Breast Height Research Articles

Growth and pulp production of eucalyptus trees affected by ceratocystis wilt

AbstractCeratocystis wilt is one of the most harmful diseases affecting eucalyptus crops and is associated with species of the complex Ceratocystis fimbriata sensu lato. This pathology leads to the obstruction of the vascular system in infected trees, resulting in symptoms such as branch wilting and death. The wood affected by the pathogen exhibits discolouration and changes in its chemical composition, which can impact the pulping process. Therefore, the objective of this work is to investigate the impact of ceratocystis wilt on growth and the pulping process when sampling whole diseased trees. For this, healthy and diseased eucalyptus trees at the harvest age of 7 years were cut down, and their dendrometric variables (diameter at breast height, height and volume) and disease severity (basal discolouration area and volume of discoloured tissue) were measured. All tree trunks, classified into different severity classes, were sampled individually, peeled, chipped and subjected to Kraft cooking (Kappa number 18 ± 0.5). Diseased trees, under the evaluated condition, exhibited an average volume of 2.5% with discolouration and a reduction in the volumetric growth of 18.1%. The wood from diseased trees showed no significant differences in the Kraft cooking variables when compared to healthy trees. This result suggests that ceratocystis wilt reduces the volumetric growth of affected trees; however, due to the low proportion of symptomatic wood observed, the utilization of wood from diseased trees does not influence pulping and can be used in the pulp production process.

Prompt Mapping Tree Positions with Handheld Mobile Scanners Based on SLAM Technology

In this study, we evaluated the performance of GeoSLAM ZEB Horizon and Stonex X120GO SLAM handheld mobile laser scanners (HMLS) to address two primary objectives. First, we aimed to assess and compare the accuracy of positioning achieved using HMLS instruments. Second, we sought to investigate the influencing factors and their impact on estimation accuracies. The factors influencing the accuracy of positioning in HMLS Simultaneous Localization and Mapping-aided solutions were defined, considering the scanner type, distance from the trajectory, forest structure, tree species, and Diameter at Breast Height. The same type of trajectory was tested in five different stand structures. The evaluation of GeoSLAM HMLS point clouds yielded an average positional RMSE of 17.91 cm, while the data extracted from the Stonex HMLS resulted in an average positional RMSE of 17.33 cm. These results underscore the significant potential of HMLS technology in addressing the critical need for precise positioning data in various applications, from forestry management to environmental monitoring, wildlife habitat assessment, and climate change studies. By harnessing the power of handheld mobile laser scanners, our research aims to enhance the accuracy and efficiency of geospatial data capture in challenging.

Gene Diversity In Seed Crop Of Taurus Cedar (Cedrus Libani A. Rich.) Over An Altitudinal Range

There could be many environmental and biological impacts such as edaphic, geographic, climatic, age, tree structure and population on morphological, physiological and genetically seed quality in plant species. Gene diversity is an important mirror of genetically seed quality. Gene diversity in seed crops were estimated based on female and male strobili productions of fifty trees (N) randomly chosen from each population sampled over an altitudinal range as low (1200-400 meters ≤ altitude), middle (1400 m < altitude ≤ 1600 m), high (1600 m < altitude ≤ 1800 m), and very high (1800 m < altitude) in Taurus cedar also known as cedar of Lebanon (Cedrus libani A. Rich.) for two consecutive years (2021&2022). The variation in strobilus production was subjected to estimation of female and male fertility variation. The total fertility variation (Ψ) was estimated from the female and male fertility variation. Impacts of some growth characteristics (tree height and diameter at breast height) on strobili productions were also investigated. Strobili productions varied among the populations and individuals within population, and between years. The differences for populations and years were also found for coefficient of variations which were mirror of fertility variation of the strobili productions. Tree height and diameter at breast height seemed more reasonable predictor than age for number of strobili. Fertility variations of female parents were generally higher than that of male in both years. First year showed generally higher parental variations in individual populations. Gene diversity (GD=1-0.5Ψ/N) ranged from 0.967 to 0.974 for the populations and years. The loss of highest gene diversity was 0.004 in low population (0.967 & 0.971) between years. Results of the study indicated that altitudinal gene diversity of seed crop could be used to produce genetically quality seed and their grading. Moreover, data sets can be used to fill the Forest Landscape Restoration library (FLR-Library).

