Dry Summer Research Articles

Recent weather extremes and their impact on crop yields of the Netherlands

We assessed impacts of recent weather extremes on yields of major food and feed crops in the Netherlands. Impacts on the arable crops potato, sugar beet, onion and winter wheat were analysed in 12 regions. Impacts on the forage crop yields grass and maize were analysed for 6 regions. This study shows impacts of weather extremes on crop yields, mediated by soil and agricultural management (irrigation, fungicides, etc). We show that two large scale weather extremes had a major impact on crop yields. The 1998 extremely wet harvesting period had a major negative impact on all tuber crops (potato, sugar beet, onion). The 2018 extremely dry summer period had a major negative impact on grass and onion. One region was found to be particularly sensitive to drought, which seems to be related to this province having poor access to irrigation. Much larger negative impact of drought in this one region shows that impact of extremes can be strongly mitigated by agricultural management (irrigation). Therefore, should access to irrigation decline in the future, impact of drought would be larger than reported here. Our analysis contributes to a deeper quantitative understanding of which weather extremes actually affect crop production and subsequently benefits the quest for adaptation options.

Climate Change Affecting Forest Fire and Flood Risk—Facts, Predictions, and Perceptions in Central and South Greece

Global Climate change (CC) is featured by long-term changes in the mean values of climatic parameters (predominantly mean temperature) and in the profile of extreme weather events (e.g., increase in frequency, intensity, lengthening, and persistence). These climatic changes are supposed to have a deterioration impact on forest fire and flood disasters. Greece, an east Mediterranean country, is featured by a wide variety of micro-climates due to its unique geographical diversity, including hot and dry summers in the eastern part of the country (where a large amount of precipitation falls in the form of showers and thunderstorms) and wet winters in the western part. The combination of certain climatic zones with unfavorable land use and land cover changing patterns has resulted in several regions being prone to flooding and forest fires. The authors, based on relevant records, consider central and south Greece as flood and forest fire hotspots and attempt to: (a) present scientific estimations of local climate changes; (b) outline recent trends in the number of respective disasters and the amount of losses in these regions; (c) address recent changes in local climatic factors that might have influenced flood and forest fire hazard and risk in these regions; and (d) study the perceptions of the lay public and management authorities regarding the accountability of CC for flood and forest fire risk and hazard changes. The results show the variability of climate changes between neighboring areas, which directly affect the risk of forest fires and floods. Especially since the beginning of the 21st century, central Greece has been experiencing dramatic increases in both risks, while in south Greece the latter remain relatively stable. With regard to the perceptions of citizens and management authorities, the mental connection of local CC with forest fires and floods is still weak if not totally missing. Since knowledge and perceptions of the local “history” of forest fires and floods and the interconnections with CC by region is very important for the local communities to take appropriate mitigation and adaptation measures, this paper outlines a methodological path for similar studies to be conducted also in other regions of the Mediterranean basin and beyond.

To -8 MPa and back: in-situ annual water relation in non-irrigated olive trees

Olive trees are known for their capability to endure and recover from low stem water potentials (Ψstem < -6 MPa) and even maintain substantial gas exchange under such conditions. In the current experiment, we tested the physiological responses of mature olive trees in-situ while enduring such Ψstem under field conditions for seven months of rainless Israeli summer. To characterize olive trees' seasonal response to drought, we followed the annual patterns (a measurement day once a month) of Ψstem, gas exchange, osmotic adjustment, and hydraulic conductance of mature bearing olive trees that were disconnected from irrigation. We found that through the dry summer, the trees gradually dehydrated to a minimum of -8.1 MPa in October. An increase of 1320 mmol/kg in the leaf osmotic concentration through the summer was part of the tree's acclimation to the low Ψstem. Surprisingly, despite the low Ψstem that have probably led to substantial xylem cavitation, the trees maintained stomatal conductance of at least 0.023 mol m-2 s-1 and positive assimilation throughout the year. Following the winter rains, the plants recovered their Ψstem, gas exchange, and hydraulic conductance to maximal values. The results demonstrate olives' remarkable ability to tolerate Ψstem while maintaining above minimal gas exchange and producing fruits.

