Strong Shading Research Articles

Land use to agriculture and planted forests strongly affect the genetic diversity of Baccharis crispa Spreng., a native herb of South America

Abstract Human population growth constantly requires an increase in the production of food and products from the timber industry. To meet this demand, agriculture and planted forests are advancing over natural areas. In view of this, it is necessary to know the effects of land use for different purposes (grain production, pastures, planted forests, fruit production, among other uses) on the genetic diversity of populations of native species. This knowledge can assist in land use planning as well as in the development of conservation strategies for native species. In this study, we evaluated the effect of land use for agriculture (mainly for cereal production) and planted forests on the genetic diversity of Baccharis crispa Spreng., a herb native to South America. To achieve our goals, we compared population genetic data obtained with three molecular markers (microsatellites, ISSR [inter-simple sequence repeat] and isoenzymes) with data on land use for agriculture and planted forests from 15 different locations. Our results showed that regardless of the molecular marker used, the greater the use of land for agriculture and planted forests, the lower was the genetic diversity of B. crispa populations. Baccharis crispa is a semi-perennial species that needs at least one year to reach its reproductive period, which is prevented in agricultural areas due to the land being turned over or dissected with herbicides every six months. In the studied regions, the planted forests are of eucalypt and/or pine, which besides being species with a high production of allelopathic substances, produce strong shading and B. crispa is a species that inhabits open grassland that needs high incidence of sunlight for development. The data obtained in our study can assist in the decision-making to use land in order to reconcile the production of supplies for humanity and for the conservation of nature.

Changes in forest structure over 23 years under disturbances in a warm temperate rain forest on Yakushima Island, Japan

AbstractClarifying the influence of disturbances by biotic and abiotic agents on long‐term changes in forest structure and demographic rates is an important task of forest ecology. Here, we investigated changes in forest structure and demographic rates and the effects of biotic and abiotic factors (sika deer, ambrosia beetle, neighborhood trees, and indices of strong wind and wetness) in a 4‐ha long‐term ecological study plot in a lowland warm temperate rain forest on Yakushima Island, Japan, from 1996 to 2019 for three regeneration groups related to gap dynamics (gap demander: GD, light shade tolerant: LS, and strong shade tolerant: SS). GD had relatively lower recruitment and survival than LS and/or SS. Changes in demographic rates were not significantly correlated with those in the index of strong wind in any regeneration group. The effects of sika deer on demographic rates did not differ among groups. Stems of Fagaceae species belonging to LS attacked by ambrosia beetles recorded in 2013 did not significantly differ in RGR and survival rates. Our results indicate that despite the relatively long monitoring period of 23 years, we did not detect significant effects of strong winds on demographic rates among regeneration groups, and shade‐tolerant species (LS and SS) showed better demographic performance than light‐demanding species (GD) and an increase in total basal area over time. We need longer monitoring of forest dynamics to understand forest responses to disturbances considering several factors, including the time lag of demographic responses to disturbances and the long‐term effects of disturbances.

Effects of light on the seedling growth and photosynthetic physiology of the sympatric invasive lianas Dolichandra unguis-cati and Anredera cordifolia

In order to explore the adaptation of sympatric invasive lianas Dolichandra unguis-cati and Anredera cordifolia to light intensity, and to study the effects of different levels of light intensity on their seedling growth and photosynthetic physiology, field shading experiments were conducted. We also selected the sympatric native lianas Hedera nepalensis var. Sinensis as a control. The results showed that, under light shade and strong light, the growth of D. unguis-cati was the best. The growth parameters, net photosynthetic rate, and water use efficiency of D. unguis-cati were the highest, and the contents of photosynthetic pigments were the highest under different light conditions. These results indicated that sufficient light could significantly promote the biomass accumulation and gas exchange of D. unguis-cati, and that D. unguis-cati could maintain efficient light trapping and light protection abilities under different light environments. Under heavy shade, the growth rate of A. cordifolia was the best. The growth parameters of A. cordifolia were significantly greater than those of D. unguis-cati and H. nepalensis var. Sinensis, and the gas exchange parameters were significantly greater than those of H. nepalensis var. Sinensis. However, the growth of the shoot system of A. cordifolia was almost halted under strong light, and the growth indexes were weaker than those of H. nepalensis var. Sinensis. In conclusion, the seedlings of D. unguis-cati had a strong ability to withstand strong light stress, and the seedlings of A. cordifolia had a strong shade tolerance but not strong light stress.

