Morphological Characteristics Of Trees Research Articles

Provenance and family variations in early growth of Manchurian walnut (Juglans mandshurica Maxim.) and selection of superior families.

This study, conducted in China in November 2020, was aimed at exploring the variations in growth traits among different provenances and families as well as to select elite materials of Juglans mandshurica. Thus, seeds of 44 families from six J. mandshurica provenances in Heilongjiang and Jilin provinces were sown in the nursery and then transplanted out in the field. At the age of 5 years, seven growth traits were assessed, and a comprehensive analysis was conducted as well as selection of provenance and families. Analysis of variance revealed statistically significant (P < 0.01) differences in seven growth traits among different provenances and families, thereby justifying the pursuit of further breeding endeavors. The genetic coefficient of variation (GCV) for all traits ranged from 5.44% (branch angle) to 21.95% (tree height) whereas the phenotypic coefficient of variation (PCV) ranged from 13.74% (tapering) to 38.50% (branch number per node), indicating considerable variability across the traits. Further, all the studied traits except stem straightness degree, branch angle and branch number per node, showed high heritability (Tree height, ground diameter, mean crown width and tapering, over 0.7±0.073), indicating that the variation in these traits is primarily driven by genetic factors. Correlation analysis revealed a strong positive correlation (r > 0.8) between tree height and ground diameter (r = 0.86), tree height and mean crown width (r = 0.82), and ground diameter and mean crown width (r = 0.83). This suggests that these relationships can be employed for more precise predictions of the growth and morphological characteristics of trees, as well as the selection of superior materials. There was a strong correlation between temperature factors and growth traits. Based on the comprehensive scores in this study, Sanchazi was selected as elite provenance. Using the top-percentile selection criteria, SC1, SC8, DJC15, and DQ18 were selected as elite families. These selected families exhibit genetic gains of over 10% in tree height, ground diameter and mean crown width, signifying their significant potential in forestry for enhancing timber production and reducing production cycles, thereby contributing to sustainable forest management. In this study, the growth traits of J. mandshurica were found to exhibit stable variation, and there were correlations between these traits. The selected elite provenance and families of J. mandshurica showed faster growth, which is advantageous for the subsequent breeding and promotion of improved J. mandshurica varieties.

East African megafauna influence on vegetation structure permeates from landscape to tree level scales

African savanna elephants (Loxodonta africana) can substantially modify their habitat through their interactions with woody vegetation. Nonetheless, the scale, intensity and characteristics of these relations are not yet fully understood. Consequently, it is unclear how vegetation-megafauna interactions can be disrupted by external factors, such as land management. This study attempted to quantify and characterize structural changes in vegetation caused by elephants, from landscape to tree level scales. We applied multi-scale geospatial tools, including airborne (ALS) and terrestrial laser scanning (TLS), to address the following questions: (1) How do elephants shape landscape level vegetation structure in conservation areas? (2) Are the impacts of elephants evident on individual tree architecture? Our study area was located at the Taita Hills Wildlife Sanctuary in South-eastern Kenya. The occurrence of elephants was estimated using elephant observation records and proximity to elephant tracks. Landscape level structure was assessed using tree density maps calculated based on individually detected treetops from ALS data. Next, TLS measurements of 72 trees were processed using quantitative structural modelling to characterize their architecture. Our results demonstrate a widespread influence of elephants on both landscape and tree level structural characteristics. This influence was strongly mediated by management, as we observed differences in vegetation structure inside and outside conservation areas. Tree density was up to 42% lower (5.84 trees/ha) in conservation areas than in non-conservation areas (10.17 trees/ha). Trees were relatively larger with closer proximity to elephant tracks, while smaller trees were more often observed in areas further away from elephants. At an architectural level, trees closer to elephant tracks had lower ratio between the crown length and the tree height, demonstrating a substantial influence of elephants on the morphological characteristics of trees. Our results highlight the importance of accounting for vegetation fauna interactions when planning conservation areas in African savannahs.

