Microclimatic Differences Research Articles

Microclimatic gradients cause phenological variations within temperate tree canopies in autumn but not in spring

Tree crowns experience strong vertical microclimatic gradients, particularly in light availability. Surprisingly, little is known about whether these gradients cause within-crown variation in leaf phenology and whether such variations represent different light-use strategies of sun- and shade leaves.In a temperate mixed forest at the Swiss Canopy Crane II site in Switzerland, we measured over three years the annual leaf phenology in the upper and lower crowns of mature trees from six broadleaved and three conifer species. We further recorded the microclimate (temperature, humidity, light) continuously in various positions within the canopy.We found microclimatic canopy gradients to be strongest during summer, but negligible in winter and spring, indicating that any phenological gradients in autumn, but not in spring, might be driven by microclimatic differences. Budbreak timing did not differ within the crowns of any of the broadleaved trees. However, in the three species with deeper crowns, leaf unfolding was up to 10 days faster in the lower crown but showed no difference in the more shallow-crowned species. Surprisingly, only the evergreen conifers Abies alba and Picea abies showed earlier bud break in the lower crowns. In autumn, senescence in all broadleaved species progressed from the upper crown downwards, resulting in up to two weeks longer vegetation seasons in the lower crown.With this first broad assessment of within-tree phenology, we show how microclimatic gradients and different light-use strategies lead to a considerable variability of within-crown phenological gradients. We interpret the faster leaf unfolding in the lower crown of three broadleaved species as a shade avoidance strategy, allowing shade branches to improve their C balance early in the season. In contrast, longer retention of lower leaves in autumn is unlikely to significantly improve the C balance, and more likely caused by higher summer temperature and irradiance in the upper leaves.

Volatile organic compound release across a permafrost-affected peatland

As the permafrost region experiences unprecedented climate warming, accelerated decomposition rates are potentially switching these cold landscapes to a hotspot of carbon emissions. In addition to the more widely studied greenhouse gases, carbon dioxide and methane, permafrost-affected soils may also be a source of volatile organic compounds (VOCs), but these reactive trace gases have so far received little attention. Nevertheless, VOCs can i) prolong the lifetime of atmospheric methane, ii) contribute to hazardous ozone production, and iii) lead to the formation of secondary organic aerosols. Consequently, changing VOC emissions may exert significant impacts on climate forcing factors that can both exacerbate or mitigate future climate change. Here, we conducted in situ measurements of soil and pond VOC emissions across an actively degrading permafrost-affected peatland in subarctic Norway. We used a permafrost thaw gradient as a space-for-time substitute that covered bare soil and vegetated peat plateaus, underlain by intact permafrost, and increasingly degraded permafrost landscapes: thaw slumps, thaw ponds, and vegetated thaw ponds. Results showed that every peatland landscape type was an important source of atmospheric VOCs, emitting a large variety of compounds, such as methanol, acetone, monoterpenes, sesquiterpenes, isoprene, hydrocarbons, and oxygenated VOCs. VOC composition varied considerably across the measurement period and across the permafrost thaw gradient. We observed enhanced terpenoid emissions following thaw slump degradation, highlighting the potential atmospheric impacts of permafrost thaw, due to the high chemical reactivities of terpenoid compounds. Higher VOC emission rates were observed in summer (June, July and August) compared to early autumn (September). Overall, our study demonstrates that VOCs are being emitted in significant quantities and with largely similar compositions upon permafrost thawing, inundation, and subsequent vegetation development, despite major differences in microclimate, hydrological regime, vegetation, and permafrost occurrence.

Microclimate and species composition shape the contribution of fuel moisture to positive fire-vegetation feedbacks

Ecosystems with positive fire-vegetation feedbacks are highly sensitive to extreme fire events, which are expected to increase in frequency with climate change. Understanding mechanisms maintaining flammability differences between alternative vegetation states is key to elucidate possible ecosystems shifts related to altered fire regimes. Here we assessed whether microclimatic differences between pyrophobic forests and pyrophilic shrublands in northwestern Patagonia can affect the fuel moisture content and partially explain their contrasting flammability. We measured dead and live fuel moisture content and recorded air temperature and relative humidity during one fire season in 10 sites corresponding to either forest or shrubland physiognomy. To disentangle effects from microclimate and species composition on live/dead fuel moisture content we used similar-composition fuels (wood sticks and single-species live leaves) and fuel mixtures (litter and a mixture of live leaves). We found that forests’ microclimate is cooler and moister than shrublands’, harbouring dead fuels with higher moisture content, irrespective of species composition. This suggests that dead fuel moisture content is contributing to make forests less flammable than shrublands. Live fuels tended to show higher moisture content under the forest microclimate, but only when single-species samples were considered. Contrarily, the species mixtures showed higher moisture content in shrublands, the most desiccant communities, suggesting that live fuel moisture content does not contribute to make shrublands more flammable.

