Increase In Summer Temperatures Research Articles

Bigleaf maple, Acer macrophyllum Pursh, decline in western Washington, USA

Acer macrophyllum is a prominent component of the western Washington landscape where it performs ecological, economic, and cultural functions. Reports of its decline and increased mortality in the Pacific Northwest were documented beginning in 2011. Symptoms of this decline include a systemic loss of vigor, loss of transpiration, and reduced photosynthesis due to leaf loss. We conducted a preliminary study of A. macrophyllum decline across western Washington in 2014–2015 and observed decline symptoms across the region, but we did not detect any specific biotic causative agents. We subsequently conducted a multi-approach study in 2017 to quantify the spatial and temporal patterns of A. macrophyllum decline in western Washington, and to examine biotic and abiotic associations with its decline. We sampled in urban and suburban areas, and in wildland forests, and collected site-specific data to test for associations with decline. We also measured elemental concentrations in foliar and soil samples to determine their association with decline. Lastly, we conducted a dendrochronological analysis to ascertain the spatial and temporal patterns of decline. We report that A. macrophyllum decline is a recent phenomenon, particularly since 2011, that was positively associated with sites closer to roads and with increased development, and with increases in summer temperatures. Site conditions, especially hotter urban sites, are predisposing A. macrophyllum to mortality. We did not detect a consistent biotic agent that could be implicated in A. macrophyllum decline. We contend that abiotic factors are either causing direct mortality to A. macrophyllum, or making then vulnerable to opportunistic biotic agents. The results of this study inform mitigating management strategies for A. macrophyllum in the forest of the Pacific Northwest.

Declining common toad body size correlated with climate warming

Abstract Accumulating evidence shows that the body size of organisms in many taxa is declining in response to global warming. We investigated the potential effect of rising temperatures on the body size of a common toad (Bufo bufo L.) population in southern England between 1983 and 2020. The body length (SVL; in millimetres) and body mass (in grams) of 15 550 males and 4004 females arriving at their breeding pond for the first time were recorded. Toad body condition was estimated using a scaled body mass index (SMI). Over the study period, the mean annual temperature increased by ~1.3 °C, whereas the mean SVL and SMI of both sexes declined. Multiple regression analysis showed that female and male SMI were negatively correlated with increases in mean summer temperatures, with females also being impacted minimally by mean winter rainfall. Mean body size (SVL) was positively correlated with toad abundance over the period between emergence as toadlets and arrival at the pond to breed for the first time. Common toads exhibited phenotypic plasticity in response to warming environmental conditions, resulting in a reduction in SMI and subsequent reductions in SVL and overall egg production, which occurred over a period of 10 years.

The tempo of greening in the European Alps: Spatial variations on a common theme.

The long-term increase in satellite-based proxies of vegetation cover is a well-documented response of seasonally snow-covered ecosystems to climate warming. However, observed greening trends are far from uniform, and substantial uncertainty remains concerning the underlying causes of this spatial variability. Here, we processed surface reflectance of the moderate resolution imaging spectroradiometer (MODIS) to investigate trends and drivers of changes in the annual peak values of the Normalized Difference Vegetation Index (NDVI). Our study focuses on above-treeline ecosystems in the European Alps. NDVI changes in these ecosystems are highly sensitive to land cover and biomass changes and are marginally affected by anthropogenic disturbances. We observed widespread greening for the 2000-2020 period, a pattern that is consistent with the overall increase in summer temperature. At the local scale, the spatial variability of greening was mainly due to the preferential response of north-facing slopes between 1900 and 2400m. Using high-resolution imagery, we noticed that the presence of screes and outcrops locally magnified this response. At the regional scale, we identified hotspots of greening where vegetation cover is sparser than expected given the elevation and exposure. Most of these hotspots experienced delayed snow melt and green-up dates in recent years. We conclude that the ongoing greening in the Alps primarily reflects the high responsiveness of sparsely vegetated ecosystems that are able to benefit the most from temperature and water-related habitat amelioration above treeline.

