Microclimatic Differences Research Articles

Estimation of the distribution of deflation sites on the territory of the Nenets Autonomous Okrug by data of remote sensing

Geoinformation assessment of deflation processes in the Arctic conditions makes it possible to move to a new technological level in the planning of forest reclamation of the landscapes of the Arctic zone. The use of forest reclamation and phytomelioration of accumulative forms makes it possible to control desertification processes. To achieve the purpose of the study – to assess the spatial distribution of deflated surface areas on the territory of the Nenets Autonomous Okrug, a geoinformation analysis of current space sensing data was carried out and the degree of degradation (deflation and anthropogenic transformation) of the territory in controlled areas was revealed, on the basis of which the necessary measures are proposed to prevent land deflation and it is planned to create an information system for monitoring and forecasting the state of soil and vegetation cover. The decoding of satellite images of deflation sites in the research area made it possible to develop vector cartographic GIS layers, which show selected coastal, continental not grown and overgrown massifs. The conducted geomorphological differentiation of deflation sites makes it possible to effectively use such parameters as tiering, exposure, meso- and microclimatic differences, as well as plan anti-deflation measures. Vector cartographic layers of the spatial distribution of sandy accumulative forms have been developed and their morphometric characteristics have been determined, the features of the development of continental and coastal deflation have been established, the areas of which are 31.51 and 20.86 thousand hectares, respectively, the total number of sites allocated by vector contours exceeds 166 thousand, and their sizes vary from 0.001 hectares to more than 5.5 thousand hectares. As a result of a spatial assessment of 68 large sandy massifs overgrown with vegetation, their area of 543.85 thousand hectares has been established.

Microclimatic variation regulates seed germination phenology in alpine plant communities

Abstract For most terrestrial plants, regeneration depends on the ability of seeds to germinate in the most favourable climatic conditions. Understanding seed germination phenology is thus crucial for predicting plant responses to environmental changes. However, a substantial gap persists regarding how microclimatic conditions influence germination in seasonal ecosystems. Here, we investigate the germination phenology of alpine plants in snow‐related microclimates as a tool for predicting the resilience of plant communities to climate change. We conducted a continuous seasonal experiment with fresh seeds to investigate germination phenology in 54 co‐occurring species from temperate and Mediterranean alpine communities. Using long‐term field microclimatic data series, we precisely mimicked two contrasting microclimatic regimes in growth chambers: (1) windy exposed edges with a snow‐free period in winter and warmer temperatures in summer (‘fellfield’) and (2) sheltered areas with lengthy snow cover and cooler temperatures (‘snowbed’). We validated the laboratory results with field sowing experiments to provide a complete picture of germination phenology. The analysis of phenology traits demonstrated that both communities displayed similar responses to microclimatic variation. Small microclimatic differences of 2–3°C a week, accumulated across a whole year in the laboratory, resulted in a quantifiable germination phenology delay in snowbed regime, with an average of 60 and 45 days for temperate and Mediterranean alpine respectively. The results from climatic chambers under realistic microclimatic regimes were consistent with the germination phenology registered from field experiments. We also observed macroclimatic effects manifested as reduced dormancy and increased autumn germination in Mediterranean alpine species. Synthesis. This study combines novel laboratory and field experimentation to tackle the understudied topic of germination phenology in habitats with sharp microclimatic gradients. Specifically, our findings suggest a predictable phenological shift in the germination of alpine plants along microclimatic gradients. In warmer conditions with reduced snow cover, alpine species are expected to advance germination 52 days on average, with potential disrupting effects on cold‐adapted species with strict germination requirements. This highlights the role of germination phenology to determine plant‐environmental relationships in mid‐latitude ecosystems, with strong impact on plant establishment and extinction risks under local microclimatic gradients.

