Tree Damage Research Articles

Factors Influencing Private Forest Owners Decision-Making Rationalities to Implement Salvage Logging after Large-Scale Natural Disturbances in Slovenia

This study examines the factors that influence the decision-making rationality of private forest owners (PFOs) when implementing salvage logging after large-scale natural disturbances. The literature suggests two main responses to large large-scale natural disturbances: performing salvage logging and no salvage at all. When salvage logging is carried out, two different strategies can be applied: clearing, i.e. all trees are removed, including damaged trees and standing survivors; and salvaging, i.e. damaged trees are removed but the surviving trees are left and some dead trees are left standing. In an online survey conducted in Slovenia in March and April 2022, responses were collected from 1515 forest-owning households. A logistic regression model was created to analyse the data and understand how socio-demographic characteristics, characteristics of forest property, forest management activities and the market influence their decisions. The results show that previous management activities and cooperation with service providers significantly influence PFOs' decision-making rationality to implement salvage logging. The study contributes to a nuanced understanding of the complex decision-making processes in forestry. Future research opportunities lie in investigating specific aspects of past management activities and understanding the dynamics in cooperation between different actors to develop customised policies for effective forest management after large-scale natural disturbances.

Ecological Response of Forest Vegetation Communities to Snow Damage: A Meta-Analysis

Damage caused by snowfall can result in broken crowns and trunks and even lead to the uprooting of forest trees. Damage or death of forest trees creates forest gaps and alters overall forest demographics, but predicting the exact nature and influence of this damage remains challenging. In general, the effects of various biotic and abiotic factors on snow damage remain understudied. To address this gap in knowledge, we conducted a meta-analysis of existing literature, ultimately screening 38 manuscripts that describe 142 plant species. Our findings indicate that snow damage significantly reduced annual litterfall, Leaf Area Index, canopy density, abundance, and area at breast height when considering plant communities. However, snow damage also tended to significantly increase Shannon’s Diversity Index, Simpson’s Diversity Index, Pielou’s Evenness Index, and diameter at breast height. In addition, at the population level, snow damage was found to significantly reduce density, abundance, and annual litterfall while significantly increasing diameter at breast height. Further, the response of different forest vegetation community characteristics to snow damage is significantly influenced by factors such as forest type, elevation, slope, and aspect.

Green Fruit‐Stem Pairing and Clustering for Machine Vision System in Robotic Thinning of Apples

ABSTRACTApples are one of the most highly‐valued specialty crops in the United States. Recent labor shortages have made crop production difficult for fruit growers, including the task of green fruit thinning. Current methods including hand, chemical, and mechanical thinning impose tradeoffs between selectivity, cost, tree damage, and speed. A robotic green fruit thinning system could potentially selectively thin fruit in a quick, cost‐effective, and non‐damaging manner. The machine vision system would be a critical component for robotic thinning, and would not only need to perform green fruit detection/segmentation, but also fruit‐stem pairing and clustering to facilitate proper decision‐making for thinning. A neural network‐based fruit and stem pairing algorithm was devised and evaluated; an LSTM‐based clustering algorithm was devised and compared to the density‐based clustering algorithm, OPTICS. The algorithms were evaluated on an image data set consisting of GoldRush, Fuji, and Golden Delicious cultivars at the green fruit stage, with evaluations on overall performance, cultivar‐wise performance, cluster size‐specific performance, and feature importance. For fruit and stem pairing, the neural network‐based pairing algorithm achieved an AP of 81.4% on all fruits and stems, and that reached 90.6% when only fruits and stems with labeled angles were considered. For green fruit clustering, the LSTM‐based clustering achieved a clustering success rate of 68.4%, whereas the OPTICS algorithm obtained 50.9%. The algorithms will be further implemented in a pipeline of a future green fruit thinning vision system, as well as integrate the use of point clouds and other 3D orchard information to improve pairing and clustering performance.

