influence of agroforestry measures. They also contribute to the effective development of preventive and regenerative protective measures and the formation of balanced forest ecosystems. [ABSTRACT FROM AUTHOR]

This paper reviews and discusses the main features of biological invasion by plants and the assisted migration theory referencing a critical common factor—belowground ecology. The risk of a plant becoming invasive and the potential failure of assisted migration programs depend on the presence or absence of soil microorganisms that regulate key ecosystem processes and mitigate adverse environmental conditions. This biotic interaction should be considered in the selection of sites for afforestation programs since it is as important as temperature and precipitation regarding conservation decisions, and assisted migration practices in response to climate change. Fungal species should be determined and included in climate change mitigation programs to avoid disease outbreaks and ensure the presence of beneficial mutualistic species in sites selected for assisted migration. Plants considered for assisted migration should pose a low risk of becoming invasive for having establishment difficulties per se. However, the real threat is that they may displace other species, introduce pathogens, or trigger disease outbreaks in introduction sites that nullify assisted migration efforts. [ABSTRACT FROM AUTHOR]

The binning of species into categorical and artificial functional groups has often been used in ecology to overcome data deficiencies with the expectation that these deficiencies and, therefore, groups will fade. Other influential work has argued that functional groups naturally arise in tree communities due to a diffuse competitive environment and a largely uniform abiotic environment leading to functional convergence. The pragmatic usage and biological arguments for functional groups have clear limitations that may make them dubious. The development of public functional trait repositories and future trait collection campaigns in undersampled regions will reduce some reliance on functional groups, but the conceptual framework underlying functional groups related to shade tolerance could be modified to include additional complexity relating to pest and pathogen interactions to result in more realistic and defendable insights into the generation and maintenance of tree biodiversity. Functional trait variation measured on continuous scales has helped ecologists to unravel important ecological processes. However, forest ecologists have recently moved back toward using functional groups. There are pragmatic and biological rationales for focusing on functional groups. Both of these approaches have inherent limitations including binning clearly continuous distributions, poor trait-group matching, and narrow conceptual frameworks for why groups exist and how they evolved. We believe the pragmatic use of functional groups due to data deficiencies will eventually erode. Conversely, we argue that existing conceptual frameworks for why a limited number of tree functional groups may exist is a useful, but flawed, starting point for modeling forests that can be improved through the consideration of unmeasured axes of functional variation. [ABSTRACT FROM AUTHOR]

Cultural land-use is an important driver of ecosystem change, influencing the composition of species across landscapes and through time. Recent research in northwestern North America has shown that historical Indigenous land-use and forest management has resulted in relict forest gardens dominated by edible fruit, nut, and berry producing trees and shrubs – many of which continue to grow adjacent to archaeological village sites today. Our research combines archaeological and ecological methods to better understand the historical ecology of seven forest gardens in the Pacific Northwest. Vascular plant communities at all sites are evaluated for distinctiveness using ANOSIM, NMDS, and indicator species analyses. We identify 15 forest garden indicator species, all of which are culturally significant edible fruit or root-bearing species. We then present the results of an intensive historical-ecological study of one site in Laxyuubm Gitselasu (Ts'msyen). Paleoethnobotanical data, soil and tree ring analyses, and radiocarbon dates show that forest management in the Gitsaex forest garden of Gitselasu pre-dates settler colonialism and shows that people likely modified soils and otherwise enhanced their immediate environment to increase the productivity of desired plant species. Given the importance of Indigenous peoples' role in sustaining forested foodsheds, there is an ongoing and urgent need to support their revitalization and management and better understand the integrated cultural practices and ecological processes that result in these vast cultural landscapes. [ABSTRACT FROM AUTHOR]

Visitor interests can be crucial to understanding humans' connectedness in nature. We analysed the relationship between people and flora and fauna species (native and exotic) through YouTube videos of a forest region (southern Patagonia) posted by visitors from different parts of the world. We characterised the species of flora and fauna observed by the visitors and calculated the time that appears in the videos as a proxy for their connectedness to biodiversity. The biodiversity observations were contrasted against visitors' sociodemographic characteristics (age and gender) by the Van der Waerden test and multivariate analyses. We created a sociogram that showed connections among species through visitor links to these data. Our results reveal different degrees of relationship between species, where some exotic ones were more preferred than natives (Van der Waerden test p = <0.100). Differences in the linkage to the flora and fauna species were related to the age and gender of the visitors. Visitor interests are modulated by access to ecosystem types (e.g. forests) and species' commonness/rarity and docility. Gender and age had less influence on the interests than expected, but it determined differential values on native and exotic diversity. Three groups of species emerged from the sociogram based on the visitor connectedness to flora and fauna species, evidencing high connections among native trees (Nothofagus spp.), exotic beavers (Castor canadensis), and native geese and ducks (e.g. Chloephaga picta). The novel approach utilised provides valuable data that can be used to test the influence of gender and age on the different biodiversity interests. This information has potential applications for nature conservation by detecting unsponsored biodiversity and ecosystem types that could be promoted, capturing the visitor interests, and improving the offer of visitor activities according to gender/age observations. [ABSTRACT FROM AUTHOR]

