Local Climate Variability Research Articles

Analysis of Climate Variability and Trends in The Context of Climate Changes: Case Study in Terengganu

Uncertainty of climate extreme nowadays causes an alteration in the local climate trend and variability. Terengganu, Malaysia recorded series of extreme drought and flood events throughout a year affected by North-East monsoonwhich will change the next climate pattern. Thus, itwill be affectingthe long-term planning and sustainability that related to the water resources in the long-term. The objective of this study was to analyse the trend changes of rainfall and temperature at Kuala Terengganu, Malaysia due to climate changes impact. The trends changes were analysed usingMan-Kendall and Sen’s Slope. The climate projection result shows the annual mean temperature is expected to have decreasing trend until end of century. However,Mar to June are expected to bit higher than historical reach to 29oCby RCP8.5. Then it will be dropped to 24oC (-5% from historical) during Northeast monsoon. Consistent to the annual rainfall, it was expected to have increasingtrendover time. The highest increasing trendwas expected to occur on Nov toDec more than40% by RCP8.5.

Forage quality of consecutive years interact to affect body condition, reproductive rate and rut phenology in Iberian red deer.

Body condition for reproduction in capital breeders such as the red deer (Cervus elaphus) is mostly determined by their stored energy reserves. Thus, environmental conditions and resource availability may affect reproductive performance and breeding success. In warm Mediterranean regions, current climate change is driving to a hotter and drier scenario that is expected to affect the biology and dynamics of many populations. We examined the impact of these local climate variations on red deer body condition and the relationship with female reproductive phenology and breeding success. We used satellite information of landscape vegetation along with a 22-year data series of direct field behavioural observations during the rutting season in Doñana National Park (SW Spain). We analyzed faecal nitrogen content (FN) from faeces collected during the rut. We found that poor vegetation availability in drier years was related to worse body condition of deer (measured by FN) and a delay in the rutting season, which associated with lower reproductive rates (measured by the proportion of females with calves observed the next year). We also evidenced an interesting interaction between environmental conditions in consecutive years on the timing of breeding season, with timing of breeding being more delayed when previous year resource availability was high and many females bred, and the consecutive one was poor, so females hardly recovered condition and the rut occurred later. These findings highlight the carry-over effect of reproduction in capital breeders and the potential impact of climate-change conditions on red deer breeding.

Sustainable Long‐Term and Wide‐Area Environment Monitoring Network Based on Distributed Self‐Powered Wireless Sensing Nodes

AbstractEnvironmental monitoring of local climatic variations plays a vital role in the research on global warming, species diversity, ecological sustainability, and so on. Traditional monitoring technologies, such as meteorological stations or satellite imagery, can give an overall environment picture but at high cost, high energy consumption, and with insufficient regional details. Here, a networking system made of low‐cost, maintenance‐free, and distributed self‐powered wireless monitoring nodes is proposed, aimed at establishing a sensing system for long‐term and wide‐area environment monitoring. It is demonstrated that, as driven by gentle wind, these distributed nodes are able to monitor temperature, humidity, and atmospheric pressure automatically, and then transfer the sensing data to receiving terminals wirelessly using triboelectric nanogenerators as energy harvesting technologies. The longest transmitting distance is 2.1 km. Additionally, a sensing network is formed. By utilizing several nodes, a 2‐km2 region is covered, and the information can be transmitted live using a relay‐technology. Furthermore, the node is demonstrated to work for weeks, and continuously send back environmental data. Since the nodes are portable and the embedded sensors are customizable, it is anticipated that the system can be multifunctional and applied in many natural areas, such as forests, prairies, mountains, lake regions, and so on.