Nonlinear multidecadal trends in organic matter dynamics in Midwest reservoirs are a function of variable hydroclimate

AbstractDissolved organic matter (DOM) and particulate organic matter (POM) can influence biogeochemical processes in aquatic systems. An understanding, however, of the source, composition, and processes driving inland reservoir organic matter (OM) cycling at a regional scale over the long term is currently unexplored. Here, we quantify decadal patterns (> 20 yr) of DOM quantity and composition and POM in 40 reservoirs in the midcontinent United States. We built 184 Random Forest models to identify how the relative influence of watershed characteristics and limnological parameters on OM dynamics may vary over time and in synchrony with hydroclimatic anomalies. The reservoir OM quantity and composition varied nonmonotonically through time and in contrast to lake browning observed in the northern hemisphere. Reservoir DOM composition switched from humic and aromatic during wet summers to aliphatic, potentially autochthonous DOM during particularly prolonged dry summers in the mid‐2000s. The shift in reservoir DOM quantity and composition could be attributed to the change in time‐varying control of watershed and limnological factors mediated by the hydroclimatic conditions. Watershed control (e.g., percent crops) was predominant during wet summers, while the effect of reservoir morphology (e.g., maximum depth) and water quality parameters (e.g., Secchi depth, chlorophyll a) were evident during dry summers. Thus, future predictions of drier conditions may promote “greening” with negative implications for reservoir water quality and treated drinking water. Considering the nonlinear nature of reservoir OM dynamics and its controls will help to better mitigate water quality issues in these constructed systems increasingly impacted by global changes.

The fall of the summer truffle: Recurring hot, dry summers result in declining fruitbody production of Tuber aestivum in Central Europe.

Global warming is pushing populations outside their range of physiological tolerance. According to the environmental envelope framework, the most vulnerable populations occur near the climatic edge of their species' distributions. In contrast, populations from the climatic center of the species range should be relatively buffered against climate warming. We tested this latter prediction using a combination of linear mixed effects and machine learning algorithms on an extensive, citizen-scientist generated dataset on the fruitbody productivity of the Burgundy (aka summer) truffle (Tuber aestivum Vittad.), a keystone, ectomycorrhizal tree-symbiont occurring on a wide range of temperate climates. T. aestivum's fruitbody productivity was monitored at 3-week resolution over up to 8 continuous years at 20 sites distributed in the climatic center of its European distribution in southwest Germany and Switzerland. We found that T. aestivum fruitbody production is more sensitive to summer drought than would be expected from the breadth of its species' climatic niche. The monitored populations occurring nearly 5°C colder than the edge of their species' climatic distribution. However, interannual fruitbody productivity (truffle mass year-1 ) fell by a median loss of 22% for every 1°C increase in summer temperature over a site's 30-year mean. Among the most productive monitored populations, the temperature sensitivity was even higher, with single summer temperature anomalies of 3°C sufficient to stop fruitbody production altogether. Interannual truffle productivity was also related to the phenology of host trees, with ~22 g less truffle mass for each 1-day reduction in the length of the tree growing season. Increasing summer drought extremes are therefore likely to reduce fruiting among summer truffle populations throughout Central Europe. Our results suggest that European T. aestivum may be a mosaic of vulnerable populations, sensitive to climate-driven declines at lower thresholds than implied by its species distribution model.