Bryophytes, which include mosses, liverworts and hornworts, indeed play a significant role in the natural dynamics of native forests. They contribute to fundamental ecological processes such as tree regeneration. In this context, the objective was to analyse the association of bryophytes with Nothofagus seedlings, as well as whether the substrates where bryophytes grew influenced bryophyte‐tree seedling association, in sub‐Antarctic forests at two contrasting landscapes (coastal and mountain) of Tierra del Fuego (Argentina), to better understand their impacts on the natural regeneration processes. We hypothesized that bryophytes act as a substrate for seed germination and initial regeneration growth in pure and mixed forests of N. pumilio and N. betuloides, resulting in widespread tree seedlings–bryophyte associations in all landscapes. In each forest and landscape location, 60 transects were established (10 m in length) to evaluate bryophyte cover (by point intercept method) and substrate type (bare soil, decaying wood and litter cover) where they were growing. An adaptation of the relative interaction index (RII) based on tree seedling cover associated with bryophyte species (%) and tree seedling cover in the absence of bryophytes (%) was calculated and analysed to assess competition or facilitation between bryophytes and tree seedlings. Nothofagus pumilio seedlings were less abundant in bryophytes compared to other substrates, suggesting an inhibitory effect on the germination and/or survival of N. pumilio. In contrast, the seedlings of N. betuloides, in both pure and mixed forests, exhibited higher abundance on bryophyte substrates, particularly in mosses at mountain landscape (RII = 0.83 ± 0.08 in litter and 0.62 ± 0.11 in decaying wood). These findings suggest that bryophytes play a facilitating role for N. betuloides seedlings during germination and initial phases of growth, mainly in the mountain. Therefore, their conservation promotes N. betuloides forest continuity, both in pure and mixed structures. [ABSTRACT FROM AUTHOR]

In the course of the study, specific primers were developed to identify 20 species of phytopathogenic bacteria from 12 genera associated with the occurrence of infectious diseases in seven forest-forming species of Belarus. The results showed that the developed oligonucleotides are specific for the 16S (mtDNA and cpDNA) and 23S rRNA genes of the studied phytopathogenic bacteria. At a further stage of research, in vitro tests will be carried out to establish the effectiveness of diagnosing bacterial marker loci, both using pure cultures of pathogen isolates and samples of affected tissues of woody plants. [ABSTRACT FROM AUTHOR]

Measuring tree growth rates is an important requirement in many scientific disciplines and forest production sector. The assessment of annual volume growth rates in standing living trees, under ambient field conditions without destroying the tree has so far only been conducted with model approaches or by repeated measurements of tree dimensions in the field. This research note proposes a novel simple non-destructive method for the estimation of annual volume increment in standing trees, based on tree ring analysis of sampling of the two increment cores for each targeted tree and simple trigonometry rules. The extracted data by the method application can be widely used in many forest disciplines, such as forest ecology, silviculture, and forest management. [ABSTRACT FROM AUTHOR]

The use of 3D (three-dimensional) scanning in calculating tree's volume is discussed and suitable equations are fitted for estimating stand volume based on stem diameter at breast height (DBH) and height in the form of power and logarithmic functions. One hundred eighty-four individuals of Hopea odorata, Dipterocarpus alatus and Afzelia xylocarpa were scanned. Then, 3D images were used to calculate an individual tree's volume, based on sectioning the main stem and branches by assuming the cylinder of each section. The results indicated that 3D image calculations underestimated volume by 2.1-4.8% compared to the water displacement method by testing spiral branches of 4.3-15.7 cm diameter. The logarithmic function is the best-fitted model for each species and the combination of three species. A. alatus, H. odorata and combination of three species require both DBH and height, while A. xylocarpa needs only DBH in volume estimation. All four best fitted equations have Adjusted R-Squared >0.88 and underestimate <0.9% 3D volume. The smallest underestimate of 0.02% 3D volume belongs to the best-fitted equation for combination of three species, indicating the potentiality of using a combination of three species equation for estimating the volume of all species, especially in natural forests. It is concluded the suitability of using the 3D scanning technique for calculating individual tree's volume with high accuracy and establishing volume equations for multiple species applications, especially in the tropical forest. [ABSTRACT FROM AUTHOR]

The main goal of this study was to evaluate the performance of AnnAGNPS (Annualized AGricultural NonPoint Source) pollution model, in calculating runoff, sediment loading and nutrient loadings for Funiu Mountain area. Most of the model input parameters were sourced from Luanchuan Forest Ecology Station (LFES) in Funiu Mountain area. The data on 23 storms in 2018 was used to calibrate the model and the data on 33 storms in 2019 for validation. The whole evaluation consisted of determining the coefficient of determination (R²), Nash-Sutcliffe coefficient of efficiency (E), and the percentage volume error (VE). Results showed that the runoff volumes were underpredicted by 5.0% with R² of 0.93 (P<0.05) during calibration and underpredicted by 5.3% with R² of 0.90 (P < 0.05) during validation. But sediment loading was able to produce a moderate result. The model underpredicted the daily sediment loading by 15.1% with R² of 0.63 (P < 0.05) during calibration and 13.5% with R² of 0.66 (P < 0.05) during validation. Nitrogen loading was overpredicted by 20.3% with R² = 0.68 (P < 0.05), and phosphorus loading performance was slightly poor with R2 = 0.65 ( P < 0.05) during validation. In general, the model performed well in simulating runoff compared to sediment loading and nutrient loadings. [ABSTRACT FROM AUTHOR]