Thermal Resilience of Citizens: Comparison between Thermal Sensation and Objective Estimation in Outdoor Spaces: A Case Study in Seville, Spain

Sanitary issues, combined with the effects of climate change, emphasize the comfort of outdoor spaces in cities. Numerous comfort models exist and can predict thermal sensation. However, these comfort indices need to be validated in hot zones and quantify the neutral range considering people’s thermal resilience. The present study investigates the outdoor thermal comfort of people who live in hot areas and are accustomed to this and quantifies this effect. For that, predictions provided by the COMFA thermal comfort model were compared with the occupants’ perceptions given in the field campaigns’ questionnaires. The field campaigns were associated with on-site monitoring of local climate variables. It was observed that during the survey period, the entire space was predicted to be uncomfortable by the COMFA model. On the contrary, the results of the questionnaires showed that the most frequently encountered thermal sensations were distributed between the comfort zone and the hot zone. The proposed methodology has been designed to be used by other researchers, and it is adaptable to other outdoor thermal comforts such as PET or ITS. The comparison between the model’s predictions and the users’ responses to space highlighted the tendency of the COMFA to overestimate the thermal sensations. This work’s results allow extending the neutral comfort band from 50 W/m2 (value of literature) to 80 W/m2. So, the paper quantifies that the effect of the thermal resilience of the people increases the thermal band of comfort by around 60%. These results will allow an accurate assessment of the effectiveness of future mitigation solutions implemented to improve outdoor thermal comfort in other world areas. It is due to the propose of a higher neutrality range researchers or designers could achieve outdoor thermal comfort in effective and reliable ways, even in hot climates.

Impacts of Climate Change on the Lives of Riverine Farmers on the Lower Rio Negro, Amazon

Global climate change, although gradual, is already clearly perceptible for the whole society; however, its impacts affect individuals and regions in diverse ways. Riverine communities in the Brazilian Amazon are highly vulnerable to this change, as seasonal hydroclimatic cycles govern their daily lives, integrate their way of life with the environment, and determine the organization of social and agricultural calendars. This work aimed to understand the impacts caused by climate change on the lives of riverine family farmers on the lower Rio Negro. Initially, through the analysis of changes in hydroclimatic trends and, later, through the description of perception, we tried to present the impacts on the ways of life to then know the climate adaptation strategies. The research was carried out in the state of Amazonas, in the riverine communities Tiririca, Marajá, Santo Antônio, and Terra Preta, located in the Rio Negro Sustainable Development Reserve, with 43 subjects through semi-structured and focus group interviews. Historical trends in the seasonality of the hydrological regime, precipitation, and temperature were analyzed, while qualitative data from environmental perception were analyzed using the technique of content analysis. Physical records of local climate variability and environmental perception are, in most cases, compatible and indicate that hydroclimatic cycles are changing. For the riverine people, the rains have been decreasing and there is unanimity in the perception that the increase in temperature is a reality that has affected their way of life at work, education, health, and food. Although communities have been developing spontaneous adaptive strategies to mitigate the effects of climate change, effective public policies need to reinforce these local responses to climate variability, contributing to the quality of life of populations.

Lobomycosis-like disease epidemiology, pathology and social affiliations in bottlenose dolphins from Southwestern Gulf of Mexico

Mycotic diseases are considered a worldwide growing concern related to public health. Lobomycosis like disease (LLD) (Lacazia loboi) is a chronic and progressive infection in skin of humans and small cetaceans present in both sides of the Americas, including Mexico but information is still limited. Marine predators are indicators of potential risks for human and wildlife health, including fungal diseases like LLD in bottlenose dolphins. Here we report the first findings of an initial assessment in LLD epidemiology, pathology, and behavioral constraints of coastal bottlenose dolphins (Tursiops truncatus) from the Southwestern Gulf of Mexico (SWGM). Overall, LLD prevalence in the population was low, within ranges reported for the species, and only in highly associated unisexual pairs near the Alvarado coastal waters. Photo-identified individuals exhibited an annual increase in average progression for LLD skin lesions. Gross lesions and skin biopsy evidenced mycotic structures and subcutaneous alterations associated to LLD. Habitat quality, demographic, and social characteristics of bottlenose dolphins are likely influencing LLD geographical expansion and temporal prevalence, but global and local climate variability may influence LLD epidemiology, implying a potential risk for human and dolphin health from coastal communities at the SWGM.

