Добірка наукової літератури з теми "Microclimatic amelioration"

AbstractRemote sensing applications are increasingly common in archaeology but they often focus on high resolution imagery and direct archaeological site detection. Moderate spatial resolution remote sensing instruments, which have (near) daily repeat intervals, but contain less detailed spectral and spatial information, have been employed much less frequently in archaeology. However, moderate remote sensing data offer distinct advantages for archaeological research as they can be used to relate archaeological, ecological, and climactic data at vast spatial scales. To show this potential, we use moderate remote sensing data to examine the impact of landscape heterogeneity on the spread of indigenous maize horticulture in the northern Great Lakes during Late Precontact (ca. AD 1200-1600). Analyzing National Aeronautics and Space Administration (NASA) Moderate Resolution Imaging Spectroradiometer (MODIS) imagery, we identify differences in freeze/thaw cycles across inland lakes in Michigan, showing that some large inland lakes produce a microclimatic amelioration, possibly extending the growing season for prehistoric maize cultivation. Conducting geospatial analyses, we find that burial mounds and maize cultivation practices were associated preferentially with larger inland lakes with microclimates. We could not have found these dynamic interrelationships between microclimates, burial mounds, and maize cultivation if not for both the frequent temporal imaging and large spatial coverage provided by moderate resolution remote sensing imagery.

Geometry plays a dominant role in thermal situations within city structures. This study aims to seek how this role affects thermal comfort of the visitors in an urban square. Computer simulations were performed along with physical measurements in an urban square during peak hot conditions of summer in Isfahan, Iran. In addition to the influence of built environment inside the square, the results confirmed the role of geometry on thermal conditions. The amelioration effect for the aspect ratio was higher than that of the orientation. Findings are useful for urban design strategies dealing with thermal comfort.Keywords: Thermal comfort; urban square; geometry; built environment eISSN 2398-4295 © 2018. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open-access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia

Abstract This study aimed to examine the thermal environment in schoolyards under Mediterranean conditions, and the impact of two interventions on the amelioration on the bioclimatic conditions. The investigation was performed for three schools in Athens, Greece, through microclimatic simulations by ENVI-met, for a typical day in June, and was evaluated based on the air and surface temperature values. The bioclimatic index Physiological Equivalent Temperature (PET) was applied to evaluate the thermal comfort conditions. By that, the school under the most adverse thermal conditions was selected for the application of two interventions, which increased the greenery by 25% (Proposal 1) and 50% (Proposal 2). The surface coating material “safety floor slabs”, was selected to replace the others in both proposals. Through microclimatic simulations, the following results were obtained: “Proposal 1” caused a 2.3°C reduction in surface temperature, and a 4% reduction in PET values. ‘Proposal 2’ caused an 8.1°C reduction in surface temperature, and an 11% reduction in PET values. The cooling effect of ‘Proposal 2’ was double compared to ‘Proposal 1’, achieving a maximum air temperature reduction by up to 0.8°C. The cooling effect produced was limited to the areas affected by tree shade, leaving the unshaded areas almost unaffected.

Since public space is usually associated with flexible open structures, this article looks into the transformation of the closed ex-ILVA grounds, as public green sphere, to underline emotional components in leftovers and urban policies, that add insights to the contemporary debate about environmental and social achievements of public spaces.The re-thinking of contaminated post-industrial landscapes as participatory places is not only a change in process, quality and meaning, but also a microclimatic amelioration by reducing urban heat intensification, proving to have increasing effects on human health and well-being. Emotional compontents about community identity, saftey and history are examined.How should a public urban park be designed by low initial and maintenance costs, supporting daily frequencies of citizens and health in mind and body, is the research question. More specific, how can contaminated sites be transfered into a healthy, sustainable and socially controlled public park, which idealy generates income, added value and increases life quality, respecting life expertancy, mortality rates and social well-being.