Deadwood plays an important role in forest ecology; its degradation and, therefore, carbon assimilation is carried out by fungi and bacteria. To quantify the abundance and distribution of microbial taxa inhabiting dead spruce logs fallen over a span of 50 years and the soil beneath, we used taxonomic profiling with NGS sequencing of hypervariable DNA fragments of ITS1 and 16S V3-V4, respectively. The analysis of sequencing data revealed a high level of diversity in microbial communities participating in the degradation of spruce logs. Differences in the relative abundance of microbial taxa between the samples of the wood that died in 1974 and 2014, and of the soil in its immediate vicinity, were visible, especially at the genus level. Based on the Lefse analysis significantly higher numbers of classified bacterial taxa were observed in the wood and soil samples from 2014 (wood: 1974-18 and 2014-28 taxa; soil: 1974-8 and 2014-41 taxa) while the number of classified fungal taxa was significantly higher in the wood and soil samples from 1974 (wood: 1974-17 and 2014-9 taxa; soil: 1974-57 and 2014-28 taxa). Most of the bacterial and fungal amplicon sequence variants (ASVs) unique to wood were found in the samples from 1974, while those unique to soil were detected in the samples from 2014. The ATR-FTIR method supported by CHN analysis revealed physicochemical changes in deadwood induced by the activity of fungal and bacterial organisms. [ABSTRACT FROM AUTHOR]

Tree regeneration is a key demographic process influencing long‐term forest dynamics. It is driven by climate, disturbances, biotic factors and their interactions. Thus, predictions of tree regeneration are challenging due to complex feedbacks along the wide climatic gradients covered by most tree species. The stress gradient hypothesis (SGH) provides a framework for assessing such feedbacks across species ranges, suggesting that competition between trees is more frequent under favourable conditions, whereas reduced competition (i.e. positive interactions) is more likely under climatic stress. Moreover, tree life‐history strategies (LHS) may shed light on how and whether the SGH explains regeneration of different tree species.To address these topics, we developed statistical models based on >50,000 recruitment events observed for 24 tree species in an extensive permanent plot network (6540 plots from 299 unmanaged European temperate, boreal and subalpine forests) covering a wide climatic gradient.We found that the effects of Leaf Area Index (as a proxy for competition) on tree recruitment changed along climatic gradients but in a species‐specific manner. Competition predominates, with its intensity decreasing under stressful conditions for most species, as predicted by the SGH. However, positive interactions were only evident for a few species. Additionally, the ability of the SGH to explain patterns of competition and positive interactions across the gradients differed among species, with some differences and exceptions that may be related to varying LHS.Synthesis. Our study shows that competition between trees toward climatic stress decreases systematically but depends on species stress tolerance to climate and shade. These findings explain within‐ and between‐species differences in tree recruitment patterns in European temperate forests. Moreover, our findings imply that projections of forest dynamics along wide climatic gradients and under climate change must accommodate both competition and positive interactions, as they strongly affect rates of community turnover. [ABSTRACT FROM AUTHOR]

Field-based learning is central to education in the biogeosciences, but COVID-19 and perennial challenges of large classes, short class times, and crowded schedules make exploration of alternative tools for field education more urgent than ever. Augmented reality (AR) is one candidate, allowing students to visit sites on their own time using a mobile app that guides them through a field trip via geolocationally triggered audio, images, and other media. Research into AR's pedagogical effectiveness is in its infancy, seldom directly comparing delivery of the same field learning activity via AR versus in person, or investigating AR's pedagogical value beyond the cognitive domain. To address this gap, we developed an AR version of an existing forest ecology field trip to a Douglas fir forest remnant in Vancouver, British Columbia, in a large undergraduate biogeoscience course, and compared student experiences of both versions. The study showed that AR can overcome obstacles to effective field education in large courses and deliver significant pedagogical benefits compared to conventional field trips, including engagement, enjoyment, flexibility, accessibility, and learning supports. With effective instructions and technological contingency planning, AR can be an effective tool for geoscientific field education and help address some larger pedagogical issues facing higher education. [ABSTRACT FROM AUTHOR]

The use of drone-borne imagery for tree recognition holds high potential in forestry and ecological studies. Accurate species identification and crown delineation are essential for tasks such as species mapping and ecological assessments. In this study, we compared the results of tree crown recognition across three neural networks using high-resolution optical imagery captured by an affordable drone with an RGB camera. The tasks included the detection of two evergreen coniferous tree species using the YOLOv8 neural network, the semantic segmentation of tree crowns using the U-Net neural network, and the instance segmentation of individual tree crowns using the Mask R-CNN neural network. The evaluation highlighted the strengths and limitations of each method. YOLOv8 demonstrated effective multiple-object detection (F1-score—0.990, overall accuracy (OA)—0.981), enabling detailed analysis of species distribution. U-Net achieved less accurate pixel-level segmentation for both species (F1-score—0.981, OA—0.963). Mask R-CNN provided precise instance-level segmentation, but with lower accuracy (F1-score—0.902, OA—0.822). The choice of a tree crown recognition method should align with the specific research goals. Although YOLOv8 and U-Net are suitable for mapping and species distribution assessments, Mask R-CNN offers more detailed information regarding individual tree crowns. Researchers should carefully consider their objectives and the required level of accuracy when selecting a recognition method. Solving practical problems related to tree recognition requires a multi-step process involving collaboration among experts with diverse skills and experiences, adopting a biology- and landscape-oriented approach when applying remote sensing methods to enhance recognition results. We recommend capturing images in cloudy weather to increase species recognition accuracy. Additionally, it is advisable to consider phenological features when selecting optimal seasons, such as early spring or late autumn, for distinguishing evergreen conifers in boreal or temperate zones. [ABSTRACT FROM AUTHOR]

This paper introduces a new modeling and inference framework for multivariate and anisotropic point processes. Building on recent innovations in multivariate spatial statistics, we propose a new family of multivariate anisotropic random fields, and from them a family of anisotropic point processes. We give conditions that make the proposed models valid. We also propose a Palm likelihood‐based inference method for this type of point process, circumventing issues of likelihood tractability. Finally we illustrate the utility of the proposed modeling framework by analyzing spatial ecological observations of plants and trees in the Barro Colorado Island data. [ABSTRACT FROM AUTHOR]

