Late Summer Season Research Articles

Density estimations of the Asiatic black bear: application of the random encounter model

ABSTRACT It is difficult to assess the population status of large terrestrial carnivores due to their low density. Recently adopted camera-trap techniques allow us to investigate many aspects of animal ecology and conservation and are widely used in wildlife population estimation. In this study, we applied the random encounter model (REM) to estimate the density of Asiatic black bears (Ursus thibetanus) in Shirakawa Village, Gifu Prefecture, Japan, from May to October 2018. We installed 24 sensor cameras in the study area. Movement speeds of seven global positioning system (GPS)-collared bears were tracked from 2008 to 2018. The population density of bears in Shirakawa Village was estimated to be 0.55 bears/km2. To apply the REM method to Asiatic black bears, we recommend (1) installing more than 30 or 40 sensor cameras and implementing the REM method in a period of 3 weeks before the late summer season (i.e. late August), after the completion of the hibernation period and when a closed population is easily maintained; and (2) correcting the distance moved by the target animal species when using GPS telemetry with a low fixed interval.

Water Vapor on Mars: A Refined Climatology and Constraints on the Near‐Surface Concentration Enabled by Synergistic Retrievals

AbstractWith the utilization of a novel synergistic approach, we constrain the vertical distribution of water vapor on Mars with measurements from nadir‐pointing instruments. Water vapor column abundances were retrieved simultaneously with PFS (sensing the thermal infrared range) and SPICAM (sensing the near‐infrared range) on Mars Express, yielding distinct yet complementary sensitivity to different parts of the atmospheric column. We show that by exploiting a spectral synergy retrieval approach, we obtain more accurate water vapor column abundances compared to when only one instrument is used, providing a new and highly robust reference climatology from Mars Express. We present a composite global data set covering all seasons and latitudes, assembled from colocated observations sampled from seven Martian years. The synergy also offers a way to study the vertical partitioning of water, which has remained out of the scope of nadir observations made by single instruments covering a single spectral interval. Special attention is given to the north polar region, with extra focus on the sublimation of the seasonal polar cap during the late spring and summer seasons. Column abundances from the Mars Climate Database were found to be significantly higher than synergistically retrieved values, especially in the summer Northern Hemisphere. Deviations between synergy and model in both magnitude and meridional variation of the vertical confinement were also discovered, suggesting that certain aspects of the transport and dynamics of water vapor are not fully captured by current models.

Species composition, structure and biomass of zooplankton in the Chukchi Sea in August-September 2019

Plankton survey was conducted in the Chukchi Sea in August-September 2019 by two research vessels: RV Professor Levanidov in the western part of the sea and RV Ocean Starr in its eastern part. Parasagitta elegans dominated everywhere in zooplankton. Beside these arrowworms, species of the arctic and arctic-boreal complex were abundant in the northwestern Chukchi Sea, as Calanus glacialis and other species typical for the adjacent East-Siberian Sea. C. glacialis was numerous in the northeastern Chukchi Sea, too, together with species of the Arctic waters and the Beaufort Sea. The southern Chukchi Sea was occupied by the waters invaded from the Bering Sea, so species of the Bering Sea complex were abundant there, as Eucalanus bungii and Neocalanus plumchrus/flemingeri, at Alaska coast together with neritic species typical for the Alaska coastal water mass. The zooplankton community structure corresponded to the spring phase of seasonal succession in the northern area, whereas to the summer phase in the southern area. Total density of zooplankton was estimated as 65 t/km2 for the northwestern part of the sea, presented mostly by large-sized fraction (56 t/km2) including arrowworms (35 t/km2) and copepods (13 t/km2), and as 48 t/km2 for the southwestern part of the sea, also mostly large-sized fraction (40 t/km2). So high zooplankton density in the western Chukchi Sea is considered as result of the Bering Sea waters advection (previously such abundance was observed in 2008 — 40 and 36 t/km2, when the advection was also active). In the eastern Chukchi Sea, the total density of zooplankton was 44 t/km2 in the northeastern area (including 29 t/km2 of large-sized fraction) and 43 t/km2 in the southeastern area, that was higher than in 2017 (15 t/km2) but lower than in 2007 (49 t/km2). However, different phases of seasonal succession should be noted: summer season in 2019, spring season in 2017, and late-summer season in 2007.