Divergent Ecological Restoration Driven by Afforestation Along the North and South Banks of the Yarlung Zangbo Middle Reach

ABSTRACTOver the past four decades, continuous afforestation in the river valley of the Yarlung Zangbo Middle Reach has effectively migrated the land degradation and enhanced the local eco‐environment. Different orientations of north and south banks (i.e., sun‐facing and shade‐facing) generate microclimates, but the diverse growth patterns of the planted forests along different banks remain unknown. In this study, long‐term Landsat observations were introduced to investigate the microclimatic effects on the growth patterns of planted forests and their subsequent effects on the land restoration during 1988–2020. Results showed that the south bank experienced a higher afforestation‐induced greening trend than the north bank, as indicated by normalized difference vegetation index (NDVI) rates of 0.0117 and 0.0081 year−1, respectively. The growth of planted forests on the north bank was more sensitive to the distance from riverway than that on the south bank, with the NDVI gradients of −0.0708 and −0.0540 km−1, highlighting a server drought stress on the north bank. Benefited from the continuous afforestation, 79% and 95% of sandy lands on the north and south banks had been restored by 2020. In summary, the microclimatic difference between banks, attributed to different solar illuminations and drought stresses, induce the diverse ecological restoration conditions. These findings offer important insights that future afforestation strategies should consider the microclimatic effect to maximize ecological benefits.

Carbon dioxide exchange and temperature sensitivity of soil respiration along an elevation gradient in an arctic tundra ecosystem

Generally, with increasing elevation, there is a corresponding decrease in annual mean air and soil temperatures, resulting in an overall decrease in ecosystem carbon dioxide (CO2) exchange. However, there is a lack of knowledge on the variations in CO2 exchange along elevation gradients in tundra ecosystems. Aiming to quantify CO2 exchange along elevation gradients in tundra ecosystems, we measured ecosystem CO2 exchange in the peak growing season along an elevation gradient (9–387 m above sea level, m.a.s.l) in an arctic heath tundra, West Greenland. We also performed an ex-situ incubation experiment based on soil samples collected along the elevation gradient, to assess the sensitivity of soil respiration to changes in temperature and soil moisture. There was no apparent temperature gradient along the elevation gradient, with the lowest air and soil temperatures at the second lowest elevation site (83 m). The lowest elevation site exhibited the highest net ecosystem exchange (NEE), ecosystem respiration (ER) and gross ecosystem production (GEP) rates, while the other three sites generally showed intercomparable CO2 exchange rates. Topography aspect-induced soil microclimate differences rather than the elevation were the primary drivers for the soil nutrient status and ecosystem CO2 exchange. The temperature sensitivity of soil respiration above 0 °C increased with elevation, while elevation did not regulate the temperature sensitivity below 0 °C or the moisture sensitivity. Soil total nitrogen, carbon, and ammonium contents were the controls of temperature sensitivity below 0 °C. Overall, our results emphasize the significance of considering elevation and microclimate when predicting the response of CO2 balance to climate change or upscaling to regional scales, particularly during the growing season. However, outside the growing season, other factors such as soil nutrient dynamics, play a more influential role in driving ecosystem CO2 fluxes. To accurately upscale or predict annual CO2 fluxes in arctic tundra regions, it is crucial to incorporate elevation-specific microclimate conditions into ecosystem models.

Assessment of Landscape Change and its Relationships with Surface Temperature and Geo-spatial Indices during 1992 - 2022 at Haldia Industrial Region, West Bengal, India

Unplanned local development and alterations in Land Use and Land Cover (LULC) are an early alert for towns and cities around the world. The population pressure has resulted in the conversion of natural land into impermeable areas, which has altered the surface energy budget and created microclimatic differences locally. The main objective of the present study is to estimate LULC changes and its relation to increases Land Surface Temperature (LST) in the Haldia Industrial Region (HIR) of West Bengal using multi-temporal Landsat 5 Thematic Mapper (TM) of 1992 and Landsat 8 Operational Land Imager (OLI) of 2022 with 30-m spatial resolution images were obtained from the USGS website. The supervised classification method was applied by using Maximum Likelihood classification (MLC) to classify the satellite images into various LULC classes such as settlement, waterbody, vegetation, agriculture land, and fallow land, respectively. The result suggested an overall increase of settlement area from 13.49 km2 in 1992 to 44.54 km2 in 2022. On the other hand, the agriculture land decreased from 214.26 km2 to 152.34 km2 due to fast urbanization, decline green lands, and expansion of barren lands. The outcome result from LST was exhibited that the LST value has increased 3.77°C during 1992 to 2022 in this study area. The Normalized Difference Vegetation Index (NDVI) was showed a strong negative relationship with LST with a determination coefficient (R2) values found as 0.491 (1992) and 0.356 (2022). The positive determination coefficient between LST with Normalized Difference Water Index (NDWI) was found as 0.0002 (1992), and 0.0417 (2022). R2 values were estimated as 0.174 (1992), and 0.0347 (2022) between LST with Normalized Difference Built-up Index (NDBI) that indicated a positive determination coefficient. The findings enhanced understanding of the relationship between urban LST and LULC in developing an inclusive climate resilience policy and making the HIR more sustainable to the effects of climate change.