The role of morphological traits in predicting the functional ecology of arboreal and ground ants in the Cerrado–Amazon transition

There is often a vertical stratification of the vegetation in tropical forests, where each forest stratum has a unique set of environmental conditions, including marked differences in habitat heterogeneity, physical complexity, and microclimate. Additionally, many tropical forests are highly seasonal, and we need to consider the temporal variation in environmental conditions when assessing the functional aspects of their organisms. Here, we tested the hypothesis that vertical stratification and seasonality shape tropical ants' functional ecology and that there are differences in the functional trait diversity and composition between arboreal and ground-dwelling ant communities. We collected ants in the arboreal and ground strata in the rainy and dry seasons in six different areas, measuring seven morphological traits to characterize their functional ecology and diversity. Irrespective of the season, we found a distinct functional composition between arboreal and ground-dwelling ants and a higher functional richness on the ground. However, ground ants were more functionally redundant than arboreal ants. The differences in functional richness and redundancy between ant inhabiting strata and season could also be observed in the community-weighted mean traits: arboreal and ground ant traits can be distinguished in Weber's length, mandible length, eye length, and eye position on the head capsule. The differences in these functional traits are mainly related to the ants' feeding habits and the complexity of their foraging substrates. Overall, by providing the first systematic comparison of continuous traits between arboreal and ground-dwelling ants, our study opens new investigation paths, indicating important axes of functional diversification of tropical ants.

Microclimate, soil chemistry, and microbiota fail to explain Euphorbia dendroidesJanzen‐Connell pattern in a shrubland

AbstractNegative plant–soil feedback can cause density and distance effects that lead to Janzen–Connell (JC) distribution. The JC hypothesis has been proposed to explain the high species diversity in tropical forests, but it has been rarely tested in species‐rich Mediterranean shrublands. In this study, we assessed whether the JC hypothesis could explain Euphorbia dendroides recruitment pattern under conspecific conditions, that is, mother plant and the canopy of Pistacia lentiscus, Juniperus phoenicea, Myrtus communis, Rosmarinus officinalis, and Olea europaea. We examined whether soil chemistry and/or soil microbiota, characterized by both bacterial and fungal communities, explained the observed JC pattern. We also explored differences in microclimate among shrub species by monitoring air temperature and light availability at different times of the year. Euphorbia recruits were almost absent under the canopy of conspecifics, being more abundant at the edge of the canopy, which fits the JC pattern. Interestingly, we also found a high density of Euphorbia recruitment under heterospecific canopies, that is, O. europaea and J. phoenicea, but a very low density under other heterospecific canopies, for example, R. officinalis and P. lentiscus. Although shrubs have a species‐specific microbiota signature under their canopy, neither the accumulation of species‐specific pathogens nor soil chemical properties explain the observed JC pattern. Despite finding that shrubs buffer high temperatures in summer, the observed microclimatic difference failed to explain the recruitment pattern. We conclude that JC is prevalent in this species‐rich Mediterranean shrubland, but the underlying mechanism remains to be investigated and clarified.

