Large Canopy Research Articles

Influence of Row Pattern and Prohexadione Calcium on Peanut (Arachis hypogaea L.) Maturity and Pod Distribution

Many newer peanut cultivars are offering improved yield benefits but have larger canopies and have taken 10 or more days longer to reach maturity levels that were historically desired for optimal profitability of a crop. Prohexadione calcium growth regulator and twin row planting pattern have previously been individually reported to increase the amount of orange, brown or black pods compared to untreated alternatives. Twin row planting (i.e., planting two rows spaced 18-cm apart on 96-cm centers) has additionally been anecdotally associated with increased concentrations of pods nearer the taproot. Objectives of this work were to evaluate maturity development in single versus twin row planted peanuts and to evaluate how prohexadione calcium application would affect maturity development and pod distribution of both single and twin row planted peanut. Four cultivars were selected based on frequency of use in South Carolina then paired into experiments based on maturity requirements. Experiments were conducted at the Edisto Research and Education Center in Blackville, SC and the Pee Dee Research and Education Center in Florence, SC in 2021 and 2022. Peanut planted in twin row planting pattern yielded greater and had a higher percentage of orange, brown or black pods and total sound mature kernels. For FloRun 331 and Georgia-16HO in twin but not single rows, prohexadione calcium treatment increased the percentage of orange, brown or black pods. Although pod distribution effects for twin rows without and single rows with prohexadione calcium varied by maturity group, twin rows with prohexadione calcium exhibited pod distributions closer to the taproot than treated single rows. Twin row plots were associated with cooler ground temperatures than single rows, while the effects of prohexadione calcium on ground temperature varied between cultivars. Increased ground temperature was negatively correlated with pod maturity and main stem heights. Results from this work contribute to our understanding of potential benefits and variability across cultivars of the use of twin row planting pattern and prohexadione calcium treatment.

Do trees use stemflow water? A manipulative experiment on Singleleaf piñon and Utah juniper in Great Basin woodlands.

It has been postulated that stemflow, precipitation that flows from plant crowns down along branches and stems to soils, benefits plants that generate it because it increases plant-available soil water near the base of the plant; however, little direct evidence supports this postulation. Were plants' crowns to preferentially route water to their roots, woody plants with large canopies could benefit. For example, piñon and juniper tree encroachment into sagebrush steppe ecosystems could be facilitated by intercepted precipitation routed to tree roots as stemflow, hypothetically reducing water available for shrubs and grasses. We tested whether Great Basin piñon and juniper trees use and benefit from stemflow. In a drier-than-average and wetter-than-average water year, isotopically labeled water was applied to tree stems to simulate stemflow. Both species took up stemflow, with label signals peaking and receding over 2-4days. Despite this uptake, no alleviation of water stress was detected in the drier year. The stemflow uptake resulted in some water stress alleviation in the wetter year, specifically for piñons, which took up water from deeper in the soil profile than did junipers. Mixing model analyses suggested that stemflow was a small fraction of the water in stems (⁓0-2%), but an order-of-magnitude larger fraction of the stemflow was transpired in those few days after addition. These findings represent a novel demonstration of the rapid uptake and use of stemflow that infiltrates the rhizosphere, but they also prompt questions about the remaining stemflow's fate and why alleviation of water stress was so minor.

Functional Characterisation of GmGASA1-like Gene in Glycine max (L.) Merr.: Overexpression Promotes Growth, Development and Stress Responses.

The presence of Gibberellic Acid-Stimulated Arabidopsis, GASA, gene family has been reported in many important plants, playing roles in various aspects of plant biology but little has been uncovered in soybeans. Soybean is one of the major plants providing nutrition for humans and livestock globally. In this study, we overexpressed a novel GASA gene (GmGASA1-like) in Glycine max and conducted bioinformatic analyses, evaluated the T2 transgenic line in an open field, and applied major stressors along with the growth promoter GA3 to investigate the potential functions of the GmGASA1-like gene. The results of bioinformatics implied that the GmGASA1-like gene is regulated by GA3, and its protein has the potential to influence key processes of plant growth and development. The transgenic plants (JN74-OE) were significantly taller and had a larger canopy in the field trial at the R1-growth stage and demonstrated superiority in some seed quantity and quality traits after harvesting. Under abiotic stresses (including cold, heat, and drought) and spraying of GA3, the level of GmGASA1-like gene expression in JN74-OE exceeded the levels measured before the treatments. Notably, the highest expression level was observed during the drought stress treatment. Photosynthesis pigments levels in both the overexpressed lines and the control group showed no significant differences. In summary, this study sheds light on the multifaceted roles of the GmGASA1-like gene, impacting soybean plant architecture, seed traits, and stress responses. Ultimately, this research paves the way for a more productive and sustainable soybean industry.