Species-specific allometric models for reducing uncertainty in estimating above ground biomass at Moist Evergreen Afromontane Forest of Ethiopia

An allometric equation is used to convert easily measured tree variables into biomass. However, limited species-specific biomass equations are available for native tree species grown in various biomes of Ethiopia. The available pantropic generic equation has resulted in biases owing to the uncertainty of the generic model estimation due to the difference in tree nature and response to growth conditions. The objective of the study is, thus, to develop a species-specific allometric equation for reducing uncertainty in biomass estimation at the Moist Evergreen Afromontane Forest in south-central Ethiopia. Five tree species were selected for model development, these selected trees were harvested and weighed in the field. The measured above-ground biomass data related to easily measured tree variables: diameter at stump height, diameter at breast height (dbh), crown diameter, and total tree height. The developed model evaluated and compared with previously published model by using measures of goodness of fit such as coefficient of determination (R2), total relative error, mean prediction error, root mean square error, and Akaike information criteria. The analysis showed that a model with dbh as a single predictor variable was selected as the best model for the estimation of above-ground biomass. It gives the highest R2 for Syzygium guineense (0.992) and the lowest for Bersama abyssinica (0.879). The additions of other tree variables did not improve the model The pantropic model by Brown overestimates the biomass by 9.6–77.8% while both Chave models resulted in an estimation error of 12–50.3%. Our findings indicated that species-specific allometric equations outperformed both site-specific and pantropic models in estimating above-ground biomass by giving 0.1% up to 7.9% estimation error for the respective tree species.

Model Pendugaan Diameter Pohon Eucalyptus Pellita Clone EP0077AA Berbasis Citra Foto (Unmanned Aerial Vehicle)

The use of remote sensing to estimate the potential of forest stands continues to develop and one of them is using unmanned aerial vehicle (PUTA) technology. But such an important parameter as the diameter of the trunk at chest level cannot be measured from the orthopoto. This research aims to determine a correlation model of aerial crown diameter with trunk diameter at breast height in PUTA-based trees. This research began in October to November l 2022 in the PT area. Arara Abadi, Minas District, Riau region. Aerial measurements of crown diameter were carried out on orthophotos of 36-month-old eucalyptus (Eucalyptus pellita) forest stands, while stem diameter at breast height was carried out terrestrially. The correlation model equations used are Linear, Power, Exponential, Polynomial, and Logarithmic. The research results show that the best model is a non-linear (polynomial) model with a positive linear correlation between stem diameter and aerial crown diameter with the equation y ꞊ 0.2537x – 0.0058x2 – 0.4812 with a coefficient of determination (R2) 0.9047 and a coefficient of correlation (r) of 0.9511. This explains that the variable diameter at chest height influences the diameter of the aerial canopy by 90.47%

Tree Species Composition and Diversity in a Secondary Forest along the Sierra Madre Mountain Range in Central Luzon, Philippines: Implications for the Conservation of Endemic, Native, and Threatened Plants

The Sierra Madre Mountain Range (SMMR) is the backbone of the Luzon Islands that contains a high concentration of highly important ecological resources distributed among the 68 protected areas therewith. The present study aimed to assess the composition and diversity of tree species in a secondary forest within the SMMR. A 2.25 km transect with 10 900-m2 plots were established to record tree species with a diameter at breast height of at least 10 cm. The findings revealed 148 individuals of trees from 38 morphospecies, 28 genera, and 20 families. Importance values unveiled the Aurora endemic Macaranga stonei Whitmore as the most important species in terms of the relative values of its abundance, frequency, and dominance. The area was also found to be home to 33 natives, 12 endemics, five IUCN threatened species, and nine Philippine threatened trees. Furthermore, the study site was also found to have considerably high diversity, with a Shannon–Weiner Index value of 3.269 and a relatively even distribution of individuals among species, as supported by the Simpson’s Evenness index value of 0.9453. Significant correlational relationships were also found among species richness, Shannon–Weiner index, and Simpson’s Evenness index, with correlation coefficients ranging from 0.881 to 0.934, with all significant at p < 0.001. Lastly, the study was able to produce a distribution map, which is necessary for implementing targeted conservation strategies. These findings provided valuable implications for future research and implementation of targeted and participatory biodiversity conservation and protection strategies.