While positive interactions have been well documented in plant and sessile benthic marine communities, their role in structuring mobile animal communities and underlying mechanisms has been less explored. Using field removal experiments, we demonstrated that a large vertebrate herbivore (cattle; Bos tarurs ) and a much smaller invertebrate (ants; Lasius spp.), the two dominant animal taxa in a semi-arid grassland in Northeast China, facilitate each other. Cattle grazing led to higher ant mound abundance compared with ungrazed sites, while the presence of ant mounds increased the foraging of cattle during the peak of the growing season. Mechanistically, these reciprocal positive effects were driven by habitat amelioration and resource (food) enhancement by cattle and ants (respectively). Cattle facilitated ants, probably by decreasing plant litter accumulation by herbivory and trampling, allowing more light to reach the soil surface leading to microclimatic conditions that favour ants. Ants facilitated cattle probably by increasing soil nutrients via bioturbation, increasing food (plant) biomass and quality (nitrogen content) for cattle. Our study demonstrates reciprocal facilitative interactions between two animal species from phylogenetically very distant taxa. Such reciprocal positive interactions may be more common in animal communities than so far assumed, and they should receive more attention to improve our understanding of species coexistence and animal community assembly.

The present study investigated the cooling effect of extensive green roofs and green façades, at the pedestrian level, of a Mediterranean densely populated neighborhood. The ENVI-met environmental model was employed to simulate the microclimatic environment on a typical summer day. Thermal conditions of the study area were evaluated based on air temperature and the Mediterranean thermal stress scale of UTCI (Universal Thermal Climate Index). Three mitigation strategies were developed to ameliorate the thermal conditions in the examined area focusing on the efficacy of green façades, green roofs, and the synergetic effect of the green façade and green roof. The mitigation strategies’ performance was evaluated in characteristic design layouts of the study area, namely the following: a typical Mediterranean square, a church with a churchyard, an avenue, NS and EW street orientations, and courtyards. Results showed that compared to the existing configuration, the synergetic effect of the green façade and green roof achieved the greatest amelioration of the thermal conditions during the hottest hours of the day (12:00–18:00) since it produced an average Tair reduction of up to 0.7 °C and a UTCI reduction of 1.6 °C (both in the courtyards design layout). Among the examined design layouts, the courtyards produced the greatest reductions in air temperature and UTCI, whereas the EW streets were the lowest.

Sponge cities provide broad hydrological functions to alleviate urban flooding and other water-related problems in China. Conventional impervious paving cannot meet contemporary sustainable city goals. The permeable paving technology offers primary benefits such as increasing stormwater infiltration, drainage, purification, groundwater recharge, and microclimatic amelioration. Few studies have evaluated the embracive range of benefits and the social functions holistically. This study aimed to develop a comprehensive benefit evaluation system to cover a broad range of indicators. Nineteen indicators were selected based on the literature review, field studies, and research experience. Organized in a three-tiered hierarchical structure, they were divided into environmental, economic, and social benefits. A grey intuitionistic fuzzy comprehensive evaluation model was built by combining intuitionistic fuzzy analysis with a grey comprehensive evaluation. The computational tools could determine the differential weights of indicators and benefit scores. Taking an example of a permeable pavement project in Quanzhou City, the comprehensive benefits were assessed and validated using our evaluation model. The results show that (1) the comprehensive benefits of the project met the economic feasibility criteria with advantages over conventional paving; (2) the environmental benefits were prominently expressed; (3) the social benefits were assessed and confirmed. The results verified the feasibility and applicability of the quantitative-qualitative model. The method could permit the integrated and systematic benefit assessment of permeable paving designs. It also provides guidance and reference to evaluate the performance of permeable pavements and their comprehensive range of benefits. The findings could reference choosing and refining designs, optimizing the benefits, and promoting a science-oriented development of permeable paving.