Plant Growth in LED-Sourced Biophilic Environments Is Improved by the Biochar Amendment of Low-Fertility Soil, the Reflection of Low-Intensity Light, and a Continuous Photoperiod.

Introducing plants in the design of biophilic indoor environments is fundamental for improving human health, well-being, and performance. Previous studies showed that the phenotype of the model plant Arabidopsis thaliana grown under LED-sourced CoeLux® lighting systems was characterized by low biomass production rates, a small leaf area, and a low lamina-to-petiole length ratio, suggesting the onset of a strong shade avoidance syndrome. Therefore, it is essential to identify new strategies to improve plant growth under these peculiar light conditions. In the present work, we investigated the effects of two growing media (i.e., low-fertility soil and soil-less substrate), solid and liquid fertilizers, manure, biochar, perlite, mirror reflection of light, and a 24 h photoperiod on A. thaliana plants growing under CoeLux® lighting systems at a light intensity of 30 μmol m-2s-1. We found that the biochar soil amendment to low-fertility soil increases both the above-ground plant biomass and leaf area. Furthermore, the application of a mirror behind the plants and a continuous photoperiod improves not only the biomass and the leaf area but also the lamina-to-petiole length ratio. The combination of different beneficial treatments can further boost plant growth in the low-intensity light environment characterizing the CoeLux® biophilic lighting systems.

Genotypic Variation of Purple Rice in Response to Shading in Yield, Anthocyanin Content, and Gene Expression.

Purple rice (Oryza sativa L.) contains anthocyanin, which acts as an antioxidant and functional food for humans. The levels of anthocyanin growth and production in rice are mainly controlled by the availability of light. However, shade can affect anthocyanin biosynthesis genes. Therefore, the objective of this study was to determine the yield and anthocyanin content among four purple rice varieties, which provide the difference in colors of purple and green leaves. This study also evaluated gene expression affected by shading treatment to understand the relation of grain anthocyanin and expression level. This research was conducted using a split plot design using four levels of shading (levels of shading from anthesis to maturity) with three replications, no shading, 30% shading, 50% shading, and 70% shading, as the main plots and purple rice varieties as subplots, KJ CMU-107, K2, K4, and KDK10, from anthesis to maturity. Shading significantly decreased yield and yield components, but increased grain anthocyanin content. Nonetheless, the response of yield and grain anthocyanin content to shading did not show a significant different between purple and green leaf varieties. In addition, the level of OsDFR gene expression was different depending on the shading level in four rice varieties. The OsDFR gene presented the highest expression at shading levels of 30% for K4 and 50% for KDK10, while the expression of the OsDFR gene was not detected in the purple rice varieties with green leaves (KJ CMU-107 and K2). The response of grain anthocyanin and gene expression of OsDFR to light treatment did not show significantly differences between the purple and green leaf varieties, suggesting that the appearance of anthocyanin in leaves might be not related to anthocyanin synthesis in the grain. Taken together, the results suggest that some purple rice varieties were more suitable for planting under low light intensity based on a lower level of grain yield loss, strong shade tolerance, and high anthocyanin content in leaf and grain pericarp. However, it is necessary to explore the effects of light intensity on genes and intermediates in the anthocyanin synthesis pathway for further study.