The Minimum Target Diameter and the Harvest Age of Oak Natural Secondary Forests in Different Sites Conditions: Case Study in Hunan Province, China

Maintaining permanent forest canopy cover and eventually harvesting timber by predetermined target diameter are often considered as a prototype for future management of the oak natural forest. However, target diameters and harvest age based on average forest growth rates from wide geographical areas often hamper improved management of oak forests. In this study, based on the sampling of 129 target trees from 51 oak natural secondary forest plots in Hunan Province, China, an individual-tree DBH (diameter at breast height) growth model of oak target trees was developed, and the site type (41 levels) was related to the model as random effects by a nonlinear mixed-effects approach. Moreover, the 41 site types were clustered into four site type groups (STG1, STG2, STG3, and STG4) by the K-means clustering algorithm to improve the model performance and practicality. With the help of the model, the five target diameters (including 24, 30, 40, 50, and 60 cm) were simulated in each of the four STGs, and the minimum target diameter was determined for each STG based on the theory of quantitative maturity. In the four STGs, the harvest age of the 24 cm diameter target ranged from 30 to 51 years; the harvest age of the 60 cm target diameter ranged from 131 to 220 years, with the oaks failing to reach 60 cm in the lowest-quality STG4; the minimum target diameter ranged from 21 cm to 29 cm. Results showed that lower-quality sites exclude higher target diameters from optimal harvesting strategies, in contrast to the higher target diameter as a more reasonable strategy in higher quality sites, and that the minimum target diameter is significantly influenced by site conditions. Therefore, it is necessary to develop a diverse target-diameter-harvesting strategy adapted for the complex site conditions of oak forests in Hunan Province towards site-specific timber management to improve the sustainability of timber production in oak forests.

Comparison of Xylem Anatomy and Hydraulic Properties in Black Locust Trees at Two Growth Stages in Semiarid China

Tree species transitioning between different developmental phases requires homeostatic adjustments in order to maintain the integrity of the tree hydraulic system. Hence, adjustments related to hydraulic traits (e.g., xylem conduit diameter) are of key functional significance. However, critical information on the differences between different developmental stages is rare. Using sapwood samples from 36 black locust trees with different growth stages (actively growing and declining stages) and a soil water gradient along a hillslope, xylem conduits at stem apexes and breast height (1.3 m above ground) stems were measured. The results showed marked differences in vascular traits between actively growing and declining trees. In contrast to actively growing trees, declining trees exhibited a reduction in conduit diameters accompanied by increased frequency with a positively skewed distribution and a subsequent decline in cumulative theoretical hydraulic conductivity. Across all sampled trees, the hydraulically weighted mean conduit diameter tapered acropetally from breast height to the stem apex. The extent of conduit tapering in actively growing trees (0.244, 95% CI 0.201–0.287) aligned with predictions from the hydraulic optimality model. Conversely, trees in a declining status displayed significantly reduced conduit tapering (0.175, 95% CI 0.146–0.198), indicating an elevation in hydraulic resistance with increasing tree height. Variations in hydraulic properties predominantly resulted from differences in tree height rather than variations in stem diameter or soil water content. The correlation between conduit diameter and soil water content in both actively growing and declining trees stemmed indirectly from variations in tree height rather than presenting a direct response to drought stress.

