Large-sized Trees Research Articles

Large-sized trees regulating the structural diversity-productivity relationships through shaping different productive processes in a tropical forest.

Forest structural diversity, a measurement indicating the spatial and size distribution of individual trees, is critical for forest productivity, which stems from the combination of different ecological processes, such as tree mortality, recruitment and growth. Here, we evaluated the relationship between structural diversity and productivity caused by different ecological processes, and tested the roles of different-sized trees in influencing this relationship in a Forest Global Earth Observatory (ForestGEO) rainforest site on the Barro Colorado Island between 2000 and 2015. Generally, we found a negative relationship between structural diversity and forest productivity. Specifically, tree mortality-induced productivity loss increased, while tree recruitment-induced productivity gain decreased, with structural diversity. In addition, the structural diversity-productivity relationship varied with tree size, which was negative for small trees but positive for large trees. Furthermore, we revealed the important role of large-sized trees, which significantly promoted structural diversity but decreased productivity through increasing biomass loss. By disentangling the components of productivity, our results provide insights on the mechanism of the relationship between structural diversity and productivity, and highlight the role of large trees in shaping this relationship.

Large-sized trees and altitude drive aboveground carbon stock in Brazilian Atlantic Cloud Forests: An approach based on carbon hyperdominant taxa.

Research about patterns of aboveground carbon stock (AGC) across different tropical forest types is central to climate change mitigation efforts. However, the aboveground carbon stock (AGC) quantification for Brazilian cloud forest ecosystems along the altitudinal gradient is still scarce. We aimed to evaluate the effects of abiotic and biotic on AGC and the AGC distribution between species and families of tree communities along an altitudinal Brazilian Atlantic cloud forest gradient of the Mantiqueira Mountain Range, Southeastern Brazil. We analyzed the relationships between AGC and biotic (taxonomic and functional diversity based on structural attributes) and abiotic factors (altitude and soil properties) across seventy plots (10×20m) distributed in seven cloud forest sites at different elevations (from 1.100 to 2.330ma.s.l.) using linear mixed models and machine learning approaches. We found significant variations in AGC stock along the altitudinal gradient, which was explained mainly by altitude and large-sized trees. We observed that approximately 5% of the total sampled individuals were responsible for >50% of the AGC stock of the tree community in the different sites. This result demonstrates how carbon-dominant tree species' have a higher relative contribution to the AGC at community level than species richness and abundance. The Myrtaceae was the most species-rich and carbon-dominant family, which holds four of the total hyperdominant species in the study region. This study reveals new and important ecological patterns of AGC stock in Southeastern Brazil's cloud forest tree communities, where large-sized trees and altitude are the main biotic and abiotic factors, respectively. These insights enhance our understanding of AGC stock in these unique forest ecosystems and emphasize the need for targeted conservation strategies that protect dominant species and their habitats.

Exploring the inhibitory activity and mechanism on lipid production in 3T3-L1 cells by hot water extract derived from Acacia confusa flowers.

Acacia confusa Merr. (Fabaceae) (A. confusa) is a native tree species of Taiwan, commonly found in the low-altitude mountains and hilly areas of the Hengchun Peninsula. This evergreen, perennial, and large-sized tree was the focus of a study that employed various chromatographic and spectroscopic methods to analyze the hot water extract of its flowers. The analysis revealed that the major components of the extract were myricitrin, quercitrin, europetin-3-O-rhamnoside, and chalconaringenin-2'-xyloside, with respective concentrations of approximately 0.22, 0.02, 0.26, and 0.10mg/g of the flowers. Subsequent cell assays were conducted to assess the inhibitory effect of the extract on lipid synthesis in fat cells. Oil Red O staining results indicated that the extract significantly suppressed fatty acid accumulation in 3T3-L1 cells, with the most pronounced effect observed at a concentration of 180μg/ml. Furthermore, the hot water extract of A. confusa flowers was found to increase the phosphorylation of AMP-activated protein kinase (AMPK), decrease the phosphorylation of cAMP response element-binding protein (CREB), and reduce the expression of glucocorticoid receptor (GR) protein. This, in turn, inhibited the expression of downstream transcription factors such as CCAT/ehancer binding proteins α (C/EBPα), CCAT/ehancer binding proteins β (C/EBPβ), CCAT/ehancer binding proteins δ (C/EBPδ), peroxisome proliferation-actived receptor γ (PPARγ), and sterol regulatory element binding proteins-1 (SREBP-1). Consequently, the expression of lipid synthesis-related proteins acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and fatty acid translocase (CD36) was reduced, ultimately inhibiting lipid generation. Therefore, the hot water extract of A. confusa flowers shows potential for development as a weight-loss tea.