Chill coma recovery of Ceratitis capitata adults across the Northern Hemisphere

The Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae), is an invasive pest, that is currently expanding its geographic distribution from the Mediterranean coasts to more temperate areas of Europe. Given that low temperature is a primary determinant of insect species’ range boundaries especially in the Northern Hemisphere with pronounced seasonality, we used chill coma recovery time for assessing latitudinal clines in basal chill tolerance of C. capitata adults. We selected six populations obtained from areas with broad climatic variability based on the main bioclimatic variables of temperature and precipitation, spanning a latitudinal range of about 19° from Middle East to Central Europe. Adults were exposed to 0 °C for 4 h, and time to regain the typical standing position of a fly at 25 °C were recorded. The post-stress survival after a period of 8 days was also recorded. Results revealed that adults from Israel and Austria were less chill tolerant than those from Greece, resulting in curvilinear trends with latitude. Analysis of macroclimatic conditions revealed combined effects of latitude (as a proxy of photoperiod) and macroclimatic conditions on chill coma recovery time. Nonetheless, there was not a deleterious effect on post-recovery survival, except for flies obtained from the northern most point (Vienna, Austria). Overall, it seems that evolutionary patterns of basal chill coma recovery time of C. capitata adults are driven mainly by local climatic variability.

Sensitivity of seasonal air temperature and precipitation, and onset of snowmelt, to Arctic Dipole modes across the Taiga Plains, Northwest Territories, Canada

AbstractNorthern high latitudes are experiencing some of the greatest increases in air temperatures on Earth. Air temperatures (along with other modulating variables including precipitation and the onset of snowmelt) are influenced by atmospheric–oceanic circulation patterns, some of which are persistent and recurrent. One pattern in particular, the Arctic Dipole (AD) anomaly, is a persistent sea‐level pressure teleconnection pattern between the Canadian Archipelago and Barents Sea that has unknown impacts on local climate variability. These patterns may be important, especially in hydro‐ecologically sensitive areas such as Northwest Territories (NWT), Canada where permafrost thaw and ecosystem changes are influenced by interannual climate variability. The goal of this research is to determine the impacts of the AD on local climate (air temperature, precipitation, snowmelt) for a 66‐year period (1950–2015) spanning both latitudinal and longitudinal gradients across NWT from north to south and foothills to plains. Deviations during strong positive and negative modes of the AD index were calculated in reference to the complete 66‐year record. Results showed considerable year‐to‐year variability in the AD pattern, with more frequent strong negative modes during the 2000s. During 1950–2015, there were 64 and 56 occurrences of strong positive and strong negative AD modes, respectively, across all seasons. Spring and summer strong AD modes led to local air temperature anomalies of greater than 0.8°C compared with the long‐term (66 years) mean. Earlier onset of snowmelt, by an average of 3–5 days, was also noted during positive AD modes. Despite strong connectivity between the AD and local air temperature, we found less correspondence between the AD and seasonal precipitation. These findings improve understanding of the impacts of the AD on local weather and climate in NWT and suggest implications for ecosystem change, such as drying and shrubification of northern boreal peatlands and possible connectivity to teleconnection impacts on wildland fire.