Summer urban heat island mitigation strategy development for high-anthropogenic-heat-emission blocks

• Results from 33 measurement points in 5 selected urban districts were analyzed. • Urban morphology explains 34% of the variation in air temperature. • Suggested morphological indices are proposed to mitigate the high temperature. • 20m buffer zone is proper to analyze microclimate in high anthropogenic heat areas. • The microclimatic prediction models were established for sustainable development. The negative impacts of urban heat island (UHI) have attracted more and more academic attention. Currently, few studies have considered the effects of anthropogenic heat emission (AHE) in different urban districts. To explore the spatial and temporal differences in microclimate in high-AHE areas, five high-anthropogenic-heat-emission blocks in Xi'an, China were selected, and the microclimatic indices of air temperature (AT) and relative humidity (RH) were measured in 33 urban points in the five typical urban blocks. Meanwhile, the urban morphological indices of 33 points were calculated in the 20 m and 50 m buffer areas (BAs). Results show that the green cover ratio (GCR), the impervious surface area ratio (ISAR), sky view factor (SVF) and reflectivity (REF) were important variables affecting microclimate. These indices explained up to 35% and 31% of the changes in AT and RH, respectively. In addition, the ISAR should be controlled within 44% and the REF should be controlled above 21.5%, in order to ensure that the maximum AT remained less than 37°C (high-temperature orange warning) inside the block on a typical summer day. This study improves the prediction method of high summer temperatures in high-AHE blocks and provides hints for developing UHI mitigation strategies.

Micrometeorological measurements of air temperature in part of the northern slope of the Western Rhodopes (preliminary results)

The present study characterizes some microclimatic differences on the northern slope of the Western Rhodopes Mountains. The data for the analysis are based on the observations at three points: Brestovitsa at the foot, Bryanovshtitsa on the slope and Vurhovruh hut on the ridge, during July and August. Average temperatures, average minimum and maximum temperatures as well as the absolute minimum and maximum temperatures were established. They decrease naturally in accordance with altitude change, showing a dependence on synoptic conditions and microclimatic differences. The vertical temperature gradient is calculated for the studied parameters, with the largest values for the absolute maximum temperature amounting to 1.1 °C and the smallest for the absolute minimum and mean minimum temperature amounting to 0.5 °C. The largest values of the vertical temperature gradient for all parameters were observed between Brestovitsa and Bryanovstitsa.

Measuring the Impact of Forest Edges on the Highly Arboreal Sahamalaza Sportive Lemur, Lepilemur Sahamalaza, in North-Western Madagascar

The progressive fragmentation of forest habitat is causing an increase in edge areas that may differ structurally and in quality from forest interiors. We investigated the impact of edge effects on habitat structure, behaviour, and ecology of the small, nocturnal, and highly arboreal Sahamalaza sportive lemur, Lepilemur sahamalaza. To understand edge effects, we established edge-to-interior gradients using temperature, humidity, and light intensity measurements along transects. From 773 h of behavioural observations on 14 individual sportive lemurs between 2015 and 2016, we compared home range sizes, activity budgets, and habitat use of animals inhabiting the edge area and those in the core forest. We found that microclimatic edge effects penetrated the forest up to 165 m, but that there was no significant edge effect on vegetation; forest vegetation was structurally variable throughout. Individual sportive lemurs living in the edge area used more trees with a diameter at breast height of less than 5 cm but showed no other behavioural differences to individuals inhabiting the core forest. The study shows that this species may not be impacted by edge effects, at least in situations in which vegetation structure is not affected, despite microclimatic differences.

Prediction of future climate in semi-arid catchment under CMIP6 scenarios: A case study of Bahi (Manyoni) catchment in Internal Drainage basin (IDB), Tanzania

Prediction of future climate is vital, especially for areas with low rainfall amounts, rapid population growth and high groundwater dependency. Bahi (Manyoni) is among the driest catchment hosting the new capital city of Tanzania which depends heavily on groundwater resources. Therefore, future climate prediction was done using the Coupled Model Intercomparison Project Phase 6 (CMIP6) scenarios of SSP126, SSP245 and SSP585. Linear Scaling (LS) bias-corrected on European center Reanalysis 5th generation (ERA5) was used to supplement temperature data. Out of 15 Global Climate Models (GCMs), CNRM-CM6-1-HR, INM-CM4-8 and INM-CM5-0 for rainfall and AWI-CM-1-1-MR, MRI-ESM2-0, EC-Earth3 and EC-Earth3-Veg for temperature were selected based on their highest performance in Taylor Skill Score (TSS) and subsequently their ensemble used. TSS of 0.83, 0.90, and 0.65 were obtained for rainfall, minimum temperature (Tmin), and maximum temperature (Tmax) ensembles respectively. LARS-WG 6.0 was applied for downscaling climatic data. Findings predicted that in 2080s for SSP126 and SSP585 scenarios, catchment mean annual rainfall to decrease between 13.8% and 4.3% in northern part, and to increase between 14.5% and 25.4% in southeast with an overall average Tmin increase between 0.2 °C and 4.5 °C and Tmax between 0.8 °C and 2.8 °C. This indicated relatively warmer and drier climate in northern compared to southern part of the catchment. These differences in microclimates could not be captured in large-scale studies such as IPCC, 2021. These findings highlighted potential climate change impacts on crop production and groundwater recharge, which contributes to Tanzania's Nationally Determined Contributions and National Adaptation Plans against future climate change.