Quantifying tree height and canopy structure in a forest in Davao Oriental State College of Science and Technology, Mati City, Davao Oriental

Forests are landscapes dominated by trees and cover approximately 30% of the earth’s land surface, housing most of its biodiversity. This study aimed to quantify the tree height and canopy structure of a man-made forest in the locality, particularly the density, relative density, frequency, relative frequency, coverage, relative coverage, diversity, and importance value of the trees in the study area. The establishment of the study area was conducted on September 8, 2017, a period of one day and a transect-quadrat method was employed to assess the trees in the forest. Two (2) species of tree were found in the study area. These were Gmelina (Gmelina arborea) and Mahogany (Swietenia macrophylia). The densest tree species was Mahogany with 0.53 followed by Gmelina with 0.47. Mahogany was also observed to have a higher frequency than Gmelina. Gmelina in the study area has larger canopy coverage and circumference at breast height than Mahogany attributed to its fast-growing nature. The diversity of tree species in the study area was found to be low, attaining only 0.47 on the Shannon-Wiener Diversity Index and 0.69 on Simpson’s Diversity Index due to the small number of tree species present. The results of the importance value were low, with 1.32 for Gmelina and 1.68 for Mahogany since they are relatively young and have similar numbers of individuals.

A multilayered urban tree dataset of point clouds, quantitative structure and graph models

The significance of urban trees in promoting human health and well-being has been amplified by urbanization and the climate change effects. Simultaneously, advancements in remote sensing techniques have enhanced the opportunities for studying urban trees. The TreeML-Data has been compiled to support these efforts. It consists of labelled point clouds of 40 scanning projects of streets in Munich, 3,755 leaf-off (scans in winter) point clouds of individual trees, quantitative structure models (QSM), tree structure measurements, and tree graph structure models of these trees. The dataset offers valuable data for generating and evaluating models in various scientific disciplines, which include remote sensing, computer vision, machine learning, urban forestry, urban ecosystem, green architecture, and graph analysis. To ensure its quality, the tree structure measurements and QSM have been crosschecked. For instance, the tree diameter at breast height (DBH) in the sample dataset exhibits a deviation of approximately 1.5 cm (4.3%) when compared to manual measurements. In conclusion, the quality checks confirm its reliability for subsequent studies when compared to manual measurements.

Zhodnocení růstu proveniencí borovice černé (Pinus nigra Arnold) ve středních Čechách ve věku 51 let

The paper contains the evaluation of 9 European black pine provenances on the research trial No. 41 – Roblín (Czech Republic) at the age of 51 years. The tested provenances originated from Bosnia and Herzegovina, Serbia, Croatia, Bulgaria, Greece, France and Slovakia. The evaluation is based on an assessment of following factors: total height, dbh, stem form, health state, defoliation, diameter of main branches, stem damage, crown density, twisted growth, stem nature pruning, cross-section, and taper. Obtained data sets were statistically analysed. The best growth both in quantitative and qualitative traits was recognised for the provenance 9 – Les Barres, Oise (France), which was excellent in height growth, health status and stem shape, and also for the Serbian provenance 2 – Crni Vrh, Titovo Užice, which excelled not only in growth rate, stem shape and health status, but also in diameter of main branches. Less suitable provenance seem to be 3 – Prušačka Rjeka, Banja Luka from Bosnia and Herzegovina (worse growth, stem nature pruning, cross-section and taper) and Croatian 5 – Južna Kandija, Osijek (worse growth, stem shape, and health). The most important for explaining the differences between provenances were the diameter at the breast height, crown density and defoliation.

PRODUCTIVE FOREST RECOVERY IN LEGAL RESERVE AREA: A CASE STUDY IN EASTERN AMAZON

This study aimed to evaluate a model for Legal Reserve (LR) recovery based on a mixed timber production system (planting + natural regeneration) in the eastern Amazon, state of Pará. For data collection, seven plots of 50 m x 20 m were established, and all individuals with DBH (diameter at breast height) ≥ 5 cm were inventoried. Species diversity, horizontal structure, and commercial wood production were assessed at 13 years of age. A total of 103 species were found, distributed among 69 genera and 33 families. The population density was 1,425 individuals per hectare, and dominance corresponded to 19.45 m².ha-1. The total wood volume was 121.4 m³.ha-1, with 63.3 m³.ha-1 coming from the planted species (S. parahyba var. amazonicum) and 58.1 m³.ha-1 from natural regeneration. Among the regenerating species, Cecropia distachya showed the highest values for the evaluated parameters. The adopted model showed potential for use in LR environmental recovery, reconciling this action with revenue generation through silvicultural interventions that can be applied to the stand, aiming for wood production. To achieve this, adjustments to the regulations governing the forest management of recovering areas are necessary.