A new modelling framework to assess changes in groundwater level

Study regionThe Southern African region consists of ten countries including, Angola, Zambia, Malawi, Namibia, Botswana, Zimbabwe, Mozambique, South Africa, Lesotho, and Swaziland. Frequent drought episodes in the arid and semi-arid parts of the region suggest the impact of climate change and the need for a sustainable framework for groundwater level assessments. Study focusIn this study, we developed a machine learning modelling framework based on the deep belief network (DBN) to predict the changes in monthly groundwater levels (CGWLs) at 1–5 month time scales for 27 groundwater wells over the southern Africa region. With a predictor dataset constituted by hydrological parameters, groundwater level estimates, and global climate indices, we ascertain the possibility of forecasting changes in groundwater levels (CGWL) up to 5-month lead times at most locations in the study region. Using the quantile regression technique, the strength of the DBN network at 90% and 95 % confidence levels were tested, and this helped to determine the accuracy of our forecasts at five months lead times over the four representative wells. New hydrological insights for the regionDeep learning offers new capabilities in evaluating non-linear hydrological systems, including groundwater analysis. The re-injection procedure of the DBN network, which allows the prior CGWL estimates to serve as inputs for the next estimate was key in maintaining the forecast accuracy in the 4th and 5th month lead times. This was evidenced in the accuracy of the four representative wells (r = 0.91, 0.87, 0.81, 0.75), which formed part of the test samples in CGWL analysis. We also observed that the DBN is highly susceptible to local climate variables and global climate indices, which are important drivers of climate change, and can have strong impact on groundwater level fluctuations. Therefore, the DBN proved to be a robust algorithm in our general assessments of groundwater level fluctuations.

Dynamics of nitrous oxide emissions from two cropping systems in southwestern France over 5 years: Cross impact analysis of heterogeneous agricultural practices and local climate variability

Nitrous oxide (N2O) emissions were measured and compared on 2 typical crop rotations of a grain farm and a dairy farm with feed cropping, over 5 years (from 2012 to 2016) in southwestern France. The annual N2O emissions of the 5 typical rotational crops of the region (summer crops: irrigated maize and sunflower; winter crops: winter wheat, rapeseed and barley) varied from 0.95 ± 0.88 to 7.96 ± 1.73 kgN ha−1, with the highest values observed on the dairy farm plot and for summer crops. N2O emissions were analysed on a daily, monthly, seasonal and annual basis, and correlated with their main direct or indirect drivers, i. e. water and nitrogen (mineral or organic) supply amount, rotational crops, vegetation covering and tillage. We observed a marked seasonal pattern of N2O emission peaks. On average, more than 50% of N2O emissions occurred during spring for summer crops, and more than 40% occurred in winter for winter crops. We have identified agricultural practices that increase N2O emissions. In particular, our results show that when the soil is left bare or with limited crop development, spring mineralization of organic N residues (from previous crop or winter cover crop) results in N losses, partly as emissions of N2O, which are detrimental to agronomic performance (low NUE). We also conducted an agronomic assessment of annual N2O emissions versus nitrogen surplus and nitrogen use efficiency (NUE), which lead us to discuss agricultural practices that may mitigate N2O emissions while optimizing agronomic and economic performance of crops. Indeed, we point out that N surplus and N fate may be controlled through the right timing of sowing, cover crop, irrigation and fertilization.

Design and Optimization of Energy Consumption for a Low-Rise Building With Seasonal Variations Under Composite Climate of India

Abstract The need for maintaining thermal comfort conditions inside the building is a significant contributor to the total energy requirements of the buildings. Thus far, limited research has offered some strategies to mitigate the effect of ambient conditions on the thermal comfort and the building energy requirements for composite climatic zone in India. In order to address this problem, this study was conducted to evaluate and analyze the impacts of four different passive design strategies, i.e., insulation, cool roof, phase change material (PCM) thermal storage system, and shading, on thermal comfort and energy demand in the two-storey building situated in the composite climate zone of Delhi, India. The results obtained by numerical simulation for four different cities, i.e., Delhi, Jaipur, Lucknow, and Indore, have been compared to study the effect of local climatic and seasonal variations within the composite climatic zones. The simulations were conducted using the Design Builder software to capture results for one year. The results indicate that no single passive design strategy is sufficient to maintain comfortable conditions inside the building. The cool roof provides significant benefits in combination with other passive technologies in all seasons except for December, January, and February. The combination of insulation and PCM is useful for winter conditions. Energy saving of up to 20.5% is possible using the combination of all four passive strategies, whereas the cool roof alone gives an 18% reduction in energy load. The PCM with a melting point of about 32 °C is suggested for the cities under study.