Artificial selection for predatory behaviour results in dietary niche differentiation in an omnivorous mammal.

The diet of an individual is a result of the availability of dietary items and the individual's foraging skills and preferences. Behavioural differences may thus influence diet variation, but the evolvability of diet choice through behavioural evolution has not been studied. We used experimental evolution combined with a field enclosure experiment to test whether behavioural selection leads to dietary divergence. We analysed the individual dietary niche via stable isotope ratios of nitrogen (δ15N) and carbon (δ13C) in the hair of an omnivorous mammal, the bank vole, from four lines selected for predatory behaviour and four unselected control lines. Predatory voles had higher hair δ15N values than control voles, supporting our hypothesis that predatory voles would consume a higher trophic level diet (more animal versus plant foods). This difference was significant in the early but not the late summer season. The δ13C values also indicated a seasonal change in the consumed plant matter and a difference in food sources among selection lines in the early summer. These results imply that environmental factors interact with evolved behavioural tendencies to determine dietary niche heterogeneity. Behavioural selection thus has potential to contribute to the evolution of diet choice and ultimately the species' ecological niche breadth.

Fungal contamination of indoor public swimming pools and their dominant physical and chemical properties

SummaryIntroductionConsidering the existence of both parasitic and fungal pathogens in the indoor public swimming pools and non-utilization of suitable filtration and disinfection systems in these places, this research aimed to determine the relationship between the indoor public swimming pools and possible pollution with parasitic and fungal agents, as well as physical and chemical characteristics of these pools and compare the results with national standards.MethodsIn this study, 11 active indoor swimming pools of Zahedan city were sampled, using plastic pump techniques, from the middle of winter to the late summer season. A total of 88 water samples (eight water samples from each pool) were examined to determine the residual chlorine, contamination with parasitic and fungal agents, using culture media and slide culture techniques. Results were analyzed with SPSS software (V16) and, Microsoft Excel (V2010).ResultsThe findings revealed fungal contamination with Cladosporium, Penicillium, Aspergillus flavus and Aspergillus fumigatus, etc. and the physicochemical factors comply with the minimum standards, which indicates the need for continuous monitoring and control of water filtration and disinfection of water in the pools.ConclusionThe results show reasonable derangement of physicochemical and microbial factors of the evaluated pools. Efforts shall be made by the concerned authorities to provide health education to users, quality water at the pools and to maintain the safety and quality of the water through proper and adequate chlorination.

Assessing the outdoor thermal comfort conditions of exercising people in the semi-arid region of India

● Field surveys were conducted for people exercising outdoor. ● Calibrated the ranges of thermal comfort indices for BSh climate ● Various ranges of microclimate parameters and thermal indices were determined. The present study investigated the thermal perceptions of people exercising outdoor during the late summer and monsoon season in the hot semi-arid region of India. The field surveys were conducted in parallel with onsite monitoring of microclimate parameters. Thermal comfort indices-Wet Bulb Globe Temperature (WBGT), Physiological equivalent temperature (PET), and Universal Thermal Climate Index (UTCI) were applied to explore the outdoor thermal comfort conditions. The neutral temperature range of people exercising was found to be 23.8-28.1°C in WBGT,26-36.4°C for PET, and 27.7-35.7°C in UTCI. It was observed that with a unit change in Mean thermal sensation votes, there was an approximately 4°C increase in dry bulb temperature; wind speed increased by 1.24 m/s; mean radiant temperature was reported to rise by 25°C. Calibration of thermal stress categories of applied indices demonstrated that all the training should be stopped when WBGT ≥40.8°C, PET ≥67.3°C, and UTCI ≥ 59.2°C. In pleasant weather conditions, the median value of T a , RH, W s , T g , T mrt , WBGT, PET, UTCI were 29°C,67.2%,0.9m/s,29.2°C,27.4°C,25.6°C,28.1°C,30.3°C respectively. The findings could be helpful in developing the sports stadium or places dedicated to exercise and preparing schedules of the sports events in the arid regions to avoid overexposure in the hot thermal environment.