Thermal regulation potential of urban green spaces in a changing climate: Winter insights

Global warming affects both summer and winter temperatures, altering the ecological and social dynamics of urban green spaces not only during the summer months but also during the winter. Strategies to mitigate climate change impacts often emphasize increasing urban vegetation cover, but the effectiveness of these green spaces in regulating the local microclimate depends on various factors, including the vegetation structure. These effects remain largely underexplored during the winter season. To investigate the thermal regulation capacity of urban green spaces we measured air temperature and humidity in 36 parks with different sizes and vegetation structures in Munich, Germany, in their non-green surroundings, as well as in a nearby forest during the 2022–23 winter. We then analyzed the relationship between the local microclimatic differences and the vegetation structure derived from mobile laser scans. In comparison with the nearby forest, we measured a winter urban heat island effect of 1.8 °C in Munich. The urban microclimates in winter were mainly influenced by the urban landscape of Munich, namely the distance to the city center with increasing air temperature closer to the center. Urban green spaces in Munich provided small but consistent local cooling and humidifying effects throughout the winter. These cooling effects largely depended on the green space size but partially also on the vegetation structure. We found a significant relationship between the microclimatic difference, the vegetation density, and the vertical homogeneity of vegetation. The canopy cover, however, could not significantly predict the cooling effect in winter. We conclude that increasing the structural complexity of urban green spaces through management decisions could improve their cooling effect and ecological value, even during winter months. To maximize the ecological and climatic benefits of urban green spaces, a nuanced understanding and management of urban microclimates is needed across all seasons.

Improved mesoscopic meteorological modeling of the urban climate for building physics applications

Meteorological mesoscale models with different urban parametrization are used to predict the local urban climate at 250 m resolution. The authors propose a hybrid machine learning approach to improve the mesoscale prediction accuracy using measured air temperature data from a sensor network and remove simulation bias. The simulation of the urban climate of Zurich during a hot summer is used as case study showing the improvements of the simulation accuracy. Based on the hybrid model results, a cumulative heat exposure index is proposed to map local hotspots in the city and assess the difference of cooling loads between rural and urban environments. Furthermore, intra-urban microclimatic differences of a typical mid-latitude city are explored to highlight the benefits of detailed simulations for building physics purposes.

Effects of canopy gaps on microclimate, soil biological activity and their relationship in a European mixed floodplain forest

Forest canopy gaps can influence understorey microclimate and ecosystem functions such as decomposition. Gaps can arise from silviculture or tree mortality, increasingly influenced by climate change. However, to what degree canopy gaps affect the buffered microclimate in the understorey under macroclimatic changes is unclear. We, therefore, investigated the effect of forest gaps differing in structure and size (25 gaps: single tree gaps up to 0.67 ha cuttings) on microclimate and soil biological activity compared to closed forest in a European mixed floodplain forest. During the investigation period in the drought year 2022 between May and October, mean soil moisture and temperature as well as soil and air temperature fluctuations increased with increasing openness. In summer, the highest difference of monthly means between cuttings and closed forest in the topsoil was 3.98 ± 9.43 % volumetric moisture and 2.05 ± 0.89 °C temperature, and in the air at 30 cm height 0.61 ± 0.35 °C temperature. For buffering, both the over- and understorey tree layers appeared as relevant with a particularly strong influence of understorey density on soil temperature. Three experiments, investigating soil biological activity by quantifying decomposition rates of tea and wooden spatulas as well as mesofauna feeding activity with bait-lamina stripes, revealed no significant differences between gaps and closed forest. However, we found a positive significant effect of mean soil temperature on feeding activity throughout the season. Although soil moisture decreased during this period, it showed no counteracting effect on feeding activity. Generally, very few significant relationships were observed between microclimate and soil biological activity in single experiments. Despite the dry growing season, decomposition rates remained high, suggesting temperature had a stronger influence than soil moisture. We conclude that the microclimatic differences within the gap gradient of our experiment were not strong enough to affect soil biological activity considerably.