Systematic review of the impact of heatwaves on health service demand in Australia

ObjectivesHeatwaves have been linked to increased levels of health service demand in Australia. This systematic literature review aimed to explore health service demand during Australian heatwaves for hospital admissions, emergency department presentations, ambulance call-outs, and risk of mortality.Study designA systematic review to explore peer-reviewed heatwave literature published from 2000 to 2020.Data sourcesArticles were reviewed from six databases (MEDLINE, Scopus, Web of Science, PsychINFO, ProQuest, Science Direct). Search terms included: heatwave, extreme heat, ambulance, emergency department, and hospital. Studies were included if they explored heat for a period of two or more consecutive days. Studies were excluded if they did not define a threshold for extreme heat or if they explored data only from workers compensation claims and major events.Data synthesisThis review was prospectively registered with PROSPERO (#CRD42021227395). Forty-five papers were included in the final review following full-text screening. Following a quality assessment using the GRADE approach, data were extracted to a spreadsheet and compared. Significant increases in mortality, as well as hospital, emergency, and ambulance demand, were found across Australia during heatwave periods. Admissions for cardiovascular, renal, respiratory, mental and behavioural conditions exhibited increases during heatwaves. The most vulnerable groups during heatwaves were children (< 18 years) and the elderly (60+).ConclusionsHeatwaves in Australia will continue to increase in duration and frequency due to the effects of climate change. Health planning is essential at the community, state, and federal levels to mitigate the impacts of heatwaves on health and health service delivery especially for vulnerable populations. However, understanding the true impact of heatwaves on health service demand is complicated by differing definitions and methodology in the literature. The Excess Heat Factor (EHF) is the preferred approach to defining heatwaves given its consideration of local climate variability and acclimatisation. Future research should explore evidence-based and spatially relevant heatwave prevention programs. An enhanced understanding of heatwave health impacts including service demand will inform the development of such programs which are necessary to promote population and health system resilience.

Diagnosis of the Extreme Climate Events of Temperature and Precipitation in Metropolitan Lima during 1965–2013

The most extreme precipitation event in Metropolitan Lima (ML) occurred on 15 January 1970 (16 mm), this event caused serious damage, and the real vulnerability of this city was evidenced; the population is still not prepared to resist events of this nature. This research describes the local climate variability and extreme climate indices of temperature and precipitation. In addition, the most extreme precipitation event in ML is analyzed. Extreme climate indices were identified based on the methodology proposed by the Expert Team on Climate Change Detection and Indices (ETCCDI). Some extreme temperature indices highlight an initial trend toward warm conditions (1965–1998); this trend has changed towards cold conditions since 1999, consistent with the thermal cooling during the last two decades in ML (−0.5 °C/decade) and other coastal areas of Peru. The variations of extreme temperature indices are mainly modulated by sea-surface temperature (SST) alterations in the Niño 1 + 2 region (moderate to strong correlations were found). Extreme precipitation indices show trends toward wet conditions after the 1980s, the influence of the Pacific Ocean SST on the extreme precipitation indices in ML is weak and variable in sign. The most extreme precipitation event in ML is associated with a convergence process between moisture fluxes from the east (Amazon region) at high and mid levels and moisture fluxes from the west (Pacific Ocean) at low levels, and near the surface.