Comparison of Growth and Leaf Color Quality of <italic>Mesembryanthemum cordifolium</italic> f. <italic>variegata</italic> as Affected by Shading Levels

Background and objective: Mesembryanthemum cordifolium is a plant belonging to the Aizoaceae family and is native to South Africa and Namibia. As a CAM plant, M. cordifolium exhibits strong resistance to drought stress and can be utilized for the removal of soil salinity and heavy metals. Furthermore, it is an important medicinal crop with anti-inflammatory and antidepressant effects. However, despite its potential benefits, research on the optimal growth environment for M. cordifolium remains scarce.Methods: Therefore, this study selected M. cordifolium f. variegata with high ornamental value as the experimental plant and compared the effects of different shading levels on the growth and leaf color quality of variegated baby sun rose (M. cordifolium f. variegata). Six shading levels (0, 35, 45, 60, 75, and 99%, respectively) were designed using polyethylene (PE) shading films.Results: The results showed that the shoot height, shoot width, dry weight, and chlorophyll content (SPAD units) were highest under the 60% shading level, while leaf length, leaf width, and fresh weight were highest under the 75% shading level. On the other hand, growth was relatively lower under the 0% shading level, which suggests that M. cordifolium f. variegata prefers shade over direct sunlight. On the contrary, M. cordifolium f. variegata showed growth even under the 99% shading level, proving to have strong shade tolerance, but the leaf color quality was lowerst.Conclusion: In conclusion, to significantly increase the size and biomass of plants and improve leaf color quality when cultivating M. cordifolium f. variegata under shading treatment, it is recommended to cultivate it under 60-75% shading levels.

Photovoltaic power stations: an opportunity to promote European semi-natural grasslands?

European semi-natural grasslands are particularly species-rich and provide many ecosystem services but depend on extensive land management. Today, these ecosystems are highly threatened by land abandonment, land use intensification and habitat destruction. The increasing construction of solar parks may contribute to habitat destruction but also provide an opportunity to restore or even create semi-natural grasslands. We studied ten solar parks along a climate gradient in Southern France to evaluate the establishment of semi-natural grasslands managed by grazing. We compared plots outside and under solar panels in terms of plant community composition, soil biodiversity and soil functioning to test whether solar panels hamper this establishment. The different microclimate under solar panels strongly affected the plant species composition and reduced the abundance of soil mesofauna and biomass of fungi and gram-negative bacteria. Outside panels, the vegetation was shaped by a climatic gradient, in particular by variations in temperature and precipitation whereas under panels variations were smaller indicating a homogenizing effect of panels on plant community composition. We found more trophic interactions between panels compared to outside and under panels suggesting a protection effect of panels between rows on the soil food web. However, plots under panels showed the lowest number of interactions demonstrating that the strong shading had a negative effect on the plant-soil food web. Solar panels therefore reduce the plant and soil biodiversity of semi-natural grasslands and disrupt ecosystem functions. In order to improve the ecological integration of solar parks, it is thus necessary to mitigate negative effects of solar panels on biodiversity or to increase the space between panels.

Patterns of Reforestation Successions on Abandoned Agricultural Lands of the Bashkir Cis-Urals

The analysis and forecasting of the course of restoration successions on abandoned agricultural lands of the Bashkir Cis-Urals are presented. It was shown that the consequences of the complex influence of various economic uses of arable land after the cessation of plowing remain for a long time in the successional series. This maintains the differences between the communities of each fallow and is the reason for the high phytocoenotic diversity. Subsequently, strong shading as a result of active reforestation leads to a decrease in species richness, leveling of floristic differences between fallow communities and convergence of phytocenoses. The rate of succession and the dynamics of the floristic composition of communities are the highest in the first 12–15 years after the withdrawal of land from agricultural use before the onset of the formation of long-derived phytocenoses with a dense tree canopy. It is predicted that succession on the fallows will be influenced by the forest vegetation directly in contact with the fallows after the formation of a dense forest stand. However, the final formation of the floristic composition of the lower layers may take more than 100–150 years.

Shading apple trees with an agrivoltaic system: Impact on water relations, leaf morphophysiological characteristics and yield determinants

