Foliage Density Research Articles

Vertical stratification of an avian community in New Guinean tropical rainforest

AbstractVertical stratification of avian communities has been studied in both temperate and tropical forests; however, the majority of studies used ground‐based methods. In this study we used ground‐to‐canopy mist nets to collect detailed data on vertical bird distribution in primary rain forest in Wanang Conservation Area in Papua New Guinea (Madang Province). In total 850 birds from 86 species were caught. Bird abundance was highest in the canopy followed by the understory and lowest in the midstory. Overall bird diversity increased towards the canopy zone. Insectivorous birds represented the most abundant and species‐rich trophic guild and their abundances decreased from the ground to canopy. The highest diversity of frugivorous and omnivorous birds was confined to higher vertical strata. Insectivorous birds did not show any pattern of diversity along the vertical gradient. Further, insectivores preferred strata with thick vegetation, while abundance and diversity of frugivores increased with decreasing foliage density. Our ground‐to‐canopy (0–27 m) mist netting, when compared to standard ground mist netting (0–3 m), greatly improved bird diversity assessment and revealed interesting patterns of avian community stratification along vertical forest strata.

Behavioral development and habitat structure affect postfledging movements of songbirds

ABSTRACTPostfledging survival of neotropical migrant songbirds has been linked to seasonal and annual changes in the environment and to individual condition. Understanding what influences variation in postfledging movements may provide insight into the differential value of habitat across life‐history stages. We conducted a radio‐telemetry study of postfledging ovenbirds (Seiurus aurocapilla; n = 45) and Acadian flycatchers (Empidonax virescens; n = 62) in mature‐forest fragments from 2012 to 2015 in Missouri, USA. We documented variability in behavior and space use and used generalized linear mixed models to evaluate the relationship of postfledging movement rates to individuals’ condition, temporal variables, and local habitat variables. We found effects of age and season on movement distances for both study species. Additionally, daily movements of fledgling ovenbirds were negatively related to understory foliage density, a characteristic previously linked to increased survival. Habitat features are useful in predicting the postfledging movements of ovenbirds. By including behavioral development (age) and season in movement models, we were able to isolate and detect habitat effects on movement of ovenbirds and Acadian flycatchers. We suggest researchers use models of daily movement to further strengthen resource quality hypotheses generated by habitat selection and survival studies. © 2016 The Wildlife Society.

Crecimiento en diámetro de Zanthoxylum kellermanii P. Wilson en una selva perennifolia del norte de Oaxaca, México

Se determinó el crecimiento estacional en diámetro de una especie de importancia maderable: Zanthoxylum kellermanii P. Wilson. Se seleccionaron 22 árboles en seis categorías diamétricas y se les instalaron bandas dendrométricas para tomar lecturas bimensuales de su crecimiento. También se registraron características relacionadas con la copa de los árboles: calidad (simetría, vigor, densidad del follaje) y posición (incidencia de luz). El crecimiento promedio anual en diámetro fluctuó de 0,86 cm a 1,87 cm en las categorías diamétricas, de 0,52 cm a 2,04 cm en las calidades de copa y de 0,73 cm a 1,70 cm en las posiciones de copa. Los análisis de varianza mostraron diferencias altamente significativas (p<0 ,001) entre categorías diamétricas, así como entre calidades y posiciones de copa. Herramientas como la banda dendrométrica apoyada en modelos de regresión fueron de gran utilidad para el registro y proyección del incremento en diámetro de la especie estudiada.

Impacts of changes in climate, land use and land cover on atmospheric mercury

Mercury is an important pollutant that can be transported globally due to its long lifetime in the atmosphere. Atmosphere-surface exchange is a major process affecting the cycling of mercury in the global environment and its impacts on food webs. We investigate the sensitivities of the air-surface exchange, atmospheric transport, and budget of mercury to projected 2000–2050 changes in climate and land use/land cover with a global chemical transport model (GEOS-Chem). We find that annual mean Hg(0) dry deposition flux over land could increase by up to 20% in northern mid-latitudes by 2050 due to increased vegetation and foliage density. Climate change can significantly affect both the wet deposition and atmospheric chemistry of mercury. In response to the projected climate change, the annual mean wet deposition flux increases over most continental regions and decreases over most of the mid-latitude and tropical oceans. The annual mean mercury wet deposition flux over northern and southern high latitudes increases by 7% and 8% respectively, largely driven by increases in precipitation there. Surface Hg(0) is predicted to increase generally, because high temperatures decrease Hg(0) oxidation by bromine and high moisture increases aqueous Hg(II) photo reduction. The combined effects of projected changes in climate, land use and land cover increase mercury deposition to the continental biosphere and decrease mercury deposition to the marine biosphere.