UAVs for forestry: Metric-semantic mapping and diameter estimation with autonomous aerial robots

To properly monitor the growth of forests and administer effective methods for their cultivation, forestry researchers require access to quantitative metrics such as diameter at breast height and stem taper profile of trees. These metrics are tedious and labor-intensive to measure by hand, especially at the scale of vast forests with thick undergrowth. Autonomous mobile robots can help to scale up such operations and provide an efficient method to capture the data. We present a set of algorithms for autonomous navigation and fine-grained metric-semantic mapping with a team of aerial robots in under-canopy forest environments. Our autonomous UAV system has 3D flight capabilities and relies only on a LIDAR and an IMU for state estimation and mapping. This allows each robot to accurately navigate in challenging forest environments with drastic terrain changes regardless of illumination conditions. Our deep-learning-driven fine-grained metric-semantic mapping module is capable of detecting and extracting detailed information such as the position, orientation, and stem taper profile of trees. This map of tree trunks is represented as a set of sparse cylinder models. Our semantic place recognition module leverages this sparse representation to efficiently estimate the relative transformation between multiple robots, and merge their information to build a globally consistent large-scale map. This ultimately allows us to scale up operations with multiple robots. Our system is able to achieve a mean absolute error of 1.45 cm for diameter estimation and 13.2 cm for relative position estimation between a pair of robots after place recognition and map merging

FLORISTIC-STRUCTURAL CHARACTERIZATION OF DEGRADED FOREST IN THE ARC OF DEFORESTATION, BRAZILIAN AMAZON

Floristic-structural characterization of degraded forest in the arc of deforestation, Brazilian Amazon. The purpose of this study was to characterize the floristic-structural aspects and the distribution of aboveground biomass (AGB) of degraded forests located in the arc of deforestation, southern Brazilian Amazon. In addition to characterizing the forest as a whole, analyses at the level of sampling units were established. Forest inventory data provided support to biomass estimates, as well as floristic-structural analysis. A survey was carried out, collecting from plots of 2,500 m² (50 x 50m) diameter at breast height (DBH >10cm) and total height (HT) of the trees. The forest showed a high concentration of species distributed in a few botanical families and a high number of locally rare species. The sampling units showed floristic similarity, identifiable by cluster analysis. On the other hand, they showed significant structural differences based on the DBH and HT variables. The AGB estimate for the area was 215.20 Mg ha-1 (± 83.73 Mg ha-1). Those results contribute to better understanding the changes in forest formations related to forest degradation in the southern Brazilian Amazon, as well as to the definition of conservation and restoration strategies for degraded forests.

Constructing a non-linear additive crown-width model system for moso bamboo forests in eastern China

ABSTRACT Tree crown can be described by various crown dimension variables, including crown width (CW), an important predictor variable in forest growth-and-yield models. Because CW is quantified as the arithmetic mean of north–south and east–west CW measurements (crown components), issues of additivity and inherent correlation between crown components exist. Using two versatile estimation algorithms (non-linear seemingly unrelated regression − NSUR – and non-linear error-in-variable models − NEIVM), we employed three methods of constructing simultaneous model systems (non-linear summation − NSE, one-step proportional weighting system − OPWS, and two-step proportional weighting system − TPWS) to effectively address those issues. The performance of the three methods was evaluated using CW measurements of moso bamboo (Phyllostachys edulis) in China. Results showed that the OPWS outperformed the NSE and the TPWS for each algorithm. NEIVM-OPWS was more accurate than TPWS, and NEIVM outperformed NSUR. Diameter at breast height, total height and mean diameter at breast height (a variable describing stand density and competition) significantly contributed to CW and its component equations. Each CW model system included additivity of the crown component equations and accounted for the inherent correlations between equations. Overall, NEIVM-OPWS provided a closer estimate of CW to the measured CW than other model systems and methods employed. An effective CW model system will help understand light capture by the bamboo canopy and contribute to the effective management of bamboo forests in China and elsewhere.