Determinants of tree population temporal stability in a temperate mixed forest over a gradient of nitrogen addition

Nitrogen (N) deposition is a significant threat to the functioning of forests and negatively impacts the delivery of forest goods and services. Contemporary management approaches seek to adapt forests to such N-deposition stressors, but to date how plant populations in natural forests respond to N deposition and what factors determine the contrasting responses among populations are still unclear. Here, we investigated the impact of N-addition (control: 0 kg ha−1 yr−1; low: 25 kg ha−1 yr−1; medium: 50 kg ha−1 yr−1; high: 75 kg ha−1 ha yr−1) on tree population temporal stability and how initial tree size, mycorrhizal type, and leaf N content (LNC; as a surrogate for functional trait composition) mediate tree population responses to N-addition in a Korean pine and mixed broadleaved dominated temperate forest in northern China. We quantified tree species population temporal stability as the ratio of mean to standard deviation of the year-by-year stem increments recorded in individual trees from 2015 to 2022 experimental period. The results showed different temporal stabilities of tree species among four N-addition levels, with the highest population stability observed within the high N-addition plots. Furthermore, initial tree size had significantly (p < 0.001) positive effects on population temporal stability. The effect of LNC and initial tree size were also contingent on the level of N applied. Specifically, increase in tree population LNC reduced population temporal stability in all plots where N was added. Our results imply that retention of large-sized trees and species with resource-conservative strategies (e.g., low LNC) could enhance forest stability under N deposition.

Demography, Structure, and Composition of a Low-Disturbance Forest in Luzon, Philippines

Tropical forests continue to face deforestation in countries such as the Philippines. To look at the long-term behavior of forests in response to intrinsic and extrinsic factors, continual monitoring of forest dynamics is needed. To do this, we established a 2-ha permanent tropical forest plot in a low-disturbance area in Maluyon, Philippines. We addressed three main questions: 1) How does the plot change through time? 2) How do different species in the plot change through time? 3) Would the responses differ by tree size? We measured, mapped, and identified all trees &gt;1 cm in diameter in 2011. In 2015, we re-measured surviving trees and measured, mapped, and identified recruits. A total of 177 tree species were found in the plot. The forest exhibited a mean growth rate of 0.054 cm/year, mortality rate of 0.011%/year, and recruitment rate of 0.019%/year. Overall growth and mortality rates were lower in Maluyon than in other plots, possibly due to the forest’s high tree density and low disturbance. Species-specific rates revealed the presence of both the growth-survival and the stature-recruitment trade-offs. Size class analysis showed higher growth rates in large-sized than in small-sized trees. In contrast, small-sized trees exhibited a higher mortality rate compared to large-sized trees, likely due to density dependence. Key findings of the study may be utilized to increase the success rate of restoration efforts in this watershed. Using a mix of fast-growing, generalist species with high survival rates (e.g., Allophyllus cobbe and Anisoptera thurifera) is highly recommended.

Understanding the influence of tree size distribution on the CTL harvesting productivity of two different size harvesting machines