Variable responses of carbon and nitrogen contents in vegetation and soil to herbivory and warming in high‐Arctic tundra

AbstractChemical responses of tundra vegetation and tundra soil to environmental changes are likely to differ, with implications for ecosystem functioning, yet they are rarely compared. Here, we aimed at comparing sensitivity and magnitude of short‐term carbon and nitrogen responses of three main tundra ecosystem compartments: vascular plants, mosses, and soil, to two environmental perturbations: herbivore disturbance and warming. In a full‐factorial field experiment in the high‐Arctic Svalbard, we simulated herbivore disturbance as spring grubbing activity by pink‐footed geese (Anser brachyrhynchus) and passively increased summer temperatures using open‐top chambers. Manipulations were set up within three habitats that differ in soil moisture and carried out for two consecutive growing seasons. Overall, we found small and few significant responses to herbivore disturbance and warming, suggesting that carbon and nitrogen contents of high‐Arctic ecosystems are relatively resistant to these perturbations, at least in the short term. However, the three ecosystem compartments still differed in their sensitivity to perturbations (vascular plants > soil > mosses), and this was exacerbated by their differential sensitivity across habitats (mesic > moist > wet). Also, while vascular plants responded to herbivore disturbance in mesic and wet habitats and to warming in mesic and moist habitats, soil and mosses only responded to herbivore disturbance in mesic and wet habitats, respectively. Responses to treatments were generally consistent across the two growing seasons, despite great differences in temperature conditions and large between‐year variations in the chemical composition of the three ecosystem compartments. These findings highlight the potential for environmental perturbations to have small, yet differential short‐term impacts on the carbon and nitrogen contents of vascular plants, mosses, and soil, both within and between tundra habitats. Our results imply that assessments of a single ecosystem compartment in a given context cannot be extrapolated to the whole ecosystem, thus stressing the importance of considering both vegetation and soil carbon and nitrogen responses, and how they display across habitats, in order to better understand how environmental changes might affect biogeochemical processes in the tundra. Longer‐term studies should dig deeper into the relative role of (simulated) global change drivers vs. natural inter‐annual climatic fluctuations for tundra ecosystem carbon and nitrogen dynamics.

The environmental history of the oxbow in the Luciąża River valley – Study on the specific microclimate during Allerød and Younger Dryas in central Poland

The vicinity of the Rozprza archaeological site (central Poland) has been the area of a series of palaeoecological studies tracking the environmental history of the Luciąża River valley up to ca. 13,200 cal. BP. Numerous subfossil palaeomeanders of different sizes have been discovered in the valley floor. Here, we present the first results of multiproxy research on the paleo-oxbow lake fill, one of the oldest in the region. The wide range of palaeoecological analyses resulted in reconstructions of vegetation history, climatic, hydrological and habitat changes. The studied oxbow was an aquatic ecosystem with diverse invertebrate fauna until the end of Younger Dryas when it transformed into a limno-telmatic habitat. The sediment composition indicates active denudation processes and several episodes of turbulent hydrological conditions. Such an increased river activity could have caused flooding, resulting in an allochthonous matter supply to the oxbow lake in Late Vistulian. Environmental changes were strictly related to the regional features of the catchment, the transformation of soils, and the hydrogeological conditions. The chironomid- and pollen-inferred climatic reconstructions indicate periods of high and low continentality. The chironomid record indicates relatively cool summer conditions in the Allerød, especially ca. 13,000 cal. BP, possibly related to the Gerzensee Oscillation. On the other hand, a distinct increase of summer temperatures in Younger Dryas (up to 16 °C) was recorded. Such a situation was also confirmed in some other studies from the region, suggesting that it might be the effect of some specific, local palaeoclimatic conditions.

