Fall Period Research Articles

Cosmogenic surface exposure (10Be) dating of raised beaches in Marguerite bay, Antarctic Peninsula: Implications for relative sea-level history

Understanding the dynamics of ice mass loss in polar regions is crucial for deciphering climate change and Glacio Isostatic Adjustment patterns. This study focuses on Marguerite Bay, located in the south-central Antarctic Peninsula. We dated raised beaches to investigate relative sea-level changes using the cosmogenic surface exposure (10Be) method. Previous studies have provided valuable insights into the region's glacial history, but limitations in dating techniques and age estimates necessitate further investigation. By analysing raised shingle beaches in Gaul Cove of Horseshoe Island and the southern coast of Calmette Bay, this research aims to contribute relative sea-level change history for these areas. In Horseshoe Island's Gaul Cove, raised beaches clustered on prominent steps reveal a 15 m relative sea-level change over the last 3.31 ka. Differently, Calmette Bay exhibits a 36 m relative sea-level fall over the last 7.29 ka. These findings indicate significant and differential glacial-isostatic adjustments in both regions during the middle and late Holocene. Additionally, our data reveal accelerated sea-level fall periods corresponding to Holocene deglaciation and glacial advance events, indicating the shorelines' relative sea-level change sensitivity to climate change.

Long-term potato response to different irrigation scheduling methods using saline water in an arid environment

Crops’ water requirement is generally higher than the annual average precipitation in arid environments characterized by scarce freshwater resources. While using saline water for irrigation can help sustain agriculture in water-stressed regions, several challenges arises concerning productivity and soil salinization. However, adoption of efficient irrigation techniques such as drip irrigation, irrigation scheduling, and deficit irrigation can help optimize water productivity and mitigate salinity problems in irrigated agriculture. In southern Tunisia, potato is considered among the main cultivated horticultural crops due to its high economic value while it is considered as a crop sensitive to salinity. This crop (cv. Spunta) was the subject of long-term studies (2002–2020) conducted during the fall period in the arid region of Médenine. The crop response to full and deficit irrigation with saline water was assessed for several seasons under contrasting climatic conditions. Scheduling using the soil water balance (SWB) method consisted of the total and/or partial replacement of accumulated crop evapotranspiration (ETc), as derived from climatic data and crop coefficients. The impact of decreasing amounts of irrigation waters on crop yield and soil salinity with waters having a salinity ranging between 3 and 7 dS m−1 was evaluated. Results showed improvements in yield (30% to 37%) obtained with the SWB strategy under actual farming conditions, supporting the use of this strategy for irrigation. Appropriate scheduling also seems to be a key element in saving water (15%–22%) and in reducing risks of soil salinization. In the dry environment of southern Tunisia, optimum supply seems to correspond to a replacement of 100% to approximately 70%–80% of ETc. Applying such irrigation levels resulted in a lower salinity buildup in the root zone and higher crop water productivity. Natural salt leaching seems to be more effective under a more humid soil profile. Yield decreases and soil salinity increases almost linearly (r2 = 0.60) with decreasing irrigation water amounts. Future work should focus on the integration of management practices when using saline water. Investigating the relationship and interaction between irrigation amounts, cultivar, fertilizer supply, and salt leaching will help in resolving productivity and environmental issues.

Changes in the epidemiological patterns of respiratory syncytial virus and human metapneumovirus infection among pediatric patients and their correlation with severe cases: a long-term retrospective study.

