Shade Trees Research Articles

‘Shade trees for the next generation’: constructing the promissory publics of prospective cohort studies

ABSTRACT Epidemiological cohort studies are a central research design in public health which appeal to, and can reinforce, specific ideas of the nation, sociality and the ‘good’ citizen. The concept of publics, the sociology of expectations and a co-productionist framework provide the theoretical frame to investigate how popular representations of two cohort studies, German National Cohort and UK Biobank, attempt to enrol a concerned public. By constructing promissory publics, cohort studies produce morally charged visions of health research and civic engagement as normative social practices. Promissory publics straddle the population and the citizen, the nation and the region, the future and the past, thus adding nuance to existing conceptual approaches. The publics of cohort studies are bolstered by the care practices of predominantly female staff, functioning as a performance of social recognition in lieu of an immediate beneficiary of research participation. Through these processes, popular representations of cohort studies intervene into much broacher visions of society and its anticipated futures, co-producing socially dominant and morally charged projections of sociality as well as health. The production of such publics thereby draws boundaries between members of the public and those practices enacted as endangering civic values. As such, cohort studies may have much broader socio-cultural ramifications that could reinforce old or reintroduce new lines of inclusion or exclusion.

Impact of 2050 tree shading strategies on building cooling demands

Impact of 2050 tree shading strategies on building cooling demands

Method for selecting ornamental species for different shading intensity in urban green spaces.

In urban areas, ornamental plants face different constraints, such as the shading of buildings and trees. Therefore, the selection of suitable species and their integration or combination with pre-existing plants is very important. Trees, shrubs, and herbaceous plant species must be distributed according to plant light requirements and shading intensity. Ornamental plants are classified into two groups based on their light intensity or shade tolerance: sun and shade species. To properly position the plants, especially in the immediate vicinity of buildings, it is necessary to study the projection of shadows during the year and the most critical periods, such as July and August. The position of ornamental species with different shading tolerances can be obtained by characterizing the leaf gas exchange for each species. Among the physiological parameters, the most important is the light compensation point, which is the light intensity corresponding to a net photosynthesis equal to zero. This means that the assimilation of carbon dioxide through photosynthesis is equal to the carbon dioxide emitted by respiration. This steady state represents the most critical condition for plants to endure the summer. The distribution of species inside a green area should be determined by considering the minimum light intensity that allows sufficient photosynthesis to compensate for the respiration rate. In this context, non-destructive leaf gas exchange, chlorophyll a fluorescence, and chlorophyll content can be useful tools for selecting suitable ornamental plants under diverse shading conditions.

Three decades of shade trees improve soil organic carbon pools but not methane uptake in coffee systems

The rapid expansion of coffee plantations in tropical area at the cost of natural forest may suppress the methane (CH4) uptake and change the soil fertility. However, observations on soil CH4 uptake rates and the ecological consequence studies on coffee-based plantations are sparse. The objectives of this study were to characterize the dynamics of CH4 uptake among natural forest, coffee monoculture (CM), and coffee intercropping with shade tree (CI), and to evaluate the key drivers of soil CH4 uptake. Results showed that the conversion of forest into 25-year and 34-year CM plantations significantly reduced the soil organic carbon (SOC) content by 57% and 76%, respectively, whereas CI plantation profoundly increased the SOC by 20%–76% compared with CM plantation. Although soils of forest, CM and CI functioned exclusively as CH4 sinks, the CM and CI plantations significantly decreased the ambient CH4 uptake rates by 64%–83% due to soil moisture shift and soil nitrate availability by using chemical fertilizer. Interestingly, the potential CH4 uptake of CM and CI plantations did not decrease and in some treatments, was even higher than that of the natural forest. Potential CH4 uptake showed a negative correlation with soil pH and SOC content, but a positive correlation with soil available phosphorus (AP). Collectively, although the SOC and soil pH were increased through intercropping with shade trees for decades, the inhibition of atmospheric CH4 uptake was still difficult to alleviate.

Microclimate reveals the true thermal niche of forest plant species.