Post-Thaw Quality of Beetal Goat Sperm Cryopreserved During Late Summer and Winter Seasons

Post-Thaw Quality of Beetal Goat Sperm Cryopreserved During Late Summer and Winter Seasons

Vertical Distribution of Phytoplankton Community and Pigment Production in the Yellow Sea and the East China Sea during the Late Summer Season

Phytoplankton community structure, which plays an important role in determining productivity and food web structure, can provide important information for understanding variations in marine ecosystems under projected climate change scenarios. Rising temperatures due to climate change will increase and intensify water stratification. To understand the community composition and distribution characteristics of phytoplankton under stratified conditions, phytoplankton pigments were analyzed in the Yellow Sea (YS) and East China Sea (ECS) during the late summer season. In addition, pigment production was measured to estimate the physiological characteristics of phytoplankton relating to light, which is an essential element of photosynthesis. During our observation period, no distinct differences were found in the community composition and pigment production of phytoplankton in the YS and the ECS, but differences in the vertical distribution were observed. Overall, the dominant phytoplankton classes at the surface depth were pico-sized cyanobacteria (46.1%), whereas micro- and nano-sized diatoms (42.9%) were the abundant most classes at a 1% light depth. The major factors controlling the vertical distributions of the phytoplankton community were temperature and nutrients (i.e., nitrate and ammonium). Cyanobacteria were positively correlated with water temperature and ammonium, whereas diatoms were negatively related to water temperature and positively correlated with nitrates. Based on the pigment production, it was found that cyanobacteria at the surface layer encountered excessive irradiance conditions during the study period. The productivity of the cyanobacterial community could be decreased under high-light and high-temperature conditions. This means that cyanobacteria could have a negative influence on the quantity and quality of food available to upper trophic organisms under warmer conditions.

Species-specific biomass and carbon flux in Sundarbans mangrove forest, Bangladesh: Response to stand and weather variables

The species-specific potentiality of mangroves in terms of ecosystem services is not well understood. Therefore, this study addressed the carbon sequestration and litterfall production potentiality of six major species in Sundarbans, Bangladesh, by evaluating three consecutive years of inventory data, including the stand variables and weather events impacts on them. The total mean aboveground, belowground biomass, biomass accumulation, and carbon accumulation rate were 243.4 Mg ha−1, 132.2 Mg ha−1, and 14.3 Mg ha−1 yr−1, 7.2 Mg ha−1 yr−1, respectively. Carbon stocks and sequestration rates are significantly influenced by stand variables such as diameter, density, and species composition. Large-sized trees and stands with lower density sequester more carbon than small-sized trees, and higher density stands. Among species, Avicennia officinalis contributed higher carbon to carbon stocks and also significantly different from other species for sequestering carbon, whereas Aglaia cucullata was the lowest. Mean annual litterfall was 10.01 Mg ha−1 yr−1, with the maximum litterfall for Hereteira fomes (19.2 Mg ha−1 yr−1) during the late summer or wet season (e.g., April to August). Litterfall showed a significant positive (p < 0.001) relation to weather variables such as rainfall, temperature, wind, etc. This study reports that the rate of carbon sequestration in Sundarbans was 17.21 Mg C ha−1 yr−1, which corresponds to 62.6 Mg ha−1 yr−1 CO2. High carbon stocks, carbon sequestration, and litterfall production rate in Sundarbans demonstrate the significance of mangrove species and Sundarbans in the global carbon budget. This information can be used in species selection for plantation, species conservation, and ecosystem management purposes at the regional and global levels.

Seasonal variation in larval growth of Eri silkworm (Samia ricini Boisduval) reared on two Ailanthus species

Present study was undertaken to evaluate the impact of different seasons in larval growth of eri silkworm (Samia ricini Boisduval) reared on Ailanthus species viz., borpat (Ailanthus grandis) and borkesseru (Ailanthus excelsa). The study revealed that the larval growth parameters of eri silkworm was found better in terms of larval duration, full grown larval weight and matured larval weight on the borpat leaves as compared to the borkesseru leaves. Considering the seasons, the full grown larval weight and matured larval weight were observed significantly higher during the autumn season but the shortest larval duration was observed during the late summer season.