We aim to investigate the prevalence of respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) among pediatric patients with acute respiratory tract illness (ARTI) in southern China both pre- and post-COVID-19 pandemic, as well as identify associated risk factors for severe infections. The study conducted a real-time PCR analysis on hospitalized children with ARTI from 2012 to 2023, specifically targeting RSV, hMPV, and other respiratory pathogens. Additionally, demographic data was collected during this analysis. The prevalence of RSV occurs triennially, and likewise, the temporal pattern of hMPV outbreaks mirrors that of RSV. The peak infection rates of RSV and hMPV occurred during and following the implementation of COVID-19 epidemic prevention and control measures. The incidence of RSV infection exhibited bimodal peaks in 2022, while hMPV demonstrated seasonal peaks during the spring, fall, and winter periods post-COVID-19 pandemic. After the COVID-19 outbreak, there has been an upward trend in the proportion of female patients and patients aged one year and older presenting with ARTI, RSV infections, and hMPV infections. Infant (OR = 4.767, 95%CI: [3.888-5.846], p < 0.0001), presence of co-infection (OR = 0.540, 95%CI: [0.404-0.722], p < 0.0001), and existence of comorbidities (OR = 1.582, 95%CI: [1.285-1.949], p < 0.0001) was the risk ratio for the severity of RSV infection. Children infected with hMPV under the age of 1 year (OR = 0.322, 95%CI: [0.180 - 0.575], p < 0.0001), as well as those with comorbidities (OR = 8.809, 95%CI: [4.493 - 17.272], p < 0.0001), have a higher risk of developing severe illness. The changing epidemiological patterns have the potential to lead to widespread severe outbreaks among children, particularly those with underlying medical conditions who may experience more severe symptoms. Conducting surveillance for pneumoviridae viruses in children is an imperative measure to establish a robust foundation for future epidemic prevention and treatment strategies.

Reliable high impedance fault detection method based on the roughness of the neutral current in active distribution systems

Detecting High Impedance Faults (HIFs) in Distribution Systems (DSs) still requires effective solutions. HIFs can cause damage, such as shock hazards and bushfires. However, conventional protection cannot identify HIFs due to their low fault current, and most existing solutions neglect the multiple operating scenarios of the DSs. Thus, this paper proposes a new self-adaptive approach for HIF detection, considering the conductor fall period in a system with distributed generation, a condition usually overlooked in existing studies. The algorithm is based only on the fundamental component and third harmonic extracted from the neutral current using the Stockwell Transform. The approach was thoroughly evaluated, considering several scenarios, such as changes in the system loading, background noise, events that can cause false detection, and variations in the distributed generator power output. The tests considered HIFs signals from real field measurements and generated by a simulation model. The results showed that the algorithm is promising, with high detection rates for all the evaluated scenarios, which included over 400,000 HIF and 6,000 non-HIF cases. Additionally, a comparison proved the superiority of the proposed approach over existing methodologies.

Metabolomic Profile and Functional State of Oat Plants (Avena sativa L.) Sown under Low-Temperature Conditions in the Cryolithozone.

Oats are one of the most useful and widespread cereal crops in the world. In permafrost conditions (Central Yakutia), based on metabolic changes in late summer-sown oat plants (Avena sativa L.), the key processes involved in the cold acclimation of a valuable cereal species were identified. During the onset of low ambient temperatures, metabolites from leaf samples were profiled using gas chromatography with mass spectrometry (GC-MS) and were analyzed using principal component analysis (PCA). A total of 41 metabolites were identified in oat leaves. It was found that acclimation to suboptimal temperatures during the fall period leads to biochemical (accumulation of mono- and disaccharides and decrease in fatty acids and polyols) as well as physiological and biophysical changes (decrease in leaf PRI reflectance indices and chlorophyll a fluorescence). Therefore, the study contributes to a more holistic understanding of oat metabolism under low-temperature cryolithozone stress. It is believed that the analysis of changes in leaf reflection properties and JIP-test parameters of chlorophyll a fluorescence using leaf metabolomic profiling can be used in the selection of valuable varieties of cereal crops to obtain plant fodders with high nutrient contents under conditions of a sharply continental climate.

QUALITY OF MARE'S MILK AND KOUMISS

Nowadays mare's milk and koumiss are in great demand in Kazakhstan. Therefore, the study of its qualitative indicators is relevant.In the article the physical and chemical parameters and vitamin content (B and C groups) of mare's milk and koumiss samples taken from peasant farms of Almaty region in the fall-winter period are studied in a comparative form.The study showed that mare's milk samples had no significant difference in total protein mass fraction in the fall and winter. In mass fraction terms of fat in the sample obtained in the fall the fat content was 2.18% higher than in the sample obtained in winter. And the mass fraction of lactose in the sample obtained in the fall was 0.14% higher than in the sample obtained in winter.According to the study results of obtained koumiss samples’ physical and chemical parameters in the fall and winter periods, the mass fraction of protein was 1.86-1.89%. Fat content of koumiss proportion prepared in the fall period was 1.84%, in the winter period-2.19%, and the average mass fraction of lactose was from 3.64 to 3.98%.The content of water-soluble vitamins B and C in samples of mare's milk and koumiss was investigated. According to the study results the content of vitamins B1, B2, B3, B5 B6 and C in the composition of mare's milk and koumiss obtained in the fall and winter periods was established.According to the general research results samples of mare's milk and koumiss products obtained from peasant farms of Almaty region have proven high quality, nutritious in food value and easily assimilated by human body.