A Baseline Study on the Water Occupancy Rates of Çermikler Dam (Sivas-Turkey) between 2015- 2019

Turkey because it is located in a semi-arid region precipitation varies greatly according to season and region. However, the increase in summer temperatures caused by climate change in Turkey, reduced winter rainfall, loss of surface waters, droughts that are more frequent, floods and erosion affects directly threatens water resources. This paper is about the water occupancy rates of Çermikler Dam in Sivas province. In this context, the water occupancy rate data of Çermikler Dam between 2015 and 2019 were evaluated. While the lowest water occupancy rate was determined as 6.2% in 2018, the highest water occupancy rate was determined as 42.0% in 2019. The average annual water occupancy rate of Çermikler Dam between 2015 and 2019 has been calculated as 24.50%. This indicates that Çermikler Dam is affected by drought. Therefore, droughts in Kızılırmak Basin where Çermikler Dam is located should be monitored. Accordingly, the waters of the Çermikler Dam should be managed. It is very important to use water rationally and efficiently.

ФИЗИОЛОГИЧЕСКИЕ АСПЕКТЫ ЗАСУХОУСТОЙЧИВОСТИ СОРТОВ ВИШНИ

There is an abnormal increase in average summer temperature in the southern region (Krasnodar Territory). This, more than ever, actualizes the problem of identifying drought-resistant varieties of fruit crops, including cherry. The purpose of this research was to study the physiological indicators of water regime: loss of water, water-holding capacity, leaf water content, abscisic acid content in leaves of different varieties of Cerasus vulgaris Mill., which determine resistance to temperature stress, as well as to identify the most drought-tolerant varieties to optimize the range of varieties for the south of our country. The studies were carried out in 2018–2019 in the Prikuban fruit-growing zone of the Krasnodar Territory. Sixteen varieties of Cerasus vulgaris Mill. were the objects of the research. Varieties ʻKrasnodarskaya sladkayaʼ and ʻKazachkaʼ served as a control. Planting schemes – 6 × 4 m and 5 × 3 m. Soil – chernozems leached. pHwater – 6.8–7.22. Humus content – 3.47 %. In summer, meteorological conditions were characterized by an abnormal temperature rise (up to 39.3 ℃) and extended periods of drought. Studying of water regime was carried out according to the modified methodology of M. D. Kushnerenko using the gravimetric method. In laboratory experiments, we used the capillary electrophoresis “Kapel 104 P” (power supply with a positive polarity; equipped with a photometric detector; set wavelength – 254 nm). In the course of the research, we revealed that the water content in cherry leaves during the period of the adverse draught (in July) was 57.9 %; in the context of studied cherry varieties, it varied insignificantly (Cv = 4.4 %). For two hours, the loss of water by the leaf apparatus was not high – from 6.5 % to 11.9 % with a low coefficient of variation by varieties (Cv = 1.9 %). The water-holding capacity of leaf tissues was 19.6 %, the range of variability of which was insignificant by varieties (Cv = 18.0–24.2 %). The average content of abscisic acid in cherry leaves was 4.3 mg/kg and varied depending on the studied cherry varieties within the range of 1.5–14.2 mg/kg. According to the complex of physiological indicators of the water regime (low water loss (6.5–7.9 %), high water-holding capacity (19.4–24.2 %) and leaf water content (58.1–61.9 %), as well as increased abscisic acids content (11.0–14.2 mg/kg)), such cherry varieties/cultivars as ʻDuke Ivanovnaʼ, ʻDuke Khodosaʼ, ʻFeyaʼ, ʻMolodezhnayaʼ and ʻErdi Botermoʼ were classified as highly drought-resistant. They are recommended for expanding the range of adaptive cherry varieties/cultivars in the southern part of Russia.