Mangroves and Associated Flora of Vashista Godavari Estuary from Darbharevu to Biyyaputippa, West Godavari District, AP, India

Mangrove ecosystem is one of the productive ecosystems in aquatic environment. Mangrove populations occurring along the Vashista branch of Godavari River were studied using line transect with 16 m² quadrates and the quadrate samples were analyzed. In the present investigation a total of 16 mangrove species were reported, out of which four are true mangrove species, six associated mangroves and six halophytes were reported. Transect studies revealed that mangroves were distributed up to 10 to 20 meters in Darbharevu and 30 to 40 meters in Biyyaputippa region. Most of the forest in Darbharevu is in form of long strip and in Biyyaputippa forest extends and density of species was high than Darbharevu. In both study sites (Darbharevu and Biyyaputippa) the species with the highest density was Suaeda monoica whereas the species with lowest density was Sonneratia caseolaris. The maximum height in these two stations varied from 5 to 10 meters only. Percentage frequencies of DBH (Density at Breast Height) classes were estimated. In the present study only two diameter classes in Darbharevu and 4 classes in Biyyaputippa were reported. This is an indicative of the small and bushy mangrove vegetation in station 1 and little bit larger canopy was reported in station 2. Anthropogenic and aqua industry play a critical impact on the survival of this mangrove ecosystems.

Commodity risk assessment of Betula pendula and Betula pubescens plants from the UK.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by plants of Betula pendula and B. pubescens imported from the United Kingdom (UK) taking into account the available scientific information, including the technical information provided by the UK. The commodities were grouped in the risk assessment as (a) bundles of 10-20 graftwood/budwood (up to 1-year-old), (b) bare root plants which include bundles of 25 or 50 seedlings or transplants (1-2 years-old), bundles of 5, 10 or 15 whips (1-2 years-old) and single bare root plants (1-7 years-old), (c) plants in pots which include bundles of 5 and 10 cell-grown plants (1-2 years-old) and rooted plants in pots (1-7 years-old), and (d) large specimen trees up to 15-years-old. All pests associated with the commodities were evaluated against specific criteria for their relevance for this opinion. Two EU quarantine pests i.e. Meloidogyne fallax and Phytophthora ramorum (non-EU isolates) and two protected zone quarantine pests i.e. Entoleuca mammata and Thaumetopoea processionea fulfilled all relevant criteria and were selected for further evaluation. For the selected pests, the risk mitigation measures described in the technical dossier from the UK were evaluated considering the possible limiting factors. For these pests an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. In the assessment of risk, the age of the plants was considered, as larger trees are more likely to be infested mainly due to longer time grown in the field. In addition, larger canopies and root systems are more difficult to inspect, thereby making the detection of pests more challenging on large trees. The likelihood of pest freedom varies among the pests evaluated, with M. fallax being the pest most frequently expected on the imported plants. The Expert Knowledge Elicitation (EKE) indicated with 95% certainty that between 9735 and 10,000 per 10,000 large specimen trees will be free from M. fallax.

Windbreak Effectiveness of Single and Double-Arranged Shelterbelts: A Parametric Study Using Large Eddy Simulation

Shelterbelts provide essential protection against wind erosion and soil degradation, as well as protection for fruit-bearing plants and crops from strong winds. Enhancing their sheltering capabilities requires optimizing their pattern and orientation, as well as defining their height and desired canopy shape, according to the desired performance. In this work, Large Eddy Simulation is employed to investigate the flow field and windbreak effectiveness of single and double-arranged shelterbelts characterized by different geometry and resistance to the air passage for neutral atmospheric condition. In particular, the canopy of the shelterbelts is modeled as an isotropic porous medium immersed in atmospheric boundary layer flow using the Darcy–Forchheimer model. Results show that a shelterbelt with a rectangular-shaped cross-section and a large canopy height results in the most significant reduction in mean wind speed and TKE, thus providing a large wind-protection region. As the spacing distance of double-arranged shelterbelts increases, the protection zones formed by both shelterbelts are reduced. The systematic comparisons of flow patterns, drag force coefficients, and windbreak effectiveness indicators of a series of single and double-arranged shelterbelts are essential for optimizing the design and management of shelterbelts.