A local population outbreak of the spongy moth, Lymantria dispar L. (Lepidoptera: Erebidae), in Lower Austria, resulted in the defoliation of an oak forest in 2018 and 2019. In the study year 2020, the population density was still high but was expected to decline. In the present work, the role of parasitoids and pathogens in the collapse of the population was investigated. In total, 20 egg masses, 680 larvae and 12 pupae of L. dispar were collected in the field from April to July 2020 and reared until the emergence of adult moths or death. Causes of mortality were determined based on emerging parasitoids and on microscope inspection of non‐parasitized cadavers. Stage‐specific mortality rates were calculated for eggs, larval stages (L1–L6) and pupae. Seven parasitoid species and three pathogens were responsible for the premature death of spongy moths. The egg parasitoid Anastatus disparis (Hymenoptera: Eupelmidae) emerged from 19% of all eggs. Larval parasitoids caused stage‐specific mortality rates from 15% to 61%. The dominant parasitoid of young and intermediate instars was the solitary wasp Glyptapanteles porthetriae (Hymenoptera: Braconidae). Mature larvae were mainly parasitized by the parasitic flies Blepharipa pratensis (Diptera: Tachinidae) and Parasetigena silvestris (Diptera: Tachinidae). Pathogens caused stage‐specific mortality rates from 11% to 41%. The nuclear polyhedrosis virus (LdNPV; Lefavirales: Baculoviridae) was the dominant pathogen in all instars. The introduced fungus Entomophaga maimaiga (Entomophthorales: Entomopthoraceae)—detected for the first time in Austria in 2019—caused low mortality rates in older larvae. Starting from high egg mass densities in spring, the spongy moth population declined to negligible levels until summer. [ABSTRACT FROM AUTHOR]

Gridded climate datasets are used by researchers and practitioners in many disciplines, including forest ecology, agriculture, and entomology. However, such datasets are generally unable to account for microclimatic variability, particularly within sites or among individual trees. One such dataset is a recent climatology of extreme minimum temperatures in the U.S. Great Lakes region, based on the Parameter–Elevation Regressions on Independent Slopes Model (PRISM) gridded temperature dataset. Development of this climatology was motivated by interest in the spatiotemporal variability of winter temperatures potentially lethal to the hemlock woolly adelgid (HWA) (Adelges tsugae Annand) (Hemiptera: Adelgidae), an invasive insect that causes mortality of eastern hemlock (Tsuga canadensis). In this study, cold-season daily minimum temperatures were monitored at six Michigan sites varying in latitude, elevation, Great Lakes proximity, and HWA infestation status, to address two objectives. First, we documented the spatiotemporal variability in daily minimum air temperatures recorded at multiple aspects and heights on selected hemlock trees. Second, this variability was characterized in the context of the PRISM extreme minimum temperature climatology. Tree-sensor air temperatures exhibited minimal relationships with aspect but considerable sensitivity to height. Daily minimum temperatures were higher for some tree sensors positioned ≤ 0.2 m above ground level during some time periods, with overall muted temporal variability, relative to an adjacent ambient sensor. This phenomenon was attributed to the insulating effects of snow cover, because the tree–ambient sensor temperature difference was positively correlated with snow depth. Overall, results indicate that such unresolved variability warrants consideration by gridded climate dataset users. [ABSTRACT FROM AUTHOR]

Affem Boussou community forest (AFC) abounds in important biological resources. This study, which contributes to its better management, examines the spatiotemporal dynamics of the vegetation and its ecological and structural characteristics to propose a zoning plan for said forest. The analysis of the spatiotemporal dynamics of land use in the AFC from Google Earth images of 2015, 2018, and 2021 revealed a regressive trend of formations: crops and fallows (−33.98%), dense dry forests (−7.92%), gallery forests (−3.46%), plantations (−100%), grassy savannahs, and meadows (−18.84%), except for tree/shrub savannahs (484.23%). The floristic inventory identified 163 species divided into 129 genera and 55 families. Fabaceae (14.02%), and Combretaceae (10.55%) are the most represented families. Anogeissus leiocarpa (5.19%) and Vitellaria paradoxa (4.72%) are the most frequent species. We note the dominance of individuals of small diameters. The regeneration potential of the AFC is 64 feet/ha due to 21 feet/ha of suckers, 29 feet/ha of seedlings, and 14 feet/ha of shoots. As a zoning plan, the AFC was subdivided into four zones: the agroforestry zone (18.80%), the sustainable production forest zone (42.22%), the buffer zone (11%), and the biological conservation zone (28%). These results constitute a scientific basis for testing ecological indicators of the sustainable management of community forests in Togo. [ABSTRACT FROM AUTHOR]