Analysis of climate change in Terskol over the last 60 years

In connection with the ongoing climatic changes, the tasks of monitoring the climate of the high-mountainous zone of the Caucasus are of particular importance. Climatological studies in this work are based on the material of long-term meteorological observations from 1961 to 2020. according to the Terskol weather station. Correlation analysis showed the spatial homogeneity of temperature changes in Terskol and weather stations of all climatic zones of southern Russia, in contrast to the regional precipitation regime with a small scale of coherence (up to 200 km). In the modern period (1991-2020), the change in average temperatures in comparison with climatic norms (1961-1990) is not confirmed by statistical estimates, with the exception of the summer season. Over the 60-year period, from 1961 to 2020, there was a statistically significant increase in average summer temperatures by 0.31 °C/10 years (D = 26.8%). At the turn of the 20th and 21st centuries a steady increase in winter, spring and annual temperatures is formed, while summer temperatures maintain a positive trend, but statistically insignificant at this time interval. Period from 2006 characterized by the addition of a statistically significant increase in the absolute maximums of all seasonal temperatures, in contrast to the sums and daily maximum precipitation, the decrease in which in the winter season is statistically insignificant, and there are no trends in other seasons. Such a prevailing thermal and precipitation regime in recent decades has become the main component of many factors leading to dangerous slope phenomena, glacier degradation and significant changes in the hydrological regime.

Regional characteristics of water use in conditions of water scarcity in steppe transboundary river basins (the Ural River basin as a case study)

The regional features of water use within the steppe biome and in conditions of water scarcity is analysed. It has established a steady trend of increasing summer temperature extremes and identified a trend in the seasonal distribution of precipitation. Rivers of the Ural River basin are found to be characterized by a decline in the percentage of spring flood runoff and an increase in the percentage of low-water seasonal runoff. This transformation of intra-annual flow is even more significant for rivers with a regulated regime. The paper defines also regional specific features concerning the use of water resources in the Ural River basin. In the Russian regions, the main portion of water resources is spent on industrial and utilities needs, and the minimum portion spent on the needs of agriculture. Another specific is a high portion of recycled water in the Russian regions, which confirms the rather efficient use of water resources in various economy sectors. The structure of water consumption in Kazakhstan regions is characterized by predominance of water use for industrial and utilities needs and preservation of a significant portion of water for agricultural supply. The results obtained show that an ambiguous and poorly predicted situation with water resources emerges in the transboundary basin of the Ural River. In this context, the priority task is to ensure the cost-effective and environmentally safe use of water resources in regions of the studied basin.

Rapid climate changes during the Lateglacial and the early Holocene as seen from plant community dynamics in the Polar Urals, Russia

ABSTRACTA detailed, well‐dated record of pollen and sedimentary ancient DNA (sedaDNA) for the period 15 000–9500 cal a bp describes changes at Lake Bolshoye Shchuchye in the Polar Ural Mountains, located far east of the classical Lateglacial sites in western Europe. Arctic tundra rapidly changed to lusher vegetation, possibly including both dwarf (Betula nana) and tree birch (B. pubescens), dated in our record to take place 14 565 cal a bp, coincident with the onset of the Bølling in western Europe; this was paralleled by increased summer temperatures. A striking feature is an early decline in Betula pollen and sedaDNA reads 300 years before the onset of the Younger Dryas (YD) in western Europe. Given the solid site chronology, this could indicate that the YD cooling started in Siberia and propagated westwards, or that the vegetation reacted to the inter‐Allerød cooling at 13 100 cal a bp and did not recover during the late Allerød. During the YD, increases in steppe taxa such as Artemisia and Chenopodiaceae suggest drier conditions. At the onset of the Holocene, the vegetation around the lake reacted fast to the warmer conditions, as seen in the increase of arboreal taxa, especially Betula, and a decrease in herbs such as Artemisia and Cyperaceae.

Population consequences of climate change through effects on functional traits of lentic brown trout in the sub-Arctic

Climate-induced plasticity in functional traits has received recent attention due to the immense importance phenotypic variation plays in population level responses. Here, we explore the effect of different climate-change scenarios on lentic populations of a freshwater ectotherm, the brown trout (Salmo trutta L.), through climate effects on functional traits. We first parameterize models of climate variables on growth, spawning probability and fecundity. The models are utilized to inform a dynamic age-structured projection matrix, enabling long-term population viability projections under climate and population density variation. Ambient temperature and winter conditions had a substantial effect on population growth rate. In general, warmer summer temperatures resulted in faster growth rates for young fish but ended in smaller size at age as fish got older. Increasing summer temperatures also induced maturation at younger age and smaller size. In addition, we found effects of first-year growth on later growth trajectories for a fish, indicating that environmental conditions experienced the first year will also influence size at age later in life. At the population level, increasing temperatures average (up to 4 °C increase in areas with mean summer temperature at approximately 12 °C) resulted in a positive effect on population growth rate (i.e. smaller but more fish) during climate simulations including increasing and more variable temperatures.