Impact of ENVI-met-Based Road Greening Design on Thermal Comfort and PM2.5 Concentration in Hot–Humid Areas

Road greening markedly impacts road thermal comfort and air quality. However, previous studies have primarily focused on thermal comfort or PM2.5 individually, with relatively few addressing both aspects comprehensively, particularly in humid regions. This study combined field measurements and simulations. It employed physiological equivalent temperature (PET) and quantified the horizontal distribution of particulate matter 2.5 (PM2.5). The research examines the effects of planting spacing, tree species, and tree–shrub combinations on pedestrian walkways in humid climates during both summer and winter. Using measured tree data and road PM2.5, a plant model was established and pollution emission parameters were set to validate the effectiveness of the ENVI-met through fitting simulations under various scenarios. The results indicated that (1) plant spacing for trees influenced both the road thermal environment and PM2.5 levels. Smaller spacing improved thermal conditions but increased PM2.5. (2) trees with large canopies and high leaf area indices (LAIs) notably enhanced thermal comfort, while those with smaller canopies and dense understories facilitated PM2.5 dispersion. The 3 m spacing resulted in a maximum absolute PM2.5 concentration difference (C) of 5.05 μg/m3 in summer and a maximum mean absolute PM2.5 concentration difference (M) in the downwind region of 2.13 μg/m3 in winter. (3) Combining trees with shrubs moderately improved pedestrian thermal comfort. However, taller shrubs elevated PM2.5 concentrations on walkways; heights ranging from 1.5 m to 2 m in summer showed higher C values of 5.38 μg/m3 and 5.37 μg/m3. This study provides references and new perspectives for the optimization of roadway greening design in humid areas in China.

Tailoring defoliation and nitrogen management for large canopy radiation use and biomass production of perennial systems destined for biorefinery

Perennial leafy grasses and legumes are promising for extraction of proteins with a green biorefinery amid increasing demand for local production. However, which defoliation strategy increases radiation-use efficiency and biomass production still needs to be determined. A multi-year field experiment started in 2019 in Denmark with fertilized grasses (perennial ryegrass, tall fescue), unfertilized legumes (alfalfa, red clover) and their fertilized mixture (grass-legume), each defoliated at 2-, 4- or 8- weeks interval, at either 7-9 or 12-14 cm defoliation height. The main aim was to quantify effects of species, defoliation height and frequency, and nitrogen application rate on canopy radiation interception, aboveground biomass and crude protein production, as well as aboveground radiation use efficiency (RUEA).The results showed that accumulated intercepted photosynthetically active radiation (AIpar) increased with increasing defoliation height and decreasing frequency for most systems, with the largest AIpar obtained seasonally by red clover (730-815 MJ m−2) and grass-legume mixture (790-826 MJ m−2) defoliated at medium to low frequency. Tall fescue defoliated at medium to low frequency yielded the highest aboveground biomass (10-14 Mg ha−1) and red clover defoliated at medium to high frequency yielded the most crude protein (2.5-2.9 Mg ha−1) compared to all other systems annually. RUEA decreased with increasing defoliation height and maximum values were achieved at medium frequency, with tall fescue having significantly higher RUEA (1.6-2.1 g MJ−1) than the other systems. Seasonally, RUEA was variable at high defoliation frequency, being consistently higher at the start and the end of the season for ryegrass and the mixture systems.This study pinpoints tall fescue and red clover as perennial crops with high agronomic productivity among tested species for green biorefinery and also concluded that red clover in temperate humid climate maximize productivity and sustainability for biorefining with defoliation at low height and medium frequency.

NOISE POLLUTION AND HEALTH IN NORTHERN GREATER MUMBAI: CASE OF RN WARD

Greater Mumbai is urbanizing at a rapid pace, leading to extensive construction activities, widespread use of machinery, and heavy traffic, which contribute significantly to noise pollution in the city. This study aims to measure noise levels in the study area, analyze their impact on residents' health, and recommend practical solutions to mitigate the adverse effects. The research methodology includes secondary data sourced from news articles to compile a literature review. Primary data is collected through a structured questionnaire administered via Google Forms to facilitate efficient data collection. A sample size of 80 respondents, randomly selected from locations with high noise levels, was chosen for the study. The key findings reveal elevated noise levels across most locations, with significant health impacts reported by respondents. These impacts include stress, sleep disturbances, and hearing impairment. The recommendations emphasize the importance of educating the public about the harmful effects of noise pollution and the need to plant large canopy trees, particularly in noisy areas, to absorb sound effectively. Additionally, hearing impairment is commonly identified as an occupational hazard, particularly among individuals working in industries associated with high noise levels.