Microclimate and Mould Growth Potential of Air Cavities in Ventilated Wooden Façade and Roof Systems—Case Studies from Norway

Harsh climatic conditions in the Nordic countries are being worsened by climate change, which increases the moisture load on building façades. New types of defects are being observed in air cavities in well-designed and well-built wooden façades and roofs. More knowledge is required on the microclimatic conditions in air cavities and roofs, and their implications for organic growth and biological deterioration. The present study collects and presents sensor data from three buildings in Norway. Collected air temperature, air humidity, and wood moisture data are compared to mould growth criteria found in scientific literature, building physics software, and national and international standards. The data shows great differences in air cavity microclimates between the case buildings and between different sensor positions within the instrumented air cavities. Air cavity temperatures are found to be lower than exterior temperatures for a substantial portion of the time. For tall buildings, the vertical positioning of a sensor influences the data more than the orientation of the façade. All three buildings feature monitoring positions with both acceptable and critically high levels of moisture to indicate mould risk. There is great variation in the estimated risk of mould growth according to the different criteria. The study indicates that the coastal climate in the south-west of Norway presents a challenge in terms of resilient building design to avoid mould growth in the ventilated air cavity.

Microclimate shapes vegetation response to drought in calcareous grasslands

AbstractQuestionsSemi‐natural grasslands have been shown to be relatively resilient to drought events, but there seems to be no uniform response of different grassland types or across species. The typical vegetation of calcareous grasslands, which are biodiversity hotspots in Europe, reportedly even profits from droughts. What was the response of their vegetation, considering different species groups, to the recent periods of intense summer droughts? How did differences in microclimate, such as between steep, south‐facing slopes (SSF) and flat or north‐facing slopes (FNF), affect species composition and drought response?LocationSemi‐arid calcareous grasslands (Mesobromion) in northwest Germany.MethodsIn 2019, we resurveyed 112 vegetation plots from 25 sites first established in 2008, after 11 exceptionally dry years. Species identities and cover were assessed in plots of 1 m2. We used linear mixed models to determine the effect of microclimate on species composition and drought response. Vegetation changes were visualised by non‐metric multidimensional scaling (NMDS).ResultsIn the initial survey in 2008, the species composition was significantly influenced by the microclimate, with positive effects of dry and warm conditions on SSF on character species. Phosphorus availability played an equally important, albeit contrasting, role. Vegetation change between 2008 and 2019 showed strong signs of the severe droughts. On SSF slopes, total species richness decreased, with negative trends for all species groups except ruderal species. Remarkably, this also affected the character species of dry grasslands. By contrast, dry conditions on FNF favoured an increase in total species richness and character species. However, eutrophication indicators increased here as well.ConclusionsWe conclude that sites with a dry and warm microclimate have to date had a positive, stabilising effect on the typical vegetation of calcareous grasslands. However, increasing droughts due to climate change pose a potential threat to the characteristic species composition, especially at sites with hot and dry microclimates.

The Influence of Transient Changes in Indoor and Outdoor Thermal Comfort on the Use of Outdoor Space by Older Adults in the Nursing Home