Widespread surface waterpCO2 undersaturation during ice-melt season in an Arctic continental shelf sea (Hudson Bay, Canada)

Estimating sea–air CO2 fluxes in coastal seas remains a source of uncertainty in global carbon budgets because processes like primary production, upwelling, water mixing, and freshwater inputs produce high spatial and temporal variability of CO2 partial pressure (pCO2). As a result, improving our pCO2 baseline observations in these regions is important, especially in sub-Arctic and Arctic seas that are experiencing strong impacts of climate change. Here, we show the patterns and main processes controlling seawater pCO2 and sea–air CO2 fluxes in Hudson Bay during the 2018 spring and early summer seasons. We observed spatially limited pCO2 supersaturation (relative to the atmosphere) near river mouths and beneath sea ice and widespread undersaturated pCO2 in offshore and ice-melt-influenced waters. pCO2 was highly correlated with salinity and temperature, with a limited but statistically significant relationship with chlorophyll a and fluorescent dissolved organic matter. Hudson Bay on average was undersaturated with respect to atmospheric CO2, which we attribute mainly to the dominance of sea-ice meltwater. We calculated an average net CO2 flux of about –5mmol CO2 m–2 day–1 (–3.3 Tg C) during the spring and early summer seasons (92 days). Combining this result with extrapolated estimates for late summer and fall seasons, we estimate the annual CO2 flux of Hudson Bay during the open water season (184 days) to be –7.2 Tg C. Our findings indicate that the bay on average is a weaker CO2 sink than most other Arctic seas, emphasizing the importance of properly accounting for seasonal variability in the Arctic coastal shelves to obtain reliable sea–air CO2 exchange budgets.

Assessing the frequency of drought/flood severity in the Luvuvhu River catchment, Limpopo Province, South Africa

The Luvuvhu River catchment experiences rainfall variability with a high frequency of extremely dry and wet conditions. Understanding the frequency of drought and floods in this catchment area is important to the agriculture sector for managing the negative impacts of these natural hazards. This study was undertaken to investigate the frequency and severity of drought/floods and linkages with the El Niño Southern Oscillation (ENSO) phenomenon. Poor and resource-limited small-scale farmers in the Luvuvhu River catchment area struggle to adjust due to decreasing crop yields and livestock mortality caused by drought and floods. Monthly rainfall data from 15 grid points (0.5° × 0.5°) was used to compute the Standardised Precipitation Index (SPI) for the period between 1979 and 2016. The 3-month SPI was calculated for the December–January–February (DJF) period. The second half of the agricultural season was selected because the influence of ENSO is high during the late summer season (DJF) in the catchment. The SPI results indicate that the agricultural seasons 1982/83, 1991/92 and 2015/16 were characterised by extreme drought. Conversely, the SPI values also show that the wettest seasons were recorded in 1998/99 and 1999/00. The catchment experiences a high frequency of moderate to severe drought in the north and north-eastern parts. Spatially, the occurrence of moderate to severe dry conditions covers large areas in the north and south-western parts. Severe to extreme wet conditions cover large areas in the north and south-eastern parts of the catchment. The SST index (Niño 3.4) shows a strong influence on rainfall variability in the catchment, resulting in either dry or wet conditions. Therefore, this study recommends further research focusing on more climatic modes that influence rainfall variability, as well as further development of drought and flood forecasting to improve farmers’ adaptations options and reliability of weather forecasts used as a tool to manage crop production.

Verification of paleo reconstructions of climatic conditions of the Late Pleistocene summer seasons based on palynological analysis of Yedoma deposits and ice wedges

The object of this research is the reconstruction of the climatic conditions of the Late Pleistocene summer seasons based on the pollen spectra of syngenetic ice wedges and inclosing Yedoma deposits. For quantitative assessment of summer temperatures and phenological relationships, the author applies the total annual thaw index, since namely the sum of positive temperatures is the only indicator that determines the beginning of pollen emission in majority of plant species. The relationship between the composition of pollen spectra and the total annual thaw index is deterministic, although it cannot be formulated strictly mathematically. Yedoma is a unique object for research by many parameters, which allows acquiring paleogeographic information on two components, such as ice wedges and deposits, because the accumulation of pollen and spores occurs differently therein. The structure of vegetation cover during the accumulation of Yedoma deposits during the Late Pleistocene differed significantly from the Holocene and modern periods, which is recorded in the pollen spectra of syngenetic deposits and ice wedges. It is established that in certain periods, the diversity of species of Late Pleistocene vegetation was higher compared to modern vegetation of tundra and forest tundra due to the large number of ecological niches and peculiarity of temperature regime of the summer season.