ECOLOGY OF HORNBILL FOOD TREES AT BUKIT BARISAN SELATAN NATIONAL PARK

Hornbills play an important role in maintaining tree gene flow among fragmented populations in forests. But hornbill populations in Asia have been declining mainly due to loss of forest cover and poaching. The presence of hornbills in a forest is highly dependent on environmental factors such as the condition of food trees in their habitat. The purpose of this study was to determine the spatial distribution, dispersion patterns, density, and diversity of hornbill food trees at Sukaraja Atas Resort (SA) and Balik Bukit Resort (BB) of Bukit Barisan Selatan National Park (BBSNP). We investigated a total of 10 transect (50 survey plots) for both SA and BB by collecting data on all types of hornbill food trees with a minimum diameter of 10 cm at breast height (DBH). We recorded 64 hornbill food tree species with a total of 98 individuals, which have a clumped and uniform dispersion pattern. This study showed that Lauraceae dominated in both resorts with the highest relative density. The results of the diversity index show that 9 transect have moderate diversity whereas 1 transect has low diversity; there was no significant difference between SA and BB. It can be concluded that the existing food trees in SA and BB may support the hornbill populations.

Effects of physicochemical characteristics on natural durability of eucalypts woods to wood-decaying fungi

This study aimed to relate the biological resistance of seven eucalypt woods to wood-decaying fungi with physicochemical characteristics of wood. Two 12-year-old trees per species were randomly sampled, removing disks at 0 (base), diameter to breast height - DBH, 25, 50, 75, and 100% of the commercial height to determine the wood specific gravity. One basal log of 2.20 m of each wooden species was obtained for chemical analysis and biological tests with brown and white rot fungi (Gleophyllum trabeum, Rhodonia placenta, and Trametes versicolor). For these tests, wood samples were taken in two positions in the radial direction of the trunk in the pith-bark direction (median heartwood and transition region; containing heartwood and sapwood), and the relation between wood natural resistance and physicochemical characteristics was established. Wood specific gravity ranged of 0.51 g cm−3 to 0.73 g cm−3, total lignin of 27.34–32.18%, and holocellulose of 53.39–66.18, not being influenced by pith-bark direction. The extractive and ash contents were affected by the pith-bark direction, in which, in general, the transition region exhibited the highest values contents. The extractive showed a negative relation (−0.67) regarding the loss of mass caused by the fungus Rhodonia placenta. For the holocellulose content, it showed positive relations (0.61; 0.54) to the degradation by Rhodonia placenta and Gleophyllum trabeum, respectively. Independently of the analyzed wood and tested fungus, the median heartwood region was more resistant to wood decay fungi than the transition region.

Phylogenetic diversity patterns of woody species across different tree sizes and spatial scales in a tropical forest community on Con Dao Islands

Understanding the maintenance of diversity and the assembly of communities is a primary concern in community ecology. This study explored the phylogenetic structure of an evergreen broadleaved tree community in Con Dao National Park, Vietnam. The survey, conducted in December 2023, encompassed all tree individuals with a diameter at breast height (DBH) ≥ 2.5 cm within a 4-ha study plot. These individuals were identified by species name, and their DBH was measured. Subsequently, a community phylogenetic tree was constructed using the Phylomatic online platform. The 4-ha study plot was subdivided into there different subplots based on three spatial scales (25 m × 25 m, 50 m × 50 m, and 100 m × 100 m) and all trees were classified into three different DBH classes (2.5 cm ≤ DBH < 10 cm representing small trees; 10 cm ≤ DBH < 20 cm as medium trees; and DBH ≥ 20 cm as large trees). The net relatedness index (NRI) and net nearest taxon index (NTI) were utilized to evaluate the phylogenetic structure and infer ecological processes. Our findings revealed a consistent decrease in both NRI and NTI with increasing spatial scales and tree sizes. These results suggest an overdispersed phylogenetic structure within the community across different spatial scales and tree sizes. Additionally, negative density dependence was found to have a pronounced effect on the phylogenetic structure, with a more significant impact on tree individuals from small and medium DBH classes than large ones. This study underscores the significance of phylogenetic density dependence as a primary mechanism governing species diversity and shaping the community structure of evergreen broadleaved forests in Vietnam.