AbstractThe lower Ica Valley on the hyperarid south coast of Peru is today largely depopulated and bereft of cultivation, yet its extensive archaeological remains attest to substantial prehispanic populations. This paper describes archaeological investigations to retrace changes in geomorphology, ecology, and land-use in Samaca, one of the riparian oasis basins of the lower Río lea, with the aim of investigating when, how, and why such changes took place. Archaeological interpretations of culture change in the region often invoke the impacts of major ENSO perturbations (El Niño). While our investigations confirm that major El Niño events around the end of the Early Intermediate Period likely offer part of the explanation for marked landscape change in the Samaca Basin, we also demonstrate the significance of more gradual, human-induced destruction of Prosopis pallida (huarango) riparian dry-forest. Huarango is a remarkable leguminous hardwood that lives for over a millennium and provides forage, fuel, and food. Moreover, it plays a crucial role in integrating fragile desert ecosystems, enhancing soil fertility and moisture, and accomplishing desalination and microclimatic amelioration. We propose that south coast valleys remained densely forested well into the Early Intermediate Period, attenuating the impact of El Niño events and supporting hitherto underappreciated agroforestry adaptations. Gradual deforestation eventually crossed an environmental threshold: river and wind erosion increased dramatically and precipitated radical desertification, feeding back into cultural changes in the Middle Horizon. Thus we argue Prosopis-human ecological relationships merit proper recognition in our archaeological interpretations of the south coast of Peru.

The alpine treeline demarcates the temperature-limited upper elevational boundary of the tree life form. However, this treeline does not always occur exclusively as a sharp “line”, outposts of tree groups (OTG) with a height of at least 3 m are often observed in microsites up to several hundred meters beyond the line of continuous forest on some mountains. This suggests that other factors such as microenvironment may play a significant role in compensating for the alpine tree facing growth-limiting low temperature conditions. To test the microenvironment effects, this study compared the differences in growing conditions (climate and soil properties) and ecophysiological performance of Erman’s birch (Betula ermanii Cham.) trees growing in a continuous treeline site (CTL, ~1950 m above sea level, a.s.l.) and OTGs (~2050 m a.s.l.) on Changbai Mountain in northeastern China. The results show the average 2-m air temperature for OTG was slightly lower in the non-growing season than which at the CTL (−10.2 °C < −8.4 °C), there was no difference in growing season air temperature and soil temperature at 10 cm depth between CTL and OTG. The contents of focal soil nutrients in CTL and OTG were similar. Difference in K and Mn contents between sites were detected in leaves, difference in K, Mn, and Zn in shoots. However, comparing similarity of ecophysiological performances at an individual level, trees at CTL and OTG show no significant difference. Our study reveals that mature trees at the CTL and OTG experience generally similar environmental conditions (climate and soil properties) and exhibit similar overall ecophysiological performance (reflected in carbon reserves and nutrients). This might provide insight into how mature trees might be able to survive in areas higher than the continuous treeline, as well as the importance of microclimatic amelioration provided by protective microsites and the trees themselves.

This study examines litter accumulation and associated soil fertility islands under kūpaoa (Dubautia menziesii) shrubs, common at high elevations in Haleakalā National Park (Maui, Hawai’i). The main purposes were to: (i) Analyze chemical and physical properties of kūpaoa leaf-litter, (ii) determine soil changes caused by organic-matter accumulation under plants, and (iii) compare these with the known pedological effects of silversword (Argyroxiphium sandwicense) rosettes in the same area. Surface soil samples were gathered below shrubs, and compared with paired adjacent, bare sandy soils; two soil profiles were also contrasted. Litter patches under kūpaoa covered 0.57–3.61 m2 area and were 22–73 mm thick. A cohesive, 5–30-mm-thick soil crust with moderate aggregate stability developed underneath litter horizons; grain aggregation was presumably related to high organic-matter accumulation. Shear strength and compressibility measurements showed crusts opposed significantly greater resistance to physical removal and erosion than adjacent bare soils. As compared to contiguous bare ground areas, soils below shrubs had higher organic matter percentages, darker colors, faster infiltration rates, and greater water-retention capacity. Chemical soil properties were greatly altered by organic matter: Cations (Ca2+, Mg2+, K+), N, P, and cation-exchange capacity, were higher below plants. Further processes affecting soils under kūpaoa included microclimatic amelioration, and additional water input by fog-drip beneath its dense canopy. Substrate modifications were more pronounced below D. menziesii than A. sandwicense. Organic matter and available nutrient contents were higher under shrubs, where soils also showed greater infiltration and water-retention capacity. These trends resulted from contrasting litter properties between plant species, as kūpaoa leaves have higher nutrient content than silversword foliage. Different litter dynamics and reproduction strategies may also explain contrasting soil properties between the monocarpic rosettes and polycarpic kūpaoa. By inducing substantial substrate changes, Dubautia shrubs alter—or even create—different microhabitats and exert critical control on alpine soil development at Haleakalā.