Urban microclimate differences in continental zone of China

In modern cities, the block geometry and land cover feature directly affect the heat transfer between ground surface and atmosphere, resulting in significant differences of local microclimate. Clarifying this difference will help to accurately predict regional building energy demand and optimize regional layout design. However, existing microclimate research mainly focuses on tropical, arid, and temperate climate regions, leaving continental areas virtually unexplored. To address this problem and clarify the interactions of the urban blocks and microclimate, the combination of the local climate zone (LCZ) scheme and fixed-point weather station monitoring is employed to investigate the variation characteristics of the thermal and humidity conditions of typical urban blocks in continental zone of China. Firstly, sixty-seven typical urban blocks with self-built, national and regional meteorological stations are selected as the object of study, and classified into twelve LCZ categories, according to their inherent features. Secondly, the spatial and temporal variation patterns of the thermal environment indexes of the twelve LCZ types are analyzed and compared. Additionally, correlation analyses and regression fittings are performed between the thermal environment indexes and the urban morphological parameters. The results indicate significant differences in thermal environment indexes among different LCZ types. The mean temperature of built types is 0.72 °C higher than land cover types. The temperature and humidity exhibit a parabolic relationship with height of roughness elements and building surface fraction respectively, while the humidity has strong negatively correlations with the impervious surface fraction and the height of roughness elements.

Unpunctual in diversity: The effect of stand species richness on spring phenology of deciduous tree stands varies among species and years.

Climatic drivers alone do not adequately explain the regional variation in budburst timing in deciduous forests across Europe. Stand-level factors, such as tree species richness, might affect budburst timing by creating different microclimates under the same site macroclimate. We assessed different phases of the spring phenology (start, midpoint, end, and overall duration of the budburst period) of four important European tree species (Betula pendula, Fagus sylvatica, Quercus robur and Tilia cordata) in monocultures and four-species mixture stands of a common garden tree biodiversity experiment in Belgium (FORBIO) in 2021 and 2022. Microclimatic differences between the stands in terms of bud chilling, temperature forcing, and soil temperature were considerable, with four-species mixtures being generally colder than monocultures in spring, but not in winter. In the colder spring of 2021, at the stand level, the end of the budburst period was advanced, and its overall duration shortened, in the four-species mixtures. At species level, this response was significant for F. sylvatica. In the warmer spring of 2022, advances in spring phenology in four-species stands were observed again in F. sylvatica and, less markedly, in B. pendula but without a general response at the stand level. Q. robur showed specific patterns with delayed budburst start in 2021 in the four-species mixtures and very short budburst duration for all stands in 2022. Phenological differences between monocultures and four-species mixtures were linked to microclimatic differences in light availability rather than in temperature as even comparatively colder microclimates showed an advanced phenology. Compared to weather conditions, tree species richness had a lower impact on budburst timing, but this impact can be of importance for key species like F. sylvatica and colder springs. These results indicate that forest biodiversity can affect budburst phenology, with wider implications, especially for forest- and land surface models.

Occupancy of urban roosts by spectacled flying‐foxes (Pteropus conspicillatus) is not affected by diurnal microclimate

AbstractOne of the most significant changes to Earth's climate in recent decades has been an increase in the frequency, intensity and duration of heatwaves. During heatwaves, animal's thermal window can be exceeded, and in extreme cases, mass mortality events have been observed. In 2018, a heatwave in north‐eastern Australia resulted in the death of approximately one‐third of the spectacled flying‐fox (Pteropus conspicillatus) population at urban roosts in Cairns. The species has now been listed as endangered with future heatwaves considered the greatest threat to its survival. In this study, we investigated long‐term climatic trends for Cairns, paying particular attention to the frequency of extreme heat events from 1943 to 2022. We then characterized the microclimate of urban flying‐fox roosts during the Austral summers of 2021/2022 and 2022/2023 across Cairns to assess the long‐term feasibility of urban spectacled flying‐fox roosts. From the long‐term climate records, we observed an overall increase in Cairns' average annual temperature of 1.3°C from 1943 to 2022 and an increase in the number of excessively hot days per decade, from 16 in the first decade (1943–1952) to 67 in the last (2013–2022). We regularly detected maximum roost temperatures of 30–35°C during our study, with excessively hot days (>35°C) recorded more frequently than expected compared to Cairns's maximum temperatures from the last decade (2013–2023). We detected only 1 day where roost temperatures exceeded 40°C and no period that replicated the 2018 heatwave conditions. Furthermore, we found a significant negative relationship between roost ambient temperature and humidity, where the hottest days also coincided with those with the lowest humidity. Importantly, we found no difference in microclimate between roosts that were occupied and unoccupied by flying‐foxes during our study, suggesting that other environmental or behavioural factors are more influential for roost selection than the roosting microclimate. Ensuring the long‐term conservation of spectacled flying‐foxes under a changing climate will require the management of urban roosts to increase their thermal resistance to heatwaves, and more research is needed to identify the variables modulating this aspect.