Recently, the requirements regarding the environment of nursing homes are high, because the elderly are a vulnerable group with limited adaptive capacity to respond to transient environmental change. This paper presents a field investigation on the influence of transient thermal comfort changes between the indoor and outdoor spaces (i.e., air temperature (Ta), solar radiation (SR), relative humidity (RH), wind speed (WS), and the thermal comfort indices of Universal Thermal Index (UTCI)) on the willingness of the elderly to use outdoor spaces of the Wanxia nursing home of Chengdu City. Results indicated that, in summer, the mean UTCI values of indoor and corridor spaces corresponded to the level of moderate heat stress, while those of road and garden corresponded to the strong heat stress level. Road and garden spaces even showed moderate heat stress in spring. Approximately 28.93% (139) of the elderly living here used outdoor spaces every day. The morning period (from 9:00 a.m. to 10:00 a.m.) was the elderly’s favorited period for using outdoor spaces in seasons. The microclimatic transient differences between indoor and outdoor spaces ranged from 0.47 °C to 2.93 °C (|ΔTa|), from 86.09 W/m2 to 206.76 W/m2 (|ΔSR|), from 5.29% to 14.76% (ΔRH), from 0.01 m/s to 0.07 m/s (|ΔWS|), and from 0.25 °C to 2.25 °C (ΔUTCI). These big microclimate differences could cause enormous health risks for the elderly in the process of indoor and outdoor space conversion. The minimal transient change occurred between corridors and indoors. Pearson correlation analysis indicated ΔTa and ΔRH between indoor and outdoor spaces were the primary meteorological factors that influenced the elderly’s willing to use outdoor spaces. The elderly preferred to live in a constant Ta and RH environment. Only when the ΔTa and ΔRH are small enough to resemble a steady-state (ΔUTCI ≤ 0.5 °C), ΔWS and ΔSI could affect the elderly’s choice of using outdoor space. Optimal design strategies were put forward for reducing the transient differences between indoor and outdoor microclimates to inspire the elderly to use outdoor spaces safely, including improving outdoor canopy coverage and indoor mechanical ventilation.

Influences of slope aspects on soil properties of Anatolian black pine forests in the semiarid region of Turkey

This study assessed the influences of slope aspect on soil physicochemical properties (soil quality indicators) on contiguous south-north facing slopes and hill plain (ridge crest) of the mid-mountain in Central Anatolia, having the same climate, vegetation and parent material. Anatolian black pine (Pinus nigra subsp. Pallasiana var. Pallasiana (Arnold)) was the dominant, and Cedar (Cedrus libani A. Richard), oak (Quercus sp.) were the co-dominant species in all aspects, whereas juniper (Juniperus sp.) was only recorded in north-facing forests. Some of the soil properties were determined on a grid with a 50 m sampling distance on the topsoil (0-15 cm depth). Accordingly, a total of 150 samples were taken from the three adjacent aspects. The data was analyzed using one-way ANOVA statistical methods. The investigated soil variables were soil organic matter (SOM), soil organic carbon (SOC), total nitrogen (TN), bulk density (BD), texture, lime (CaCO3), and pH. The showed that differences between SOC, BD and soil texture were statistically significant at 0.05 levels. Topographic aspect induced microclimatic differences were found to be important factors for the significant variations in SOC stocks. The resulting analyses showed no significant variation (p < 0.05) across slope aspects for SOM, TN, lime, and pH. The differences may be attributed to topographic aspect induced microclimatic differences, which cause differences in the biotic soil component and organic matter trend and affect soil fertility. These results suggest that the slope aspect affects the soils of mountain forests through their direct influence on radiation, evaporation, biological activity, and soil moisture content.

Effects of nest-box environment on fledgling success rate and pathogen load.

Nest boxes have been used for many decades as tools for conservation and to study avian population dynamics. Plastic is increasingly used as a material for nest boxes, but no studies have investigated effects of this different material. Two consecutive studies were conducted to investigate effects of nest-box environment on nidicolous parasites, bacteria and fungi, as well as nest success, in blue tits Cyanistes caeruleus and great tits Parus major. The first compared microclimate and parasite and pathogen load in plastic and wooden nest boxes. The second tested the nest protection hypothesis – that birds naturally incorporate aromatic herbs into nests to decrease nest parasites and pathogens – by comparing parasite and pathogen load in plastic nest boxes to which aromatic or non-aromatic plant material was added. No significant difference in nest-box temperature or relative humidity was found between plastic and wooden boxes. Wooden boxes, however, contained 30-fold higher numbers of fleas and a higher total bacterial load on chicks. Fledging success for blue tit broods was significantly higher in wooden boxes. Parasites and bacteria did not decrease by the inclusion of aromatic herbs. The results increase the evidence base for nest-box design in support of plastic, which can provide an appropriate alternative nest-box material to wood, with apparently no difference in microclimate and no increase in the load of measured parasites and pathogens.