Les interactions entre plantes dans les milieux impactés par les métaux/métalloïdes dépendent de nombreux facteurs et sont encore très peu connues. Tout d’abord elles semblent dépendre du niveau de pollution métallique du milieu, mais aussi des stratégies fonctionnelles végétales des plantes interagissant. D’autre part, les plantes peuvent avoir plusieurs types d’effets sur leur environnement proche, effets s’exprimant à des temporalités différentes. En effet, les plantes ont un effet immédiat via leur canopée et racines sur les ressources et le microclimat à proximité. Aussi, au cours d’une saison de végétation, les plantes peuvent avoir des effets liés à la production de la litière et sa décomposition dans les sols sous leur canopée. A plus long-terme, lorsque ce cycle de production/décomposition est répété au fil des années, les plantes vont avoir un effet lié à la dynamique de la matière organique dans les sols. Dans cette thèse, notre objectif principal était de différencier ces effets, et de comprendre comment les stratégies fonctionnelles végétales des plantes pouvaient influencer les différents effets en jeu le long de gradients de pollution métallique. Nous avons étudié ces effets pendant trois années (entre 2020 et 2022) dans une ancienne vallée minière des Pyrénées Ariégeoises (Sentein, France). Dans cette zone d’étude, nous avons étudié les interactions entre plantes par des méthodes observationnelles et de transplantations de cibles avec contrôle de la présence de canopée et/ou de la litière des plantes, sur trois sites d’étude : un terril avec une pollution homogène et deux zones de résidus miniers avec des pollutions hétérogènes créant un gradient de pollution. Le long des gradients étudiés, les effets de canopée et de prélèvement racinaire ont suivi l’Hypothèse du Gradient de Stress, passant de la compétition à la facilitation avec l’augmentation de la pollution. Cette facilitation était d’autant plus forte que les espèces produisant l’effet sont dites « exploitatrices » (en lien avec l’exploitation des ressources du sol et Leaf Economic Spectrum), et bénéficiait le plus aux plantes les moins tolérantes aux métaux. Les effets positifs étaient surtout liés à l’amélioration des conditions microclimatiques lors d’épisodes chauds et secs en été. Concernant les effets liés à la production et décomposition des litières, des effets négatifs sur les plantes cibles ont été démontrés, suggérant des effets dits d’allélopathie élémentaire, et liés à la forte concentration en éléments métalliques dans les litières en décomposition. Ces effets négatifs de litière étaient maximums dans les milieux les moins pollués où les plantes métallophytes accumulatrices (qui ont des fortes teneurs en métaux dans leurs feuilles) et les plantes moins tolérantes aux métaux interagissaient. Ils étaient particulièrement marqués pour les cibles sensibles à la pollution métallique. Les résultats de cette thèse donnent des pistes potentielles pour utiliser la facilitation dans un cadre de phyto-management de milieux pollués par les métaux/métalloïdes, en prenant en compte explicitement les stratégies fonctionnelles végétales des plantes en interactions et le niveau de pollution en jeu. Des résultats obtenus pendant la canicule de 2022 nous donnent aussi une bonne vision des évolutions attendues des différents effets impliqués dans les interactions entre plantes dans les écosystèmes métallifères dans un contexte de changement climatique
Plant-plant interactions have been overlooked in metal/metalloids-impacted environments and are likely driven by several factors whose influence is barely known. First, plant-plant interactions depend on the level of metal pollution, but also on the functional plant strategies of the interacting plants. Furthermore, plants can have several type of effects on their immediate environment, acting at different timescales. Plants canopy and roots have an instantaneous influence on the microclimate and available resources in their immediate vicinity. Then, during a growing season, the production of litter and its decomposition beneath their canopy can influence soil chemical and physical properties. In the longer term, when this cycle of litter production/decomposition is repeated over the years, the dynamics of the organic matter will influence soil conditions even more. In this thesis, our main objective was to delineate these effects, and to understand how plant functional strategies can influence these various effects along metal pollution gradients. We studied these effects during three consecutive years (from 2020 to 2022) in a former mining valley in the French Pyrenees (Sentein, Ariège, France). In this area, we studied interactions between plants using observational and target transplantation methods controlling for the presence of plant canopy and/or plant litter, in three study sites: a slag heap with homogeneous pollution and two mine tailings areas with heterogeneous pollution creating a gradient of pollution. Along these gradients, short-term canopy and root-uptake effects followed the Stress Gradient Hypothesis, switching from competition to facilitation as pollution increased. This facilitation was stronger when the species producing the effect were acquisitive (in relation with soil resources and the Leaf Economic Spectrum), and benefits more the low metal-tolerant plants. These positive effects were mainly due to the improvement of micro-climatic conditions during hot and dry episodes in summer. Concerning the effects linked to litter production and decomposition, negative effects on target plants were found, suggesting the so-called “elemental allelopathic” effects, in relation with the high concentration of metallic elements in the decomposing litter. These negative litter effects were more important in the least polluted environments, where metal-accumulating metallophyte plants (which have high concentration of metals in their leaves) and less metal-tolerant plants interacts. They were particularly marked for targets sensitive to metal pollution. The results of this thesis give important perspectives regarding the use of facilitation for the phyto-management of metals/metalloids-polluted environments, given that the functional strategies of interacting plants and the level of pollution involved are explicitly considered. Additionnaly, the results obtained during the 2022 heatwave provide useful insights regarding the expected evolution of the different effects driving plant interactions in metalliferous ecosystems in a climate change context