Effect of Pruning in Coffee-Based Agroforestry System on Soil Chemical Properties

The low coffee productivity in smallholder coffee-based agroforestry systems and soil fertility degradation indicate mismanagement in soil and plant systems. The study examined pruning management practices on soil chemical properties in smallholder coffee agroforestry systems. Different pruning management were examined on UB forest coffee-pine agroforestry, namely pruned pine and unpruned coffee (T1), unpruned pine and pruned coffee (T2), and unpruned pine and unpruned coffee (T3). Each treatment has four replications, a total of 12 plots (size 2×3 meters for each plot). Soil samples were taken from five sampling points in each plot, ranged between 0-50 cm from the coffee stems at two different soil depths (ie, 0-20 cm and 20-40 cm) in each plot. Unpruned pine and coffee pruned (T2) plots had 21% to 61% higher total N at 20-40 cm soil depth than the other plots. Meanwhile, total K, soil exchangeable K and Na were higher from 21% to 335% in plots with pine and coffee without pruning (T1) as compared to unpruned pine with pruned coffee (T2) and pine and coffee without pruning (T3), preferably at 0-20 cm soil depth. Lastly, the unpruned pine and unpruned coffee management (T3) had 98% to 162% higher soil exchangeable Ca and Mg at a depth of 0-20 cm as compared to the other plots. The study suggests that tree management can affect soil chemistry. The study also found differences in litter input and microclimate (i.e., temperature, moisture and humidity levels, both on soil and air) between plots which are potentially affected by decomposition rate of soil organic matter and nutrient mineralization.

Strong differences in microclimate among the habitats of a forest-steppe ecosystem

Microclimate has a substantial impact on plant composition, survival, and growth, as well as ecosystem processes. Although microclimatic conditions in anthropogenically fragmented ecosystems have received considerable scientific attention, they are understudied in naturally fragmented ecosystems, including forest-steppes. In addition, earlier investigations in these mosaics only measured microclimate parameters for a very short period (i.e., 24 hours on a single summer day). In the present study, the long-term microclimatic conditions were described in multiple habitat types, both woody and non-woody, in a sandy forest-steppe ecosystem in the Kiskunság, central Hungary. The aim of this study was to answer (1) how air humidity and temperature conditions differ among the studied habitats during the growing season and (2) which habitats are more stressed to vegetation growth regarding vapor pressure deficit (VPD). Wireless sensors recording air temperature and humidity values were used to monitor microclimatic parameters. VPD values were calculated based on the obtained air temperature and humidity, and two thresholds at 1.2 and 3.0 kPa were defined. To compare mean air temperature and humidity variables, as well as above-threshold VPD rate among habitat types, general linear models were used. Our results indicated that open grasslands were the warmest and driest habitats. Among woody habitats, south-facing edges had the harshest microclimatic conditions. The current work also found that small forest patches and larger forest patches had similar air temperature and humidity variables. Regarding VPD, open grasslands were the most stressed for vegetation growth from May to October. During the summer season, forest patches had a small moderating effect at the limiting threshold of 1.2 kPa VPD, but a stronger moderating effect at the 3.0 kPa threshold. With ongoing climate change, this role of forest patches is expected to become increasingly important in forest-steppes. Therefore, it is suggested that the remaining near-natural forest stands in sandy forest-grassland ecosystems should be prioritized for protection, and that scattered trees or groups of trees of native species should be established in extensive treeless grasslands.

Same, same, but different: dissimilarities in the hydrothermal germination performance of range-restricted endemics emerge despite microclimatic similarities.