High Mountain Asian glacier response to climate revealed by multi-temporal satellite observations since the 1960s

Knowledge about the long-term response of High Mountain Asian glaciers to climatic variations is paramount because of their important role in sustaining Asian river flow. Here, a satellite-based time series of glacier mass balance for seven climatically different regions across High Mountain Asia since the 1960s shows that glacier mass loss rates have persistently increased at most sites. Regional glacier mass budgets ranged from −0.40 ± 0.07 m w.e.a−1 in Central and Northern Tien Shan to −0.06 ± 0.07 m w.e.a−1 in Eastern Pamir, with considerable temporal and spatial variability. Highest rates of mass loss occurred in Central Himalaya and Northern Tien Shan after 2015 and even in regions where glaciers were previously in balance with climate, such as Eastern Pamir, mass losses prevailed in recent years. An increase in summer temperature explains the long-term trend in mass loss and now appears to drive mass loss even in regions formerly sensitive to both temperature and precipitation.

Assessment of glacier status and its controlling parameters from 1990 to 2018 of Hunza Basin, Western Karakorum.

Ice masses and snow of Hunza River Basin (HRB) are an important primary source of fresh water and lifeline for downstream inhabitants. Changing climatic conditions seriously put an impact on these available ice and snow masses. These glaciers may affect downstream population by glacial lake outburst floods (GLOF) and surge events due to climatic variation. So, monitoring of these glaciers and available ice masses is important. This research delivers an approach for dynamics of major glaciers of the Hunza River Basin. We delineated 27 major glaciers of HRB and examined their status by using Landsat (OLI, ETM+, ETM, TM), digital elevation model (DEM) over the period of 1990-2018. In 1990, the total area covered by these glaciers is about 2589.75 ± 86 km2 and about 2565.12 ± 68km2 in 2018. Our results revealed that from 2009 to 2015, glacier coverage of HRB advanced with a mean annual advance rate of 2.22 ± 0.1 km2 a-1. Conversely, from 1994 to 1999, the strongest reduction in glacier area with a mean rate of - 3.126 ± 0.3 km2 a-1 is recorded. The glaciers of HRB are relatively stable compared to Hindukush, Himalayan, and Tibetan Plateau region of the world. The steep slope glacier's retreat rate is more than that of gentle slope glaciers, and the glaciers below an elevation of 5000 m above sea level change significantly. Based on climate data from 1995 to 2018, HRB shows a decreasing trend in temperature and increasing precipitation. The glacier area's overall retreat is due to an increase in summer temperature while the glacier advancement is induced possibly by winter and autumn precipitation.

Examining the Economic Impacts of Climate Change on Net Crop Income in the Ethiopian Nile Basin: A Ricardian Fixed Effect Approach

Climate change affects crop production by distorting the indestructible productive power of the land. The objective of this study is to examine the economic impacts of climate change on net crop income in Nile Basin Ethiopia using a Ricardian fixed effect approach employing the International Food Policy Research Institute (IFPRI) household survey data for Ethiopia in 2015 and 2016. The survey samples were obtained through a three-stage stratified sampling technique from the five regions (Amhara, Tigray, Benishangul Gumuz, Oromia, and Southern Nation Nationality and People (SNNP) along the Nile basin Ethiopia. There are only 12–14% female household heads while there are 80–86% male households in the regions under study. In the regions, more than half of (64%) the household heads are illiterate and almost only one-tenth of them (12%) had received remittance from abroad from their relatives or children. Crop variety adoption rate is minimal, adopted by the 31% of farmers. Only 30% of the surveyed farmers mentioned that they planted their crop seeds in row whereas the rest 70% had not applied this method. The regression results from the fixed effect least square dummy variable model showed that literacy, household size, remittance, asset value, and total land holdings have significant and positive impacts on the net crop income per hectare. The regional dummy variables estimate indicated that all the regions are negatively affected by climate change at varying levels. Strategies to climate change adaptation have significant and positive contributions in leveraging the damaging effects of climate change. The results also showed that increased winter and summer temperature and rainfall increase net crop income per hectare. The estimated coefficient of the interaction term of spring temperature and rainfall is significant and negative. On the other hand, while the mean annual temperature is damaging to crops, annual rainfall is beneficial. It can be deduced that, while increased temperature and rainfall in summer and winter increase the net crop income, the converse is true for winter and spring seasons. The study also proposes a specific, context-dependent, farm-level adaptation analysis of how farmers cope with the different climatic impacts of the Nile Basin and maintain the income levels that they have previously enjoyed.