Tree size is one of the major factors that determines harvester productivity and is heavily influenced by forest managerial activities. Stand silvicultural management can lead to managing tree size, the distribution of tree size, and tree height amongst others. Understanding the effect of tree size distribution on harvesting productivity is central for optimizing management of operations. To investigate the effects of tree size distribution on harvester productivity, productivity functions for a medium and larger-sized harvester were applied to harvester derived tree size distributions from 35 clearfelled pine stands. These functions were applied to a normal distribution of trees covering the same tree size ranges. Productivity differences were analysed on a stand-by-stand basis. Results showed that for the larger harvester, productivity rates remained constant (67.1 vs. 67.6 m3·PMH− 1) indicating relatively little sensitivity to variations in tree size distributions. Although the standard deviation (SD) halved from 11.6 to 5.6 in the case of the uniform tree distribution. The smaller harvester productivity decreased by 15% from 47.3 to 40.1 m3·PMH− 1 and the coefficient of variation (CV) by 6% in the same transition to a uniform distribution. Further investigation was done on more skewed tree size distributions, a family of nine Weibull distributions was generated, representing combinations of three mean DBH classes (25 cm, 30 cm, and 35 cm) and three levels of CV (15%, 20%, 25%), for each DBH class. Results clearly indicate that different distribution shapes have different effects on different machine sizes, and that a low CV correlates to a higher productivity in larger tree sizes. A more uniform tree size distribution also provides more predictable results (lower CV), which would promote machine scheduling and result in fewer discrepancies on production rates.

IRGWP: An international network of key players for a better understanding and industrial developments in wood protection and preservation

IRGWP: An international network of key players for a better understanding and industrial developments in wood protection and preservation

Species identity and tree size drive residual tree mortality in island remnants in burned and harvested boreal forests

Ecosystem-based Forest Management (EBM) is a global paradigm with different forms of implementation. In North America, a key aspect of EBM is the emulation of natural disturbances such as wildfire, with retention forestry representing one dominant approach to implementation. Retention is intended to reduce the contrast between ecological legacies present in fire-disturbed and harvested stands by leaving unharvested patches or “island remnants”. These island remnants provide refugia for forest species, accelerate forest regeneration, and supply coarse woody material over time. However, the objectives of leaving retention patches could be compromised by excessive post-disturbance tree mortality, which may erode canopy cover in patches. Comparisons of residual tree mortality in dispersed retention or partial harvest to reference forests and clearcuts exist, but rarely have comparisons to island remnants created by wildfires been made, despite this being the model for these patches. Here, we sampled island remnants in burned and harvested areas in aspen-dominated mixedwood forests in Alberta, Canada, a decade after disturbance. We sought to: (i) test for differences in post-disturbance tree mortality in island remnants (fire versus harvest) (ii) determine if forest island edges experience higher tree mortality than plots located in the interior, and (iii) examine whether tree species, tree size, and stand density influence tree mortality patterns. Post-disturbance tree mortality was quantified using visual field surveys. Additionally, we dated a sub-sample of trees to quantify temporal patterns of tree mortality. We found that harvest-created island remnants did not exhibit higher residual tree mortality than similar-sized fire island remnants. Edge effects also had no impact on tree mortality, irrespective of disturbance type. Aspen (Populus tremuloides) had higher mortality than spruce (Picea glauca), and small-sized trees had a higher probability of mortality than large-sized trees. While previous studies have reported elevated rates of mortality for retention trees in relation to reference stands, we found similar mortality rates for trees in fire and harvest island remnants. These results support the continued implementation of retention forestry using island remnants within the scope of EBM in Alberta to promote forest recovery and resilience following disturbances.

Size-focused conservation may fail to protect the world’s oldest trees

Old trees are irreplaceable natural resources that provide multifaceted benefits to humans. Current conservation strategies focus primarily on large-sized trees that were often considered old. However, some studies have demonstrated that small trees can be more than thousands of years old, suggesting that conventional size-focused perceptions may hamper the efficiency of current conservation strategies for old trees. Here, we compiled paired age and diameter data using tree-ring records sampled from 121,918 trees from 269 species around the world to detect whether tree size is a strong predictor of age for old trees and whether the spatial distribution of small old trees differs from that of large old trees. We found that tree size was a weak predictor of age for old trees, and diameter explained only 10% of the total age variance of old trees. Unlike large-sized trees that are mainly in warm, wet environments and protected, small old trees are predominantly in cold, dry environments and mostly unprotected, indicating that size-focused conservation failed to protect some of the oldest trees. To conserve old trees, comprehensive old-tree recognition systems are needed that consider not only tree size but also age and external characteristics. Protected areas designed for small old trees are urgently needed.