Landscape configuration and storm characteristics drive spatial patterns of wind disturbance in boreal forest landscapes

ContextWind is an important disturbance in circumboreal forests, and its frequency and severity may change with climate change, highlighting the need to understand the drivers of wind disturbance. Currently, how landscape configuration drives wind disturbance is poorly understood.ObjectivesWe investigated whether and how landscape configuration is related to the extent and spatial pattern of wind disturbance, and how these relationships vary between windstorms and thunderstorms.MethodsWe used salvage logging data after 16 storms that occurred in Finland between 2011 and 2021. We placed a total of 301 landscapes, each encompassing an area of 8024 ha, within the storm tracks and used regression models to test how wind disturbance extent, disturbance patch size, number of disturbance patches, and disturbance patch clustering were related to landscape configuration and storm characteristics.ResultsIncreasing mean gap size and edge density, including permanent openings (e.g., lakes) and recent harvest gaps, increased disturbance extent, disturbance patch size, and number of disturbance patches. Conversely, increasing mean harvest gap size decreased disturbance patch clustering. Increasing wind speed had the largest contribution to increasing disturbance extent and number of disturbance patches, and decreasing disturbance patch clustering, with the magnitude of the effect varying between windstorms and thunderstorms.ConclusionsThe extent and spatial pattern of wind disturbances varied with landscape configuration and storm characteristics. Disturbance patches were larger in landscapes with large canopy gaps, resulting in a greater disturbance extent, exacerbated by increasing wind speed and thunderstorm development.

Forest stand dynamics of a short‐stature tree species: Ecological knowledge for sustainable forest management

Abstract Worldwide, the implementation of forest management guidelines has tried to mimic natural forest dynamics. The Oliver forest stand dynamics model has been successful in bridging natural forest dynamics associated with the disturbances of various spatial scales and silviculture also related to various spatial scales of management. However, the application of this model (and others) is restricted to tall forests. We claim here that the general research and commercial interest bias towards tall tree species has permeated silviculture and forest management, and that both the stand dynamics of short‐stature tree species and their treatment have remained largely unexplored and unknown. Using one short‐stature tree species, Nothofagus antarctica, as a model system, we show that this species indeed follows a stand dynamic different from other tall Nothofagus‐dominated forests in southern South America. This species forms short, mature, even‐aged stands without large canopy gaps that promote tree regeneration. With this in mind, we propose a conceptual ecology‐based silvicultural guideline focusing on the creation of strip cuts or gaps along with topsoil scarification to ensure regeneration and forest reorganization after disturbances. Policy implications. The acknowledgement that short‐stature tree species follow a stand dynamic different from tall tree species necessarily implies that they must be managed differently. This recognition, along with the implementation of ecology‐based silvicultural recommendations, represents strong arguments to make modifications to forest legislation that, together, must be aimed at conservation and sustainable forest management.

Optimizing an efficient urban tree strategy to improve microclimate conditions while considering water scarcity: a case study of Cairo

This study aims to develop an efficient urban tree strategy (UTS) to enhance the microclimate conditions of cities that suffer from heat stress and strong solar radiation, such as the metropolitan area of Greater Cairo. Cairo recently lost its limited greenery to enhance traffic. The proposed UTS aims to achieve a balance between enhancing microclimate conditions and considering the city’s water scarcity. It seeks to consider all strategic factors suitable for local conditions, including the selection of tree species (Step 1), the utilization of new technologies for irrigation (Step 2), and the optimization of the usage of an efficient number of trees (Step 3). When applying the strategy’s recommendations to a study area within Cairo’s downtown center and when testing different tree coverage percentages within urban canyons of various aspect ratios and orientations using ENVI-met, the microclimate conditions are significantly enhanced in certain streets during summertime compared to wintertime. Applying the UTS not only enhances thermal comfort but also helps to create a better comfort zone during certain hours. In one street, for example, there are average physiological equivalent temperature (PET) reductions of − 5.18° and − 6.36° at 16:00 and 17:00, respectively, which also changes the thermal comfort zone from extreme heat stress to very heat stress. The results show a strong positive correlation between thermal comfort enhancement and a reduction in the total mean radiant temperature (TMRT), verifying that shading plays a primary role in enhancing the microclimate conditions of urban canyons. Applying the UTS to the study area significantly enhances the microclimate conditions. Furthermore, through the implementation of irrigation technologies that are part of the UTS, water demand is reduced to only 15% when trees with larger canopies are used. Additionally, when the tree coverage percentage reaches 35 to 50% in some streets, it results in a significant enhancement in the PET.