Implementing set operations over moving regions using the component moving region model

Many natural phenomena are intuitively represented as spatiotemporal data objects, or moving objects. For example, vehicles, rivers, hurricanes, low pressure systems, areas of high density of foliage, etc align well with a geometric representation, and all change position or shape over time. Moving object models exist that represent real world objects as point, line, and region geometries that change continuously over time, leading to research into spatiotemporal analysis functionality over these objects. Models of moving objects are ideal for representing data streams that record the motion of spatial data over time. However, the implementation of operations to support spatiotemporal analysis over moving objects, particularly over moving regions, has proven difficult. In this paper, we develop a mechanism to support the implementation of the set operations of intersection, union, and difference between pairs of moving regions. The mechanism builds on the Component Model of Moving Regions and the semantic specifications of its operations. Specifically, we develop a generalized method of computing an intermediate data structure from which the results of various operations are then derived. The mechanism utilizes well-known 2D and 3D operational primitives and achieves O(nlgn) time complexity using appropriate data structures.

Suitability of Taxodium distichum for Afforesting the Littoral Zone of the Three Gorges Reservoir.

The littoral zone ecosystem of the Three Gorges Reservoir (TGR) has become significantly degraded by annual cycles of prolonged winter flooding and summer drought. For purposes of flood control and sediment management, the water level in the reservoir is lowered by 30 m during the summer monsoon season and raised again to 175 m above sea level each year at the end of the monsoon period. To explore an effective way to promote biodiversity and associated ecosystem services, we examined Taxodium distichum as a species for afforesting the littoral zone. Sapling growth variations were measured after two rounds of winter flooding. Dominant influence factors were determined by redundancy analysis. Herb community similarities between the experimental afforested areas and nearby control areas were assessed to detect the ecosystem influence of the experimental afforestation. 94.5% of saplings planted at elevations above 168 m survived. All measured growth indices (tree height, diameter at breast height, crown width and foliage density) decreased as the flood depth increased. Completely submerged saplings had a mean dieback height of -0.65 m. Greater initial foliage density led to increased tree height and stem diameter. Shannon-Wiener indices were not significantly different between plots in experimental and control areas, but the low similarity of herb communities between experimental and control areas (0.242 on average) suggested that afforestation would enrich plant community structure and improve littoral zone ecosystem stability. Because littoral zone afforestation provides several ecosystem services (habitat, carbon sink, water purification and landscaping), it is a promising revegetation model for the TGR.

Social variables exert selective pressures in the evolution and form of primate mimetic musculature.

Mammals use their faces in social interactions more so than any other vertebrates. Primates are an extreme among most mammals in their complex, direct, lifelong social interactions and their frequent use of facial displays is a means of proximate visual communication with conspecifics. The available repertoire of facial displays is primarily controlled by mimetic musculature, the muscles that move the face. The form of these muscles is, in turn, limited by and influenced by phylogenetic inertia but here we use examples, both morphological and physiological, to illustrate the influence that social variables may exert on the evolution and form of mimetic musculature among primates. Ecomorphology is concerned with the adaptive responses of morphology to various ecological variables such as diet, foliage density, predation pressures, and time of day activity. We present evidence that social variables also exert selective pressures on morphology, specifically using mimetic muscles among primates as an example. Social variables include group size, dominance 'style', and mating systems. We present two case studies to illustrate the potential influence of social behavior on adaptive morphology of mimetic musculature in primates: (1) gross morphology of the mimetic muscles around the external ear in closely related species of macaque (Macaca mulatta and Macaca nigra) characterized by varying dominance styles and (2) comparative physiology of the orbicularis oris muscle among select ape species. This muscle is used in both facial displays/expressions and in vocalizations/human speech. We present qualitative observations of myosin fiber-type distribution in this muscle of siamang (Symphalangus syndactylus), chimpanzee (Pan troglodytes), and human to demonstrate the potential influence of visual and auditory communication on muscle physiology. In sum, ecomorphologists should be aware of social selective pressures as well as ecological ones, and that observed morphology might reflect a compromise between the demands of the physical and the social environments.