Enhanced awareness of height-diameter allometry in response to climate, soil, and competition in secondary forests

The allometry between tree height (H) and diameter (DBH) is a central part of accurate carbon estimation and forest ecological evaluation. However, our awareness of the H-DBH allometry response to stressors is incomplete. For instance, pairwise and higher-order interactions of climate, soil, intraspecific competition, and interspecific competition were ignored, which may have led to important ecological insights not explored in H-DBH allometry. Besides, although secondary forests are cost-friendly mitigation tools requiring rational management, research on H-DBH allometry and management of secondary forests is far from adequate. Therefore, we pioneered the consideration of pairwise and higher-order interactions of competition, climate, and soil to enhance awareness of the relationship between stressors and H-DBH allometry. Moreover, H-DBH simulations under different competitive combinations were provided based on the actual local environmental levels, with the aim of providing targeted recommendations for secondary forests. The results showed that MAT (mean annual temperature), CF (coarse fragments), intraspecific BAL (the basal area of trees larger than the subject tree), and interspecific BAL were dominant stressors. The pairwise, third-, and fourth-order interactions significantly affected and improved the H-DBH model. The interactions affected H more than independent effects at times, and higher-order interactions produced comparable contributions to pairwise interactions. The independent and interactive effects of stressors on H were greatest in medium- and large-sized trees, which suggested sampling medium- and large-sized trees could reduce cost. Furthermore, the influencing directions of stressors on H were inconstant and depended on the gradients of other stressors due to the presence of interactions, which is generally consistent with the pressure gradient hypothesis and ecological laws. The simulation results indicated that the desired H-DBH allometry could be obtained by adjusting BALinter and BALintra according to the actual environmental level and management objectives of each stand. This study highlights the importance of considering interactions in credible H-DBH modeling, stressor impact analysis, and forest management policy development. Given the likelihood of ongoing climate change in the future, this study will assist in promoting sustainable management and informed decision-making in secondary forests.

Quantification of β-Sitosterol by Validated High Performance Thin Layer Chromatography (HPTLC) Densitometric Method in the Flowering Buds of &lt;i&gt;Mesua ferrea&lt;/i&gt; Linn

The medium-sized to large-sized tree Mesua ferrea Linn, commonly known as Nagakesara in India, can grow to be around 20 to 30 meters high and has incredibly durable wood. The fruiting season runs from January to March and April to October. The buds are globular, 2mm diagonally, and have scales in the axillary buds. It includes a significant amount of β-sitosterol amides, which are important from a biological perspective. In the current study, we used high-performance thin-layer chromatography (HPTLC) in association with densitometry to quantify these marker chemicals from Mesua ferrea Linn flowering buds. The technique was found to be accurate. For intra-day analysis, the relative standard deviation (RSD) values of β-sitosterol ranged from 1.16 to 1.60%, while for inter-day analyses, the values ranged from 0.68 to 1.77%. By performing a recovery study at three different levels for the standard chemicals, the accuracy of the approach was assessed, and average recoveries were determined to be 99.98%. It was observed that this TLC-densitometric approach was accurate, specific, particular, sensitive, and easy. For the simultaneous analysis of β-sitosterol from flowering buds of Mesua ferrea Linn, it can be employed in regular quality control.

Associations between tree characteristics and street crime: A case study in downtown Austin, TX

Urban trees play a critical role in livable and safe communities. Few studies have attempted to comprehensively examine a set of tree-related characteristics by using multiple measures through aerial imagery, street view imagery, and tree inventories in relation to street crime, especially in downtowns with busy street activities. This study examined to what extent tree attributes were associated with street crime at the street segment scale. This study also aimed to investigate the relationships of proxy measures for view-obstructive levels of trees with street crimes. Using downtown Austin, Texas as a study area, we analyzed micro-level crime incidents at a street segment level: 518 street segments in total within the downtown neighborhood. We used violent and property crime incidents that occurred on the streets between 2014 and 2019. A series of negative binomial regressions were employed to explore the associations of the characteristics of trees with street crime. After adjusting for socioeconomic and built environment variables, tree canopy coverage using aerial imageries and tree coverage using Google Street View images had inverse relationships with both violent and property street crime rates while size-weighted tree density using tree inventory was only associated with violent street crime rate. The tree coverage in the bottom-half of GSV images was inversely associated with violent street crime rate but not with property street crime rate. Additionally, we found that large-sized tree density (DBH≥30 cm and 40 cm) was inversely associated with both types of crime rates while small-sized tree density (DBH≤20 cm) was positively associated with property crime rate. While further research is needed to validate the view-obstructing effects of small-sized tree density and tree coverage in the bottom-half of GSV images, it is important to consider factors such as appropriate tree size and the potential for view-obstruction to maximize the benefits of urban trees in crime prevention.