Species distributions are conventionally modelled using coarse-grained macroclimate data measured in open areas, potentially leading to biased predictions since most terrestrial species reside in the shade of trees. For forest plant species across Europe, we compared conventional macroclimate-based species distribution models (SDMs) with models corrected for forest microclimate buffering. We show that microclimate-based SDMs at high spatial resolution outperformed models using macroclimate and microclimate data at coarser resolution. Additionally, macroclimate-based models introduced a systematic bias in modelled species response curves, which could result in erroneous range shift predictions. Critically important for conservation science, these models were unable to identify warm and cold refugia at the range edges of species distributions. Our study emphasizes the crucial role of microclimate data when SDMs are used to gain insights into biodiversity conservation in the face of climate change, particularly given the growing policy and management focus on the conservation of refugia worldwide.

Effects of shading, soil moisture, fertilizations and sowing time on isoflavone content of soybean seed in Hokkaido

ABSTRACT Aiming to produce soybean seeds with high yield and high isoflavone content in Hokkaido, which has cool weather, we evaluated the effects of shading, soil moisture, fertilizations (K,N,P,Mo) and sowing time on yield and seed isoflavone content using mainly a high-isoflavone variety, Yukipirika. Shading treatments of 50 % and 70 % during the seed filling stage in a greenhouse decreased both yield and isoflavone content. Applying four soil moisture treatments from pF 1.5 to pF 2.8 in the seed filling stage in a greenhouse gave a positive correlation between soil moisture and both yield and isoflavone content. K fertilization treatments with different amount and various types of fertilizers were conducted in fields at medium or high level of K2O in soils typical of Hokkaido uplands. The additional K treatments did not increase yield or isoflavone content significantly in the field experiments. N (urea foliar application) treatments in fields did not affect yield and isoflavone content significantly. And P (phosphite root application) and Mo (seed treatment) in fields did not change isoflavone content, either. Sowing two weeks and four weeks later than the standard sowing time in a field decreased the yield but did not change the isoflavone content. From a practical application perspective, for producing soybean seeds with high isoflavone contents and high yield in Hokkaido, it is effective to plant at a standard time with a normal amount of fertilizer in fields with minimum shade and to maintain the soil moisture at well-watered levels during the seed filling stage.

Adaptation of soybean varieties on teak shaded land in Grobogan Regency, Indonesia

One of the efforts to increase soybean production is to increase the planted area under tree stands by paying attention to shade tolerant varieties. The experiment was carried out in Grobogan, Central Java in October-December 2019. The study was done using Factorial Completely Randomized Block Design. The first factor was teak shading i.e. under teak stands aged 1-2 years, teak aged 3-4 years and teak aged ≥ 5 years and the second factor was soybean varieties i.e. Dena 1 and Anjasmoro. Data were analyzed by analysis of variance. The results of statistical analysis showed that the shade of teak trees had a significant effect on the number of productive branches at the age of 8 weeks after planting. Soybean plants under the shade of teak aged 1-2 years formed the highest root nodules and were significantly different from those planted under the shade of teak aged 3-4 years and shaded teak aged 5 years. The Anjasmoro variety planted under the shade of 1-2 years old teak produced the highest number of pods of 64 pods/plant. The lowest number of pods was indicated by the Dena 1 variety planted under teak stands aged 5 years (12 pods/plant).

Effects of light on growth and biomass of Dendrobium officinale (Kimura et Migo) grown in ThaiNguyen province, Vietnam

Dendrobium officinale Kimura et Migo (DO), one of the valuable and scarce medicinal orchids, in nature. Applying technical measures to regulating growth, increasing artificial plant biomass and conserving this herb is necessary. This research was conducted to evaluate the effect of shade treatments (30, 50, 70, and 90%) and light color (white, purple, blue, and red) on growth and biomass of the DO under greenhouse conditions in Thai Nguyen province, Vietnam. The results revealed that shading 50% and 70% significantly influenced on growth and biomass. Using red light is the best for growth, biomass, and increasing contents of polysaccharide and alkaloid. These results should be recommented in production technology of the DO.