Projected changes in mean annual cycle of temperature and precipitation over the Czech Republic: Comparison of CMIP5 and CMIP6

The multi-model ensembles like CMIP5 or CMIP6 provide a tool to analyze structural uncertainty of climate simulations. Currently developed regional and local climate change scenarios for the Czech Republic assess the uncertainty based on state-of-the-art Global Climate Model (GCM) and Regional Climate Model (RCM) ensembles. Present study focuses on multi-model spread of projected changes in long-term monthly means and inter-annual variability of monthly mean minimum, mean and maximum daily air temperature and monthly mean precipitation. We concentrate in more detail on the simulation of CNRM-ESM2-1, the driving GCM for the convection permitting ALADIN-Climate/CZ simulation contributing to the local scenarios in very high resolution. For this GCM, we also analyze a mini-ensemble with perturbed initial conditions to evaluate the range of internal climate variability. The results for the Czech Republic reveal minor differences in model performance in the reference period whereas quite substantial inter-generation shift in projected future change towards higher air temperature and lower summer precipitation in CMIP6 comparing to CMIP5. One of the prominent features across GCM generations is the pattern of summer precipitation decrease over central Europe. Further, projected air temperature increase is higher in summer and autumn than in winter and spring, implying increase of thermal continentality of climate. On the other hand, slight increase of winter precipitation and tendency towards decrease of summer precipitation lead to projected decrease of ombric continentality. The end of 21st century projections also imply higher probability of dry summer periods, higher precipitation amounts in the cold half of the year and extremely high temperature in summer. Regarding the CNRM-ESM2-1, it is often quite far from the multi-model median. Therefore, we strictly recommend to accompany any analysis based on the simulation of nested Aladin-CLIMATE/CZ with proper uncertainty estimate. The range of uncertainty connected to internal climate variability based on one GCM is often quite large in comparison to the range of whole CMIP6 ensemble. It implies that when constructing climate change scenarios for the Central Europe region, attention should be paid not only to structural uncertainty represented by inter-model differences and scenario uncertainty, but also to the influence of internal climate variability.

The imprint of hydroclimate, urbanization and catchment connectivity on the stable isotope dynamics of a large river in Berlin, Germany

• Isotope monitoring in Berlin during the 2018 – 2020 drought. • Large-scale hydroclimate dynamics determine isotope patterns in the Spree. • Berlin’s green spaces largely disconnected from surface waters. • Catchment- & city-scale measures needed to adapt water resources to climate change. Sustainably meeting the growing water demand of cities during a changing climate will be a major challenge in the near future. Adjusting water management strategies towards preserving urban water resources while best utilizing urban “blue” and “green” infrastructure will require precise knowledge of urban water cycling, storage and losses across large built-up areas. To gain this understanding, using stable isotopes of water as tracers in the hydrological cycle can provide valuable insights, but their application remains challenging in complex and heterogeneous metropolitan areas. This study used stable isotopes, combined with hydrometric and climatic data, to assess the imprint of the urban area and climate warming on a large urbanised river system, the River Spree in Berlin, Germany, during the exceptionally warm and dry 2018 – 2020 period. Isotope dynamics in the Spree reflected gradually varying seasonal patterns with more enriched values in summer and more depleted values in winter. Large-scale climate variability and evaporative losses in the upstream catchment, along with anthropogenic activities, impacted isotope and discharge dynamics in the Spree, especially during warm and dry summer and autumn periods. In local urban sub-catchments, variability of isotope dynamics and subsequent water ages and transit times were largely affected by engineered system components, i.e. catchment imperviousness, connectivity to storm drains and effluent discharge. Berlin’s green spaces were largely disconnected from surface waters. Urban trees in particular had high water demands during dry periods that may be hard to sustain, as trees showed slower replenishment of soil moisture during winter, resulting in shorter recharge periods under trees. More research will be needed on: (a) how planting design with alternations of urban grassland, shrub and trees can enhance infiltration and maintain water demands for trees during drought; and (b) on better quantifying open-water evaporation in the upstream catchment to fully account for catchment water losses. To sustainably manage and preserve not just Berlin’s but also similar cities’ water resources in the future, our results indicate that both integrated city- and catchment-scale measures will be necessary.