Mangrove freeze resistance and resilience across a tropical‐temperate transitional zone

Abstract Freeze events govern the distribution and structure of mangrove ecosystems, especially in tropical‐temperate transitional zones. Understanding mangrove responses to freezing is crucial for predicting their poleward expansion under climate change. However, there is a need for field‐based measurements of mangrove freeze resistance and resilience. After an extreme winter storm in December 2022, we measured mangrove post‐freeze damage and recovery (January and November 2023), building on a pre‐freeze baseline assessment conducted in July 2022 across 12 sites along the temperature gradient of Florida's Gulf of Mexico coast (USA). Low‐temperature thresholds for leaf damage to Avicennia germinans, Rhizophora mangle and Laguncularia racemosa were quantified near −6, −4 and − 4°C, respectively. Thresholds for mortality were found to be near −6 to −7°C for A. germinans and −4 to −5°C for R. mangle. A threshold for loss of reproductivity in A. germinans was identified near −6 to −7°C. Resprouting was observed in all three species but limited to just one individual for R. mangle. Surviving A. germinans resprouted vigorously and had the greatest number of resprout branches, which was proportional to leaf damage. Tall A. germinans had a higher resprout percentage than short trees. Strata‐specific differences in freeze damage were most pronounced for R. mangle, with higher damage in tall versus short trees, while no difference was found between A. germinans strata. These results suggest that R. mangle population recovery may depend on the growth of short trees, while A. germinans can recover from all strata. Minimum air temperature was strongly correlated with mangrove height and above‐ground biomass. Projections of future minimum temperature and species‐specific freeze degree days predict warming winters, suggesting further mangrove development and range expansion under climate change. Synthesis: Collectively, our study advances understanding of mangrove responses to freezing and identifies low‐temperature thresholds for each species, aiding predictions of mangrove range expansion.

Optimizing Olive Harvesting Efficiency Through UAVs and AI Integration

Olive harvesting, integral to global agriculture, faces challenges with traditional gathering methods which are labor-intensive and limited in precision, highlighting the need for innovative approaches. The study explores the application of Unmanned Aerial Vehicles (UAVs) in olive harvesting, with the aim to enhance efficiency and sustainability. Traditional methods, employing wood rakes, sticks, and rudimentary mechanical devices, pose challenges with high labor intensity and potential tree damage. UAVs present a transformative solution, offering aerial surveying, high-resolution imaging, and harvest timing data collection. This study evaluates existing olive harvest technologies, illuminating the superior efficiency of UAVs in minimizing damage and maximizing yield. The Potohar region in Pakistan exemplifies one area of intensive olive production, emphasizing the need for precision Agri-techniques. This study introduces the conceptual design of olive harvesting using drones, demonstrating its potential to revolutionize traditional practices, provide real-time monitoring, and enhance environmental sustainability. Results indicate substantial reductions in non-harvestable fruit and wood damage with drone-based harvesting, underscoring its promise for increased yield and reduced environmental damage. In conclusion, this study advocates for the adoption of precision agriculture techniques, integrating Artificial Intelligence and aerial technologies, to propel the olive industry's productivity and environmental impact forward.

Public Food Trees’ Usage and Perception, and Their Potential for Participatory Edible Cities: A Case Study in Birjand, Iran

Public food trees are increasingly popular among researchers, urban planners, and citizens for their diversity of social, provisional, and environmental benefits. However, more research is needed to determine how to overcome their barriers. Here we used a qualitative approach to explore the usage and perception of public fruit trees and attitudes towards public usage and participation in two urban green spaces harboring fruit trees in Birjand, Iran: Tohid Park and Akbarieh Garden. Semi-structured interviews were conducted with twelve visitors to both spaces, four administrators, and eight workers. Almost all visitors had great personal experience and interest in picking fruit; nevertheless, usage in these green spaces was low, partly due to social norms. Almost all visitors appreciated the public fruit trees for the diverse pleasures that they provide (sensory, emotional, cognitive, experiential, social). Ten also had a high interest in participating in their management, especially in Tohid Park due to its greater social impact. Education and access limitation were suggested by some as important to reduce tree damage and maximize production. Our findings expand our understanding of how citizens relate to public urban fruit trees and can be involved in co-management schemes, thereby contributing to building smart and participatory edible cities.