Assessing and predicting land use/land cover, land surface temperature and urban thermal field variance index using Landsat imagery for Dhaka Metropolitan area

Climate change is occurring because of an increase in greenhouse gases such as carbon dioxide, methane, and others, which act as a partial blanket for the planet and store solar energy radiation, resulting an increase in land surface temperature (LST). Cities that are already suffering from the urban heat island (UHI) effect , which will withstand the worst of these more extreme heat events. The extent of the impermeable layer and changes in LST are inextricably linked to the severity and commencement of UHI events, which can be measured using the urban thermal field variance index (UTFVI). Land use/Land cover (LULC) change was assessed using support vector machine (SVM) supervised classification, seasonal (summer and winter) LST, and UTFVI variations from Landsat 4–5 TM and Landsat 8 OLI satellite images for the years 2000, 2010, and 2020. Furthermore, in Dhaka, Bangladesh, the cellular automata-based artificial neural network (CA-ANN) algorithm was utilized to forecast LULC, seasonal LST and UTFVI for 2030. From 2000 to 2020, the results demonstrated a large net change in urban areas (+20.52%), whereas vegetation, bare land, and water bodies were all decreased with net changes of -5.72%, -11.19%, and -3.6%, respectively. According to projected LSTs, the net increase in summer and winter temperatures from 2020 to 2030 will be 13% and 20%, respectively, in the highest temperature group (greater than 35 °C). Furthermore, the projected UTFVI showed that in 2030, roughly 72% (up from 58% in 2020) and 69% (up from 47 percent% in 2020) of total area will be covered by stronger and strongest UTFVI zones. Correlation analysis was statistically significant (p value < 0.05), and the relationship between LST and NDBI was strong and positive, but strongly negative with NDVI. The accuracy examination of all the maps revealed a high degree of estimating, with kappa values of more than 80%. By giving significant insights on urban settings and promoting city competency, the study will broaden the perspectives of city planners and policymakers.

Heat health risk assessment analysing heatstroke patients in Fukuoka City, Japan.

BackgroundClimate change, as a defining issue of the current time, is causing severe heat-related illness in the context of extremely hot weather conditions. In Japan, the remarkable temperature increase in summer caused by an urban heat island and climate change has become a threat to public health in recent years.MethodsThis study aimed to determine the potential risk factors for heatstroke by analysing data extracted from the records of emergency transport to the hospital due to heatstroke in Fukuoka City, Japan. In this regard, a negative binomial regression model was used to account for overdispersion in the data. Age-structure analyses of heatstroke patients were also embodied to identify the sub-population of Fukuoka City with the highest susceptibility.ResultsThe daily maximum temperature and wet-bulb globe temperature (WBGT), along with differences in both the mean temperature and time-weighted temperature from those of the consecutive past days were detected as significant risk factors for heatstroke. Results indicated that there was a positive association between the resulting risk factors and the probability of heatstroke occurrence. The elderly of Fukuoka City aged 70 years or older were found to be the most vulnerable to heatstroke. Most of the aforementioned risk factors also encountered significant and positive associations with the risk of heatstroke occurrence for the group with highest susceptibility.ConclusionThese results can provide insights for health professionals and stakeholders in designing their strategies to reduce heatstroke patients and to secure the emergency transport systems in summer.