Experimental investigation of soiling effects on the photovoltaic modules energy generation

Abstract The article describes an experimental investigation of the impact of soiling on the photovoltaic modules in northeastern, Iraq. Over five months, the voltage, current power and energy curves of two identical modules with varying cleaning strategies (one was naturally dusty while the other was cleaned regularly) were measured. The impact of soiling on the daily energy produced as well as rain accumulation and particulate matter concentrations are discussed. The results indicated that no losses occurred during wet seasons, but a considerable decline in performance was found during dry periods owing to soiling. Additionally, it was discovered that soiling has a bigger effect on the maximum power than the short-circuit current. After two dry summer months, the greatest power loss of up to 22% was seen. The daily energy loss due to soiling was determined to be 16% on average. Furthermore, there are four polynomial models that have been drowned in prediction photovoltaic module (voltage, current, power, and energy) degradation due to the accumulation of dust.

A warm and humid paleoecological context for the Neanderthal mountain settlement at the Navalmaíllo rockshelter (Iberian Central System, Madrid)

Neanderthals have been claimed to have had a selective adaptation to rugged, wooded landscapes that would have partially compensate their high basal metabolic rate and locomotor energetic costs through reducing search time and increasing diet breadth. The archaeological site of the Navalmaíllo rockshelter (Pinilla del Valle, Madrid), located in a mountain environment in central Iberian Peninsula, has been interpreted as a repeated short-term occupation hunting camp by Neanderthal groups, mainly focused on primary access to large bovids and cervids. Navalmaíllo rockshelter has also furnished fish, toads, frogs, tortoises, lizards and snakes remains. This association of amphibians and reptiles suggests a much warmer climate (+2.8 °C) for layer F than at present, with similar temperatures during the summer but higher temperatures throughout the remaining months. Rainfall was slightly more abundant (+180.6 mm) than today, with a more contrasted regime during the year, with rainier winters and drier summers. A two-month period of aridity is observed during summer, representing a similar duration to present-day climatic conditions. Reconstructed landscapes are mainly constituted by open areas with dry grassland and rocky or stony areas, evolving laterally to humid meadows, probably close to the aquatic and peri-aquatic areas, such as rivers or ponds with riverside vegetation. Woodland environments are also well represented around the site, with medium scrublands to forest formations. Fish complete this reconstruction by documenting the presence of a pre-mountain well-developed river system characterized by relatively cold, permanent, oxygen-rich, and running waters. Such reconstruction is in disagreement with previous pollen interpretation for Layer F that suggested a very open and cold environment. Our new interpretation suggests that the Neanderthal occupation of the Navalmaíllo rockshelter occurred during a somewhat temperate and humid period, probably within the later part of the Marine Isotope Stage 5, effectively favouring the presence of a high biodiversity around the site.

Le condizioni delle foreste italiane stanno peggiorando a causa di eventi climatici estremi? Evidenze dalle reti di monitoraggio nazionali ICP Forests - CON.ECO.FOR.

Tree defoliation and mortality are triggered in Europe by extreme climatic events that are recurring since the beginning of XXI century. Data from the ICP Forests monitoring networks reveal a general worsening of tree conditions in the last ten years, as consequence of the drought and heat waves that affected the Southern (2017) and Central Europe (2018-2019). In Italy a significant increase of defoliation and tree mortality, assessed on the extensive (Level I) monitoring network, was observed after the 2017 dry summer, which impacted mainly the broadleaved forests (beech and oak forests) in the peninsular regions. Coniferous forests of the alpine belt were severely impacted in 2021, probably because of the co-occurrence of multiple causes, involving windstorm and bark beetle attacks. Chestnut forests suffer from pest (insect and pathogen) attacks. The intensive (Level II) monitoring network provides cases of study and allows to carry out specific cause-effect studies concerning the physiological effects on the environmental impacts, as well to observe the ecological processes following the disturbing events. Defoliation caused by drought or pest attacks induces the loss of physiological defenses (namely non-structural carbohydrates), that need several years to be restored. Then, the occurrence of more frequent and repeated heat and drought waves can produce irreversible effects. In this view, the long-term forest health monitoring is key to detect the extent and direction of changes in forest structure and composition, and represents an important tool for forest conservation and management.