For more than three decades, major efforts in sampling and analyzing tree diversity in South America have focused almost exclusively on trees with stems of at least 10 and 2.5 cm diameter, showing highest species diversity in the wetter western and northern Amazon forests. By contrast, little attention has been paid to patterns and drivers of diversity in the largest canopy and emergent trees, which is surprising given these have dominant ecological functions. Here, we use a machine learning approach to quantify the importance of environmental factors and apply it to generate spatial predictions of the species diversity of all trees (dbh ≥ 10 cm) and for very large trees (dbh ≥ 70 cm) using data from 243 forest plots (108,450 trees and 2832 species) distributed across different forest types and biogeographic regions of the Brazilian Amazon. The diversity of large trees and of all trees was significantly associated with three environmental factors, but in contrasting ways across regions and forest types. Environmental variables associated with disturbances, for example, the lightning flash rate and wind speed, as well as the fraction of photosynthetically active radiation, tend to govern the diversity of large trees. Upland rainforests in the Guiana Shield and Roraima regions had a high diversity of large trees. By contrast, variables associated with resources tend to govern tree diversity in general. Places such as the province of Imeri and the northern portion of the province of Madeira stand out for their high diversity of species in general. Climatic and topographic stability and functional adaptation mechanisms promote ideal conditions for species diversity. Finally, we mapped general patterns of tree species diversity in the Brazilian Amazon, which differ substantially depending on size class. [ABSTRACT FROM AUTHOR]

Dendrometer bands have been proposed as an accurate method for measuring tree growth. However, the constrained observation window and the material used in them hamper long-term tree growth monitoring. This study devised a dendrometer band made from stainless steel and primarily extended the extension length of the band spring to yield ample space to monitor diameter increments long-term. A total of more than 500 individual trees, including both coniferous and broadleaf trees, were examined. We compared the dendrometer band's long-term performance with diameter tape for 5- and 10-year measurements. The results showed that the measurements of the two methods were highly correlated (R > 0.89) in both measuring periods. Differences between the two measurements for individual trees were typically less than 5 mm, and the mean differences at a stand level were less than 2 mm. These consistent observations suggested that the dendrometer band measurements were reliable for long-term measurement. Using the dendrometer bands, we further demonstrated the annual tree growths of diameter at breast height (DBH) and basal area (BA) for ten years of measurements. The size-dependent relationships between DBH/BA growth and initial DBH were also presented. Owing to their simple installation, low cost, and reliable measurement, these dendrometer bands would be helpful in forestry and forest ecology research. [ABSTRACT FROM AUTHOR]

In the interview transcript below, Emeritus Professor Dr. Dieter Mueller-Dombois talks about his prolific career in the Department of Botany (now a program within the Life Sciences Department) at the University of Hawai'i at Mānoa in Honolulu, Hawai'i. Dr. Mueller-Dombois describes major projects and publications across his time in Canada, Sri Lanka, and Hawai'i, his experiences as a soldier in WWII, and his deep appreciation for the Hawaiian flora and for the Botany Department that inspired and nourished his far-reaching and deeply impactful contributions to the field of forest ecology. Included is a discussion of his work on 'ōhi'a (Metrosideros polymorpha) stand-level dieback in the 1980s in connection to the more recent episode of rapid 'ōhi'a death. Although the Botany Department is now merged with other departments, Dr. Mueller-Dombois hoped for it to remain with a distinct identity. In his view, it was an amiable department that made critical contributions to understanding and protecting the tremendous natural and cultural heritage of Hawai'i. [ABSTRACT FROM AUTHOR]

Attention is drawn to scientifically based theoretical and practical approaches to the implementation of the concept of sustainable forest management and, accordingly, to ensuring the principles of sustainable forestry aimed at the adequate protection, use, and regeneration of forest resources in Ukraine during Russia's war against Ukraine. The main socio-economic and ecological aspects that influence the implementation of the concept of sustainable forest management at the national and regional level in the current conditions of Russia's military aggression against Ukraine are considered. The changes in the forest sector in the conditions of war are reflected, which must be considered from the point of view of understanding the principles of sustainable development, sustainable forestry, and the concept of sustainable forest management. It is proposed to develop and implement a theoretical, methodological, and practical approach to the implementation of the concept of sustainable forest management in Ukraine which would take into account the regional differences regarding the organisation and development of forestry in Ukraine. [ABSTRACT FROM AUTHOR]

Forest roads are an important part of forest management, both in terms of cost and impact on surrounding ecosystems. Existing tools to simulate the construction of forest roads have been designed for tactical or operational planning purposes, for relatively small areas (<10 000 ha) and small-scale topographic information. Hence, no forest road simulation tool properly exists to assist forest landscape ecology and management research. Here, we present the Forest Roads Simulation (FRS) extension for the LANDIS-II model—a spatially explicit landscape simulation model of forest succession and disturbances. The FRS extension simulates forest road networks via a least-cost path algorithm accounting for landscape structure, decision inputs, and forest road types. We demonstrate the accuracy with which the FRS extension reproduces several key characteristics of existing road networks in two managed regions in Quebec, Canada: road density, road position, and fragmentation of the landscape. The FRS extension is easy to parameterize, proposing many options for researchers to simulate forest road networks at a strategic level in managed landscapes. It can tackle new research questions investigating the effects of forest roads within management strategies, such as the cost of road construction and habitat fragmentation, across large management units and long planning horizons. [ABSTRACT FROM AUTHOR]

Summary: Seminal scientific papers positing that mycorrhizal fungal networks can distribute carbon (C) among plants have stimulated a popular narrative that overstory trees, or 'mother trees', support the growth of seedlings in this way. This narrative has far‐reaching implications for our understanding of forest ecology and has been controversial in the scientific community. We review the current understanding of ectomycorrhizal C metabolism and observations on forest regeneration that make the mother tree narrative debatable. We then re‐examine data and conclusions from publications that underlie the mother tree hypothesis. Isotopic labeling methods are uniquely suited for studying element fluxes through ecosystems, but the complexity of mycorrhizal symbiosis, low detection limits, and small carbon discrimination in biological processes can cause researchers to make important inferences based on miniscule shifts in isotopic abundance, which can be misleading. We conclude that evidence of a significant net C transfer via common mycorrhizal networks that benefits the recipients is still lacking. Furthermore, a role for fungi as a C pipeline between trees is difficult to reconcile with any adaptive advantages for the fungi. Finally, the hypothesis is neither supported by boreal forest regeneration patterns nor consistent with the understanding of physiological mechanisms controlling mycorrhizal symbiosis. [ABSTRACT FROM AUTHOR]