Effect of Foliar Spray with Some Growth Stimulants on Growth and Productivity of Some Varieties of Tomato Grown In the Late Summer Seasons

Effect of Foliar Spray with Some Growth Stimulants on Growth and Productivity of Some Varieties of Tomato Grown In the Late Summer Seasons

Big bats binge bad bugs: Variation in crop pest consumption by common bat species

As generalist predators, insectivorous bats exploit fluctuations in prey distribution and abundance. A more nuanced understanding of the influence of bats on arthropod pests requires documentation of the pest species bats consume and of the conditions associated with variation in rates of pest consumption. Here, we used high-throughput metabarcoding of DNA extracted from bat feces to investigate diets of 180 bats representing three Vespertilionidae species common to the southeastern US, a region dominated by agriculture and pine plantations. We detected 23 species of agricultural pests in bat diets, including pests responsible for severe economic damage, such as Helicoverpa zea, Spodoptera frugiperda, Chloridea virescens and Chrysodeixis includens. Incidence of pest consumption was high: 61% of all bats had consumed at least one agricultural pest species, with each bat consuming an average of 1.7 pest species. The likelihood of consumption of pests to row crops and the average size of pests consumed varied by bat species, with a large foliage-roosting species (Lasiurus seminolus) consuming a greater variety of pest species and pest species larger in size than smaller crevice, cavity, and cave roosting bat species (Nycticeus humeralis, Myotis austroriparius). Likelihood of pest consumption also varied among sampling periods (season) and among bats of different sizes (as reflected by wing length and mass). Overall, likelihood of pest consumption was higher in the late summer season than during spring or early summer, and higher among larger bats than smaller bats. Bat characteristics and seasonality were generally more effective than geographic features and weather conditions in predicting pest consumption patterns. Strategies for enhancing pest consumption services by bats in agroecosystems should strive to maintain and enhance diverse bat populations on a landscape scale by protecting and augmenting roost structures appropriate for each species. Our finding of widespread pest consumption by bats contributes to mounting evidence worldwide of the important role bats play in agricultural systems and highlights the value of incorporating bat conservation into integrated pest management programs globally.

Seasonal effects of altered precipitation regimes on ecosystem-level CO2 fluxes and their drivers in a grassland from Eastern Australia

We evaluated the impacts of altered precipitation regimes on multiple aspects of the C cycle, including C fluxes, plant and soil microbial communities, and plant-soil interactions in a south-eastern Australian grassland. Our experimental treatments, operated through an automated system, included: (i) reduced and (ii) increased rainfall amount by 50%, (iii) reduced rainfall frequency but no change in amount (i.e., more extreme downpours), (iv) and an extreme summer drought. Temporal dynamics of ecosystem-level CO2 fluxes fluctuated seasonally and were driven by variations in soil water availability, soil temperature and photosynthetically active radiation. Reducing the frequency of rainfall events, but without change in the amount of rainfall, resulted in lower ecosystem-level net CO2 uptake due to relatively greater Reco stimulation after the heavy downpours, particularly during the late summer season. The extreme summer drought downregulated both respiration and photosynthesis. Microbial abundance and activity did not change in response to rainfall manipulation and were not strongly related to precipitation-driven changes in C cycling. In contrast, a greater proportion of live to dead plant biomass, in turn driven by greater water availability, was a main driver of greater respiration and photosynthesis. Our study suggests that grasslands could shift from net C sinks to C neutral or even net sources of C under future scenarios of more variable rainfall regimes, thus reinforcing climate change.