Advances in Legume Systematics 14. Classification of Caesalpinioideae. Part 2: Higher-level classification.

Caesalpinioideae is the second largest subfamily of legumes (Leguminosae) with ca. 4680 species and 163 genera. It is an ecologically and economically important group formed of mostly woody perennials that range from large canopy emergent trees to functionally herbaceous geoxyles, lianas and shrubs, and which has a global distribution, occurring on every continent except Antarctica. Following the recent re-circumscription of 15 Caesalpinioideae genera as presented in Advances in Legume Systematics 14, Part 1, and using as a basis a phylogenomic analysis of 997 nuclear gene sequences for 420 species and all but five of the genera currently recognised in the subfamily, we present a new higher-level classification for the subfamily. The new classification of Caesalpinioideae comprises eleven tribes, all of which are either new, reinstated or re-circumscribed at this rank: Caesalpinieae Rchb. (27 genera / ca. 223 species), Campsiandreae LPWG (2 / 5-22), Cassieae Bronn (7 / 695), Ceratonieae Rchb. (4 / 6), Dimorphandreae Benth. (4 / 35), Erythrophleeae LPWG (2 /13), Gleditsieae Nakai (3 / 20), Mimoseae Bronn (100 / ca. 3510), Pterogyneae LPWG (1 / 1), Schizolobieae Nakai (8 / 42-43), Sclerolobieae Benth. & Hook. f. (5 / ca. 113). Although many of these lineages have been recognised and named in the past, either as tribes or informal generic groups, their circumscriptions have varied widely and changed over the past decades, such that all the tribes described here differ in generic membership from those previously recognised. Importantly, the approximately 3500 species and 100 genera of the former subfamily Mimosoideae are now placed in the reinstated, but newly circumscribed, tribe Mimoseae. Because of the large size and ecological importance of the tribe, we also provide a clade-based classification system for Mimoseae that includes 17 named lower-level clades. Fourteen of the 100 Mimoseae genera remain unplaced in these lower-level clades: eight are resolved in two grades and six are phylogenetically isolated monogeneric lineages. In addition to the new classification, we provide a key to genera, morphological descriptions and notes for all 163 genera, all tribes, and all named clades. The diversity of growth forms, foliage, flowers and fruits are illustrated for all genera, and for each genus we also provide a distribution map, based on quality-controlled herbarium specimen localities. A glossary for specialised terms used in legume morphology is provided. This new phylogenetically based classification of Caesalpinioideae provides a solid system for communication and a framework for downstream analyses of biogeography, trait evolution and diversification, as well as for taxonomic revision of still understudied genera.

Summer habitat for the female Tricolored Bat (Perimyotis subflavus) in Tennessee, United States

Abstract The Tricolored Bat is an imperiled species due to white-nose syndrome. There is limited information available on roosting and foraging area use of the species to support planning and management efforts to benefit recovery in the Southeastern United States. Female tricolored bats exit hibernation and allocate energy toward disease recovery, migration, and reproduction. Providing and managing for summer habitat is 1 strategy to promote recovery. We sought to: (1) determine local- and landscape-scale factors that influence female Tricolored Bat roost selection; (2) quantify land cover use in core and overall foraging areas; and (3) define foraging area size and distances traveled by female tricolored bats in Tennessee. Bats in this study roosted in trees of variable sizes, in multiple tree species with large canopy volumes, and almost always roosted in trees with dead leaf foliage suspended in the canopy. Forest plots used by bats had trees averaging 30 cm diameter at breast height, basal areas averaging 27 m2/ha, contained multiple tree species, and comprised around a 50:50 ratio of canopy and subcanopy trees. Bats did not roost in coniferous forest areas and were only located in deciduous and mixed forest areas. Bats foraged near and directly over water, in open areas, and along forest edges. This study increases our knowledge on habitat requirements of the species in a temperate region dominated by unfragmented forests and many large water bodies and serves a baseline for management and efforts to benefit survival, reproduction, and population recovery.