Istanbul is an important city whose population has been increasing continuously from the past to the present. This increase has led to the emergence of new residential areas, and therefore, to the constant expansion of the boundaries of the settlement. Today's core of the city of Istanbul is the historical region called the city wall. Until the 1950s, the settlement was mainly concentrated in this area and its immediate vicinity. There were more industrial facilities outside this region. In the time leading up to the construction of the first bridge into the Bosphorus, the population was generally gathered between the coastal and the D100 highway. After the construction of the first bridge in 1973, the boundaries of the settlement began to shift to the north of the D100 highway. When the second bridge to the Bosphorus (Fatih Sultan Mehmet) was built in 1988, the boundaries of the settlement expanded further north. Since this year, the bridge has been built together with the II. The area between the Ring Road (TEM) and the D-100 highway has been the scene of a busy settlement. During these years (1970-1990), which constituted the highest period of migration from the countryside to the city, the population of Istanbul increased more than twice. In the time leading up to the construction of the third Bosphorus bridge (Yavuz Sultan Selim), the settlement experienced a rapid expansion to the north of the TEM road. Istanbul, which has experienced the same periodic process twice in the past, is experiencing it again with the construction of the third bridge. This time, the city's borders have entered a continuous expansion circuit towards the Black Sea. During these processes, the city's green areas have rapidly declined and the urban areas have continuously increased. In order to detect this change in periods, periodic satellite images were classified through GIS and Remote Sensing programs and the evolution of green areas were revealed. The findings revealed that the green areas have been decreasing continuously since 1975 and this is closely related to the bridges and connection roads. It has been revealed that the process that the city has experienced in the past will live again with the newly built bridge, and this time the process will be faster. In this new period, the Black Sea will form the new border of the city. This shows us that the city is pushing the boundaries of expansion and that the new green spaces will lose their function. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the development of Aspidosperma discolor A. DC. seedlings two different origins subjected to full sunlight or different shading levels in a forest nursery, in addition to identifying its effective ecological group. Closed and pre-mature greenish-yellow colored follicles were collected from 10 randomly selected mother trees in two natural populations of lowland Dense Ombrophilous Forest fragments, both in Pernambuco, Brazil. The seedlings of these seeds were developed under different shading levels. After the seedlings were developed, the following variables were evaluated: number of leaves, leaf area and dry biomass. The species showed favorable phenotypic plasticity for its acclimatization in environments with moderate to intermediate shading conditions, a characteristic evidenced in small gaps; as well as for dense conditions, typical of vegetation with a closed canopy. A shading level of 50% stood out to produce A. discolor seedlings in a forest nursery, as it favors greater growth and biomass of the shoot and root parts. In addition, it presents peculiar ecological behavior of facultative sciophilous taxa or intermediate succession stages. [ABSTRACT FROM AUTHOR]

Close-to-nature forestry is a promising approach for satisfying the criteria of sustainable forestry. This draws attention to natural forests as a comprehensive source of information for forest management. The purpose of this study is to investigating the structure of mosaics of developmental phases and to determine their area based on structural parameters as identification keys in oriental beech virgin forests, which are rarely studied. To this aim, one 10 hectare area in parcel 513, series 5, Eshkateh-Chal forestry project was selected and the location, species type, stem number, gap area, diameter at breast height and tree height of all trees taller than 7.5 centimeters were measured. We also measured standing and lying dead trees (snags and logs). Based on our results, five developmental phases of innovation, regeneration, optimal, aging and degradation were identified in the study area. The results showed that the highest and lowest number of trees were related to the innovation phase (393 trees perhectare) and the aging phase (148 ha-1) respectively. In the study area the phases of innovation, regeneration, optimal, aging, and degradation covered 30.5%, 18.8%, 14.0%, 10.8% and 25.9%, respectively. The highest number of dead trees (41 ha-1) was observed in the degradation phase. Except for the optimal phase, where the abundance of snags was higher, in all developmental phases the abundance of logs was higher than that of snags. 2.5% of the study area were covered with canopy gaps and 7.7% with expanded gaps. Our results on tree dimensions and deadwood presence suggest that the studied intact stands were old growth and their structure deviated considerably from managed forests. Silvicultural interventions can be designed to emulate the developmental phases of virgin forests. [ABSTRACT FROM AUTHOR]