• Study of the effects of fluctuating shading on an apple orchard using agrivoltaism. • Shading in orchard allowed a less stressful environment and reduced water needs. • Shading increased specific leaf area and reduced leaf photosynthetic rates. • Strong shading over 3 years reduced floribundity and alternate bearing behaviour. • Shading has low impact on fruit size due to higher water content in shaded fruits. The installation of dynamic photovoltaic panels over apple orchards could meet the challenges of protecting orchards from climate change and drive the energetic transition. However, the impact of solar panel's shading on apple performance needs to be investigated before being commercially adopted. A dynamic agrivoltaic system was installed in the south of France over a 10-year-old 'Golden Delicious' apple orchard and studied during three experimental seasons (2019–2021). This study aimed to evaluate the impact of fluctuating shading (photovoltaic panel orientation to maximise panel light interception) on water relations, leaf morphophysiological characteristics and yield determinants. With the selected photovoltaic design and strategy, trees were grown under a fluctuating shading (variable shading between 4% and 88% during the day) with a mean shading rate of 50–55%. On average, the air temperature was reduced by 3.8 °C, while relative humidity was increased by 14% under shading conditions. Depending on the season, the lower radiation and stressful microclimate decreased the irrigation between 6% and 31%. Fluctuating shading reduced the photosynthetic capacity of leaves and increased their specific leaf area (thinner leaves). The reduction in carbohydrate assimilation under shading was associated with lower starch reserve accumulation in the shoots (-7%), lower flower intensity at the shoot scale (-31%) and a lower proportion of trees with a high floribundity in 2020 (-45%). However, less alternate bearing was observed under shading, and better frost protection resulted in a higher proportion of trees bearing fruit under photovoltaic panels (+31%) and number of fruits per fruit-bearing tree (+44%) in 2021. Fruit size was less sensitive than fruit number to shading. Fruit size was reduced by 17% in 2019 but maintained in 2020 and 2021, probably due to a better water status of shaded trees that accumulated more water. Fruit dry matter content under shading was reduced by an average of 24%. In conclusion, agrivoltaic systems may reduce alternate bearing behaviour in apple trees, showing the importance of carrying out a multi-year study. However, the fluctuating shading strategy tested in this study did not maintain sufficient yields, with yields below 40 t/ha in all three years of study. Identifying the positive and negative effects of shading in this study may be useful for the development of sustainable apple orchard shading strategies.

INV-Flow2PoseNet: Light-Resistant Rigid Object Pose from Optical Flow of RGB-D Images Using Images, Normals and Vertices.

This paper presents a novel architecture for simultaneous estimation of highly accurate optical flows and rigid scene transformations for difficult scenarios where the brightness assumption is violated by strong shading changes. In the case of rotating objects or moving light sources, such as those encountered for driving cars in the dark, the scene appearance often changes significantly from one view to the next. Unfortunately, standard methods for calculating optical flows or poses are based on the expectation that the appearance of features in the scene remains constant between views. These methods may fail frequently in the investigated cases. The presented method fuses texture and geometry information by combining image, vertex and normal data to compute an illumination-invariant optical flow. By using a coarse-to-fine strategy, globally anchored optical flows are learned, reducing the impact of erroneous shading-based pseudo-correspondences. Based on the learned optical flows, a second architecture is proposed that predicts robust rigid transformations from the warped vertex and normal maps. Particular attention is paid to situations with strong rotations, which often cause such shading changes. Therefore, a 3-step procedure is proposed that profitably exploits correlations between the normals and vertices. The method has been evaluated on a newly created dataset containing both synthetic and real data with strong rotations and shading effects. These data represent the typical use case in 3D reconstruction, where the object often rotates in large steps between the partial reconstructions. Additionally, we apply the method to the well-known Kitti Odometry dataset. Even if, due to fulfillment of the brightness assumption, this is not the typical use case of the method, the applicability to standard situations and the relation to other methods is therefore established.

Microalgae growth in ultra-thin steady-state continuous photobioreactors: assessing self-shading effects

To disclose the net effect of light on microalgal growth in photobioreactors, self-shading and mixing-induced light–dark cycles must be minimized and discerned from the transient phenomena of acclimation. In this work, we performed experiments of continuous microalgal cultivation in small-scale photobioreactors with different thicknesses (from 2 to 35 mm): working at a steady state allowed us to describe the effect of light after acclimation, while the geometry of the reactor was adjusted to find the threshold light path that can discriminate different phenomena. Experiments showed an increased inhibition under smaller culture light paths, suggesting a strong shading effect at thicknesses higher than 8 mm where mixing-induced light–dark cycles may occur. A Haldane-like model was applied and kinetic parameters retrieved, showing possible issues in the scalability of experimental results at different light paths if mixing-induced light–dark cycles are not considered. To further highlight the influence of mixing cycles, we proposed an analogy between small-scale operations with continuous light and PBR operations with pulsed light, with the computation of characteristic parameters from pulsed-light microalgae growth mathematical modeling.