Global hydroclimatic drivers of terrestrial water storage changes in different climates

The Gravity Recovery and Climate Experiment (GRACE) mission provides an unprecedented way to assess terrestrial water storage changes (TWSC) worldwide. However, hydroclimatic drivers of GRACE-derived TWSC in different climates have not been systematically examined, which hinders its applications in water resources management and hydrological model development. In this study, we derived the monthly TWSC using the GRACE dataset, and analyzed its partial correlations with precipitation (P), evapotranspiration (ET), runoff (R), and temperature (T) from 2003 to 2019 under the Köppen-Geiger world climate classification system. Relative contributions of the four hydroclimatic elements (P, ET, R, and T) to TWSC were quantified using the hierarchical partitioning method. The results indicate that P mainly controls TWSC in tropical climates, hot semi-arid climate, and temperate and continental climates with dry winter. ET is the primary driver of TWSC in mid- and high-latitude regions that feature temperate and continental climates with no dry season, subarctic climates, and polar climates. T mainly influences TWSC in cold arid climates, temperate and continental climates with dry summer or no dry season, and ice cap climate. However, TWSC in many arid climates near the Tropic of Cancer and the Tropic of Capricorn are not well explained by all four hydroclimatic variables according to their non-significant partial correlations. Large trends in annual TWSC are found in South America, western Canada, eastern contiguous United States, and Africa, which are likely due to marked changes in P based on their similar spatial pattern. In particular, decreasing TWSC are found in most continental climates, which manifests a deterioration of water resources availability in these regions. Overall, our results clarify the major hydroclimatic drivers of TWSC in different climates at a global scale, which may help improve TWSC modeling and prediction through a judicious selection of explanatory hydroclimatic variables in different climates.

Saltwater Intrusion of Coastal Karstic Aquifer on the Example of the Boljkovac Water Supply Pumping Station near Zadar, Croatia

Numerous coastal karst springs of the Mediterranean region have problems with salinization. Salinization usually occurs during summer dry periods as a result of long droughts and excessive pumping for water supply. The Boljkovac water supply pumping station has slightly increased parameters that indicate the possibility of salinization during the dry summer periods, but the main salinization occurs post heavy rains which appear after long dry periods in the fall, winter, and spring. Due to the occasional occurrence of salinization, continuous monitoring of the aquifer by depth was set up at the piezometric well drilled near the water supply pumping station. The results of the monitoring were analyzed in relation to external factors that can negatively affect the disruption of the labile dynamic balance of salt and fresh water. The analyzed external factors are the pumping rate for the water supply, the amount of precipitation, surface flow and the interaction of surface water and groundwater, as well as the sea level changes. In Croatia, and the wider Mediterranean area, there are a large number of springs and water wells that have the same or similar problems, so the results of this analysis can be used in designing monitoring and setting up management systems for these coastal aquifers.

The effects of antecedent dry days and land use types on urban runoff quality in a semi-Arid region

ABSTRACT This study simulated the effects of land-use changes on runoff pollution in a catchment of Tehran, Iran. The catchment has a semi-arid climate, a relatively long period from dry summer to rainy autumn and highly varying precipitation levels. Urban runoff samples were collected from six stations including five different land-based activities and a mixed land-use, which supported all land-use types. Event Mean Concentration (EMC) was applied to determine the Nonpoint Source (NPS) pollution of urban runoff such as Total Suspended Solid (TSS), Total Nitrogen (TN), Total Phosphorus (TP) and heavy metals, including zinc (Zn), copper (Cu) and lead (Pb), in five land-uses. Sampling was performed during five events with different Antecedent Dry Days (ADDs) in time period 2019-2020. The Storm Water Management Model (SWMM) was employed to simulate the quality of urban runoff base on measured EMCs in each event for the different parameters under investigation and the average of measured EMCs. The results illustrated that that the maximum and minimum amount of EMCs were pertained to the events with 115 and 1 dry days respectively. While, daily simulation of runoff pollution based on measured amount of EMCs in the catchment indicated that the calibration criteria such as Root Mean Square Error (RMSE), Normalized Objective Function (NOF), Nash-Sutcliffe Efficiency (NSE) and R 2 were very good for the minimum amount of EMCs and satisfactory for the average of EMC`s calculated, NSE values was not satisfactory for the maximum amount of EMCs. Uncertainty of ADDs can significantly affect the results of the maximum EMC simulation. This study also found higher TSS and TP concentrations in runoff in open space land-use and significantly higher heavy metals and TN concentrations in runoff in the industrial land-use compared with other land-use types in the catchment.