Pengaruh Naungan dan Dosis Fungi Mikoriza Arbuskular terhadap Pertumbuhan Kopi Arabika (Coffea arabica) Fase TBM

The growth of Arabica coffee plants in the immature phase can be improved by shade application thus the plants absorb sunlight optimally and AMF to maintain soil fertility through the AMF association with the roots of the Arabica coffee plants. This research aims to determine the shading type and AMF dosage that increasing the growth of Arabica coffee plants (Coffea arabica) in the immature phase. This research was conducted at the Experimental Field of the Faculty of Agriculture, Padjadjaran University, Jatinangor, Sumedang, West Java, with an altitude of ±750 m above sea level from February 2023 to May 2023. The design used was a split plot design with three replications. The main plot was the type of shade which consisted of three levels, namely: 65% paranet shade, gamal shade trees with a ratio of gamal to coffee of 1:2, and shade trees of gamal with a ratio of gamal to coffee of 1:4. Subplots were AMF doses consisting of four levels: without AMF (control), AMF doses of 40g/plant, AMF doses of 50g/plant, AMF doses of 60g/plant. The results showed that there was an interaction effect between the shade of the gamal shade tree and the dose of AMF in the ratio of gamal to coffee 1:2 and the AMF dose of 40g/plant on the parameter of increase in stem diameter at 10-12 WAP. There is an independent effect of the type of shade of gamal shade trees with a ratio of gamal to coffee of 1:4 on the parameters of increase in leaf number 6-12 WAT, increase in branch length 2 WAT, increase in stem diameter 8-10 WAT, and chlorophyll index 2 WAT.

Influence of shading intensity on chlorophyll, carotenoid and metabolites biosynthesis to improve the quality of green tea: A review

Tea plant (Camellia sinensis L.) is an economically important beverage crop cultivated worldwide. Tea is the most popular non-alcoholic beverage, which is manufactured from fresh shoots of tea plants. The aroma, taste and color of tea are the most important index for determining tea quality. Manipulating light transmission by shading is the most effective method of improving the nutritional value and sensory qualities of tea. Shading on tea plant enhances the taste and aroma of tea by affecting the synthesis of free amino acids, flavonoids and aromatic compounds. Also, shading can significantly increase the chlorophyll content of tea leaves, leading to enhanced tea leaf coloration. Thus, the expression of genes related to chlorophyll biosynthesis, free amino acids biosynthesis and flavonoids biosynthesis pathways are significantly regulated by shading treatment to increase the overall quality of tea plants. However, the shading-induced regulatory mechanism remains unclear. Therefore, this review summarizes up to date knowledge of the shading effects on chlorophyll, carotenoid and quality-related metabolites biosynthesis for improvement of taste, aroma and color quality of green tea.

Coffee Farmers as Agents of Change in Conservation of Rare Saninten Tree Plants (Castanopsis argantea Blume A.DC) Innovation in Suntenjaya, Lembang, Bandung

Biodiversity development innovations in Indonesia are quite diverse, collaboration between stakeholders is a catalyst for change. Saninten tree (Castanopsis argantea Blume A.DC) is one of the rare plants with endangered IUCN status that is being conserved by PT Pertamina Patra Niaga DPPU Husein Sastranegara in Suntenjaya, Lembang, Bandung. Increasing community capacity in conservation activities is one of the important elements for conservation to be successful. This important element is embodied by inviting coffee farmers around the conservation area to be able to protect rare plants while at the same time planting coffee in the same place, because coffee that grows under the shade of trees will produce coffee beans that have a unique taste.

Insect pest predation by arthropods and birds in different land use types with varying woody vegetation composition in agroecosystems of central Oromia, Ethiopia

Biological control by predators of insect pests is an important benefit of biodiversity, having a contribution to agricultural production. By preying on crop infesting insect pests, predatory arthropods and birds can provide an important ecosystem service. They support agricultural productivity, boosting crop yield and reducing demand for pesticides expense. Habitat quality of land use types, i.e., explained by vegetation cover, can impact the provision of ecosystem services thereby influencing the prevalence of the predators and their predation rates. In order to better understand the level of insect pest control service by predators, we conducted a field experiment to investigate levels of predation, using an attack on artificial caterpillars in response to land use types varied in vegetation cover. We found the attack rate by arthropods was more consistent across land use types than by birds, and the attack by birds was higher in modified land use types with sparse woody vegetation. Moreover, the attack rate for birds showed a decreasing tendency with increasing woody species richness, cover and stem density, while it showed less variation for arthropods. We conclude that biological control by birds is more effective in habitats with simplified vegetation cover than for arthropods in agricultural landscapes. Therefore, we recommend the prevalence of shade trees and small forest patches in agricultural landscapes for supporting the increased levels of insect pest control services provided by predatory birds and arthropods.