Impact of Canopy Coverage and Morphological Characteristics of Trees in Urban Park on Summer Thermal Comfort Based on Orthogonal Experiment Design: A Case Study of Lvyin Park in Zhengzhou, China

As an integral part of urban forests, urban parks play a vital role in mitigating urban heat islands (UHI) and providing residents with comfortable outdoor recreational plots. For high-quality use of the trees in regulating the thermal comfort of urban parks, previous studies primarily focused on the microclimate variations caused by tree coverage and morphological features separately. However, there is still a lack of systematic understanding of how tree canopy coverage (TCC) and its morphological elements, including leaf area index (LAI), trunk height (TH), and crown diameter (CD), combined affect the thermal comfort in the urban park. This study employed an orthogonal experiment design and ENVI-met software to simulate the microclimate of various multi-factor combination models in the case of a typical urban park in a temperate continental climate zone in China, analyzing the simulated result through physiological equivalent temperature (PET). Results show that the contribution ratio of various elements to the thermal environment vary over time. In studied elements, the contribution ratio of TCC to PET is consistently higher than 50% during the morning, midday, and evening periods, reaching a peak of 67% in the evening. The maximum contribution ratios for CD, TH, and LAI occur during midday, morning, and midday, respectively, with corresponding contribution ratios of approximately 22%, 10%, and 9%, respectively. The ranking of elements affecting thermal comfort in the urban park generally is TCC, CD, LAI, TH throughout the day, apart from the morning, when the influence of TH is greater than LAI. The optimal combination of elements is 85% TCC, 4m TH, 3.9 LAI, and 7m CD, and thirteen combinations of element cases meet the thermal comfort requirements during summer. The research findings highlight the significance of optimizing the configuration of trees in creating a more comfortable and inviting space for human activities.

Testing a Method Based on an Improved UNet and Skeleton Thinning Algorithm to Obtain Branch Phenotypes of Tall and Valuable Trees Using Abies beshanzuensis as the Research Sample.

Sudden changes in the morphological characteristics of trees are closely related to plant health, and automated phenotypic measurements can help improve the efficiency of plant health monitoring, and thus aid in the conservation of old and valuable tress. The irregular distribution of branches and the influence of the natural environment make it very difficult to monitor the status of branches in the field. In order to solve the problem of branch phenotype monitoring of tall and valuable plants in the field environment, this paper proposes an improved UNet model to achieve accurate extraction of trunk and branches. This paper also proposes an algorithm that can measure the branch length and inclination angle by using the main trunk and branches separated in the previous stage, finding the skeleton line of a single branch via digital image morphological processing and the Zhang-Suen thinning algorithm, obtaining the number of pixel points as the branch length, and then using Euclidean distance to fit a straight line to calculate the inclination angle of each branch. These were carried out in order to monitor the change in branch length and inclination angle and to determine whether plant branch breakage or external stress events had occurred. We evaluated the method on video images of Abies beshanzuensis, and the experimental results showed that the present algorithm has more excellent performance at 94.30% MIoU as compared with other target segmentation algorithms. The coefficient of determination (R2) is higher than 0.89 for the calculation of the branch length and inclination angle. In summary, the algorithm proposed in this paper can effectively segment the branches of tall plants and measure their length and inclination angle in a field environment, thus providing an effective method to monitor the health of valuable plants.