Structural reorganization in beech forests in central Germany as response to drought-induced mortality in the overstory

Prolonged periods of extreme heat and drought are changing forest health and forest structure. Loss of vitality, signs of dieback, and mortality of trees are reported in many regions of the world. There is a need for information on the quantification of drought effects on forest structure in order to detect drought stress at an early stage. Furthermore, forest structure is linked to growth processes that result from single tree and stand dynamics. In this study, we used mobile laser scanning to objectively assess forest structure in European beech (Fagus sylvatica L.) stands differently affected by drought. We used the box-dimension as a holistic measure of structural complexity that jointly describes both distribution and amount of plant material in a forest, and canopy cover as a measure for overall defoliation. We observed large canopy gaps in heavily damaged stands, but the overall structural complexity of the forest stands remained unchanged. However, when dividing the 3D forest stand model from mobile laser scanning into 5 m height layers, we noticed a “structural flip” with reduced structural complexity in the upper parts of the forests and increased structural complexity in the lower strata. This indicates that the forests are responding to drought with increased mortality of mature trees, resulting in increased light availability in the understory and consequently increased growth of the understory trees. The rather indifferent overall structural complexity of the investigated forests was due to the reorganization of structures by shifting the major foliage layer from top-to-bottom and is interpreted as a successful ecosystem-scale response to the drought events. However, it is unclear how these forests will respond to repeated droughts. The “structural flip” should therefore be regarded as an early warning signal pointing to increased ecosystem stress, though the stress level has not yet exceeded the adaptive capacity in the investigated forest.

Interactions between beech and oak seedlings can modify the effects of hotter droughts and the onset of hydraulic failure.

Mixing species with contrasting resource use strategies could reduce forest vulnerability to extreme events. Yet, how species diversity affects seedling hydraulic responses to heat and drought, including mortality risk, is largely unknown. Using open-top chambers, we assessed how, over several years, species interactions (monocultures vs mixtures) modulate heat and drought impacts on the hydraulic traits of juvenile European beech and pubescent oak. Using modeling, we estimated species interaction effects on timing to drought-induced mortality and the underlying mechanisms driving these impacts. We show that mixtures mitigate adverse heat and drought impacts for oak (less negative leaf water potential, higher stomatal conductance, and delayed stomatal closure) but enhance them for beech (lower water potential and stomatal conductance, narrower leaf safety margins, faster tree mortality). Potential underlying mechanisms include oak's larger canopy and higher transpiration, allowing for quicker exhaustion of soil water in mixtures. Our findings highlight that diversity has the potential to alter the effects of extreme events, which would ensure that some species persist even if others remain sensitive. Among the many processes driving diversity effects, differences in canopy size and transpiration associated with the stomatal regulation strategy seem the primary mechanisms driving mortality vulnerability in mixed seedling plantations.

Simulating the 3D Distribution of Absorbed Shortwave Radiation in a Tree Crown: Comparison of Simplified and Monte Carlo Models

AbstractUrban trees are expected to alleviate severe thermal environments in summer. The absorbed shortwave radiation is a key variable to estimate the microclimatic effects of trees. In numerical simulation tools for the urban and built thermal environment, the difficulty lies in how to calculate the absorbed radiation in terms of accuracy and computational load. Here we investigated the difference between a radiative transfer model calculating scattering by the Monte Carlo method and a simpler model that accounts for scattering by modifying the optical depth. The calculations of absorbed radiation were performed under various conditions of leaf normal distribution and zenith angle of incident radiation, using tree models represented by voxels with different leaf area density values. For the photosynthetically active radiation, the relative difference between models was less than 10% for most cases. For the near‐infrared radiation, the difference was also small for a large canopy consisting of several trees. The difference was 30%–60% and 0%–20% for zenith angles of incident radiation of 0° and 60°, respectively, for small isolated trees with a crown height and width of less than 5 m, which was a significantly different condition from a uniform canopy. This large difference was related to the uniformity of the canopy and was explained by the transmittance from each voxel to the outside of the canopy. The present study enables us to evaluate the applicability of the simple model and correct the difference from the Monte Carlo model.

Xylella fastidiosa subsp. pauca, Neofusicoccum spp. and the Decline of Olive Trees in Salento (Apulia, Italy): Comparison of Symptoms, Possible Interactions, Certainties and Doubts.