Distribution and Genetic Variability of Bemisia tabaci Cryptic Species (Hemiptera: Aleyrodidae) in Italy.

Simple SummaryBemisia tabaci is a key pest of horticultural, fibre and ornamental crops, primarily as a vector of plant viruses. This whitefly is considered as a complex of morphologically indistinguishable species that differ in several biological traits. In Italy, the Mediterranean (MED) and Middle East–Asia Minor 1 (MEAM1) species are known to be present in southern regions as well as in Sicily and Sardinia, where they have been responsible for economically important yield losses to horticultural crops since the 1990s. Recent reports of infestations in some areas of central Italy prompted a reassessment of the species distribution in the country, and several sites have been inspected at different central and southern regions and in the main islands. The survey confirmed that B. tabaci is nowadays established in central Italy even at more northern latitudes than those noticed before, with MED that is clearly prevailing on MEAM1 species throughout the country. The extensive presence of B. tabaci in Italy causes new concerns for the growing number of horticultural and ornamental productive sites that are potentially endangered by whitefly-transmitted viruses. The prevalence of the MED species is even more worrying for its ability to rapidly develop insecticide resistances.Bemisia tabaci is a key pest of horticultural, fibre and ornamental crops worldwide, primarily as a vector of plant viruses. In Italy, B. tabaci has established since the 1980s–1990s in southern regions as well as in Sicily and Sardinia. Recent reports of infestations in some areas of central Italy prompted a new survey to assess the whitefly distribution in the country as well as to update the species and haplotype composition of the populations present in southern Italy and in the main islands. The survey confirmed that B. tabaci is nowadays established in central Italy even at more northern latitudes than those noticed before. Most of the specimens collected throughout the country belonged to the Mediterranean (MED) species. The MEDQ1 and Q2 haplogroups were prevailing in open-field and greenhouse cultivations, respectively, except in Sardinia where only Q1 specimens were found on a wide range of crops and weeds. Population genetics analyses showed that several MEDQ1 haplotypes currently occur in Italy and their distribution is unrelated to evident temporal and geographic trends, except for a new genetic variant which seems to have originated in Sardinia. The MED species is known to better adapt to insecticide treatments and high temperatures, and its northward spread in Italy may have been favoured by the intensive agricultural practices and steady increase in both winter and summer temperatures occurring in the last few decades. The extensive presence of B. tabaci in Italy proves that a strict surveillance for possible new outbreaks of whitefly-transmitted viruses should be addressed to a range of sites that are expanding northwards.

IMPACT OF CLIMATE CHANGE ON THE NET REVENUE OF MAJOR CROP GROWING FARMERS IN PAKISTAN: A RICARDIAN APPROACH

Climate change has severely affected the crops’ productivity during the last few decades across the agrarian economies of the world, thereby resulting in a considerable loss per farmer in the yearly net revenue. Pakistan’s agriculture is sensitive to warming and it experienced an adverse effect in the net farm revenue (NFR). This study primarily predicts the adverse climate effects and estimates the NFR of the farmers of five major crops (wheat, rice, cotton, sugarcane and maize) in two different seasons, winter (Rabbi) and summer (Kharif), in Pakistan. This study is based upon the secondary cross-sectional data [Household Integrated Economic Survey of Pakistan (HIES), 2015–2016] along with the time series data regarding climatic variables from 1981 to 2016. A well-established Ricardian approach has been employed to test the association between net revenue of the farmer and climatic variability. Results of overall study conclude that increases in average summer (winter) temperature and average winter (summer) rainfall have adverse (favorable) impacts on all of the crops’ productivity during both seasons, winter (Rabbi) and summer (Kharif), in Pakistan, thus leading to a decline (an increase) in NFR. Future increases in temperature will be harmful and may lead to significant loss in the revenue amount. The analysis of adaptation techniques exhibits beneficial impacts on the NFR and it is concluded that adaptations are helpful tool for the farmers to minimize revenue loss.