An analysis of Thysanoptera associated with the flowers of some stone fruits in Mersin Province (Türkiye): composition, distribution, population dynamics and damage status

The distribution, abundance and damage status of Thysanoptera species were investigated in two different regions of Mersin Province, Türkiye between 2020 and 2021. A total of 18 Thysanoptera species were determined, with Thrips major Uzel, 1895 and Frankliniella occidentalis (Pergande, 1895) (Thysanoptera: Thripidae) being the most common. While nectarine had the highest diversity of habitats for thrips, plum displayed greater richness in terms of species composition. Adult thrips primarily inhabited flowers while T. major larvae were present during petal fall periods. No larvae of F. occidentalis or Thrips tabaci Lindeman,1889 (Thysanoptera: Thripidae) were found on the plant parts sampled throughout the samplings. Although no visible signs of damage by adult thrips were observed on the flowers, typical damage in the form of silvery scars appeared on the young fruits of nectarines and plums. The average rate of scarred fruit of nectarines or plums varied between 2-7%. Finally, T. major was the main pest thrips species responsible for damaging fruits of the plums and nectarines in Mersin.

Effects of fall-spring cement applications on soil physico-mechanical quality of seed bed and seedling emergence.

The physico-mechanical quality of the seed bed is extremely important not only for the soil air-water dynamics, but also for the germination, seedling emergence, and development of the plants. The crust layer formed after precipitation and irrigation in soils with poor structural properties is among the most important indicators of the lower seedbed quality. While there are different applications to increase the physico-mechanical quality of the seedbed, there are also cement applications that provide rapid aggregate formation and stability. The effects of cement application on the soil mechanical quality and seedling emergence of clay textured soil with poor structural characteristics were investigated in the present study. For this purpose, a total of 36 small plots with a size of 2.4 m2 were created. Cement was applied at 0.25-0.5-1 and 2% doses to 18 plots in the fall period, and to the other 18 plots in the spring period. After the treatment, soil samples were taken for analysis before the planting period and the number of seedling emergence was determined by planting the bean plant during the planting period. According to the results of the study, it was found that cement applied in two periods caused an increase in soil aggregate stability, decreased penetration resistance, modulus of rupture, and dispersion rate, and increased water holding capacity to a limited extent. On the other hand, cement application also had positive impacts on the emergence of the bean plant. The 1% dose of the spring application of cement was more effective on the determined soil structural characteristics and seedling emergence.

The role of supplemental lighting during late fall and winter on photosynthetic and non-photosynthetic pigments biosynthesis of cut rose flower (Rosa hybrida cv. ‘Dolce Vita’)

ABSTRACT Low levels of natural light within the late fall and winter periods are main restricting factors for greenhouse-cut rose flower production in northern countries. Here, the effects of supplemental lighting on photosynthetic and non-photosynthetic pigments and the morphological response of cut rose flower cv. ‘Dolce Vita’ were investigated. Four different supplemental lighting regimes, including 85, 170, 255, and 340 μmol·m−2·s−1 PPFD using a high-pressure sodium lamp for a six-hour day extension started at sunset were applied to rose plants during late fall and winter. With increasing light intensity to 255 μmol·m−2·s−1 PPFD, the content of chlorophyll a, total chlorophyll, carotenoid content, and the ratio of chlorophylls a/b as well as amount of anthocyanins greatly improved. The highest phenol content and total antioxidant capacity was observed in 170 μmol·m−2·s−1 PPFD. Moreover, extending of daylength by light intensity of 255 μmol·m−2·s−1 PPFD had a significant affirmative effect on traits of growth, including flower stem length (P < 0.01), leaf number (P < 0.05), renewal bud formation (P < 0.05), time of harvesting (P < 0.05), and vase life of cut flowers (P < 0.01). Considering physiological and morphological improvement, extending of daylength from 10-h to 16-h by supplemental light of 255 μmol·m−2·s−1 PPFD would be the best choice to cultivate cut rose flower cv. ‘Dolce Vita’.