Xylella fastidiosa subsp. pauca (XFP), Neofusicoccum mediterraneum, N. stellenboschiana and other fungi have been found in olive groves of Salento (Apulia, Italy) that show symptoms of severe decline. XFP is well known to be the cause of olive quick decline syndrome (OQDS). It has also been assessed that Neofusicoccum spp. causes a distinct disease syndrome, namely, branch and twig dieback (BTD). All these phytopathogens incite severe symptoms that can compromise the viability of large canopy sectors or the whole tree. However, their specific symptoms are not easily distinguished, especially during the final stages of the disease when branches are definitively desiccated. By contrast, they can be differentiated during the initial phases of the infection when some facets of the diseases are typical, especially wood discoloration, incited solely by fungi. Here, we describe the typical symptomatological features of OQDS and BTD that can be observed in the field and that have been confirmed by Koch postulate experiments. Similar symptoms, caused by some abiotic adverse conditions and even by additional biotic factors, are also described. Thus, this review aims at: (i) raising the awareness that declining olive trees in Salento do not have to be linked a priori to XFP; (ii) defining the guidelines for a correct symptomatic diagnosis to orient proper laboratory analyses, which is crucial for the application of effective control measures. The possibility that bacterium and fungi could act as a polyspecies and in conjunction with predisposing abiotic stresses is also widely discussed.

Flying through the forest canopy: Movement patterns and habitat selection of rescued and wild Harpy Eagles in the Brazilian Amazon

We tracked six Harpy Eagles (Harpia harpyja) by satellite telemetry from 2011 to 2021 in the Brazilian Amazonia, analyzing the used area, movements parameters and habitat selection functions for three of them: one adult within its breeding site, one translocated adult, and a four-years old floating subadult. We used the first-passage time to assess the scale at which these individuals respond to the environment, and the behavioral change point analysis to determine behavioral states parameters across trajectories. We fitted a logistic linear regression model with used-available locations and environmental covariates: slope, Terrain Ruggedness Index (TRI), Normalized Difference Vegetation Index (NDVI), land cover, and habitat edge as predictor variables. Harpy Eagle locations were highly related with “Forest” land cover and high NDVI values. The subadult and the translocated adult selected for “Secondary Forest” within their home ranges, which highlights the importance of this type of habitat in fragmented landscapes. In addition, we found behavioural differences in the movement paths of rehabilitated individuals of Harpy Eagle that are subsequently released to the wild. In conclusion, we suggest including in conservation management not only the nest tree and its immediately surrounding but also an area over landscape scale to optimize and promote the functional connectivity, with a safe and efficient dispersion of immatures. Linking Harpy Eagle´s movement locations to resources (land cover, NDVI), risks (forested habitat edge) and environmental conditions (slope, terrain ruggedness) is an opportunity to learn about habitat selection by this large canopy predator. The Harpy Eagle movement ecology has a potential relationship with the spatial dynamics of prey in the forest canopy, which needs to be further addressed in future research.

Design and Spray Performance Evaluation of an Air–Ground Cooperation Stereoscopic Plant Protection System for Mango Orchards

With the aim of solving the problems of high labor intensity, low operational efficiency, and poor deposition distribution uniformity in the mango canopy associated with traditional plant protection devices, an air-ground co-operation stereoscopic plant protection system consisting of an orchard caterpillar mist sprayer and a six-rotor plant protection UAV was designed to jointly undertake plant protection operations in mango orchards. We tested the spraying performance of the system on mango trees, compared with the single-machine operation, the air–ground co-operation system could significantly increase the droplet coverage on the upperside of mango leaves in each part of the canopy (a 14.7% increase for the mist sprayer and 12.9% for the UAV). This increased the active component deposition distribution uniformity in the mango canopy but could not significantly improve the deposition and coverage of droplets on the underside of leaves compared with the mist sprayer and plant protection UAV. Due to the characteristics of the mango canopy such as large leaf length and thickness and complex leaf inclination distribution, this led to poor deposition distribution uniformity of the two spray units, and the overall CV was over 150%. The pesticide active ingredients were almost uniformly distributed in the vertical direction when the application ratios (ground implements/plant protection drones) were 8/2 and 7/3, offering a promising protocol for reduced pesticide application in mango orchards. This study presents promising data that support the innovative integration of drones into crop protection programs for large canopy crops (e.g., mango) and provides guidance for the ACSPPS system in reduction and precision application research.