Landscape forest cover and local vegetation structure mediate multitrophic relationships but not the leaf damage in cacao trees

Cacao is the most important agricultural product in the southern region of Bahia state, Brazil, with 70 % of its production occurring under the traditional agroforestry where cacao is mostly shaded by native trees. This traditional system allows to reconcile the production with the maintenance of the portion of original biodiversity. However, increased deforestation and intensified agroforestry management aimed at boosting productivity may impact the diversity of native species and the services they provide. In this context, our aim was to disentangle the role of landscape forest cover and the local vegetation complexity on predation of caterpillars and herbivory of cacao plants located in agroforestry systems. The study was conducted across 18 cacao agroforest sites in southern Bahia located in landscapes with different amounts of forest cover. We assessed predation rate using dummy caterpillars, sampling understory birds and arthropods and collected leaves of cacao trees to analyze damage by herbivory. We also measured shading levels and the abundance of cacao trees in each agroforestry. Predation pressure on dummy caterpillars was positively influenced by the abundance of total predators and the level of landscape forest cover and negatively by the number of cacao trees. Even so, we found no evidence that landscape, local features or the actual invertebrate assemblages (predators or herbivores) influenced the cacao leaf damage. The findings highlight the multifaceted interactions between ecological factors, predation pressure, and leaf damage within cacao agroforestry systems.

Phylogeography of the ambrosia beetle Euwallacea interjectus (Coleoptera: Curculionidae: Scolytinae): an emerging poplar pest and its Fusarium mutualists from poplar plantations in China.

Native to Asia, Euwallacea interjectus (Blandford) (Coleoptera: Curculionidae: Scolytinae) is a destructive and invasive pest of live trees, and now it has been found in the United States and Argentina. In recent years, this pest appeared in high densities in poplar monocultures from Eastern China (Jiangsu and Shanghai) and Argentina and caused significant poplar mortality. However, the origin of the pests related to tree damage and the Fusarium mutualists from some poplar zones in China remained unclear. Here, we provided a broader phylogeographic analysis of E. interjectus based on the mitochondrial gene (cytochrome c oxidase I) to determine the global genetic structure of this species. Five mitochondrial lineages were found in the native area. Populations introduced to the United States were originated from 4 localities. The Argentine population was derived from Japan. The species was observed with strikingly high level of cytochrome c oxidase I intraspecific divergence that exceeded interspecific divergence, but the high intraspecific variation was correlated with geographical locations among the native populations. Two nuclear genes (arginine kinase and carbamoyl-phosphate synthetase 2-aspartate transcarbamylase-dihydroorotase) were more conservative, and intraspecific differences were lower than interspecific differences. The mitochondrial genetic variation was probably caused by evolution of lineages among geographically isolated populations. But it is immature to infer the existence of cryptic species based on cytochrome c oxidase I differences. All samples collected from poplar populations were indigenous and formed close relationship with a specimen from eastern and southern China. Surprisingly, pests from poplar populations in Jiangsu and Shanghai showed different haplotypes and mutualists. This suggested that the control strategies should consider the genetic and mutualistic diversity of beetles at different poplar localities.

Effects of crown condition, tree damage, and site Quality on forest health in Gapoktan Wana Karya I

Forests are land in which there are flora and fauna life that are symbiotic with each other so as to form various ecosystems. Forests have a very important role for the components that make up them and for the surrounding environment. Damage that occurs to trees and their constituent soil can disrupt the ecosystem in them which can have an impact on the function of the forest. The importance of the role of forests for the surrounding environment, it is necessary to monitor the health condition of forests to have benefits so that forests are monitored for sustainability so that forests can carry out their functions optimally. This study aims to find the value of forest health conditions in land cultivated by Gapoktan Wana Karya I (Gapoktan WK) and to determine the influence of tree damage indicators, header conditions, and site quality on forest health. The forest health condition in this study was monitored through three indicators, namely tree damage, header condition, and site quality with Forest Health Monitoring (FHM) as the method. Then for the influence use simple linear regression. The results of the research on forest health conditions in Gapoktan WK showed an average value of 4.5, which was included in the medium category. The results of the simple linear regression analysis showed that the indicators of canopy condition and site quality had a unidirectional influence on forest health while the tree damage indicators had an influence but in the opposite direction on the forest health value.