Effects of shading at different growth stages with various shading intensities on the grain yield and anthocyanin content of colored rice (Oryza sativa L.)

Colored rice is a high-quality and high-added-value rice that has attracted increasing attention in recent years. Therein, the main functional substance in colored rice is anthocyanin, which plays an important role in anti-aging, inhibiting adipocyte accumulation, preventing cancer and treating cancer. However, there are few studies on the effects of shading at different growth periods with various shading intensities on the grain yield and anthocyanin content of colored rice. Field experiments were conducted in Hainan Province in 2020 and 2021, and two inbred rice cultivars, Youxianghongdao (YXHD) and Suixiangheinuo (SXHN), were adopted. Shading treatments were conducted at three different growth periods: shading from the regreening stage to the mid-tillering stage (S1), shading from the mid-tillering stage to the full heading stage (S2), and shading from the full heading stage to the maturity stage (S3). Based on the treatment of these three shading growth stages, three shading intensities were incorporated, including shading 20% (D1), 40% (D2) and 60% (D3) light intensities. No shading during the whole growth stage was used as a control (CK). The results indicated that the grain yield and anthocyanin content of both colored rice varieties were most sensitive to shading treatment during S3 among the three shading periods. The grain yields of both colored rice varieties decreased as the shading intensity increased for the three shading periods. In addition, the grain anthocyanin content of the red rice variety (YXHD) decreased as shading intensity increased under S1 and S2, while under S3, the grain anthocyanin content increased as shading intensity increased. However, for the black rice variety (SXHN), the anthocyanin content in grains showed an opposite trend with the changes in both shading intensity and shading period. Above results suggested that SXHN was more suitable for planting in the rainy season with low light intensity than YXHD based on low grain yield loss, strong shade tolerance and high anthocyanin content. However, it is necessary to explore the effects of light intensity on the anthocyanin synthesis mechanism in the near future. • Colored rice is a high-quality and high-added-value rice that has attracted increasing attention in recent years. • Colored rice varieties were most sensitive to shading treatment during the full heading to maturity stage. • The grain yield of colored rice decreased as the shading intensity increased. • The grain anthocyanin content of YXHD decreased as the shading intensity increased. • For SXHN, the anthocyanin content showed the opposite trend with the changes in both shading intensity and shading period.

Effects of Strong Shading Treatment on Plucked New Shoot Yield, Leaf Color, Free Amino Acid Content, and Unrefined Tea Quality in Tea Cultivars Recommended by the Shizuoka Prefecture

Effects of Strong Shading Treatment on Plucked New Shoot Yield, Leaf Color, Free Amino Acid Content, and Unrefined Tea Quality in Tea Cultivars Recommended by the Shizuoka Prefecture

An improved search ability of particle swarm optimization algorithm for tracking maximum power point under shading conditions

Introduction. Extracting maximum possible power from solar energy is a hot topic of the day as other sources have become costly and lead to pollution. Problem. Dependency on sunlight for power generation makes it unfeasible to extract maximum power. Environmental conditions like shading, partial shading and weak shading are the major aspect due to which the output of photovoltaic systems is greatly affected. Partial shading is the most known issue. Goal. There have been many proposed techniques and algorithms to extract maximum output from solar resources by use of photovoltaic arrays but every technique has had some shortcomings that couldn’t serve the complete purpose. Methodology. Nature inspired algorithms have proven to be good to search global maximum in a partially shaded multipeak curve which includes particle swarm optimization, artificial bee colony algorithm, and flower pollination algorithm. Methods. Particle swarm optimization algorithm is best among these in finding global peaks with less oscillation around maximum power point, less complexity, and easy to implement nature. Particle swarm optimization algorithm has the disadvantage of having a long computational time and converging speed, particularly under strong shading conditions. Originality. In this paper, an improved opposition based particle swarm optimization algorithm is proposed to track the global maximum power point of a solar photovoltaic module. Simulation studies have been carried out in MATLAB/Simulink R2018a. Practical value. Simulation studies have proved that opposition based particle swarm optimization algorithm is more efficient, less complex, more robust, and more flexible and has better convergence speed than particle swarm optimization algorithm, perturb and observe algorithm, hill climbing algorithm, and incremental conductance algorithm.