Natural disturbances change forest habitat quality for many species. As the extent and intensity of natural disturbances may increase under climate change, it is unclear how this increase can affect habitat quality on different spatial scales. To support management tools and policies aiming to prevent habitat loss, we studied how habitat quality develops in the long run depending on the disturbance severity using a space‐for‐time substitution approach.We explored the effects of time since disturbance (0–250 years) and disturbance severity (20%–100% canopy removal) on structure‐based habitat quality indicators in European primary Norway spruce Picea abies forests using 1000 m2 circular plots in hierarchical design (a total of 407 plots in 35 stands). Disturbance history was reconstructed from tree cores. Habitat quality indicators were modelled as a function of the severity of the most severe disturbance and the time since this disturbance. We hypothesised that high within‐stand habitat heterogeneity is formed by different successional stages after disturbances of various intensities.The results showed a U‐shaped response of habitat quality to post‐disturbance habitat succession on the plot scale. The decline deepened with disturbance severity. The U‐shape response occurred in: large tree occurrence, amount of standing and lying deadwood, diversity of understory and understory openness. The spatial diversity in disturbance parameters increased spatial diversity of habitat quality on a stand level as expected. This high within‐stand habitat heterogeneity also decreased with increasing age of the most recent disturbance. This suggests that the absence of young successional stages results in the absence of some important elements for biodiversity, for example sun‐exposed snags.Synthesis and applications. Our results demonstrate that currently intensifying natural disturbance regime can consequently result in a lower habitat heterogeneity. In managed spruce forests after natural disturbances, we recommend at least the partial retention of biological legacies to preserve habitat heterogeneity and to avoid uniform and dense plantations resulting in a greater homogenisation. To emulate the natural disturbances pattern, spruce forests should be managed with a wide range of harvested patches of the size limited by a local natural disturbance regime creating spatial heterogeneity. [ABSTRACT FROM AUTHOR]

The article discusses the 2022 North American Forest Ecology Workshop (NAFEW) with the theme "Turning Ecological Answers into Forest Management Actions," highlighting the importance of forest science in sustainable forest management practices and how the research community contributes to evidence-based policies.

Bryophytes play important role in forest ecosystem functioning and their distribution and diversity are driven by numerous environmental factors. The aim of the present study was to bring new insights in deeper understanding of terrestrial bryophytes diversity in temperate forests, as well as to determine the environmental factors which have predominant influence on ground-floor bryophytes. The survey was conducted in Fruška Gora Mountain (Serbia) across seven forest sites where ground-bryophytes were sampled. Soil moisture, temperature, and pH were measured as soil characteristics, while herbaceous cover, litter cover, stream distance, number of trees and shrubs were used as characteristics of stand structure. Species richness, Shannon diversity index, and evenness index were used as diversity measures. Generalised linear model and canonical correspondence analysis (CCA) were used to test the influence of environmental variables on bryophyte diversity. Litter cover was the most important explanatory variable, followed by soil moisture, stream distance and tree number, respectively. Overall, the stand structure was found to have a greater impact on ground-floor bryophyte diversity compared to soil characteristics. Identification of the most significant ecological factors affecting the diversity and distribution of bryophytes in forest ecosystems is of great importance in forest ecology with the aim of defining adequate management methods to preserve the biodiversity of forests, with particular emphasis on endangered and rare bryophyte species. [ABSTRACT FROM AUTHOR]

The phytopathogen Phytophthora parasitica, from the Oomycetes class, known to be the tobacco black shank agent, can induce devastating diseases in various crop, plant and forest ecosystems. The genus Phytophthora has been studied at the cellular level, suggesting that different developmental steps are induced by the expression of some specific genes. However, these studies have only been carried out on certain species, such as Phytophthora infestans and Phytophthora cactorum. As for Phytophthora parasitica, which can be considered as one of the top ten oomycete pathogens due to the economic impact and effect it has on food security, even less functional analyses and transcriptomics data are available. To date, little is known about the protein expression of Phytophthora parasitica, information that is essential for achieving a better understanding of this species. In this study, we aimed to gain insight into the proteomics of the mycelium of the Phytophthora parasitica strain INRA 310 by addressing the following questions: (i) how many predicted proteins can be detected on the mycelium of P. parasitica INRA 310, and (ii) what proteins can be detected? The proteomics experiments were performed on the mycelium of the strain Phytophthora parasitica INRA310, using the nanoliquid chromatography-MS/MS technique. A total of 219 proteins were identified, including ten unknown proteins and 209 proteins involved in lipid, carbohydrate, nucleotide, energy production and other metabolic pathways. This proteomics study is, to our knowledge, the first to be performed on the mycelium of Phytophthora parasitica INRA 310. It gives a brief first insight into its in vitro-expressed proteins. This work may be the first step before further, more comprehensive studies are undertaken with the aim of better understanding the biology of this species and its pathogenicity. [ABSTRACT FROM AUTHOR]

Forest wildfire impact is widely believed to increase with time since disturbance, presenting a dilemma for the persistence of fire‐sensitive species. However, in south‐western Australia, disturbance has been shown to increase wildfire likelihood for some decades before it again declines. It has been proposed that this trend occurs through 'ecological controls' on wildfire such as the self‐thinning of fire‐stimulated understorey growth.Here, we analyse six proposed ecological controls using a surveyed chronosequence of a Eucalyptus jacksonii forest community. We quantify plant growth (growth and self‐pruning) and succession (changing plant traits, self‐thinning), along with consequent changes in surface and suspended litter. We then use a biophysical, mechanistic model to predict the dynamics of flame height and canopy scorch/consumption, along with suppression difficulty during wildfire conditions. To identify the importance of each potential ecological control, we separately manipulate them to grow hypothetical forests from 1 to 100 years; each with one of the controls removed. We then model flame height in each to compare with the original forest that had all controls present.Fire initially promoted dense understorey regeneration, but ecological controls transferred this biomass from fuel (likely to ignite) to overstorey shelter (unlikely to ignite, creating a less flammable microclimate). The effect of these changes was to alter modelled fire behaviour, such that flame dimensions in mature forest were half those in regrowth, canopy damage greatly reduced, and fire suppression opportunities maximised. The primary controls were self‐thinning and self‐pruning.Forest growth and succession explains observed trends in flammability dynamics in south‐western Australian forests, and the persistence of fire‐sensitive species over time. Approaches that cooperate with, rather than disrupt, these processes therefore provide a pathway to mitigate current climatic effects on fire. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