ИЗУЧЕНИЕ МОРФОЛОГИЧЕСКИХ ПРИЗНАКОВ И ФЛУКТУИРУЮЩЕЙ СПОСОБНОСТИ ЛИСТОВОГО АППАРАТА БЕРЕЗЫ ПОВИСЛОЙ

As a result of the increasing anthropogenic and technogenic impact on forest ecosystems, ecological monitoring over the changing indicators of growth and condition of trees has acquired a particular importance. Along with many traditional observation methods based on the analysis of water, soil and air samples, methods of bioindication of the assimilation apparatus have recently been used, which show the level of changes in the morphological characteristics of trees depending on the external negative impact of the environment. The purpose of the research is to determine the state of silver birch forest cultures in the green zone of a city of Nur-Sultan using bioindication methods. The object of research was the assimilation apparatus of 12-year-old silver birch forest cultures which at the age of 7 were transplanted from the strips to the spaces between strips. The morphological features and fl uctuating asymmetry of the leaves were studied. The crops of silver birch were classified as weakened plantations with a coefficient of relative viability of 54.2-73.0%. In 2019, the average level of deviation from the norm corresponded to the crops transplanted at a low elevation and non-transplanted at a high elevation, a slight deviation from the norm was observed in trees transplanted at a higher elevation. In 2020, condition of silver birch plantings decreased to the 4th point of the asymmetry index. The deterioration of the condition of trees is associated with an increasing anthropogenic load on plantations and environmental pollution. Since the pressure of these negative factors on the environment will not decrease, but will only exponentially rise, it is proposed to start taking measures to increase the sustainability of plantings (thinning, use of fertilizers, and addition of growth stimulants, etc.).

Tree Transpiration and Urban Temperatures: Current Understanding, Implications, and Future Research Directions

Abstract The expansion of an urban tree canopy is a commonly proposed nature-based solution to combat excess urban heat. The influence trees have on urban climates via shading is driven by the morphological characteristics of trees, whereas tree transpiration is predominantly a physiological process dependent on environmental conditions and the built environment. The heterogeneous nature of urban landscapes, unique tree species assemblages, and land management decisions make it difficult to predict the magnitude and direction of cooling by transpiration. In the present article, we synthesize the emerging literature on the mechanistic controls on urban tree transpiration. We present a case study that illustrates the relationship between transpiration (using sap flow data) and urban temperatures. We examine the potential feedbacks among urban canopy, the built environment, and climate with a focus on extreme heat events. Finally, we present modeled data demonstrating the influence of transpiration on temperatures with shifts in canopy extent and irrigation during a heat wave.

Vegetation Design as User’s Thermal Modifier at Urban Park

The study aims to investigate the potential of vegetation design as a microclimatic modifier at KLCC park. The scope of the study is to determine the impact of vegetation types towards thermal comfort. The different morphological characteristics of trees, shrubs and groundcover, and its planting configurations could be the best indicator to determine the outdoor thermal satisfaction among users. The results indicate the sampling points with various types of vegetation including hardy canopied trees, dense shrubs and groundcovers recorded lowest air temperature, and more visitors were comfortable doing activities in that area compared to points with fewer layers of vegetation.

Effect of fungal endophytes on morphological characteristics, nutrients content and longevity of plane trees (Platanus orientalis L.)

ABSTRACTThe plane tree is one of the most frequently used street trees in urban landscape in Iran and some Mediterranean countries and some age-old ones are found in these countries. Endophytes are microorganisms which associate with healthy plant tissues, persisting without causing diseases symptoms in the host and normally benefitting them through improving plant ability to withstand environmental stresses. In this contribution, the hypothesis of fungal endophytes existence in the plane trees as well as their relationship with morphological characteristics of trees and nutrient elements of leaves were studied in the central part of Iran. The experiment was performed according to an unbalanced completely randomized design. Approximate age and height of plane trees were recorded and then the greenness and visual appearance were evaluated. Healthy shoots and bark pieces were collected and surface sterilized then placed in petri dishes containing PDA. The results showed that endophytes frequency were significantly greater in age-old trees (60.04%) than young ones (39.96%). Endophytes existence had a positive correlation with iron (Fe) and potassium (K) concentrations of the leaves, and trees height and circumference. Also, there was a positive correlation between the presence of fungal endophytes and improved visual appearance of plane trees. The results suggest that fungal endophytes association enhanced nutrient elements assimilation in trees contributing at least partly to elevated survival of age-old plane trees.

3D Tree Modeling and Visualization Simulation Based on Fractal

In this paper, we propose a 3D tree simulation method which is based on fractal theory and combined with the morphological characteristics of trees. By modifying a few simple parameters we can achieve the realization of different types of 3D tree automated generation. According to the tree structure fractal self-similar characteristic, combined with the morphological characteristics of the trees, we abstract identified class to realize the description of each organs attributes and functions; Using random control function to improve the fractal iterative methods to make the generated trees more realistic; With the help of the developing platform of Visual C++ language and OpenGL, we can realize 3DTrees optimize modeling and visualization simulation. Experiments show that the method generates visually convincing results.