Extreme wet precipitation and mowing stimulate soil respiration in the Eurasian meadow steppe

The imbalance of terrestrial carbon (C) inputs versus losses to extreme precipitation can have consequences for ecosystem carbon balances. However, the current understanding of how ecosystem processes will respond to predicted extreme dry and wet years is limited. The current study was conducted for three years field experiment to examine the effects of environmental variables and soil microbes on soil respiration (Rs), autotrophic respiration (Ra) and heterotrophic respiration (Rh) under extreme wet and dry conditions in mowed and unmowed grassland of Inner Mongolia. Across treatments (i.e. control, dry spring, wet spring, dry summer and wet summer), the mean of Rs was increased by 24.9 % and 24.1 % in the wet spring and wet summer precipitation treatments, respectively in mowed grassland. In other hand, the mean of Rs was decreased by −22.1 % and −3.5 % in dry spring and dry summer precipitation treatments, respectively in mowed grassland. The relative contribution of Rh and Ra to Rs showed a significant (p < 0.05) change among simulated precipitation treatments with the highest value (76.18 %) in wet summer and 26.41 % in dry summer, respectively under mowed grassland. Rs was significantly (p < 0.05) affected by the interactive effect of extreme precipitation and mowing treatments in 2020 and 2021. The effects of precipitation change via these biotic and abiotic factors explained by 52 % and 81 % in Ra and Rh, respectively in mowed grassland. The changes in microbial biomass carbon (MBC) and nitrogen (MBN) had significant (p < 0.05) direct effects on Rh in both mowed and unmowed grasslands. The influence of biotic and abiotic factors on Rs was stronger in mowed grasslands with higher standardized regression weights than in unmowed grassland (0.78 vs. 0.69). These findings highlight the importance of incorporating extreme precipitation events and mowing in regulating the responses of C cycling to global change in the semiarid Eurasian meadow steppe.

Within-species variation of seed traits of dune engineering species across a European climatic gradient.

Within-species variation is a key component of biodiversity and linking it to climatic gradients may significantly improve our understanding of ecological processes. High variability can be expected in plant traits, but it is unclear to which extent it varies across populations under different climatic conditions. Here, we investigated seed trait variability and its environmental dependency across a latitudinal gradient of two widely distributed dune-engineering species (Thinopyrum junceum and Calamagrostis arenaria). Seed germination responses against temperature and seed mass were compared within and among six populations exposed to a gradient of temperature and precipitation regimes (Spiekeroog, DE; Bordeaux, FR; Valencia, ES; Cagliari, IT, Rome, IT; Venice, IT). Seed germination showed opposite trends in response to temperature experienced during emergence in both species: with some expectation, in populations exposed to severe winters, seed germination was warm-cued, whereas in populations from warm sites with dry summer, seed germination was cold-cued. In C. arenaria, variability in seed germination responses disappeared once the seed coat was incised. Seed mass from sites with low precipitation was smaller than that from sites with higher precipitation and was better explained by rainfall continentality than by aridity in summer. Within-population variability in seed germination accounted for 5 to 54%, while for seed mass it was lower than 40%. Seed trait variability can be considerable both within- and among-populations even at broad spatial scale. The variability may be hardly predictable since it only partially correlated with the analyzed climatic variables, and with expectation based on the climatic features of the seed site of origin. Considering seed traits variability in the analysis of ecological processes at both within- and among-population levels may help elucidate unclear patterns of species dynamics, thereby contributing to plan adequate measures to counteract biodiversity loss.

Effect of Seasonal Variation on Leaf Cuticular Waxes’ Composition in the Mediterranean Cork Oak (Quercus suber L.)