Climate Change Adaptation and Mitigation Strategies in Madda Walabu District, Bale Zone, Southeast Ethiopia

Climate change is one of the most serious environmental challenges affecting people all over the world causing widespread agitation and having an impact on economic systems such as agricultural production. Local communities in Madda Walabu District of Bale Zone, Southeast Ethiopia, are heavily dependent on agriculture. In contrast, the agricultural activity of the local community was depressed by threats such as increased temperature, prolonged drought, and changes in rainfall distribution. To mitigate the adverse consequences of climate change, it is important to understand the local knowledge of adaptation and mitigation actions. This research was a look into the climate change adaptation and mitigation in Ethiopia’s Madda Walabu District households to survive. The objective of the study was to investigate climate change adaptation and mitigation strategies for the synergy of the communities in the Madda Walabu District. A multistage stratified random sampling procedure and three villages were randomly selected. A total of 150 sample households from the three villages were interviewed. Descriptive statistics were employed to analyse data, and the Statistical Package for Social Science (SPSS) was used for analysis. The results showed that most of the respondents have perceived an increase in temperature, fluctuation in the rainy season, and a decrease in the amount of rainfall. The respondents perceived that they are vulnerable to local climate variability. This study also revealed that 78% of the respondents followed different adaptation strategies to climate change, such as irrigation intensification, agroforestry, agronomic, and cultural practices. Adaptation and mitigation measures can be developed by enhancing the adaptive and mitigating capacity of forest-dependent communities. Therefore, awareness creation on climate change, variability, adaptation, and mitigation measures should be considered toward enhancing the adaptive capacity of the local communities in line with providing seasonal weather information. More research in the domain of climate change and mitigation techniques is needed as several statistical results were not as predicted, and the amount of adaptation and mitigation synergies was low. Furthermore, the study’s households were predominantly pastoralists, and their climate change adaptation and mitigation strategy for the livestock sector was an issue that needed to be addressed urgently.

Rhizosphere 16S-ITS Metabarcoding Profiles in Banana Crops Are Affected by Nematodes, Cultivation, and Local Climatic Variations.

Agriculture affects soil and root microbial communities. However, detailed knowledge is needed on the effects of cropping on rhizosphere, including biological control agents (BCA) of nematodes. A metabarcoding study was carried out on the microbiota associated with plant parasitic and other nematode functional groups present in banana farms in Tenerife (Canary Islands, Spain). Samples included rhizosphere soil from cv Pequeña Enana or Gruesa and controls collected from adjacent sites, with the same agroecological conditions, without banana roots. To characterize the bacterial communities, the V3 and V4 variable regions of the 16S rRNA ribosomal gene were amplified, whereas the internal transcribed spacer (ITS) region was used for the fungi present in the same samples. Libraries were sequenced with an Illumina MiSeq™ in paired ends with a 300-bp read length. For each sample, plant parasitic nematodes (PPN) and other nematodes were extracted from the soil, counted, and identified. Phytoparasitic nematodes were mostly found in banana rhizosphere. They included Pratylenchus goodeyi, present in northern farms, and Helicotylenchus spp., including H. multicinctus, found in both northern and southern farms. Metabarcoding data showed a direct effect of cropping on microbial communities, and latitude-related factors that separated northern and southern controls from banana rizosphere samples. Several fungal taxa known as nematode BCA were identified, with endophytes, mycorrhizal species, and obligate Rozellomycota endoparasites, almost only present in the banana samples. The dominant bacterial phyla were Proteobacteria, Actinobacteria, Planctomycetes, Bacteroidetes, Chloroflexi, and Acidobacteria. The ITS data showed several operational taxonomic units (OTUs) belonging to Sordariomycetes, including biocontrol agents, such as Beauveria spp., Arthrobotrys spp., Pochonia chlamydosporia, and Metarhizium anisopliae. Other taxa included Trichoderma harzianum, Trichoderma longibrachiatum, Trichoderma virens, and Fusarium spp., together with mycoparasites such as Acrostalagmus luteoalbus. However, only one Dactylella spp. showed a correlation with predatory nematodes. Differences among the nematode guilds were found, as phytoparasitic, free-living, and predatory nematode groups were correlated with specific subsets of other bacteria and fungi. Crop cultivation method and soil texture showed differences in taxa representations when considering other farm and soil variables. The data showed changes in the rhizosphere and soil microbiota related to trophic specialization and specific adaptations, affecting decomposers, beneficial endophytes, mycorrhizae, or BCA, and plant pathogens.