While educationally beneficial, place-based learning can be challenging to implement in an applied forest ecology course that draws a diversity of students with limited forest experience. I describe a semester-long sequence of labs designed to instill place-based learning principles. The semester begins with an observational lab to develop an initial personal forest relationship, with future learning reinforcing and cultivating this bond. Forest-specific labs cover key applied ecology concepts while continuing to expand on students' place knowledge with an overarching forest management plan to provide real-world application and expression of understanding. [ABSTRACT FROM AUTHOR]

As more intense and more frequent natural hazards result in human and economic losses, fires, and more specifically wildfires in wildland-urban interface/intermix (WUI) are among the natural hazards that present a substantial, albeit preventable risk of ecological and human disasters. Although wildfires are a largely researched area of study in forest ecology and natural sciences across the globe, with social science and interdisciplinary studies of risk catching up, WUI areas across North, Central and South America that show an increase in wildfire risk are currently under-researched, with the exception of Canada and the US. In this paper, we focus on wildfires in the Mexican WUI, which have historically been seen as a threat to forest ecosystems rather than as a threat to populations. This paper sets out to understand to what extent the under-researched WUI wildfires present risk to WUI populations in Mexico using a mixed methods approach. We perform a Mexico WUI fire diagnostics by drawing on the official datasets, documentation regarding preparedness, mitigation and response to wildfires affecting urban populations, and where information is lacking, we review media news sources regarding the outcomes for populations in the past WUI wildfires in Mexico. We conclude that a substantial proportion of WUI territory in Mexico is at risk from wildfires, potentially causing harm to populations in the future. Thus, more should be done to prepare these populations to respond, and mechanisms for fire risk mitigation, wildfire adaptation and recovery from fire effects should be developed. [ABSTRACT FROM AUTHOR]

Most of the human population lives in cities, and understanding their impact on freshwater environments is essential. Streams in cities face many environmental challenges that have been described in the concept of Urban Stream Syndrome. This concept illustrates urban streams' biological, hydrological, chemical, and physical stressors. In tropical streams, these stressors impact shrimp, fish, insects, and other macroinvertebrates that inhabit the freshwater ecosystems. Freshwater shrimp are vulnerable to urban activities, physical, chemical, and ecological impacts. For this reason, these organisms have been used as biological indicators of stream health in the tropics. The shredder shrimp Xiphocaris elongata plays a fundamental role in the organic matter process and decomposition. The objectives of this study were to characterize the population of X. elongata and to identify differences in the abundance of X. elongata between urban and forest streams. Our results showed that highly urbanized areas have a significantly lower abundance of the shredder shrimp X. elongata than medium or low urban reach in the urban and forested watersheds. This study also showed that physicochemical and geomorphological variables are important environmental factors that influence the abundance of X. elongata in Puerto Rican streams. [ABSTRACT FROM AUTHOR]

In a time of rapid global change, the question of what determines patterns in species abundance distribution remains a priority for understanding the complex dynamics of ecosystems. The constrained maximization of information entropy provides a framework for the understanding of such complex systems dynamics by a quantitative analysis of important constraints via predictions using least biased probability distributions. We apply it to over two thousand hectares of Amazonian tree inventories across seven forest types and thirteen functional traits, representing major global axes of plant strategies. Results show that constraints formed by regional relative abundances of genera explain eight times more of local relative abundances than constraints based on directional selection for specific functional traits, although the latter does show clear signals of environmental dependency. These results provide a quantitative insight by inference from large-scale data using cross-disciplinary methods, furthering our understanding of ecological dynamics. [ABSTRACT FROM AUTHOR]

Tropical forests harbour the highest levels of terrestrial biodiversity and represent some of the most complex ecosystems on Earth, with a significant portion of this diversity above ground. Although the vertical dimension is a central aspect of the ecology of forest communities, there is little consensus as to prominence, evenness, and consistency of community‐level stratification from ground to canopy. Here, we gather the results of 62 studies across the tropics to synthesise and assess broad patterns of vertical stratification of abundance and richness in vertebrates, the best studied taxonomic group for which results have not been collated previously. Our review of the literature yielded sufficient data for bats, small mammals, birds and amphibians. We show that variation in the stratification of abundance and richness exists within and among all taxa considered. Bat richness stratification was variable among studies, although bat abundance was weighted towards the canopy. Both bird richness and abundance stratification were variable, with no overriding pattern. On the contrary, both amphibians and small mammals showed consistent patterns of decline in abundance and richness towards the canopy. We descriptively characterise research trends in drivers of stratification cited or investigated within studies, finding local habitat structure and food distribution/foraging to be the most commonly attributed drivers. Further, we analyse the influence of macroecological variables on stratification patterns, finding latitude and elevation to be key predictors of bird stratification in particular. Prominent differences among taxa are likely due to taxon‐specific interactions with local drivers such as vertical habitat structure, food distribution, and vertical climate gradients, which may vary considerably across macroecological gradients such as elevation and biogeographic realm. Our study showcases the complexity with which animal communities organise within tropical forest ecosystems, while demonstrating the canopy as a critical niche space for tropical vertebrates, thereby highlighting the inherent vulnerability of tropical vertebrate communities to forest loss and canopy disturbance. We recognise that analyses were constrained due to variation in study designs and methods which produced a variety of abundance and richness metrics recorded across different arrangements of vertical strata. We therefore suggest the application of best practices for data reporting and highlight the significant effort required to fill research gaps in terms of under‐sampled regions, taxa, and environments. [ABSTRACT FROM AUTHOR]