Effects of artificial canopy shading on vegetative growth and ripening processes of cv. Nero d'Avola (Vitis vinifera L.).

The biology of the grapevine (Vitis vinifera L.) is clearly influenced by the climatic conditions of the growing environment, where temperature and light play a major role in modifying plant physiology. In the scenario of climatic changes, radiative excess, correlated to the increase in temperature, can concretely subject the photosynthetic apparatus to a condition of light saturation and cause a drastic reduction in photochemical efficiency, giving rise to chronic photoinhibition phenomena. Undoubtedly, the ripening behavior also undergo evident alterations; the problem of sugar ripening, which is often strongly accelerated, is induced not only by high temperatures but also by the excess concentration of carbon dioxide (CO2), which results in a higher ripening. In addition, high berry temperatures favor a reduction in the concentration of organic acids. The reported trends indicate that the need for urgent action is closely linked to the future environmental impacts that these changes could have on the entire wine sector. In recent years, shade treatments have been applied to the vine canopy to overcome this issue. The objective of this study was to determine how artificial canopy shading affects the vines vegetative growth and the ripening processes of Vitis vinifera cv. Nero d'Avola during the 2019-2020 vegetative seasons. Three treatments were established: shading treatment with a green net (shade factor 27%), shading treatment with a white net (shade factor 32%), and untreated vines, thus naturally exposed to light radiation. Artificial shading, applied at full fruit set, interfered with the microclimate of the vines, causing partial effects on the grape ripening processes. At harvest, significant differences were found between the treatments in terms of sugars, also shading treatments increased must acidity and decrease pH. Results obtained on vegetative parameters, suggest that the shading treatment delays leaf fall, with potentially positive effects on the starch accumulation on perennial reserve organs to be exploited at the following season's sprouting. Shading significantly reduced berry size, with obvious consequences on bunch weight and yield per vine. In 2020, shaded plants showed a delay in all the phenological phases. The total anthocyanins content was not changed by the shading treatment. The results obtained confirm the importance of net coverage on the microclimate of the vines, vegetative-productive activity, and grapes quality. From this point of view, the net covering technique can be a tool for controlling grapes ripening dynamics in the context of climate change.

The Interaction between Strigolactone and Auxin Results in the Negative Effect of Shading on Soybean Branching Development

The plant architecture of higher plants is regulated through environmental and genetic factors, as well as phytohormones. Phytohormones play a critical role in regulating shoot branching. We determined the branching phenotype of D16 and N99-6, the content of strigolactones, the genetic expression level, and the interaction between auxin and strigolactones. We found that the branching development of the two soybean varieties under shading was significantly slower than that under normal light. The average branch length of N99-6 decreased by 40.9% after shading; however, the branch length of D16 was not significantly affected. Meanwhile, the branch formation rate in D16 was significantly higher than in N99-6. In addition, after shading treatment, the content of strigolactones in D16 and N99-6 axillary buds increased significantly, and the expression of phytochrome genes, PhyA and PhyB, showed opposite changes. However, strigolactone synthesis gene GmMAX4 and signal transduction gene GmMAX2 expression levels of D16 were lower than those of N99-6 after 24 h of shading. In addition, the application of strigolactone inhibitor TIS108 and auxin inhibitor NPA to soybean had no significant effect on the branch phenotype. The expression of the GmMAX2 gene was significantly up-regulated after the external application of the auxin analog, and the expression of auxin transporter gene GmPINI was significantly down-regulated after external application of the strigolactone analog under shade. In this study, we investigated the adverse effect of shade on soybean branching development, which may be due to the interaction of strigolactones with auxins.