Hyperspectral imaging has become one of the most popular technologies in plant phenotyping because it can efficiently and accurately predict numerous plant physiological features such as plant biomass, leaf moisture content, and chlorophyll content. Various hyperspectral imaging systems have been deployed in both greenhouse and field phenotyping activities. However, the hyperspectral imaging quality is severely affected by the continuously changing environmental conditions such as cloud cover, temperature and wind speed that induce noise in plant spectral data. Eliminating these environmental effects to improve imaging quality is critically important. In this thesis, two approaches were taken to address the imaging noise issue in greenhouse and field separately. First, a computational simulation model was built to simulate the greenhouse microclimate changes (such as the temperature and radiation distributions) through a 24-hour cycle in a research greenhouse. The simulated results were used to optimize the movement of an automated conveyor in the greenhouse: the plants were shuffled with the conveyor system with optimized frequency and distance to provide uniform growing conditions such as temperature and lighting intensity for each individual plant. The results showed the variance of the plants’ phenotyping feature measurements decreased significantly (i.e., by up to 83% in plant canopy size) in this conveyor greenhouse. Secondly, the environmental effects (i.e., sun radiation) on aerial hyperspectral images in field plant phenotyping were investigated and modeled. An artificial neural network (ANN) method was proposed to model the relationship between the image variation and environmental changes. Before the 2019 field test, a gantry system was designed and constructed to repeatedly collect time-series hyperspectral images with 2.5 minutes intervals of the corn plants under varying environmental conditions, which included sun radiation, solar zenith angle, diurnal time, humidity, temperature and wind speed. Over 8,000 hyperspectral images of corn (Zea mays L.) were collected with synchronized environmental data throughout the 2019 growing season. The models trained with the proposed ANN method were able to accurately predict the variations in imaging results (i.e., 82.3% for NDVI) caused by the changing environments. Thus, the ANN method can be used by remote sensing professionals to adjust or correct raw imaging data for changing environments to improve plant characterization.