INCIDENCE AND SEVERITY OF DAMAGE AGENTS ON ESTABLISHED TREES IN URBAN GREEN AREAS

Trees in urban green areas (UGAs) face various stress-inducing factors that, together with the incidence and severity of damage agents, reduce their growth and health condition. The objective of this study was to characterize the incidence and severity of damage to trees located in 21 UGAs in the city of Texcoco, Mexico, as well as the relationship between their health, green area typology, and urban infrastructure. Using tree damage indicators, the incidence of two damage agents per tree was determined, and seven damage groups were identified: biotic agents, parasitic and epiphytic plants, insects, animals, abiotic agents, and anthropogenic factors. A damage severity index (DSI) was estimated at species level and by green area. Chlorophyll fluorescence was used to assess stress as an indirect measure of tree health condition in UGAs, and surrounding urban infrastructure was classified. A total of 1543 trees were assessed, and 23 damage agents were identified, affecting 9.95 % of the foliage, 10.24 % of the branches, 4.47 % of the trunk, and 0.45 % of the root collar and roots. As for incidence, 60.01 % showed no damage at all, 29.49 % showed only one agent, and 10.5 % showed two agents. Most of the trees at the UGAs were found to be under stress (≤ 0.78) and uncorrelated with DSI; however, the index was different by species and UGA (p ≤ 0.05). Insect damage and poor management practices were associated with the presence of buildings, busy roads, and people congregation areas inside UGAs.

Effects of prescribed fire on planted oak growth and survival in restored savannas

Most oak savannas in the Midwestern United States have been lost to agriculture and habitat degradation. Because of their rarity and high plant and animal diversity, savannas are often a target for restoration, which frequently relies on the direct planting of oak seedlings to establish the necessary canopy. Returning fire to the system is critical to the herbaceous component, but with planted seedlings, managers risk damaging or killing trees if burning is introduced too soon. We studied the growth and physiological responses of three oak species (Quercus alba, Quercus macrocarpa, and Quercus velutina) to prescribed fire to determine impacts on planted trees. This study utilized two restored oak savanna units that were planted in 1995 and 1998, each with burned and unburned areas. We tracked trees ranging from 0.9 to 29.8 cm in diameter at breast height (DBH) to determine the size threshold above which top kill is unlikely and documented differences in leaf structure and extension growth between the burned and unburned areas. There was no mortality observed. Moreover, no trees larger than 4 cm DBH were top killed by the fire. Fire responses in leaf mass per unit area and chlorophyll content were small and inconsistent across species. However, all oak species grew more in burned areas than trees in adjacent unburned areas. Therefore, the addition of low‐intensity prescribed fire to an oak savanna planting may increase the growth rate of planted trees with minimal risk of mortality once trees have reached sufficient size.

Climate risk analysis of low-altitude tea gardens in central Taiwan using a Bayesian network.

Tea is a vital agricultural product in Taiwan. Due to global warming, the increasing extreme weather events have disrupted tea garden conditions and caused economic losses in agriculture. To address these challenges, a comprehensive tea garden risk assessment model, a Bayesian network (BN), was developed by considering various factors, including meteorological data, disaster events, tea garden environment (location, altitude, tea tree age, and soil characteristics), farming practices, and farmer interviews, and constructed risk assessment indicators for tea gardens based on the climate change risk analysis concept from the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC AR5). The results demonstrated an accuracy of over 92% in both validating and testing the model for tea tree damage and yield reduction. Sensitivity analysis revealed that tea tree damage and yield reduction were mutually influential, with weather, fertilization, and irrigation also impacting tea garden risk. Risk analysis under climate change scenarios from various global climate models (GCMs) indicated that droughts may pose the highest risk with up to 41% and 40% of serious tea tree growth damage and tea yield reduction, respectively, followed by cold events that most tea gardens may have less than 20% chances of serious impacts on tea tree growth and tea yield reduction. The impacts of heavy rains get the least concern because all five tea gardens may not be affected in terms of tea tree growth and tea yield with large chances of 67 to 85%. Comparing farming methods, natural farming showed lower disaster risk than conventional and organic approaches. The tea plantation risk assessment model can serve as a valuable resource for analyzing and offering recommendations for tea garden disaster management and is used to assess the impact of meteorological disasters on tea plantations in the future.