Enhancing prediction accuracy of foliar essential oil content, growth, and stem quality in Eucalyptus globulus using multi-trait deep learning models.

Eucalyptus globulus Labill., is a recognized multipurpose tree, which stands out not only for the valuable qualities of its wood but also for the medicinal applications of the essential oil extracted from its leaves. In this study, we implemented an integrated strategy comprising genomic and phenomic approaches to predict foliar essential oil content, stem quality, and growth-related traits within a 9-year-old breeding population of E. globulus. The strategy involved evaluating Uni/Multi-trait deep learning (DL) models by incorporating genomic data related to single nucleotide polymorphisms (SNPs) and haplotypes, as well as the phenomic data from leaf near-infrared (NIR) spectroscopy. Our results showed that essential oil content (oil yield) ranged from 0.01 to 1.69% v/fw and had no significant correlation with any growth-related traits. This suggests that selection solely based on growth-related traits did n The emphases (colored text) from revisions were removed throughout the article. Confirm that this change is fine. ot influence the essential oil content. Genomic heritability estimates ranged from 0.25 (diameter at breast height (DBH) and oil yield) to 0.71 (DBH and stem straightness (ST)), while pedigree-based heritability exhibited a broader range, from 0.05 to 0.88. Notably, oil yield was found to be moderate to highly heritable, with genomic values ranging from 0.25 to 0.60, alongside a pedigree-based estimate of 0.48. The DL prediction models consistently achieved higher prediction accuracy (PA) values with a Multi-trait approach for most traits analyzed, including oil yield (0.699), tree height (0.772), DBH (0.745), slenderness coefficient (0.616), stem volume (0.757), and ST (0.764). The Uni-trait approach achieved superior PA values solely for branching quality (0.861). NIR spectral absorbance was the best omics data for CNN or MLP models with a Multi-trait approach. These results highlight considerable genetic variation within the Eucalyptus progeny trial, particularly regarding oil production. Our results contribute significantly to understanding omics-assisted deep learning models as a breeding strategy to improve growth-related traits and optimize essential oil production in this species.

The relationship between the abundance of non-native tree species and the community structure of resident woody species in tropical montane forest of West Usambara Mountains, Tanzania

Non-native tree species are globally claimed as liable to the encroachment of natural forests in their proximity resulting to the loss of biodiversity. This study was conducted in Magamba Nature Forest Reserve (MNFR) in West Usambara Mountains of Tanzania. A total of 96 (20 m x 20 m) plots were established to record all woody plants with Diameter at Breast Height (DBH) ≥ 5 cm while two nested plots of 2 m x 5 m were set to measure any plant with DBH ≥ 1 cm but less than 5 cm. Furthermore, two nested plots of 1 m x 1 m were established within the bigger plot in order to assess and record seedlings (DBH < 1 cm). Generalized Linear Models (GLMs) were used to assess the relationship between total abundance, species diversity, richness, evenness, and biomass of resident species and the abundance of Acacia melanoxylon and Eucalyptus grandis. Findings show a significant (p < 0.05) decrease of abundance of all resident woody species, adults, saplings and seedlings with an increase in the abundance of A. melanoxylon. The study also showed that the species richness and diversity of all resident species decreased with increasing the abundance of non-native species (p < 0.05). The abundance of E. grandis did not show significant (p > 0.05) association when assessed against the total abundance, species diversity, richness and evenness of all the resident woody species. This non-significant result may not necessarily mean no effect. This is because the P-value does not explain the size of the effect in biological data. Further analysis revealed that, the biomass of resident species was negatively related to the abundance of non-native species A. melanoxylon (p = 0.003) and E. grandis (p = 0.038). The negative relationship between the abundance, richness, diversity, evenness, and biomass of the resident woody species and the abundance of non-native species portrayed in this study raise an alarm. Therefore, there is need for setting monitoring and control mechanism to stop further spread of the non-native tree species in MNFR and hence, save the remaining biodiversity of the area.