Long-term dynamics of a Cladocora caespitosa bank as recorded by a Posidonia oceanica millenary archive

Along most Mediterranean coasts, the endemic seagrass species Posidonia oceanica builds extensive meadows and complex peat-like bioconstruction known as ‘mattes’. These belowground deposits are recognized as a valuable long-term archive allowing the reconstruction and the study of palaeo-climatic and palaeo-ecological changes in the coastal environment over the Holocene period. One of the P. oceanica matte cores sampled during a coring survey along the eastern continental shelf of Corsica Island (France, NW Mediterranean) revealed the unprecedented finding of a dead bank of the scleractinian coral Cladocora caespitosa embedded in the matte. Measurement of the morphological and biometrical features of corallite fragments coupled to biogeosedimentological analysis and radiocarbon dating contributed to provide a basis for the reconstruction of the stratigraphic sequence since the mid-Holocene (last 4750 years). The study of the sediment core enabled identification of three major phases: (i) the settlement of the C. caespitosa colonies (~4750-3930 cal yr BP), (ii) the coexistence of the C. caespitosa bank and the P. oceanica meadow (~3930-1410 cal yr BP), followed by (iii) the death of the coral bank and the development of only the P. oceanica meadow (~1410 cal yr BP-present). The sclerochronological analysis completed on the well-preserved corallite fragments revealed that the mean annual growth rate of the coral ranged between 1.9 and 3.1 mm yr−1 with a mean value estimated at 2.3 ± 0.8 mm yr−1. Trend analysis showed semi-millennial to millennial oscillations in annual growth rates which are probably related to environmental climatic changes since the Cold Phase of the Subatlantic period (2925-2200 cal yr BP). During the Roman Warm Period (2200-1500 cal yr BP), the decline and the death of the bank (~1410 cal yr BP) was probably due to the combined effect of a prolonged increase in summer temperatures and an increase in the competition with the P. oceanica meadow.

Predicting city-scale daily electricity consumption using data-driven models

• We studied how city electricity use is influenced by weather and COVID-19 pandemic. • Seven data-driven models were applied and evaluated for data of three cities. • Gradient boosting tree model delivers the most accurate prediction with CVRMSE of 4%−6%. • 1 °C increase of ambient temperature drives up the three cities electricity usage by around 5%. • COVID-19 curtailment reduced city-scale electricity usage by 2%−12%. Accurate electricity demand forecasts that account for impacts of extreme weather events are needed to inform electric grid operation and utility resource planning, as well as to enhance energy security and grid resilience. Three common data-driven models are used to predict city-scale daily electricity usage: linear regression models, machine learning models for time series data, and machine learning models for tabular data. In this study, we developed and compared seven data-driven models: (1) five-parameter change-point model, (2) Heating/Cooling Degree Hour model, (3) time series decomposed model implemented by Facebook Prophet, (4) Gradient Boosting Machine implemented by Microsoft lightGBM, and (5) three widely-used machine learning models (Random Forest, Support Vector Machine, Neural Network). Seven models are applied to the city-scale electricity usage data for three metropolitan areas in the United States: Sacramento, Los Angeles, and New York. Results show seven models can predict the metropolitan area's daily electricity use, with a coefficient of variation of the root mean square error (CVRMSE) less than 10%. The lightGBM provides the most accurate results, with CVRMSE on the test dataset of 6.5% for Los Angeles, 4.6% for Sacramento, and 4.1% for the New York metropolitan area. These models are further applied to explore how extreme weather events (e.g., heat waves) and unexpected public health events (e.g., COVID-19 pandemic) influence each city's electricity demand. Results show weather-sensitive component accounts for 30%–50% of the total daily electricity usage. Every degree Celsius ambient temperature increase in summer leads to about 5% (4.7% in Los Angeles, 6.2% in Sacramento, and 5.1% in New York) more daily electricity usage compared with the base load in the three metropolitan areas. The COVID-19 pandemic reduced city-scale electricity demand: compared with the pre-pandemic same months in 2019, daily electricity usage during the 2020 pandemic decreased by 10% in April and started to rebound in summer.