Seed germination responses for most narrow-range endemic species are poorly understood, imperilling their conservation management in the face of warming and drying terrestrial ecosystems. We quantified the realized microclimatic niches and the hydrothermal germination thresholds in four threatened taxa (Tetratheca erubescens, Tetratheca harperi, Tetratheca paynterae subsp. paynterae and Tetratheca aphylla subsp. aphylla) that are restricted to individual Banded Ironstone Formations in Western Australia. While T. aphylla subsp. aphylla largely failed to germinate in our trials, all other species demonstrated extended hydrothermal time accumulation (186-500°CMPadays), cool minimum temperatures (7.8-8.5°C), but broad base water potential thresholds (-2.46 to -5.41MPa) under which germination occurred. These slow germination dynamics are suggestive of cool and wet winter months, where soil moisture is retained to a greater capacity in local microsites where these species occur, rather than the warmer and drier conditions in the surrounding arid environment. Hydrothermal time-to-event modelling showed that each species occupied unique hydrothermal germination niches, which correspond with the microclimatic differences the species are exposed to. Our results provide a baseline understanding for environmental and germination thresholds that govern the recruitment, and ultimately the population structure and persistence, of these short-range endemic plants. In addition, our results can aid future conservation, as well as restoration actions such as translocation to bolster population numbers and to mitigate against losses due to anthropogenic disturbance and global environmental change.

Design strategies for renovation of public space in Beijing's traditional communities based on measured microclimate and thermal comfort

This paper proposes design strategies for renovating traditional communities in Beijing based on measured microclimate and thermal comfort and preserving historical authenticity to empower residents to make autonomous decisions about the renovation process. Based on the collected data from 11 hutongs and 102 courtyards in Dongcheng District, 4 representative courtyards and 2 representative hutongs are summarized. Microclimate data were collected in the representative months of January and September 2022. The design guidelines for 4 courtyards and 2 hutongs design guidelines, including 20 renovation modes, are proposed through on-site measurement and thermal comfort analysis. Due to the difference in microclimate, the proposed design guidelines can only be applied to the public space of traditional communities in Beijing but not to the public space in traditional villages in the suburbs. The application of the results also faces two challenges: the willingness of the public to participate in the renovation work and the demolition of illegal buildings. This study emphasizes human comfort as a factor to be considered in renovation projects. This study provides a standardized method for public space renovation in historic districts through microclimate analysis and thermal comfort assessment.

Maintenance schedule optimization based on distribution characteristics of the extreme temperature and relative humidity of Cave 87 in the Mogao Grottoes

Frequent fluctuations in microclimate inevitably cause serious irreversible damage to cultural heritage (such as high risks of cracking, flaking, salt efflorescence, swelling, disaggregation, surface layer detachment, and even microbe diseases). For the caves closed to the visitors, specifying a more rational schedule to minimize human influences on the microclimate is urgent and significant for daily maintenance of the Mogao Grottoes. Interior microclimate fluctuations are caused by air convection between the inside and outside environments, which is highly related to internal and external microclimate differences. Therefore, the occurrence times of the extreme values of temperature (T), relative humidity (RH), T difference (inside T minus outside T), and RH difference (inside RH minus outside RH) between the inside and outside environments of Cave 87 were analysed. The results indicated that the times of the extreme T/RH and T/RH differences showed obvious seasonal characteristics. From April to September, both the daily minimum T and RH differences mainly occurred from 8 am ~ 11 am, and the maximum differences were observed from 16 pm ~ 21 pm. This indicates that door openings for daily investigation and maintenance should be arranged in the morning rather than in the afternoon. The times of the daily extreme T and RH differences occurred from 16 pm ~ 19 pm (minimum) and 8 am ~ 11 am (maximum) from January ~ March and October ~ December, and the door opening time should be accordingly optimized. The analysis results provide more reasonable and specific door opening times for Cave 87 and a scientific reference for preventive conservation of the Mogao Grottoes.