Determining the Extent of damage in Snapped Southern Yellow Pine Trees with Acoustic Testing

Abstract Salvage of downed timber following a windstorm allows recovery of management options for landowners and wood products for industry. Because wood volumes are large and logging, transportation, mill storage, and processing capacities are limited, avoiding the selection of logs with damage can conserve those resources. Visual damage indicators are typically used to select and differentiate products, but damaged logs are still delivered to mills. Following experimental tree winching in 2021 and a tornado in 2023, we assessed lengths of broken trees with a Fakopp microsecond timer. Using a recognized defect limit (10% deviation from the maximum acoustic velocity) about 80 percent of volume in broken tops could be recovered. Standard rules of thumb applied from the end of visible damage resulted in the recovery of about 50 percent of the volume with a relatively low defect rate (<10%). Applying bucking rules developed from acoustic measurements based on distance from snap might be easier to apply and increase recovery rates to over 70 percent of broken top volume.

Fire up Biosensor Technology to Assess the Vitality of Trees after Wildfires.

The development of tools to quickly identify the fate of damaged trees after a stress event such as a wildfire is of great importance. In this context, an innovative approach to assess irreversible physiological damage in trees could help to support the planning of management decisions for disturbed sites to restore biodiversity, protect the environment and understand the adaptations of ecosystem functionality. The vitality of trees can be estimated by several physiological indicators, such as cambium activity and the amount of starch and soluble sugars, while the accumulation of ethanol in the cambial cells and phloem is considered an alarm sign of cell death. However, their determination requires time-consuming laboratory protocols, making the approach impractical in the field. Biosensors hold considerable promise for substantially advancing this field. The general objective of this review is to define a system for quantifying the plant vitality in forest areas exposed to fire. This review describes recent electrochemical biosensors that can detect plant molecules, focusing on biosensors for glucose, fructose, and ethanol as indicators of tree vitality.

Sensitivity of Fire Indicators on Forest Inventory Plots Is Affected by Fire Severity and Time since Burning

Forest inventory data are useful for determining forest stand structure, growth, and change. Among the information collected on forest inventory plots by the USDA Forest Service Forest Inventory and Analysis Program, attributes characterizing various types of disturbance provide researchers a means of selecting plots specifically affected by disturbances, such as fire. We determine the performance of three of these attributes as indicators of recent fires on forest inventory plots of the United States by comparing them to independent records of wildland fire occurrence. The indicators are plot-level observations of fire effects on (1) general site appearance, (2) tree mortality, and (3) damage to live trees. Independent spatial layers of wildland fire perimeters provide an approach to test indicator performance and identify characteristics of fires that may affect detection. The sensitivities of indicators are generally higher in the West relative to the East. Detection rates exceed 90 percent for the Pacific Coast forests but seldom reach 80 percent in the East. Among the individual indicators, site appearance has higher identification rates than tree indicators for fires in the Pacific Coast, Great Plains, North, and South regions. Tree mortality is the most important single indicator for identifying Rocky Mountain fires. Tree damage is more important than tree mortality in the South; otherwise, the tree damage indicator is of relatively lower importance, particularly where high-severity fires are common, and tree survival is low. The rate of detection by the indicators is affected by the severity of the fire or the recency of the fire. The joint effect of severity and recency influence all three indicators for the Pacific Coast and Rocky Mountain fires, as well as the site appearance indicator in the South. Only a small proportion of fires are clearly missed by all three of the indicators.