Disruption ofNisotra basselaeoviposition to improve pest management onAbelmoschus manihotin the Solomon Islands

Slippery cabbage, Abelmoschus manihot Medicus, is a leafy vegetable crop grown throughout the Pacific, especially in Melanesian countries where it is a popular leafy vegetable. The slippery cabbage flea beetle, Nisotra basselae (Bryant) (Coleoptera: Chrysomelidae) was first recorded in the Solomon Islands in 1981; it has since become a severe pest of A. manihot and it is present in most islands in the archipelago. Very little was known about the biology or ecology of the beetle prior to this study. Adult beetles defoliate the crop but immature development is completed below ground, where the three larval instars feed on A. manihot roots. In laboratory and field studies we found that following maturation the beetle feeds and mates on A. manihot leaves. Female beetles descend the plant stems at night and deposit their eggs in small clusters close to roots beneath the soil surface. In laboratory studies > 95% of eggs were laid within 2 cm of the plant stem and in field studies a strong positive correlation between adult density on foliage and egg density on roots was detected. In field studies female beetles were collected in Tangle-foot traps at the base of plant stems, leading to a decline in adult density and suggesting a high degree of fidelity to individual host plants. Mechanical disruption of preferred oviposition sites with copra sacking significantly reduced egg densities on roots and adult densities on foliage when compared to standard practice (bare soil), the application of mulch or undersowing with clover. Results are discussed in the context of ongoing work to develop cultural control based IPM strategies for N. basselae on A. manihot in the Solomon Islands.

Including trees in the numerical simulations of the wind flow in urban areas: Should we care?

Although trees are numerous in urban areas, their dynamic effects on the wind flow are usually approximated or neglected altogether in many wind engineering studies, especially those based on numerical modeling. This study investigates the effect of the inclusion of trees in numerical simulations of wind flow in urban area. Three approaches are used to include the dynamic effect of trees: the basic approach (tree effects are neglected), the implicit approach (tree effects are included in the surface parameterizations), and the explicit approach (trees are represented by porous media). Several test cases have been adopted in order to cover a wide range of urban complexities, wind directions, foliage densities, and tree planting configurations. The results show that there are significant effects of trees when the explicit approach is used compared to the basic and the implicit approaches. Thus tree effects need to be considered using an explicit approach to simulate wind flow in urban area. Also, many parameters such as wind direction, foliage density, and urban configuration are believed to influence the intensity of trees effects. This study emphasizes the importance to explicitly consider the effects of trees in numerical model investigations for the wind flow in urban areas.

Description of the airflow produced by an air-assisted sprayer during pesticide applications to citrus

Atmospheric drift of plant protection products is considered a major source of air pollution during pesticide applications. Citrus protection against pests and diseases usually requires application of these products using air-blast sprayers. Many authors have emphasized the influence of vegetation on the risk of spray drift. The aim of this work was to describe in detail how the airflow from an air-blast sprayer behaves when it reaches citrus trees and, in particular, the effect that the tree canopy has on this flow. Tests were conducted at a commercial citrus orchard with conventional machinery, placed parallel to a row of trees. Air velocity and direction was measured using a 3D ultrasonic anemometer in 225 points situated in three parallel planes perpendicular to the equipment. The stability of the airflow at each measuring point was studied and the mean velocities were graphically represented. Two vortexes, one behind the canopy, and another over the tree, have been deducted and never been reported before. Both may have an important influence on the trajectories of the sprayed droplets and, as a consequence, on the way in which plant protection products are diffused into the atmosphere. Observed turbulence intensities were higher than in similar experiments conducted in other tree crops, which may be attributable to the higher air volume generated by the machinery used for citrus protection and to the higher foliage density of citrus orchards.

Terrestrial lidar remote sensing of forests: Maximum likelihood estimates of canopy profile, leaf area index, and leaf angle distribution

Terrestrial laser scanning (TLS) swings a tiny-footprint laser to resolve 3D structures rapidly and precisely, affording new opportunities for ecosystem studies, but its actual utility depends largely on efficacies of lidar analysis methods. To improve characterizing forest canopies with TLS, we forged a methodological paradigm that combines physics and statistics to derive foliage profile, leaf area index (LAI), and leaf angle distribution (LAD): We modeled laser–vegetation interactions probabilistically and then developed a maximum likelihood estimator (MLE) of vegetation parameters. Unlike classical gap-based algorithms, MLE explicitly accommodates laser scanning geometries, fully leverages raw laser ranging data, and simultaneously derives foliage profile and LAD. We evaluated MLE using both synthetic lidar data and real TLS scans at sites in Everglades National Park, USA. Estimated LAI differed between algorithms by an average of 26%. Compared to classical gap analyses, MLE derived foliage density profile and LAD more accurately. Also, MLE has a rigorous statistical foundation and generated error intervals better indicative of the true uncertainties of estimated canopy parameters—an aspect often overlooked but essential for credible use of lidar vegetation products. The theoretical justification and experimental evidence converge to suggest that classical gap methods are sub-optimal for exploiting tiny-footprint lidar data and MLE offers a paradigm-shifting alternative. We envision that MLE will further boost confident use of terrestrial lidar as a versatile tool for environmental applications, such as forest survey, ecological conservation, and ecosystem management.