Microclimate of Tropical Paddy Rice as Influenced by Water Management

The effects of water management on the microclimate of paddy rice under tropical field conditions have not been well documented. This study investigates changes in the microclimate of paddy rice and its influence on rice yield under different water management. Field experiments were conducted for two cropping seasons in Nueva Ecija, Philippines. The treatments were continuous flooding (CF), saturated soil condition (SSC), and safe alternate wetting and drying (AWD). Significant changes in the rice microclimate were observed during the dry season, wherein drying the field was possible. A general trend showed lower soil, meristem, and canopy temperatures in AWD and SSC than in CF. Consistently, significantly lower temperatures ranging from 22.64‒28.13 °C were observed during the reproductive stage and 23.03‒28.47 °C during the maturity stage under water-saving techniques compared to CF across both daytime and nighttime. In all growth stages, the canopy temperature was significantly lower in AWD by 0.36‒0.48 °C at nighttime compared to other treatments. However, there was a shift of higher canopy humidity (> 80) in AWD (albeit not significant with CF) in both daytime and nighttime. Seasonal variations of the canopy temperature and humidity at nighttime showed lower in the dry season than the wet season. Under normal conditions, differences in microclimate between CF and AWD did not significantly affect the grain yield despite the water savings of the latter by 78%. The findings of this study underscore AWD's role in lowering the microclimate of the rice plant when there are extreme heat episodes in a tropical environment.

Large mammalian herbivores affect arthropod food webs via changes in vegetation characteristics and microclimate

Abstract Large mammalian herbivores are vital components of terrestrial ecosystems, influencing the plants they feed on, but also serving as ecosystem engineers that impact the occurrence and survival of many other organisms. Arthropods are the most abundant and diverse animal group on earth, filling all trophic levels in food webs and facilitating essential ecosystem services. However, the impacts of large herbivores on arthropod communities and the mechanisms via which these impacts are mediated are not fully understood. Here, we experimentally separated the mechanistic pathways whereby large herbivores affect arthropod food webs using a 24‐year manipulative multi‐site field experiment in the Netherlands. We analysed the abundance, biomass and community composition of arthropods in the plant canopy and on the soil surface, both in grazed sites or sites where large herbivores were excluded. We found that the presence of large herbivores resulted in considerable differences in vegetation properties and microclimate which influenced the abundance and biomass of arthropods to varying trophic levels. Large herbivore grazing enhanced the overall abundance and biomass of arthropod herbivores, pollinators, omnivores and soil‐dwelling predators, but reduced that of detritivores, scavengers, parasitoids and canopy predators. Structural equation models revealed that different trophic groups are affected by grazing via different pathways. Specially, large herbivores facilitated herbivores via increasing plant quality and enhanced ground‐dwelling predators via increasing plant diversity. In contrast, plant‐dwelling predators were suppressed via decreased plant quantity, and parasitoids were mainly affected by changes in microclimate conditions. Synthesis. Our results show that large mammalian herbivores play a significant role in shaping grassland arthropod food webs, and that these impacts were independently mediated by multiple aspects of vegetation properties, that is, physical structure, plant diversity, standing crop biomass and leaf nutrient content. Arthropods of different trophic groups responded differently to the large herbivores, and these functional group‐specific responses in turn may have strong cascading effects on numerous ecosystem services.

Effects of the Bamboo Communities on Microclimate and Thermal Comfort in Subtropical Climates

Urban greening is the most effective way to regulate the microclimate environment and thermal discomfort. However, despite being an important type of vegetation, relatively few studies have investigated the effect of bamboo on microclimate characteristics and thermal comfort. In this study, the microclimate characteristics and the differences in the thermal comfort provided by common bamboo communities in East China were investigated in summer and winter, and the effects of canopy structure characteristics on microclimate and thermal comfort were analyzed. The results showed that there were significant differences in microclimate between bamboo communities and the control check in summer, but the differences in air temperature in winter were not obvious. In the daytime during summer, the maximum daily average temperature of the bamboo community decreased by 2.6 °C, and the maximum temperature–humidity index (THI) decreased by 1.1 °C. In the daytime during winter, the maximum daily average temperature increased by 0.5 °C and the maximum THI increased by 0.8 °C. Among the different bamboo communities, Sinobambusa tootsik var. laeta and Pseudosasa amabilis had better effects on improving microclimate and thermal comfort, while the effects of Phyllostachys nigra and Phyllostachys heterocycla ‘Pubescens’ were relatively small. Aspects of canopy structure, especially leaf area index and canopy coverage, had the greatest influence on the microclimate environment, while air temperature made the greatest contribution to thermal comfort. The goal of our study is to quantify the data to confirm the role of bamboo in improving urban climate problems and human comfort and to further select the appropriate bamboo species for urban green spaces and to utilize the ecological benefits of bamboo to optimize the human living environment.

Strong differences in microclimate among the habitats of a forest-steppe ecosystem

Strong differences in microclimate among the habitats of a forest-steppe ecosystem