Modeling the Impacts of Climate Change on Crop Yield and Irrigation in the Monocacy River Watershed, USA

Crop yield depends on multiple factors, including climate conditions, soil characteristics, and available water. The objective of this study was to evaluate the impact of projected temperature and precipitation changes on crop yields in the Monocacy River Watershed in the Mid-Atlantic United States based on climate change scenarios. The Soil and Water Assessment Tool (SWAT) was applied to simulate watershed hydrology and crop yield. To evaluate the effect of future climate projections, four global climate models (GCMs) and three representative concentration pathways (RCP 4.5, 6, and 8.5) were used in the SWAT model. According to all GCMs and RCPs, a warmer climate with a wetter Autumn and Spring and a drier late Summer season is anticipated by mid and late century in this region. To evaluate future management strategies, water budget and crop yields were assessed for two scenarios: current rainfed and adaptive irrigated conditions. Irrigation would improve corn yields during mid-century across all scenarios. However, prolonged irrigation would have a negative impact due to nutrients runoff on both corn and soybean yields compared to rainfed condition. Decision tree analysis indicated that corn and soybean yields are most influenced by soil moisture, temperature, and precipitation as well as the water management practice used (i.e., rainfed or irrigated). The computed values from the SWAT modeling can be used as guidelines for water resource managers in this watershed to plan for projected water shortages and manage crop yields based on projected climate change conditions.

Response of Snap Bean Plants to some Treatments under Temperature Stress Conditions

This work was carried out at the Experimental Farm of El-Baramoon Research Station, Horticulture Research Institute, Agricultural Research Center, Giza, Egypt, during the early winter season of 2017/2018 and 2018/2019 and late summer seasons of 2018 and 2019 to study the effect of soil applications, i.e., seaweed (5 gm/100 L) (feldspar 75 kg/fed.), foliar applications, i.e., chitosan (175 ppm), yeast extract (20 ml/l), proline (50 ppm), salysilic acid (150 ppm), ascorbic acid (200 ppm), potassium silicate (100 ppm), ATP (0.03 gm/l), Royal jelly (0.1 g/l), fulvic acid (0.25 g/l) and citric acid (0.3 g/l). on growth, yield and chemical composition on snap bean cv. Giza 6. The obtained results revealed that, summer season data gave higher value of growth, yield and chemical composition of plants compared with the winter seasons date. Soil addition with seaweed at 5gm/l and spraying chitosan at 175 ppm gave the highest growth, yield and chemical components of bean plants, followed by yeast extract at 20 ml/l, and proline at 50 ppm. Sowing snap bean cv. Giza 6 in 20th May with adding seaweed as a soil at 5 gm/l and spraying with chitosan at 175 ppm introduced the best interaction with respect to growth, yield and chemical composition of plant. From the obtained results it could be recommended that sowing snap bean cv. Giza 6 in 20th May with seaweed extract addition at 5g/100 L. and spraying with chitosan at 175 ppm and/or yeast extract at 20 ml/l, and/or proline at 50 ppm improved growth, yield and chemical composition of snap bean growing at summer season.

Effect of some Treatments to Reduce the Injury of High Temperature on Sweet Pepper Grown in Late Summer Season

Effect of some Treatments to Reduce the Injury of High Temperature on Sweet Pepper Grown in Late Summer Season

Low Abundance of Three Tick Species in the Piedmont of North Carolina.

Multiple species of ticks, including Ixodes scapularis (Say, Ixodida:Ixodidae), Amblyomma americanum (L., Ixodida:Ixodidae), and Dermacentor variabilis (Say, Ixodida:Ixodidae), occur in high and increasing abundance in both the northeast and southeast United States. North Carolina is at the nexus of spread of these species, with high occurrence and abundance of I. scapularis to the north and A. americanum to the south. Despite this, there are few records of these species in the Piedmont of North Carolina, including the greater Charlotte metropolitan area. Here, we update the known occurrence and abundance of these species in the North Carolina Piedmont. We surveyed for ticks using cloth drags, CO2 traps, and leaf litter samples at a total of 79 sites within five locations: Mecklenburg County, South Mountains State Park, Stone Mountain State Park, Duke Forest, and Morrow Mountain State Park, all in North Carolina, during the late spring, summer, and fall seasons of 2019. From these surveys, we had only 20 tick captures, illuminating the surprisingly low abundance of ticks in this region of North Carolina. Our results indicate the possibility of underlying habitat and host factors limiting tick distribution and abundance in the North Carolina Piedmont.