Integration of Light and Auxin Signaling in Shade Plants: From Mechanisms to Opportunities in Urban Agriculture.

With intensification of urbanization throughout the world, food security is being threatened by the population surge, frequent occurrence of extreme climate events, limited area of available cultivated land, insufficient utilization of urban space, and other factors. Determining the means by which high-yielding and high-quality crops can be produced in a limited space is an urgent priority for plant scientists. Dense planting, vertical production, and indoor cultivation are effective ways to make full use of space and improve the crop yield. The results of physiological and molecular analyses of the model plant species Arabidopsis thaliana have shown that the plant response to shade is the key to regulating the plant response to changes in light intensity and quality by integrating light and auxin signals. In this study, we have summarized the major molecular mechanisms of shade avoidance and shade tolerance in plants. In addition, the biotechnological strategies of enhancing plant shade tolerance are discussed. More importantly, cultivating crop varieties with strong shade tolerance could provide effective strategies for dense planting, vertical production, and indoor cultivation in urban agriculture in the future.

Surface coating preparation of spherical magnetic materials

Magnetic materials are being increasingly used in anti-counterfeiting coatings, but the dark colors of magnetic materials greatly limit their applications. This necessitates the development of light-colored magnetic materials. In this study, the heterogeneous precipitation method was used to deposit a layer of titanium dioxide (TiO2) on the surface of magnetic spherical metal particles, followed by the deposition of a layer of Ag by the reduction method, in order to achieve a light color. In the experiment, the particles were initially coated with a few tens of nanometers of TiO2 with a strong shading effect, followed by a further coating of Ag of the same thickness with a similar shading performance. Not only did this achieve a lighter color, but there was no reduction in the magnetic properties of the material after the application of the coating. Scanning electron microscopy (SEM), scanning electron microscopy and energy-dispersive spectroscopy (SEM-EDS), X-ray diffractometry (XRD), and other methods were used to study the changes in morphology and composition before and after the magnetic material was coated. A magnetic tester was used to study the changes in magnetic strength before and after the magnetic material was coated.

Seasonal variations in macrofauna distribution according to the distance from a herbaceous strip in a Mediterranean alley cropping plot

In alley cropping systems, herbaceous strips planted with trees are added into cropped fields. These systems could provide a favorable habitat for many organisms, producing shade in summer and litter in autumn, but their impacts on soil macrofauna are poorly studied, with most samplings limited to one date and therefore one season only. This study investigated the seasonal variations in the spatial distribution of soil macrofauna in a Mediterranean alley cropping plot. We sampled three different shading treatments: a strong shading treatment with lightly-pruned trees, a light shading treatment with pollarded trees, and a no-shade treatment without trees in the herbaceous strips. We measured the density of macrofauna individuals classified into different taxonomic and functional groups by the extraction of 25*25*25 cm soil cores in the herbaceous strip (with or without trees), and in the crop alley at 1 m and 2.5 m from the herbaceous strip. We found a similar response of macrofauna density to the distance from the herbaceous strip for all shading treatments. However, this response was strongly dependent on the season. In spring, just after soil tillage, most soil macrofauna presented higher densities in the herbaceous strip than in the crop alley, except for plant feeders. In early summer, this trend was mostly visible for earthworms, Diplopoda and adult Coleoptera. In autumn, higher densities in the herbaceous strip than in the crop alley were only significant for anecic and endogeic earthworms, while other macrofauna categories presented similar densities at all distances from the herbaceous strip, due to an increase in macrofauna density in the crop alley. These large seasonal variations in spatial distribution of soil macrofauna highlight the importance of temporal repetitions when studying community responses to agroforestry system design and management. The mechanisms by which population densities increased in the crop alley a few months after soil perturbation require further investigation.