Quercus suber L. (cork oak) leaves were analyzed along one annual cycle for cuticular wax content and chemical composition. This species, well adapted to the long dry summer conditions prevailing in the Mediterranean, has a leaf life span of about one year. The cuticular wax revealed a seasonal variation with a coverage increase from the newly expanded leaves (115.7 µg/cm2 in spring) to a maximum value in fully expanded leaves (235.6 µg/cm2 after summer). Triterpenoids dominated the wax composition throughout the leaf life cycle, corresponding in young leaves to 26 µg/cm2 (22.6% of the total wax) and 116.0 µg/cm2 (49% of the total wax) in mature leaves, with lupeol constituting about 70% of this fraction. The total aliphatic compounds increased from 39 µg/cm2 (young leaves) to 71 µg/cm2 (mature leaves) and then decreased to 22 µg/cm2 and slightly increased during the remaining period. The major aliphatic compounds were fatty acids, mostly with C16 (hexadecanoic acid) and C28 (octacosanoic acid) chain lengths. Since pentacyclic triterpenoids are located almost exclusively within the cutin matrix (intracuticular wax), the increase in the cyclic-to-acyclic component ratio after summer shows an extensive deposition of intracuticular waxes in association with the establishment of mechanical and thermal stability and of water barrier properties in the mature leaf cuticle.

Thermal behavior of pervious concrete in dry conditions

As the world becomes more urbanized, concerns are growing about the phenomenon of urban heat islands (UHIs). In addition to the environmental function of stormwater management, pervious concrete (PC) pavements are also a solution that can help mitigate increasing urban temperatures, through cooling by evaporation. Several studies in the literature have focused on the evaporative cooling effect of PC, which requires the presence of water either from precipitation or irrigation. However, in countries that have dry summers and where watering techniques are complicated to implement, in hot weather and dry conditions, PC can have a higher temperature than traditional impermeable concrete. The main objective of this paper is therefore to study the influence of thermophysical parameters on the surface temperature of PC, with a view to designing a mix that minimizes its surface temperature in dry conditions. The thermal behavior of PC and ordinary impermeable concrete (OC) in dry condition have been studied both analytically and experimentally. All heat fluxes involved in the energy balance at the surface of both pavements were analyzed. The results show that PC has a surface temperature up to 6 °C higher than OC during the day and up to 4 °C lower during the night. Increasing the thermal conductivity of the pervious concrete makes the surface temperature of PC lower during the day but higher at night. On the other hand, increasing albedo makes the surface temperature of the pavement lower both during the day and during the night. Finally, the sensitivity study shows that the albedo has a greater influence on the maximum surface temperature of the PC than does thermal conductivity. To decrease the maximum temperature of PC, it is recommended to avoid the use of lightweight aggregates and to use finer and lighter colored aggregates (to increase the albedo), having high thermal conductivity. This mix optimization may be limited by the hydraulic properties of the PC due to its influence on the open porosity.

Cultural layers and a paleosol of a Late Medieval settlement as proxies of environmental change and anthropogenic influence – A case study of Tula Kremlin, Russia

An archaeological pit with a buried paleosol overlain by four cultural layers was studied at the site of Tula Kremlin (Central Russian Upland) using macro- and micromorphological, microbiomorphic and physicochemical methods. As a result, we obtained a paleoenvironmental reconstruction of landscape changes, characteristics of early human occupation stages and an explanation of why this large cultural and economic center of the late Middle Ages was located within the floodplain of the Upa River. The absence of fluvial deposits and gleyic features within the profile of the buried soil indicates that the site, confined to the basement terrace, has never been flooded. The buried soil of Tula Kremlin and the surface soils on the adjacent uplands are formed in similar loess sediments and have similar profiles. Prior to the construction of fortifications, the study site was used as a ploughland or a garden for a short period. Pedogenic features that were preserved within the cultural layers showed that cultural layer 1 (17th-18th centuries) was formed under relatively humid climatic conditions, whereas cultural layer 2 (16th-17th centuries) developed under slightly drier and cooler conditions. The paleosol buried under those cultural layers at the end of 15th- beginning of 16th centuries, as compared to the surface soil, showed clearer signs of humus accumulation and weaker greyzemic features, what allows us to reconstruct a warmer climate with drier summers during the Medieval Climate Anomaly.