Long Range (LoRa) and Alert Network System for Forest Fire Prediction

Forest fires are a regular occurrence throughout the year with an increasing intensity in the summer and fall periods. Forest fires pose a significant threat to ecosystems, property and human lives. Early detection and rapid response are critical to mitigate the devastating effects of these fires. This article presents a Long Range (LoRa) Alert Network System designed for the early prediction and timely notification of forest fires. The system leverages LoRa technology to create a robust and cost-effective wireless communication network in remote forested areas. These fires primarily stem from various natural and environmental phenomena and natural disasters. The timely dissemination of forest fire alerts was hampered, resulting in delays in fire management. In order to address this issue, efforts were made to enhance the capability for prompt forest fire detection. The challenges predominantly revolve around forested regions where data communication infrastructure is deficient. In the event of a forest fire, there exists a network barrier that impedes information transmission. Consequently, forest fire detection systems leveraging Mesh LoRa networks and image processing networks have been devised. An integrated module within the LoRa/GPS HAT has been explored as a potential solution to the fire predicament. The Flame Sensor Module, functioning as a fire detection sensor component, and the LoRa/GPS HAT, serving as a hardware medium for radio frequency data transmission communication, have been employed. The interconnection of these devices within a network facilitates the development of a prototype fire detection system. Combining a Flame Sensor Module with a LoRa/GPS HAT is indeed a viable approach to creating a prototype fire detection and alert system. By combining the Flame Sensor Module with the LoRa/GPS HAT, a scalable and cost-effective fire detection and alert system appropriate for distant and wooded locations with limited traditional communication infrastructure is created. This system can play a crucial role in early fire detection, potentially reducing the severity of forest fires and protecting both natural resources and human lives.

Distribution of Living Benthic Foraminifera in the Baffin Bay and Nares Strait in the Summer and Fall Periods: Relation with Environmental Parameters

Arctic climate warming leads to drastic changes in sea ice dynamics, hence impacting primary productivity but also the benthic communities. Therefore, to assess the response of living benthic foraminifera to contrasting Arctic environments, surface sediments from nine stations were collected during the summer of 2014 and fall of 2015 in the Baffin Bay and Nares Strait. Living standing stock are systematically low in the eastern and western Baffin Bay and much higher in the North Water Polynya and the Kane Basin located at the entrance and in the center of Nares Strait, respectively. High living benthic foraminiferal densities in the NOW reflect higher TOC while the highest density in the Kane Basin coincides with lower TOC but higher C/N and higher δ13Corg. The contribution of agglutinated species is on average very high for the whole study area and dominated by the species Adercotryma glomeratum, Lagenammina arenulata, and Reophax scorpiurus. Calcareous species, dominated by Nonionellina labradorica and Melonis barleeanus, are more abundant in the North Water Polynya and the Kane Basin. The very high living standing stock observed in the Kane Basin might be related to the northern position of the ice arch that summer during 2014 and therefore a particularly scarce sea ice cover might have allowed massive phytoplankton production during that season. In this study, the distribution of living benthic foraminifera is discussed according to several environmental parameters such as water masses, phytoplankton productivity, and organic matter fluxes.

Hot stops: timing, pathways, and habitat selection of migrating eastern whip‐poor‐wills

Although miniaturized data loggers allow new insights into avian migration, incomplete knowledge of basic patterns persists, especially for nightjars. Using GPS data loggers, this study examined migration ecology of the eastern whip‐poor‐will Antrostomus vociferus, across three migration strategies: flyover, short‐stay, and long‐stay. We documented migration movements, conducted hotspot analyses, quantified land cover within 1 and 5 km buffers at used and available locations, and modeled habitat selection during migration. From 2018–2020 we captured breeding whip‐poor‐wills from three study sites in Massachusetts and programmed GPS tags to collect data during fall and spring migration periods. Across 19 individual males (nine of them with repeated years of data), GPS tags collected 479 locations, where 30% were classified as flyover points, 33% as short‐stays, and 37% as long‐stay locations. We documented seasonal flexibility in migration duration, routes, and stopover locations among individuals and between years. Analyses identified hotspot clusters in fall and spring migration in the Sierra de Tamaulipas in Mexico. Land cover at used locations differed across location types at the 5 km scale, where closed forest cover increased and crop cover decreased for flyover, short‐stay, and long‐stay locations, and urban cover was lowest at long‐stay locations. Discrete choice modeling indicated that habitat selection by migrating whip‐poor‐wills differs depending on the scale and migration strategy. For example, at the 5 km scale birds avoided urban cover at long‐stay locations and selected closed forest cover at short‐stay locations. We suggest that whip‐poor‐wills may use land cover cues at large spatial scales, like 5 km, to influence rush or stay tactics during migration.