Genome-Wide Characterization of PEBP Gene Family and Functional Analysis of TERMINAL FLOWER 1 Homologs in Macadamia integrifolia.

Edible Macadamia is one of the most important commercial nut trees cultivated in many countries, but its large tree size and long juvenile period pose barriers to commercial cultivation. The short domestication period and well-annotated genome of Macadamia integrifolia create great opportunities to breed commercial varieties with superior traits. Recent studies have shown that members of the phosphatidylethanolamine binding protein (PEBP) family play pivotal roles in regulating plant architecture and flowering time in various plants. In this study, thirteen members of MiPEBP were identified in the genome of M. integrifolia, and they are highly similarity in both motif and gene structure. A phylogenetic analysis divided the MiPEBP genes into three subfamilies: MFT-like, FT-like and TFL1-like. We subsequently identified two TERMINAL FLOWER 1 homologues from the TFL1-like subfamily, MiTFL1 and MiTFL1-like, both of which were highly expressed in stems and vegetative shoots, while MiTFL1-like was highly expressed in young leaves and early flowers. A subcellular location analysis revealed that both MiTFL1 and MiTFL1-like are localized in the cytoplasm and nucleus. The ectopic expression of MiTFL1 can rescue the early-flowering and terminal-flower phenotypes in the tfl1-14 mutant of Arabidopsis thaliana, and it indicates the conserved functions in controlling the inflorescence architecture and flowering time. This study will provide insight into the isolation of PEBP family members and the key targets for breeding M. integrifolia with improved traits in plant architecture and flowering time.

Temperature and Tree Size Explain the Mean Time to Fall of Dead Standing Trees across Large Scales

Dead standing trees (DSTs) generally decompose slower than wood in contact with the forest floor. In many regions, DSTs are being created at an increasing rate due to accelerating tree mortality caused by climate change. Therefore, factors determining DST fall are crucial for predicting dead wood turnover time but remain poorly constrained. Here, we conduct a re-analysis of published DST fall data to provide standardized information on the mean time to fall (MTF) of DSTs across biomes. We used multiple linear regression to test covariates considered important for DST fall, while controlling for mortality and management effects. DSTs of species killed by fire, insects and other causes stood on average for 48, 13 and 19 years, but MTF calculations were sensitive to how tree size was accounted for. Species’ MTFs differed significantly between DSTs killed by fire and other causes, between coniferous and broadleaved plant functional types (PFTs) and between managed and unmanaged sites, but management did not explain MTFs when we distinguished by mortality cause. Mean annual temperature (MAT) negatively affected MTFs, whereas larger tree size or being coniferous caused DSTs to stand longer. The most important explanatory variables were MAT and tree size, with minor contributions of management and plant functional type depending on mortality cause. Our results provide a basis to improve the representation of dead wood decomposition in carbon cycle assessments.

Decision tree post-pruning without loss of accuracy using the SAT-PP algorithm with an empirical evaluation on clinical data

A decision tree (DT) is one of the most popular and efficient techniques in data mining. Specifically, in the clinical domain, DTs have been widely used thanks to their relatively easy explainable nature, efficient computation time, and relatively accurate predictions. However, some DT constriction algorithms may produce a large tree size structure which is difficult to understand and often leads to misclassification of data in the testing process due to poor generalization. Post pruning (PP) algorithms have been introduced to reduce the size of the tree structure with a minor (or not at all) decrease in the accuracy of classification while trying to improve the model’s generalization. In this paper, we propose a new Boolean satisfiability (SAT) based PP algorithm called SAT-PP. Our algorithm reduces the tree size while preserving the accuracy of the unpruned tree. We implemented our algorithm on a medical-related classification data sets since in medical-related tasks we emphatically try to avoid decreasing the model’s performance when better training is not an option. Namely, in the case of medical-related tasks, one may prefer an unpruned DT model to a pruned DT model with worse performance. Indeed, we empirically obtained that the SAT-PP algorithm produce the same accuracy and F1 score as the DT model without PP while statistically significantly reducing the model size and as a result computation time (6.8%). In addition, we compared the proposed algorithm with other PP algorithms and found similar generalization capabilities.