Identifying the Factors behind Climate Diversification and Refugial Capacity in Mountain Landscapes: The Key Role of Forests

Recent studies have shown the importance of small-scale climate diversification and climate microrefugia for organisms to escape or suffer less from the impact of current climate change. These situations are common in topographically complex terrains like mountains, where many climate-forcing factors vary at a fine spatial resolution. We investigated this effect in a high roughness area of a southern European range (the Pyrenees), with the aid of a network of miniaturized temperature and relative humidity sensors distributed across 2100 m of elevation difference. We modeled the minimum (Tn) and maximum (Tx) temperatures above- and below-ground, and maximum vapor pressure deficit (VPDmax), as a function of several topographic and vegetation variables derived from ALS-LiDAR data and Landsat series. Microclimatic models had a good fit, working better in soil than in air, and for Tn than for Tx. Topographic variables (including elevation) had a larger effect on above-ground Tn, and vegetation variables on Tx. Forest canopy had a significant effect not only on the spatial diversity of microclimatic metrics but also on their refugial capacity, either stabilizing thermal ranges or offsetting free-air extreme temperatures and VPDmax. Our integrative approach provided an overview of microclimatic differences between air and soil, forests and open areas, and highlighted the importance of preserving and managing forests to mitigate the impacts of climate change on biodiversity. Remote-sensing can provide essential tools to detect areas that accumulate different factors extensively promoting refugial capacity, which should be prioritized based on their high resilience.

Trade-offs between succulent and non-succulent epiphytes underlie variation in drought tolerance and avoidance.

Epiphyte communities comprise important components of many forest ecosystems in terms of biomass and diversity, but little is known regarding trade-offs that underlie diversity and structure in these communities or the impact that microclimate has on epiphyte trait allocation. We measured 22 functional traits in vascular epiphyte communities across six sites that span a microclimatic gradient in a tropical montane cloud forest region in Costa Rica. We quantified traits that relate to carbon and nitrogen allocation, gas exchange, water storage, and drought tolerance. Functional diversity was high in all but the lowest elevation site where drought likely limits the success of certain species with particular trait combinations. For most traits, variation was explained by relationships with other traits, rather than differences in microclimate across sites. Although there were significant differences in microclimate, epiphyte abundance, and diversity, we found substantial overlap in multivariate trait space across five of the sites. We found significant correlations between functional traits, many of which related to water storage (leaf water content, leaf thickness, hydrenchymal thickness), drought tolerance (turgor loss point), and carbon allocation (specific leaf area, leaf dry matter content). This suite of trait correlations suggests that the epiphyte community has evolved functional strategies along with a drought avoidance versus drought tolerance continuum where leaf succulence emerged as a pivotal overall trait.

Stand age related differences in forest microclimate

Quantifying spatio-temporal variation in forest microclimate is important to understand the habitat associations of some species, identify potential refugia, and manage forests in a changing climate. We quantified relationships between microclimatic conditions and stand age using a detailed case study of the Mountain Ash (Eucalyptus regnans) forests in south-eastern Australia. We deployed sensor buttons to capture data on day-time and night-time seasonal (Julian Day) temperature profiles in even-aged stands that were 12-years-old, 30–40-years-old, ∼82–95-years-old, and 200+ -years-old. We constructed Bayesian generalised linear models (GLMs) to quantify the main and interacting effects of stand age and topographic factors and foliage cover on seasonal profiles for: median, maximum and variability in day-time and night-time temperature.The most parsimonious model for median day-time temperature included a main effect of midstory and overstory cover, both of which were inversely related to median day-time temperature. The most parsimonious model for median night-time temperature measures included an additive effect of forest age and seasonality. Temperatures for the youngest forests (that were 12-years-old) were different from other age classes and were characterised by the lowest median and minimum night-time temperatures.The most parsimonious model for day-time maximum temperature and day-time interquartile range included an interaction between forest age and Julian day. Day-time maximum temperatures were warmest in 12-year-old forest. The coolest maximum day-time temperatures in summer were generally in old growth stands (200+ -year-old). The greatest variability in maximum day-time temperatures was in 12-year-old forest whereas, in general, old growth stands experienced the least variable day-time temperatures. Our sensor data also showed that old growth forests were characterised by fewer days above 30, 35 and 40 degrees than 12-year old forest. Our empirical data contain compelling evidence that the youngest forests were characterised by the hottest day-time temperatures, the coldest night-time temperatures, and the most variable day-time and night-time temperature regimes. Age class differences in stand structure (e.g. canopy height, prevalence of large old trees and dense wet understorey) may explain stand age related seasonal differences in local microclimatic conditions.