Contrasting State‐Dependent Effects of Natural Forcing on Global and Local Climate Variability

AbstractNatural forcing from solar and volcanic activity contributes significantly to climate variability. The post‐eruption cooling of strong volcanic eruptions was hypothesized to have led to millennial‐scale variability during Glacials. Cooling induced by volcanic eruption is potentially weaker in the warmer climate. The underlying question is whether the climatic response to natural forcing is state‐dependent. Here, we quantify the response to natural forcing under Last Glacial and Pre‐Industrial conditions in an ensemble of climate model simulations. We evaluate internal and forced variability on annual to multicentennial scales. The global temperature response reveals no state dependency. Small local differences result mainly from state‐dependent sea ice changes. Variability in forced simulations matches paleoclimate reconstructions significantly better than in unforced scenarios. Considering natural forcing is therefore important for model‐data comparison and future projections.

Climate variability and trends in the Endorheic Lake Hayk basin: implications for Lake Hayk water level changes in the lake basin, Ethiopia

For sustainable climate hazard management, climate information at the local level is crucial for developing countries like Ethiopia, which has an exceptionally low adaptive capacity to changes in climate. As a result, rather than making local decisions based on findings from national-scale studies, the study area’s research gap of local level climate variability and trend was investigated within the endorheic Lake Hayk basin for the historic series from 1986 to 2015 to scientifically show climate change/variability implications on Lake Hayk water level variations. To achieve the study objective, the precipitation, temperature (station and ERA5 reanalysis product) and Lake water level (patchy lake level fused with remotely sensed water areas) were examined using various statistical approaches with the integration of remote sensing and geographical information system. The major findings revealed less variable (CV = 16.66%) and statistically nonsignificant declining trends (− 33.94 mm/decade) in annual precipitation. Belg and bega seasonal precipitations showed highly variable (CV = 43.94–47.46%) nonsignificant downward trends of 4.57 mm and 22 mm per decade respectively, whereas kiremt precipitation showed moderate variability (CV = 23.80%) and increased nonsignificantly at a rate of 21.89 mm per decade. Annual and seasonal mean temperatures exhibited less variable but statistically significant rising trends ranging from 0.20 to 0.45 °C each decade. The lake’s water level showed less variable nonsignificant rising trends (70 mm to 120 mm per year) on annual and seasonal scales between 1999 and 2005. The lake's surface area has decreased from 2243.33 ha in 2005 to 2165.33 ha in 2011. During 2011–2015, it demonstrated a high variable (CV > 30%) statistically significant dropping trend ranging from − 250 mm to − 340 mm per year on annual and seasonal periods. The study discovered that the endorheic lake Hayk basin was dominated by variable and diminishing precipitation, as well as continuous warming trends, particularly in recent years. It is argued that this climatic state was having a negative impact on Lake Hayk’s substantially dropping water level, necessitating an immediate basin-based water management decision to save Lake Hayk from extinction.

Divergent Hydrological Responses to Forest Expansion in Dry and Wet Basins of China: Implications for Future Afforestation Planning