Influences of greening and structures on urban thermal environments: A case study in Xuzhou City, China

Under the influences of global warming and urbanization, the urban thermal environment has gradually deteriorated, threatening human health. Based on the mobile sampling method, urban thermal environment data and street images were collected synchronously at pedestrian height in Xuzhou City, China, in late summer of 2020. Images were predicted and identified by SegNet, and the proportions of various objects were calculated in separate images, including the green view index (GVI, the vegetation proportion), construction view index (CVI, proposed to represent constructions proportion) and other view index (OVI, proposed to represent rest objects proportion). Various statistical methods were used to analyse urban thermal environment data and the above indices. Correlation analysis indicated that air temperature (Ta) was negatively and positively correlated with GVI and CVI (at the 0.01 level), while absolute humidity (H) was positively and negatively correlated with GVI and CVI (at the 0.01 level), respectively. Stepwise regression indicated the relative importance of GVI to Ta, and the relative importance of CVI to H was 100 %. The analytical hierarchy process indicated the joint effect of the three indicators explained only 50 % of the spatial variations in Ta and H over the sampling route, indicating that other factors influenced the urban thermal environment. Through a comparison between the two clustering analyses, we identified outliers located near crossroads, water bodies, mountains and high-rise buildings, which could be attributed to the hard surface, high openness or strong shading effect of high-rise buildings. In conclusion, a variety of urban elements influence the urban thermal environment, and the complex synergistic effect is worthy of further study to provide scientific input for urban planning, urban design and landscape design.

On-Campus Pocket Parks for Enhancing Outdoor Learning Experience in Malaysian Universities

Recently, small nearby outdoor spaces have become an important tool to improve academic outcomes by enhancing students' social-learning experience. However, nearby open spaces and pocket parks of Malaysian universities lack the absorption of informal and formal outdoor education that may affect the academic experience, especially in the outdoor spaces. Therefore, there is a need to enhance students' on-campus learning experience in Malaysian universities. This study aimed to investigate the visually preferred pocket parks criteria to promote students' learning experience on Malaysian campus grounds; this is in line with the Twelfth Malaysia Plan for 2021-2025. This study employed a visual-verbal preference survey (VVPS) conducted in three Malaysian universities, including Universiti Malaya (UM), Universiti Putra Malaysia (UPM), and Universiti Kebangsaan Malaysia (UKM), to assess the visual preferences of 415 students toward six pocket parks sceneries. Multiple regression analysis was used to predict the relationship between students' outdoor learning experience and preferred pocket parks criteria. The result showed that pocket parks that provide a strong shade, variety in softscape and activities, and bench hardscape contributed to enhancing students' outdoor learning. The result indicated that providing on-campus pocket parks with the preferred design criteria can enhance the learning experience. Thus, the current study contributed to integrating nearby pocket parks in outdoor learning to improve campus urban design and academic experience. The study's findings are of great importance for policymakers and academic administration, landscape and urban planners, and researchers in the field in creating an academically responsive campus.

Identifying the optimal travel path based on shading effect at pedestrian level in cool and hot climates

As shading affects thermal environments and intentions of outdoor activities, studying shaded areas is necessary to increase pedestrian travel choice. This study provided a new insight by calculating the shading length based on LiDAR data and then identifying the optimal pathway for demonstrating the shading effects at different times in summer and winter. The Kowloon Peninsula of Hong Kong was selected as the study area. Results revealed that streets oriented N-S and NE-SW before and at noon and N-S and E-W after noon are beneficial for strong shading effects in summer, and streets oriented NE-SW and NW-SE during 8:00–10:00 and 14:00–16:00 and streets oriented N-S and NW-SE at 12:00 are suitable for travel with intense solar radiation in winter. The area percentages of overlapping areas of pathways oriented E-W and N-S at different times in summer and winter demonstrated what times pedestrians can choose to go through the overlapping pathways (e.g. pathways oriented E-W during 8:00–10:00 and during 14:00–16:00) or stay in the overlapping open spaces. The more overlapping pathways based on the random points were found at different times in winter than summer. The study reflects when and in which public spaces individuals can walk or perform outdoor activities.