What was Killing Babies in Hermoupolis, Greece? An Investigation of Infant Mortality Using Individual Level Causes of Death, 1861–1930

This paper employs individual level cause of death data from the port city of Hermoupolis on the Greek island of Syros, in order to test the newly-constructed ICD10h coding system. By constructing cause specific death rates for infants from the late 19th century to early 20th century, the paper contributes to a comparative approach, which aims to show how causes of death differ across several locations within Europe and how they develop over time. Given the scarcity of cause of death data both at the individual and aggregate level in Greece roughly prior to the 1920s, the availability of such data in the draft death registers (for sporadic runs of years in the second half of the 19th and early 20th century) and the civil registration (from 1916 onwards) in Hermoupolis provides a deeper understanding of the history of cause-of-death reporting in the country. Infant mortality in Hermoupolis was relatively high throughout the study period, with water-food borne diseases accounting for the highest number of infant deaths, especially during the hot and dry summer months. While the prominent winter peak of neonatal mortality but also congenital-birth disorders could be partially associated with birth seasonality and/or low temperatures over the winter months. Finally, certain vague terms such as 'atrophy' and 'athrepsy', but especially 'drakos' require further investigation until they are firmly understood.

A Hierarchical Ecosystem Approach to Evaluate Global Warming Impacts in Three Global Ecoregions

Global warming has substantial effects on terrestrial ecosystems in the different ecoregions. A hierarchical ecosystem approach was conducted to analyze global warming influences with global warming impacts on the three distinct global ecoregions. The ecosystem classification of land (ECL) has been developed and integrated into a hierarchical system. Recently, the hierarchical ecosystem classifications in the 300 Dry Domain of the United States, 100 Polar Domain of Canada, and 500 Plateau Domain of China were demonstrated and explored in studying the environmental system changes and global warming impacts. This article presents the distinctive dissimilarity in each ecoregion and demonstrates the ecosystem responses linked to the hierarchical ecosystem structure and ecological function level. 1) In the Dry Domain, the warmer and wetter climate of Utah gave rise to Rocky Mountain subalpine conifer forests and Great Basin pinyon and juniper woodlands suitable for growth, which corresponds to Utah’s Climate life zone and is affiliated with the middle levels of ECL, scale ranging from U7 up to U4. Conversely, in a warmer and drier climate in Utah, annual plant species and invaded species shifted and expanded at the lower levels of ECL, scale ranging from U10 up to U9. 2) In the Polar Domain, a warmer and wetter winter of the Yukon climate influences the Spruce treeline moving northward and to higher elevations, as well as for the Arctic tundra and alpine tundra. Arboreal species grow fast to reach fructification. These typically appeared in the middle levels of ECL with ranging from Y8 up to Y5, and changed the carbon budget to a carbon sink, with a scale ranging from Y4 up to Y2. With a warmer and drier summer, shrubification in Yukon occurs rapidly, in a range from Y6 to Y5. Potentilla shrub and Salix shrub expand to the Arctic tundra region. 3) In the Plateau Domain, the annual air temperature Increased by 0.5o C/10 y over the last 45 years, and the temperature fluctuations have significantly affected the essential changes in the global energy balance and carbon budget in the upper levels of ECL, scale ranging from Q4 up to Q1. However, the precipitation showed no noticeable difference. The alpine tundra vegetation was simulated by the Vegetation Dynamic Simulation Model (VDSM) integrated with scenarios of a global temperature increase of 1 to 3°C. This illustrated the vegetation biomass changes in the lower levels to middle levels of ECL with ranging from Q8 up to Q6, and the vegetation distribution dynamics appeared in upper levels of ECL with ranging from Q4 up to Q1.