Acoustic Characterization around the CalWave Wave Energy Converter

Sound generated by marine energy (ME) installations in the ocean environment remains a particular concern for environmental permitting despite the limited evidence showing low levels of ME sounds relative to other anthropogenic sounds. In an effort to increase understanding of potential environmental effects of marine energy projects and help reduce barriers to marine energy deployments, a new acoustic monitoring technology, the NoiseSpotter®, was developed and recently demonstrated around CalWave’s operational scaled xWave™ wave energy converter (WEC). The NoiseSpotter® improves upon traditional acoustic sensing techniques by use of a cost-effective, compact array of acoustic particle velocity sensors that characterizes, classifies, and provides accurate location information for anthropogenic and natural sounds in real time. Results are presented from co-deployments of NoiseSpotter® with the operational CalWave WEC that were conducted over a 9-day period in fall 2021 offshore of Scripps Research Pier in San Diego, California, USA. The multi-day deployment of the NoiseSpotter® at 100 m from the CalWave WEC revealed a rich library of sounds that include: Low-level (~95 dB re 1 µPa relative to an ambient noise floor between 80-90 dB re 1 µPa) sounds from the WEC associated with the deliberate actuation of mechanical components, Sounds from a hovering helicopter, Marine mammal vocalizations, and, Small boat engines. Sound levels from the WEC were placed within the context of ambient sounds, and reveal little deviation from the ambient soundscape. The azimuthal anisotropy of WEC sound was investigated via deployments along four cardinal directions around the WEC. While a noticeable increase was observed along the north-south orientation, the sound levels along all directions still showed little deviation relative to the ambient noise floor. Analysis of low-level WEC sounds in conjunction with exploratory machine learning techniques demonstrate the utility of directional acoustic sensing in distinguishing marine energy sounds from the myriad other sounds in the surrounding ocean environment.

Investigation of water-soil-plant relationships based on hazardous and macro-micro element concentrations on Orontes River, Türkiye

Arundo donax and Phragmites australis were examined in 4 different periods (June and October for 2 years), heavy metal and mineral element accumulations in plants were evaluated, and water-soil-plant relationships were revealed. Element distributions, bioaccumulation factors (BAF) and translocation factors (TF) in different parts of the investigated plant species were also determined. BAFs of elements calculated by using the concentration values in underground parts and sediment samples were between 1.02 and 4.96. While the highest TF was determined as 8.07 for Zn between washed leaf and stem in A. donax, the lowest TF was determined as 0.05 for Fe between stem and underground part. Corresponding highest and lowest TFs for P. australis were 11.80 for Cu between washed leaf and stem, and 0.02 for Fe between stem and underground part, respectively. The results were supported by MANOVA statistical analyzes. Additionally, the macro-micro elements and heavy metal accumulation levels in the parts of the Orontes River ecosystem were significantly higher in the fall periods compared to the spring periods. Our research revealed that the versatile accumulation properties and high accumulation ability of A. donax for Cd, Cr, and Ni and of P. australis for Cd, Co, Cu, Ni, Pb, and Zn.

Utility of daily 3 m Planet Fusion Surface Reflectance data for tillage practice mapping with deep learning