Clustered tree size analysis of bio-productivity of Dinghushan National Nature Reserve in China

Over various terrain types, natural forests exhibit tree size and biomass variation. We started long- term research that consists of forest vegetation surveys in the Dinghushan National Nature Reserve to comprehensively investigate productivity based on the structure and species composition of China’s forest communities. We grouped the trees into three categories, i.e., as large or mature (DBH &amp;gt; 30 cm), medium-sized or growing (DBH 10–30 cm), and small-sized or regenerating seedlings (DBH &amp;lt; 10 cm). Forest data observations, i.e., species DBH, height, and biomass components (trunk, leaves, branches, above-ground dry weight, and below-ground dry weight) were recorded by use of standard protocols. All recorded observations were statistically analyzed by use of SPSS version 25. To comprehend the connections between the many elements of forest bio-productivity, linear regression analysis was utilized. Total above-ground biomass was 34.19 ± 5.75Kg/tree, but varied results were obtained when the forest was clustered based on DBH. Large-sized trees contributed an average of 2400.54 ± 510.4 kg/tree (93.24%), while medium-sized trees contributed 171.61 ± 25.06 kg/tree, and the least was regenerating seedlings which contributed 3.013 ± 0.07 kg/tree. There were positive linear relationships for all life forms between biomass and DHB, as well as DBH and height. The evergreen broadleaved shrubs were shorter in height (3.06 ± 0.99 m) than palm-leaved life forms (19.29 ± 5.39 m). Height influenced biomass accumulation and hence C gain, where life forms with tall stands had higher biomass. Generalized biomass estimation without clustering based on life forms or size class underestimates biomass components and hence lower C stocks for most forests worldwide. It’s also crucial to remember that trees with big DBH have tall, broad, well-lit crowns, which raise the primary productivity of forests and increase carbon storage. Besides natural disturbance (Typhoon) and climate change, it could be interesting to understand the relationship between soil resources such as nutrient and soil moisture content. These are factors that have direct impact on growth and biomass accumulation.

Elephant rewilding affects landscape openness and fauna habitat across a 92-year period.

Trophic rewilding aims to promote biodiverse self-sustaining ecosystems through the restoration of ecologically important taxa and the trophic interactions and cascades they propagate. How rewilding effects manifest across broad temporal scales will determine ecosystem states; however, our understanding of post-rewilding dynamics across longer time periods is limited. Here we show that the restoration of a megaherbivore, the African savannah elephant (Loxodonta africana), promotes landscape openness (i.e., various measures of vegetation composition/complexity) and modifies fauna habitat and that these effects continue to manifest up to 92 years after reintroduction. We conducted a space-for-time floristic survey and assessment of 17 habitat attributes (e.g., floristic diversity and cover, ground wood, tree hollows) across five comparable nature reserves in South African savannah, where elephants were reintroduced between 1927 and 2003, finding that elephant reintroduction time was positively correlated with landscape openness and some habitat attributes (e.g., large-sized tree hollows) but negatively associated with others (e.g., large-sized coarse woody debris). We then indexed elephant site occurrence between 2006 and 2018 using telemetry data and found positive associations between site occurrence and woody plant densities. Taken alongside the longer-term space-for-time survey, this suggests that elephants are attracted to dense vegetation in the short term and that this behavior increases landscape openness in the long term. Our results suggest that trophic rewilding with elephants helps promote a semi-open ecosystem structure of high importance for African biodiversity. More generally, our results suggest that megafauna restoration represents a promising tool to curb Earth's recent ecological losses and highlights the importance of considering long-term ecological responses when designing and managing rewilding projects.

Evaluation of In-Field Inoculation Methods for Characterization of Macadamia Germplasm to Husk Spot Incidence and Severity.