AbstractAfforestation to control soil erosion has been implemented throughout China over the past few decades. The long‐term hydrological effects, such as total water yield and baseflow, of this large‐scale anthropogenic activity remain unclear. Using six decades of hydrologic observations and remote sensing data, we explore the hydrological responses to forest expansion in four basins with contrasting climates across China. No significant change in runoff was found for the period 1970–2012 for the cold and dry Hailar River Basin in northeastern China. However, both forest expansion and reduced precipitation contributed to the runoff reduction after afforestation since the late 1990s. Similarly, afforestation and drying climate since the mid‐1990s induced a significant decrease in runoff for the Weihe River Basin in semi‐arid northwestern China. In contrast, the two wet basins in the humid southern China, Ganjiang River Basin and Dongjiang River Basin, showed insignificant changes in total runoff during their study periods. However, the baseflow in the winter dry seasons in these two watersheds significantly increased since the 1950s. Our results highlight the long‐term variable effects of forest expansion and local climatic variability on basin hydrology in different climatic regions. This study suggests that landuse change in the humid study watersheds did not cause dramatic change in river flow and that region‐specific afforestation policy should be considered to deal with forestation‐water quantity trade‐off. Conclusions from this study can help improve decision‐making for ecological restoration policies and water resource management in China and other countries where intensive afforestation efforts are taking place.

Integrating microclimatic variation in phenological responses to climate change: A 28‐year study in a hibernating mammal

AbstractPhenological shifts associated with directional changes in climate, resulting in earlier spring activities, have been documented in several animal species. However, the extent to which species respond to overall climate change versus local climate variation is rarely studied. In addition, climate data are usually averaged over large spatial scales, even though local heterogeneity in habitats may be high, and species might be more susceptible to changes in local rather than global climate conditions. In this study, we examined the effects of spatiotemporal climate variation and climate change on the phenology of a hibernating mountain rodent, the Columbian ground squirrel (Urocitellus columbianus). Over 28 years of research (1992–2019), we studied the relationship between the microclimatic conditions experienced by adult and juvenile ground squirrels from four neighboring meadows, and their dates of emergence from hibernation. We used a microclimate model to calculate microclimate variables (local snow depth, soil temperature, air temperature, wind speed, and humidity) at an hourly scale, a 5‐m spatial resolution, and at animal height on the study sites over 28 years. Emergence dates varied with age and sex, among years, as well as among and within meadows, with some areas averaging up to 10 days earlier emergence dates from hibernation than others. While emergence dates tended to be delayed throughout the study period, long‐term temporal changes and interannual variability in emergence dates differed among meadows and depended on individual age and sex. Dates of hibernation emergence were correlated with local climate variables considered either during hibernation or during the preceding summer. Ground squirrels emerged earlier in years or at locations when/where snow melted earlier (years: all individuals excluding 2‐year‐old males, locations: yearlings and older females), and when the previous summer was less windy (≥3‐year‐old individuals) and more humid (2‐year‐old males). Two‐year‐old male ground squirrels also emerged later in locations where snow depth during winter was higher. Using a microclimate model allowed realistic predictions of phenological responses to climate, highlighting its potential for research on animal responses to abiotic change.

Elevational and local climate variability predicts thermal breadth of mountain tropical tadpoles

The climate variability hypothesis posits that increased environmental thermal variation should select for thermal generalists, while stable environments should favor thermal specialists. This hypothesis has been tested on large spatial scales, such as latitude and elevation, but less so on smaller scales reflective of the experienced microclimate. Here, we estimated thermal tolerance limits of 75 species of amphibian tadpoles from an aseasonal tropical mountain range of the Ecuadorian Andes, distributed along a 3500 m elevational range, to test the climatic variability hypothesis at a large (elevation) and a small (microhabitat) scale. We show how species from less variable thermal habitats, such as lowlands and those restricted to streams, exhibit narrower thermal tolerance breadths than highland and pond‐dwelling species respectively. Interestingly, while broader thermal tolerance breadths at large scales are driven by higher cold tolerance variation (heat‐invariant hypothesis), at local scales they are driven by higher heat tolerance variation. This contrasting pattern may result from divergent selection on both thermal limits to face environmental thermal extremes at different scales. Specifically, within the same elevational window, exposure to extreme maximum temperatures could be avoided through habitat shifts from temporary ponds to permanent ponds or streams, while minimum peak temperatures remained invariable between habitats but steadily decreased with elevation. Therefore an understanding of the effects of habitat conversion is crucial for future research on resilience to climate change.