Hedgerow rejuvenation management affects invertebrate communities through changes to habitat structure

Hedgerows are an important semi-natural habitat for invertebrates and other wildlife within agricultural landscapes. Hedgerow quality can be greatly affected either by over- or under-management. Neglect of hedgerows is an increasingly important issue as traditional management techniques such as hedgelaying become economically unviable. In the UK, funding for hedge management is available under agri-environment schemes but relatively little is known about how this impacts on wider biodiversity. We used a randomised block experiment to investigate how habitat structural change, arising from a range of techniques to rejuvenate hedgerows (including more economic/mechanised alternatives to traditional hedgelaying), affected invertebrate abundance and diversity. We combined digital image analysis with estimates of foliage biomass and quality to show which aspects of hedge structure were most affected by the rejuvenation treatments. All investigated aspects of habitat structure varied considerably with management type, though the abundance of herbivores and predators was affected primarily by foliage density. Detritivore abundance was most strongly correlated with variation in hedge gap size. The results suggest that habitat structure is an important organising force in invertebrate community interactions and that management technique may affect trophic groups differently. Specifically we find that alternative methods of hedgerow rejuvenation could support abundances of invertebrates comparable or even higher than traditional hedgelaying, with positive implications for the restoration of a larger area of hedgerow habitat on a limited budget.

Assessing growth performance and deficiency of climber species on tropical greenwalls

Vertical greening can contribute to urban green infrastructure, urban heat-island amelioration and climate adaptation. Tropical greenwall practice, hindered by inadequate scientific knowledge and experience, can benefit from objective assessment of species performance and growth deficiency. Comprehensive survey of critical climber-plant traits shortlisted 20 potentially suitable species. A climber-selection matrix was established to facilitate species selection and greenwall design. Perennial woody climbers with ornamental flower or foliage and biological potential to reach 13-m height were preferred. They represented two attachment modes, namely mesh-climber and concrete-(bare-wall)climber groups. A field study was designed to monitor their growth from seedlings in experimental plots. Growth conditions were optimized by providing high-quality soil mix and irrigation. The 32-month study period included three active-growing seasons with two interspersed slow-growing seasons. Field assessment methods were developed to acquire systematic data on plant performance indicators and deficiency symptoms. Key attributes were selected to compute climber performance index (CPI) and climber deficiency index (CDI) as synoptic representation of greenwall-application suitability. Mesh-climbers performed much better than concrete-climbers across all key performance indicators, and with notably better CPI. They demonstrated faster establishment and growth rates and more ornamental flowers. The two groups had similar CDI mainly due to insufficient foliage density and foliage loss. For mesh-climbers, Quisqualis indica, Wisteria sinensis and Lonicera japonica had excellent performance, and the remaining species were good to fair. For concrete-climbers, only Parthenocissus dalzielii was rated good and Campsis grandiflora fair, with the rest poor to very poor.

Cooling performance of residential greenery in localised urban climates: a case study in Shanghai China

Residential greenery provides accessible amenity space and moderated microclimate for local community. Research has indicated that the cooling performance of urban greenery is impacted by the geometry and fabric of surrounding humanised envelope. The paper proposes a research framework inspired by the idea of urban climate zone (UCZ) to investigate cooling performance of residential greenery in localised urban climates. The inner-city of Shanghai was divided into four UCZs, the meteorological as well as greenery form/density data was measured from ten residential quarters throughout four UCZs. The tree canopy shading and overall foliage density, qualified by the tree view factor and green plot ratio respectively, were found capable of partly explaining the variation in air temperature mitigation. The local urban effect has notable effect on the cooling rates. Residential greenery should be integrated into local green network to optimise its cooling performance.