Nesting activity of Lepidochelys olivacea, and the effect of artificial shade at Cascajilloso beach, a newly inhabited nesting site in Pacific Panama

AbstractSea turtle nesting activity on newly monitored beaches yield important data to support future regional and global conservation assessments. Here, we report on nesting activity of Olive Ridley (Lepidochelys olivacea) at Cascajilloso beach in Pacific Panama based on data from a new hatchery during seasons 2019, 2020 and 2021. Further to this, we conducted a field experiment analyzing the effects of artificial shade versus unshaded treatments on hatchlings' biometric characteristics, hatching success, incubation success and the incubation period. The analyses of three seasons showed that nesting activity, based on number of egg clutches transferred to the hatchery, reached a peak between September (33%) and October (25%). Curved carapace length (CCL) of nesting females (64.3–66.2 cm) was similar to other populations of the Eastern Tropical Pacific (ETP). The number of eggs clutches were 80 in 2019, 73 in 2020 and 108 in 2021; however, the clutch size was slightly smaller (93.92 ± 18.78 eggs) compared with other populations of the ETP. This could be a phenotypic variation of nesting females at this beach. The ability to move egg clutches to the hatchery was affected during 2020 season due to COVID19 restrictions. Heavy rainfall during the incubation period caused a reduction in ambient temperature resulting in cooler (maximum average 29.9°C) nest temperatures registered under artificial shade and unshaded treatments. This could result in males hatchlings during the 2020 season. The warmer temperatures in our experimental nests produced heavier hatchlings contrary to general assumptions, but this was also related to straight carapace length only after a threshold value of 40 mm. Hatchlings under the artificial shade were able to grow to a certain size but potentially at the costs of storing less mass (trade‐off). Ongoing beach patrolling and hatchery management techniques with long‐term baseline data collection are needed to secure the nesting population of L. olivacea in this recently surveyed beach.

Antibacterial, Antimitotic and Anti-Inflammatory Efficacy of Delonix regia Flower Extracts

Delonix regia is a multipurpose tree, it is harvested from the wild for a wide range of local uses, including for medicines, food, timber, fuel and beads. It is cultivated as a shade tree in plantations and is used to stabilize and enrich the soil. This species is one of the most widely cultivated ornamental plants in the world, being grown as an ornamental plant in gardens and by the sides of roads throughout the tropics. The main objective of the study was to understand the effect of the Delonix regia flower extract for its antibacterial, anti-inflammatory and antimitotic study. For the analysis of the antibacterial study, the ethanolic extraction method was used and the extract was dissolved in DMSO and distilled water which was further tested on the clinical strains of Staphylococcus and Enterococcus faecalis, where zone of inhibition was observed for both the strains. For the analysis of the anti-inflammatory study human blood was used, the inflammatory test was carried by the Hemolysis Inhibition Assay, post the analysis the extract showed potential to inhibit the breakdown of red blood cells. For the analysis of antimitotic activity Macrotyloma uniflorum (horse gram) was suspended in the chemotherapy drug- Vinblastin along with control and dilutions of the flower extract, which was quantitatively assessed. The results implied that the flower extract has properties that can inhibit the growth of cells/gram.

Effect of tree shade on behavior and haircoat temperature of grazing dual-purpose cows in a hot and humid tropical environment

We evaluated the behavior and skin temperature of dual-purpose cattle that grazed pastures having high (HC), low (LC), and no (NC) tree cover during the rainy and dry seasons in the hot and humid tropics of Mexico. We observed twenty-four adult cows (eight per treatment) over 24 days during each season, recording skin temperature and the time related to different daily activities. Across treatments, cows spent the same amount of time foraging during the rainy season (P > 0.05), but cows under HC spent less time during the dry season (P < 0.0001). During the rainy season, cows under HC showed more motivation to continue grazing than becoming restless or beginning rumination (P < 0.001) or roaming more than in other treatments (P < 0.001). During the dry season, cows under HC and LC also had less probability of initiating rest than NC (P < 0.001). Cows under HC had greater motivation to transition from grazing to roaming and less incentive to pass from rumination to rest than cows under LC and NC (P < 0.001). The frequency of water consumption was greater during the dry season (P < 0.001) and consistently high under NC (P < 0.0001). Skin temperature did not differ among treatments during the rainy season (P = 0.261), but during the dry season, it was greater under NC (P < 0.001). Tree cover improves cow behaviors by increasing the impetus to graze and perform daily activities, which contributes to reduced skin temperature during hotter seasons.