Reintroduced, but not accepted: Stakeholder perceptions of beavers in Germany

Abstract While reintroductions of regionally extinct native species usually benefit ecosystems, reintroduced animals often struggle to locate appropriate habitats where they can establish themselves without conflict with humans. European beavers (Castor fiber) were successfully reintroduced to Germany almost 60 years ago and have reached high abundances again. As beavers can damage trees and change landscapes, they are increasingly in conflict with humans. We investigated human perceptions of beavers in Germany using an online survey, as they are an example of a reintroduced species with an expanding population and potential conflicts with humans. We asked participants about their emotions (anger, fear, interest, joy) towards beavers and what they consider to be acceptable beaver habitats. Of nearly 1500 survey participants, 803 (53%) were from the general public, 475 (32%) from the agricultural sector and 219 (15%) from forestry. People in these sectors had very different perspectives: beavers were positively perceived by the general public, but negatively by stakeholders working in agriculture and forestry. Independently of stakeholder groups, we also found regional differences, as participants from Bavaria—the German state with the highest beaver densities—viewed beavers more negatively than those from the rest of Germany. Zoos and wildlife parks, as well as urban and nature conservation areas, were considered to be the most acceptable habitats for beavers, whereas survey participants did not accept private gardens and cultivated areas as beaver habitats. We discuss the sources of negative emotions towards beavers and how ecologically suitable habitats differ from those that appear acceptable by humans. Even 60 years after their reintroduction, beavers in Germany are still being recognized as both a novelty and a nuisance. Our findings highlight the need for active beaver management and increased public engagement to enable positive coexistence between beavers and humans in Germany. Read the free Plain Language Summary for this article on the Journal blog.

Effects of stand structure on ecological benefits and tree growth of Haloxylon ammodendron plantations: A meta‐analysis

AbstractHaloxylon ammodendron is a typical tree species in arid region for windbreak and sand fixation. Understanding how stand structure (i.e., afforestation density, forest type, and stand age) of H. ammodendron impacts ecological benefits and tree growth status has great implications for desertification control in arid area. We obtained a dataset of 446 observations from 79 studies related to H. ammodendron plantations for meta‐analysis. Stand age was the key factor affecting performances of windbreak, tree canopy, and soil properties while afforestation density was more important in determining tree survival rate. Wind speed in H. ammodendron plantations was reduced by 52% in general compared to that at the site without any plantations and decreased as the increasing density. With the increase of stand age, soil carbon, nitrogen, and phosphorus accumulated continuously, but soil moisture in 0–60 cm depth decrease when trees grew up to nearly 20 years. Within 4000 plants ha−1, responses of survival rate, tree height, ground diameter, and canopy decreased with the increase of afforestation density. Compared with mono‐species plantation, mixed afforestation was more beneficial to windbreak and survival, while it damaged tree growth. Combining the ecological functions and tree growth of H. ammodendron plantations, the afforestation density and forest age should be controlled to 450–900 plants ha−1 and 20 years, respectively, as the upper limit. Therefore, besides reasonable afforestation density, management measures for regulations of forest age and existing stand density were important to maintain higher ecological benefits and better tree growth of H. ammodendron plantations.

Modelling internal stem damage in savanna trees: Error in aboveground biomass with terrestrial laser scanning and allometry

Abstract Forests and woodlands are critical terrestrial carbon stores. Tree aboveground biomass (AGB) can be estimated using allometric models and terrestrial laser scanning (TLS). However, internal tree stem damage from biotic decay is an unresolved source of error for both TLS and allometries, with implications for accurate carbon assessment. We destructively harvested 63 TLS‐scanned trees in an Australian savanna, quantified internal damage in each tree by sampling cross sections at multiple heights, and modelled the effect of damage on AGB estimation for individual trees and total estimated biomass. We tested the performance of TLS AGB modelling against five allometries, applying both database and field‐measured wood specific gravity. For TLS‐modelled and allometric AGB estimates, we tested if tree size and level of internal stem damage contributed to AGB deviations. Approximately half of the trees in the study sustained 1–10% damage by volume, which was most extensive in the base and main trunk, decreasing into the crown. On average, damaged trees had 5% internal stem damage (by volume, SD = 6.65%), with some as high as 30%. We found TLS‐derived quantitative structural models (TLS‐QSMs) using field‐measured wood specific gravity to be most accurate in estimating total biomass (R2 = 0.99, +0.59% bias). TLS‐QSMs tended to overpredict AGB of large, damaged trees, and AGB estimates from allometric models were largely unaffected by internal damage. For individual trees, all methods were effective for predicting field‐measured AGB (R2 > 0.84) and several ASMs performed well (± ~10% bias). In the absence of local wood specific gravity calibration, a pantropical ASM was most accurate. For systems where internal stem damage is low (<10% of tree volume), TLS can be used to estimate AGB with low levels of error, however more damaged wooded ecosystems (>10%) are likely to produce inflated biomass estimates if TLS is used without calibration for damage. Internal stem damage should be quantified in ASMs and incorporated into TLS‐modelled AGB calibration to avoid biomass overestimation and maintain high standards of precision in forest carbon accounting.