Tillage practices alter soil surface structure that can be potentially captured by satellite images with both high spatial and temporal resolution. This study explored tillage practice mapping using the daily Planet Fusion surface reflectance (PF-SR) gap-free 3 m data generated by fusing PlanetScope with Landsat-8, Sentinel-2 and MODIS surface reflectance data. The study area is a 220 × 220 km2 agricultural area in South Dakota, USA, and the study used 3285 PF-SR images from September 1, 2020 to August 31, 2021. The PF-SR images for the surveyed 433 fields were sliced into 10,747 training (70%) and evaluation (30%) non-overlapping time series patches. The training and evaluation patches were from different fields for evaluation data independence. The performance of four deep learning models (i.e., 2D convolutional neural networks (CNN), 3D CNN, CNN-Long short-term memory (LSTM), and attention CNN-LSTM) in tillage practice mapping, as well as their sensitivity to different spatial (i.e., 3 m, 24 m, and 96 m) and temporal resolutions (16-day, 8-day, 4-day, 2-day and 1-day) were examined. Classification accuracy continuously increased with increases in both temporal and spatial resolutions. The optimal models (3D CNN and attention CNN-LSTM) achieved ∼77% accuracy using 2-day or daily 3 m resolution data as opposed to ∼72% accuracy using 16-day 3 m resolution data or daily 24 m resolution data. This study also analyzed the feature importance of different acquisition dates for the two optimal models. The 3D CNN model feature importances were found to agree well with the tillage practice time. High feature importance was associated with observations during the fall and spring tillage period (i.e., fresh tillage signals) whereas the crop peak growing period (i.e., tillage signals weathered and confounded by dense canopy) was characterized by a relatively low feature importance. The work provides valuable insights into the utility of deep learning for tillage mapping and change event time identification based on high resolution imagery.

Nunataryuk field campaigns: understanding the origin and fate of terrestrial organic matter in the coastal waters of the Mackenzie Delta region

Abstract. Climate warming and related drivers of soil thermal change in the Arctic are expected to modify the distribution and dynamics of carbon contained in perennially frozen grounds. Thawing of permafrost in the Mackenzie River watershed of northwestern Canada, coupled with increases in river discharge and coastal erosion, triggers the release of terrestrial organic matter (OMt) from the largest Arctic drainage basin in North America into the Arctic Ocean. While this process is ongoing and its rate is accelerating, the fate of the newly mobilized organic matter as it transits from the watershed through the delta and into the marine system remains poorly understood. In the framework of the European Horizon 2020 Nunataryuk programme, and as part of the Work Package 4 (WP4) Coastal Waters theme, four field expeditions were conducted in the Mackenzie Delta region and southern Beaufort Sea from April to September 2019. The temporal sampling design allowed the survey of ambient conditions in the coastal waters under full ice cover prior to the spring freshet, during ice breakup in summer, and anterior to the freeze-up period in fall. To capture the fluvial–marine transition zone, and with distinct challenges related to shallow waters and changing seasonal and meteorological conditions, the field sampling was conducted in close partnership with members of the communities of Aklavik, Inuvik and Tuktoyaktuk, using several platforms, namely helicopters, snowmobiles, and small boats. Water column profiles of physical and optical variables were measured in situ, while surface water, groundwater, and sediment samples were collected and preserved for the determination of the composition and sources of OMt, including particulate and dissolved organic carbon (POC and DOC), and colored dissolved organic matter (CDOM), as well as a suite of physical, chemical, and biological variables. Here we present an overview of the standardized datasets, including hydrographic profiles, remote sensing reflectance, temperature and salinity, particle absorption, nutrients, dissolved organic carbon, particulate organic carbon, particulate organic nitrogen, CDOM absorption, fluorescent dissolved organic matter intensity, suspended particulate matter, total particulate carbon, total particulate nitrogen, stable water isotopes, radon in water, bacterial abundance, and a string of phytoplankton pigments including total chlorophyll. Datasets and related metadata can be found in Juhls et al. (2021) (https://doi.org/10.1594/PANGAEA.937587).

Effects of Climate Change on Navigability Indicators of the Lower Athabasca River, Canada

The lower Athabasca River (Canada) has experienced notable declines in streamflow and increasing oil sands development since the 1970s. This study investigates the potential impacts of climate change on navigability using both observed historical and projected future flows derived via hydrological simulations driven by an ensemble of statistically downscaled general circulation model climate data. Our use of proposed indices that form the Aboriginal Navigation Index (ANI) and a new index based on percentage over threshold (POT) occurrences yielded novel insights into anticipated changes to the flow regime. Comparisons of near (2041–2070) and far (2071–2100) future periods with the historical baseline (1981–2010) yielded results that project significant reductions in the 500 m3 s−1 POT during the fall navigability period spanning weeks 34 to 43, as well as reductions in the integrated ANIFall. These results indicate that challenging navigational conditions may become more frequent in the second half of the 21st century, not only during this fall period but also earlier into the summer, due to a shift in the flow regime, with potentially severe impacts on the users of the river channels. Our assessment approach is transferable to other regional study areas and should be considered in water management and environmental flow frameworks.