Characterization of Air Profiles Impeded by Plant Canopies for a Variable-Rate Air-Assisted Sprayer

<abstract> <bold><sc>Abstract.</sc></bold> The preferential design for variable-rate orchard and nursery sprayers requires that the sprayers are able to control the liquid and air flow rates based on the canopy structure in real time. Demand for this advanced feature has increased rapidly with the public demand for reductions in pesticide use. A variable-rate, air-assisted, five-port sprayer had been in development to achieve variable discharge rates of both liquid and air. To verify the capability of varying the airflow rate by changing the fan inlet diameter of the sprayer, air jet velocities impeded by plant canopies were measured at various locations inside tree canopies of three different sizes and foliage densities. Air jet velocities were adjusted by changing the sprayer fan inlet diameter with an airflow regulator and measured with a constant-temperature anemometer coupled with hot-wire probes. Peak air velocity and airflow pressure decreased with foliage density and canopy depth. For the 0.34 m fan inlet diameter, the airflow pressure ratio of the front portion to the back portion of the canopies was 2.45 for a 1.65 m tall and 13.4 leaf area index (LAI) Tsuga canadensis (Tree 1), 1.43 for a 2.35 m tall and 2.5 LAI Ficus benjamina (Tree 2), and 1.64 for a 3.0 m tall and 1.5 LAI Acer rubrum (Tree 3). Similarly, the front-to-back peak air velocity ratios were 8.55, 1.59, and 1.89 for Tree 1, Tree 2, and Tree 3, respectively. Variations were significant for peak air velocities and airflow pressures among the three different tree volumes and foliage densities. Increasing the fan inlet diameter from 0.13 to 0.34 m increased average airflow pressure from 2.84 to 4.01 kg m^-2, from 3.88 to 5.82 kg m^-2, and from 2.46 to 3.75 kg m^-2 inside the canopies of Tree 1, Tree 2, and Tree 3, respectively, while it also increased average peak air velocity from 2.6 to 4.5 m s^-1, from 5.5 to 9.1 m s^-1, and from 3.0 to 5.2 m s^-1 inside the three tree canopies. Therefore, the new sprayer design with an airflow regulator to alter the fan inlet diameter was able to provide variable airflow for different canopy sizes and foliage densities and offered a potentially effective approach to discharge uniform airflow profiles to carry droplets with efficient spray penetration into plant canopies.

Relative roles of resource stimulus and vegetation architecture on the paths of flies foraging for fruit

Many animals use their perceptual abilities to orient and locate resources in architecturally complex environments. However, it is not well known how the strength of a stimulus source affects the geometry of animal movement in architecturally complex environments. We mapped the 3D vegetation architecture of four apple trees of varying morphology and age and recorded the paths of apple maggot flies Rhagoletis pomonella foraging for artificial fruit. We compared the observed movement with the one obtained from a random walk model on a graph to estimate both 1) the attraction radius and strength of a fruit and 2) the relative roles of the architecture of vegetation and of the strength of attraction of a fruit on the movement of flies. The attraction radius is the maximal distance at which a stimulus source biases the movement of individuals and the attraction strength measures how strong this bias is. Plant architectural complexity is defined according to both foliage density and its 3D distribution within the canopy. A single fruit induces a bias in the path orientation of an insect that is at a large distance, relative to a tree volume, but it has no effect on the step length of moves. The plant complexity makes a minor contribution to defining the radius of the sphere of attraction, but a large contribution to the attraction strength. Conditional on visiting the location, the plant architecture plays a minor role compared to that of the presence of the fruit. Our findings show that the complexity of the environment can alter the use of sensory information, which has important implications for animal movements in complex environments. The importance of our results in animal dispersal and foraging is considered.

A physically based vegetation index for improved monitoring of plant phenology

Using a spectral vegetation index (VI) is an efficient approach for monitoring plant phenology from remotely-sensed data. However, the quantitative biophysical meaning of most VIs is still unclear, and, particularly at high northern latitudes characterized by low green biomass renewal rate and snow-affected VI signals, it is difficult to use them for tracking seasonal vegetation growth and retrieving phenology. In this study we propose a physically-based new vegetation index for characterizing terrestrial vegetation canopy green leaf area dynamics: the plant phenology index (PPI). PPI is derived from the solution to a radiative transfer equation, is computed from red and near-infrared (NIR) reflectance, and has a nearly linear relationship with canopy green leaf area index (LAI), enabling it to depict canopy foliage density well. This capability is verified with stacked-leaf measurements, canopy reflectance model simulations, and field LAI measurements from international sites. Snow influence on PPI is shown by modeling and satellite observations to be less severe than on the Normalized Difference Vegetation Index (NDVI) or the Enhanced Vegetation Index (EVI), while soil brightness variations in general have moderate influence on PPI. Comparison of satellite-derived PPI to ground observations of plant phenology and gross primary productivity (GPP) shows strong similarity of temporal patterns over several Nordic boreal forest sites. The proposed PPI can thus serve as an efficient tool for estimating plant canopy growth, and will enable improved vegetation monitoring, particularly of evergreen needle-leaf forest phenology at high northern latitudes.