Vandalism on city trees: a case study from KNUST campus, Ghana

ABSTRACT Tree vandalism has harmful consequences that impact the performance of trees, affecting the flow of their benefits to society. However, questions about the common forms of tree vandalism and factors contributing to a tree’s vulnerability to vandalism have not been well researched. Using the campus of Kwame Nkrumah University of Science and Technology as a case study, the current research identified the common forms of tree vandalism and determined the relationship between these forms and tree species, size, and location. The study area was stratified into three based on land use: Faculty area, Students’ residence, and Lecturers’ residence. Using the Quantum Geographic Information System (QGIS), 100 × 100 m grids were laid on the study area map, and 10% of the grids were randomly selected from each stratum. All trees within the selected grids were identified and assessed. A total of 185 incidents of tree damage were recorded from the 131 trees assessed across the three strata. The highest incidence of damage recorded was broken branches (90), while burnt trees had the lowest frequency of occurrence (6). A total of 61 trees from 19 species were recorded as vandalised according to our classification. Tree size and proximity to the road network did not influence the type of tree vandalism recorded. However, our study suggests that tree vandalism may be location-specific, with trees in highly visible and crowded areas more likely to be vandalised with acts that seek people’s attention, while those in isolated areas are less likely to be vandalised through attention-seeking acts. This study is among the few which has attempted to empirically document a common phenomenon that has received less attention and has been overlooked in several societies.

Frost Damage Mitigation in Flowers and Fruitlets of Peach and Almond from the Application of a Multi-Attribute Approach Biostimulant.

To prevent frost damage in fruit trees, growers employ passive and active methods, and one of these second methods is the use of biostimulant compounds against abiotic stress. In this study, two trials were conducted to evaluate the effectiveness of a multi-attribute approach biostimulant-containing α-tocopherol, boron, and glycols, in peach ('UFO-4' cultivar) and almond ('Vairo' cultivar) trees. In a first trial, one-year-old shoots with flowers were collected after 24 h, 48 h, and 96 h of the biostimulant applications. Two different application rates of the product (1000 and 2000 cc ha-1) were tested and compared to an untreated control. In a second trial, one-year-old shoots with fruitlets were collected after 24 h of the biostimulant applications. In this case, only an application rate (2000 cc ha-1) was tested. In the two trials, the collected one-year-old shoots were subjected to different frost temperatures using a controlled environment chamber. The damage level was assessed by a morphological analysis of the flowers and fruitlets 96 h after each frost cycle simulation. The lethal temperatures (LT10, LT50, and LT90) of each treatment were calculated by probit analysis. The product applied 24 h and 48 h before the frost simulations significantly decreased the LT10 and LT50 in 1.5 °C in peach flowers, and 2.5 °C in almond flowers (a temperature reduction of 50% and 75%, respectively). These results were more consistent when the application volume was 2000 cc ha-1, instead of 1000 cc ha-1. Significant differences between treated and non-treated fruitlets were observed only in almond fruitlets, with LT10 and LT50 being 0.5 °C lower in treated fruitlets (20% reduction). In conclusion, the multi-attribute approach biostimulant applied 24 or 48 h before the frost reduced the mortality of peach and almond flowers, but its effectiveness to protect fruitlets after bloom was inconsistent.