Effects of canopy connectivity on the arboreal ant community in coffee shade trees

AbstractCanopy connectivity influences foraging, movement, and competition in arboreal ant communities. Understanding how canopy connectivity affects arboreal ant communities could inform the development of management practices that maximize services from known biocontrol agents. We experimentally manipulated connectivity between the crowns of large shade trees to investigate the effects of canopy connectivity on arboreal ant species richness and composition in a coffee agroecosystem. A linear mixed‐effects analysis showed that the number of species observed at baits set in tree crowns increased significantly after the crowns had been connected with nylon ropes. Crowns that were connected increased in similarity of ant species composition, particularly between adjacent connected crowns. Connectivity may increase the number of species present in tree crowns by allowing ants to move and forage in the canopy while bypassing trunks with more aggressive, territorial species such as Azteca sericeasur. Because twig‐nesting species in the upper canopy have been shown to act as biocontrol agents of herbivores, an increase in species richness in tree crowns could have positive implications for agricultural pest‐control services.Abstract in Spanish is available with online material.

Allometric relationships between stem diameter, height and crown area of associated trees of cocoa agroforests of Ghana

Allometric models which are used to describe the structure of trees in agroforestry systems are usually extrapolated from models developed for trees in forest ecosystems. This makes quantitative assessment of the functions of shade trees in agroforestry systems challenging since increased availability of light and space in these systems may induce structural differences from those growing under forest conditions. We addressed this issue by providing species-specific allometric information on the structural characteristics of associated shade trees on cocoa agroforestry systems and assessed if allometries conformed to theoretical predictions. At the plot level, stand and soil characteristics affecting tree structural characteristics were assessed. The study was conducted in cocoa agroforestry systems at Suhum, Ghana. The height-diameter at breast height (H-DBH) allometry had the best fits (R2 = 53–89%), followed by the crown area (CA)-DBH allometry (R2 = 27–87%) and then the CA-H allometry (R2 = 22–73%). In general, the scaling exponents of the CA-DBH, H-CA and H-DBH allometries conformed to the metabolic scaling theory (MST). However, both the CA-DBH and H-DBH allometries diverged from the geometric similarity model. Though forest tree species had similar crown areas as fruit trees, they were slenderer than fruit trees. Tree slenderness coefficients were positively correlated with soil P, Ca, Cu and the ratios (Ca + Mg):K, (Ca + Mg):(K + Na) and Ca:Mg, but not C:N while DBH and H were correlated with soil P and C:N ratio. Our results show that critical soil nutrients and their ratios affects shade tree structural attributes (e.g. slenderness and CA), which possibly restrict variations in species-specific allometries to a narrow range on cocoa systems. Furthermore, shade tree species richness and density are better predictors of relative canopy projection area (a proxy for shade intensity) than tree species diversity. In conclusion, the results have implications for shade tree species selection, monitoring of woody biomass and maintenance of biodiversity.

Quantifying the cumulative cooling effects of 3D building and tree shade with high resolution thermal imagery in a hot arid urban climate

Shading is an effective heat-mitigation strategy, with tree and building shade naturally cooling heated surfaces in hot-arid climates. However, increasing shade through tree planting and building arrangement has associated costs, such as tree maintenance and loss of solar access. To make strategic decisions, quantifying shade’s cooling effectiveness is crucial. This study examines the extent to which shade reduces land surface temperature (LST) in a hot-arid residential environment by considering shade’s areal coverage, overall duration, and time of day. Using fine-resolution 3D city models (1 m/pixel), land cover classification (1 m/pixel), and high-resolution thermal imagery (6 m/pixel) for Tempe, Arizona, USA, hourly shade calculations are conducted from 7:30 to 13:30 on July 12, 2011. The relationships among the observed LST at 13:30, land cover types, and shade characteristics are analyzed using linear and spatial regressions. The results reveal that shade’s cooling effect is cumulative, rather than instantaneous, as surface cooling by earlier shade persists to later times to some degree. Areas shaded for longer hours are cooler than those shaded only temporarily. The results further indicate that tree-shaded areas are significantly cooler than those shaded by other features, including buildings, with the difference increasing with shade duration. Shifting a 6 × 6 m area from 0% to 100% shade in the early morning generates a 2.3℃ LST reduction at 13:30. The same shift in shade for the whole morning and the entire period (7:30–13:30) would lower LST by 8.3℃ and 11.3℃, respectively. The importance of temporal shade planning and policy recommendation for urban heat mitigation is discussed.