Horse Chestnut (Aesculus hippocastanum L.) Urban Habitat - Pollution Influence on Some Phenotypic and Morphological Characteristics

Background and purpose: Horse chestnut (Aesculus hippocastanum L.) may be found in most urban areas in Croatia. Over the years it showed to be resistant to various negative urban influences. In this research we tested trees on randomly selected streets with intense traffic in smaller towns. The main goal of this research was to establish the link between pollution and tree growth and to analyze to what extent pollution influences the increase in the measured parameters. Materials and methods: The research was done in 7 settlements, in towns with the population of up to 75 000 inhabitants. The measured parameters were the morphological characteristics of trees, shoots, leaves and nuts. From the selected branches we measured the annual shoot (thickness and length), leaves, the number of flowers and nuts. The crown transparency was assessed according to the ICP Forest method. Results and conclusions: The phenotype of the urban Horse chestnut significantly differs from its natural phenotype, and it is transformed by multiple radical pruning, what may be seen in the following ratios: the diameter at breast height tree height, trunk height tree height, crown height – tree height, crown width – crown height. The most significant characteristic of the tree is the vitality expressed by crown-damage classes. On the selected trees the worst crown damage class was “3b” and the best was “0”. The measured parameters of yearly shoot characteristics were defined. All measured parameters (trees, shoots, leafs and nuts) show significant differences from the given average values.

Environmental controls on growing-season sap flow density of Quercus serrata Thunb in a temperate deciduous forest of Korea

Sap flux density (SFD) measurements were used, in combination with morphological characteristics of trees and forest structure, to calculate whole-tree transpiration, stand transpiration (St) and mean canopy stomatal conductance (Gs). Analysis based on the relationships between the morphological characteristics of trees and whole tree water use, and on the responses of SFD and Gs to short wave radiation (RR), vapor pressure deficit (VPD) and soil water content (SWC) during drought and non-drought periods were conducted. The results showed a strong positive correlation between whole tree transpiration and both tree diameter at breast height (DBH) (<TEX>$r^2$</TEX> = 0.95, P < 0.05) and sapwood area (SA) (<TEX>$r^2$</TEX> = 0.98, P < 0.05). Relationships between SFD and DBH (<TEX>$r^2$</TEX> = 0.25), as well as SA (<TEX>$r^2$</TEX> = 0.17) were weak. Daily SFD of Quercus serrata Thunb was closely related to VPD and RR. Although operating at different time scales, RR and VPD were important interacting environmental controls of tree water use. SFD increased with increasing VPD (<1 kPa) and RR. SWC had a considerable effect on stand transpiration during the drought period. The relationships between SFD, VPD and RR were distorted when SWC dropped below 35%.

Over-mature beech trees (Fagus orientalis Lipsky) and close-to-nature forestry in northern Iran

Oriental Beech is the most important commercial tree species in northern Iran. In recent years wood production companies interested in felling large beech trees for profit have challenged advocates of close-to-nature silviculture who favor conservation. Our study objective was to assess the economic value of over-mature beech trees by relating tree diameter (DBH) to amount of decay. Based on the location of onset of decay, we categorized three types of decay as stump, stem, and crown decay. Trees of greater diameter (age) typically showed greater decay in the stem. Percent of decayed volume, diameter of decayed tissue, and length of decay in tree stems varied between 0.5%–64.3%, 15 cm–75 cm, and 2.0–19.5 m, respectively. With increasing trunk diameter, the proportion of truck decay increased. Red heart and dark red heart constituted 25% and 14.3% of sampled trees, respectively. However, we found no correlation between intensity of stem decay and morphological characteristics of trees. Seedlings were not abundant around the bases of over-mature trees, suggesting that the trees did not contribute to regeneration of the stand. Beech trees of diameter >1 m do not provide valuable round wood for industries and cause to raise wood production costs. We recommend that these trees >1 m DBH should be retained in forest stands because of their low commercial value but high ecological and conservational values such as maintaining biodiversity in forest ecosystems.