Building Envelope and the Outdoor Microclimate Variable of Vernacular Houses: Analysis on the Environmental Elements in Tropical Coastal and Mountain Areas of Indonesia

Temperature and humidity are essential factors in analyzing a building’s thermal performance. This research presents the differences in field measurements of vernacular houses in coastal and mountain areas in Indonesia. Field measurements were taken for five consecutive days in four vernacular houses. The variables were measured at the beginning and at the peak of the rainy season. Analysis included a combination of graphic and descriptive methods. The research results show that the location difference between coast and mountain results in a relatively high difference in temperature (43.6%). The outdoor temperature in the mountain area is lower than that of the coastal area. The outdoor humidity of the mountain area is 0.69% higher than that of the coastal area. In the tropical coastal area, the outdoor temperature of the exposed-brick house is 0.94% lower than that of the coastal wooden house. The outdoor air humidity of the brick house is 0.89% higher than that of the coastal wooden house. In the tropical mountain area, the outdoor temperature of the exposed-stone house is 2.47% lower than that of the wooden house. The outdoor air humidity of the stone house is 0.4% lower than that of the wooden house. The outdoor conditions affect the indoor conditions of the respective houses. These microclimatic differences are influenced by micro-environmental factors, such as the density of surrounding buildings, amount of vegetation, and shading. The research shows that height difference is the most dominant factor influencing outdoor microclimate. Regional microclimate becomes the basis for determining the most suitable envelope materials in different areas. The innovative contribution of the work is, among other benefits, the identification of factors that influence the wellbeing of the buildings’ users in the researched geographical area and the analysis of the interaction of the external and internal environment of buildings. From the above facts, it follows that the results of this work can contribute to the development of prediction models to determine the type of cover, material, shape, and load-bearing elements needed to create comfortable and energy-efficient buildings.

Long-term microclimate study of a peatland in Central Europe to understand microrefugia

Peatlands perform many important ecosystem functions at both the local and global scale, including hydrologic and climatic regulation. Although peatlands often act as climatic microrefugia, they have rarely been the subject of long-term microclimatic studies. In this study, we aimed to compare the local climatic conditions of a mid-forest mire to that of an open area and examine the differences in microclimates within the mire based on plant community diversity, shading, and water table depths. The peatland studied in this work was significantly cooler than the reference site, mainly due to a higher decline in nighttime air temperatures. However, the daily maximum air temperature near the ground was often higher. We also noticed that microclimates significantly differed within the studied peatland. Wet and shaded microsites were cooler than the sites having a lower water level and receiving higher amounts of solar radiation. The results of the study suggest that peatlands have locally cooler climates, and thus can serve as climate change refugia. These findings can help us interpret reconstructed data from the peat archive, and, when combined with experiments, identify tipping points for peatland ecosystems.

Fungal fruit body assemblages are tougher in harsh microclimates

Forest species are affected by macroclimate, however, the microclimatic variability can be more extreme and change through climate change. Fungal fruiting community composition was affected by microclimatic differences. Here we ask whether differences in the fruiting community can be explained by morphological traits of the fruit body, which may help endure harsh conditions. We used a dead wood experiment and macrofungal fruit body size, color, and toughness. We exposed logs of two host tree species under closed and experimentally opened forest canopies in a random-block design for four years and identified all visible fruit bodies of two fungal lineages (Basidio- and Ascomycota). We found a consistently higher proportion of tough-fleshed species in harsher microclimates under open canopies. Although significant, responses of community fruit body size and color lightness were inconsistent across lineages. We suggest the toughness-protection hypothesis, stating that tough-fleshed fruit bodies protect from microclimatic extremes by reducing dehydration. Our study suggests that the predicted increase of microclimatic harshness with climate change will likely decrease the presence of soft-fleshed fruit bodies. Whether harsh microclimates also affect the mycelium of macrofungi with different fruit body morphology would complement our findings and increase predictability under climate change.