Six decades of North American bird banding records reveal plasticity in migration phenology.

The timing of avian migration has evolved to exploit critical seasonal resources, yet plasticity within phenological responses may allow adjustments to interannual resource phenology. The diversity of migratory species and changes in underlying resources in response to climate change make it challenging to generalize these relationships. We use bird banding records during spring and fall migration from across North America to examine macroscale phenological responses to interannual fluctuations in temperature and long-term annual trends in phenology. In total, we examine 19 species of North American wood warblers (family Parulidae), summarizing migration timing from 2,826,588 banded birds from 1961 to 2018 across 46 sites during spring and 124 sites during fall. During spring, warmer spring temperatures at banding locations translated to earlier median passage dates for 16 of 19 species, with an average 0.65-day advancement in median passage for every 1°C increase in temperature, ranging from 0.25 to 1.26 days °C-1 . During the fall, relationships were considerably weaker, with only 3 of 19 species showing a relationship with temperature. In those three cases, later departure dates were associated with warmer fall periods. Projecting these trends forward under climate scenarios of temperature change, we forecast continued spring advancements under shared socioeconomic pathways from 2041 to 2060 and 2081 to 2100 and more muted and variable shifts for fall. These results demonstrate the capacity of long-distance migrants to respond to interannual fluctuations in temperatures, at least during the spring, and showcase the potential of North American bird banding data understanding phenological trends across a wide diversity of avian species.

The influence of conditions in Lake Superior and the Bois Brule River, Wisconsin on returns of migratory rainbow trout

Rainbow trout were introduced to Lake Superior in the late 1800’s and exhibit a potamodromous life history and exhibit high variability in reproductive success. We examined reproductive variability in the Bois Brule River, WI (Lake Superior), through analyses of returns of wild first spawning (hereafter “maiden” returning) adults. We used classification and regression tree analyses to identify in-stream and in-lake (western Lake Superior) sources of variability and to identify the environment (stream or lake) that was most influential to the returns to each location. Among in-stream influences, high discharge rates in the spring period (March – May) during a pre-smolt’s first stream year were the strongest source of variability and were negatively correlated with returns. High discharge during the fall period from September to November in the pre-smolt first stream year was also negatively correlated with numbers of maiden returning steelhead from that year class. When variables associated with Lake Superior were considered, maiden returns were positively correlated with higher lake surface temperatures in Lake Superior. Returns were negatively correlated with the abundance of adult rainbow smelt and bloater suggesting a possible competitive interaction among those species. Finally, we also observed a conditional (minor) positive effect of age-0 smelt abundance indicating the importance of this prey for juveniles in colder years in western Lake Superior. Taken together, our findings indicate that both streamand lake conditionsin their first lake year are important sources of variability and point to spates in the spring and fall as initialcontrolling variables.

Contrasting effects of an extended fall period and winter heatwaves on the overwintering fitness of diapausing disease vector, Aedes albopictus

Climate change is expected to dramatically alter autumnal and winter conditions in many temperate regions. However, limited data is available to accurately predict how these changes will impact species’ overwinter survival and post-winter fitness. Here, we determine how a longer, warmer fall period and winter heatwaves affect overwintering fitness and post-winter performance of the invasive mosquito vector, Aedes albopictus. We found that a longer, warmer fall period representative of early entry into diapause did not affect overwinter survival but did lead to reduced post-winter performance for multiple traits. Specifically, larvae that experienced longer, warmer fall conditions as diapause embryos exhibited reduced post-diapause larval starvation tolerance, increased post-diapause larval mortality, and longer post-diapause larval development compared to individuals from the short-fall treatments. These negative post-diapause fitness effects likely resulted from the greater energetic demands and/or damage incurred during the warmer, longer fall period. In contrast, exposure to winter heatwaves increased overwinter survival, possibly by allowing diapausing embryos to escape or repair cold injury. Finally, fall treatment and winter heatwaves had an interactive effect on male development time, while neither treatment impacted pupal mass in either sex. Overall, our results highlight that experiments that fail to measure post-diapause fitness are likely to substantially under-estimate the impacts of climate change on post-winter performance. Additionally, our results emphasize that it is crucial to consider the potentially conflicting effects of different aspects of climate change on a species’ overall overwintering success.