Assessing the impact of large‐scale water table modifications on riparian trees: a case study from Australia

AbstractMining below groundwater tables is increasing globally, yet little is known of how associated large‐scale modification of water tables impact functioning of surrounding ecosystems. We used measurements of foliage density (ρF) and sapwood‐related sap flow (QS) to assess effects of depth to groundwater on Eucalyptus victrix, a tree species that is common in riparian zones in central and northern parts of Australia.Foliage density (ρF) varied with season and among sites. Of itself, ρF provided a partial indicator of how trees responded to falling (more than 10 m) and rising (more than 9 m) water tables. Assessment of QS was highly informative. Across all sites, QS was least (90–130 l m−2 sapwood h−1) where groundwater was naturally deep (30 m) or had fallen substantially over the past 4 years (from 8 to 19 m). Fastest rates of QS (&gt;245 l m−2 sapwood h−1) were recorded where groundwater had risen to a depth similar to a site where depth to groundwater remained stable at 6–7 m. Our analyses of daytime and night‐time QS emphasize that water use by E. victrix is highly plastic and opportunistic. We discuss how empirical analysis of QS, coupled with a sound understanding of local hydrogeology, can help assess responses in ecosystem function to large‐scale modification of groundwater levels – an important issue globally, as well as in Australia. Copyright © 2014 John Wiley &amp; Sons, Ltd.

Evaluating drought response of Southern Cape Indigenous Forests, South Africa, using MODIS data

Indigenous forests in South Africa cover less than 0.5% of the total land area but are a valued resource under threat from fragmentation, fires, exploitation, and climate change. The largest indigenous forest complex is located along the southern coast of the Western Cape Province. This complex is made up of sub-forests distinguished by different structural and edaphoclimatic attributes. It has been hypothesized that these sub-forests exhibit different resistance to stressors, such as drought. A time series of MODIS 250 m enhanced vegetation index (EVI) data were used to characterize the foliage condition of the three distinctive sub-forests before, during, and after a severe drought in 2009. The goal was to determine how these sub-forests responded to this disturbance. EVI anomalies for the drought and post-drought periods were calculated using annual median EVI values, since removal of outliers based on quality control flags that accompany the MODIS products or noise-filtering techniques proved to be ineffective. Results of the study indicated that pre-drought foliage density EVI was not controlled by differences in water availability, but may have been due to other edaphoclimatic or structural attributes. Maximum foliage loss occurred one year after the driest year, indicating the cumulative effects of drought stress on forest production and retention of foliage. The hypothesized stress resistance capacity of the three sub-forests was found to correspond to their rate of post-drought recovery. There is a need to tie these satellite observations of forest drought response to ground observations of forest condition, growth, and specific site attributes.

Seasonal effectiveness of a Korean traditional deciduous windbreak in reducing wind speed

Little is known about how the increased porosity of a deciduous windbreak, which results from loss of leaves, influences wind speed reduction. We hypothesized that, with loss of foliage, the wind speed reduction effectiveness of a deciduous windbreak decreases on near leeward side but not on further leeward side and that wind speed recovers faster in the full foliage season than in other seasons. During summer, autumn, and winter (full, medium, and non-foliage season, respectively), we observed wind speed and direction around a deciduous windbreak in a traditional Korean village on windward and near and further leeward sides (at -8H, 2H, and 6H; H = 20 m, a windbreak height). We used a linear mixed effects model to determine that the relative wind speed reduction at 2H significantly decreased from 83% to 48% (<TEX>$F_{2,111.97}=73.6$</TEX>, P < 0.0001) with the loss of foliage. However, the relative wind speed reduction at 6H significantly increased from 26% to 43% (<TEX>$F_{2,98.54}=18.5$</TEX>, P < 0.0001). Consequently, wind speed recovery rate between 2H and 6H in summer was two times higher than in autumn and ten times higher than in winter (<TEX>$F_{2,102.93}=223.1$</TEX>, P < 0.0001). These results indicate that deciduous windbreaks with full foliage seem to induce large turbulence and increase wind speed recovery rate on leeward side. Our study suggests that further research is needed to find the optimal foliage density of a deciduous windbreak for maximizing windbreak effectiveness regardless of seasonal foliage changes.