Husk spot, a fungal disease of macadamia pericarps (Pseudocercospora macadamiae), induces premature abscission in several major commercial cultivars. Breeding for resistance to husk spot is a priority of the Australian macadamia industry. Due to the large tree size of macadamia and high numbers of progeny in breeding populations, inoculating for resistance screening is laborious and time consuming. Previously utilized methods included direct applications of P. macadamiae suspensions and the hanging of bags of diseased husks above developing fruit in tree canopies. In this study, both methods were modified to allow for efficient application in large-scale breeding populations, and their efficacy was evaluated. Two quantities of diseased husk per bag, 'large' (75 g) and 'small' (30 g), and two concentrations of sprayed P. macadamiae suspensions, 'stock' (5 × 105 propagules/ml) and 'dilute' (2.5 × 105 propagules/ml), were tested across two fruiting seasons. Treatments were compared against a control (sterile water) in commercial cultivars A38 and A4. Husk spot incidence and severity produced by small bags were significantly affected by season. A significant season effect was less common for other treatments. All four treatments infected over 50% of target fruit in each season, but the highest husk spot incidence across both seasons (≥85%) was produced from large bags. Overall, the large bags were the most reliable method for infection of target fruit. Results also demonstrate the importance of considering the effect of season when selecting husk spot inoculation methods.

The effects of climate and land use change on the potential distribution and nesting habitat of the Lesser Adjutant in Nepal

Climate change and land use change pose a threat to the world's biodiversity and have significant impacts on the geographic distribution and composition of many bird species, but little is known about how they affect threatened large-sized waterbird species that rely on agricultural landscapes. To address this gap, we investigated how climate and land use changes influence the distribution and nesting habitats of the globally vulnerable Lesser Adjutant (Leptoptilos javanicus) in Nepal. Between 2012 and 2023, we collected distribution data from 24 districts and nesting site information from 18 districts. In a nation-wide breeding survey conducted in 2020, we documented a total of 581 fledglings from 346 nests in 109 colonies. The ensemble model predicted a current potential distribution of 15% (21,637 ​km2) and a potential nesting habitat of 13% (19,651 ​km2) for the species in Nepal. The highest predicted current suitable distribution and nesting habitat was in Madhesh Province, while none was predicted in Karnali Province. The majority of this predicted distributional and nesting habitat falls on agricultural landscapes (>70%). Our model showed a likely range expansion of up to 15% (21,573 ​km2) for the distribution and up to 12% (17,482 ​km2) for the nesting habitat under SSP5–8.5 scenarios for the 2070s. The range expansion is expected to occur mainly within the current distribution and breeding range (Tarai and some regions of Siwalk), particularly in Lumbini and Sudurpashchim provinces, and extend to the northern portions (Siwalik and Mid-hill regions) in other provinces. However, the current Protected Areas and Important Bird and Biodiversity Areas are inadequate for providing optimal habitats for the species. Although the model suggests range expansion, the use of such novel habitats is primarily contingent on the availability and protection of large-sized trees (particularly Bombax ceiba, observed in 65% of colonies) in agricultural regions where nesting occurs. Therefore, our research suggests that agricultural landscapes should be prioritized in management plans for the conservation of the Lesser Adjutant in Nepal.

Wood quality of residual branches of Hymenaea courbaril L. from logging in the Amazon rainforest

Abstract Branches remain in the forest environment as logging activity residue. Considering the large size of many Amazonian trees, their branches have considerable dimensions and can contribute to a sustainable wood alternative for various applications. Due to the formation of reaction wood in the branches, relevant macro and ultrastructural changes can occur in its characteristics in relation to the trunk wood. However, the woods of the branches are not technologically well known. Therefore, this work aimed to evaluate the wood quality of branches of Hymenaea courbaril L., comparing it with wood of trunks. The extractives and lignin contents, basic density, shrinkage, fiber biometry, microfibril angle and mechanical resistance to compression parallel to the fibers were analyzed. The branch wood had smaller fiber dimensions and a higher microfibril angle than the trunk wood. The basic density was similar between these materials. The linear and volumetric shrinkages were smaller in the branch wood than in the trunk, while the axial shrinkage was higher in the branch. The parallel compressive strength was also lower in the branch wood than in the trunk. The branch wood has properties suitable for products with higher added value such as furniture, decorative objects, floors and utensils in general.