Early Autumn Research Articles

Observation of Abyssal Circulation to the West of the Luzon Strait, South China Sea

Abstract South China Sea (SCS) abyssal circulation largely contributes to water renewal, energy budget, and sedimentary processes in the deep ocean. The three-dimensional abyssal circulation west of the Luzon Strait (LS) in the northern SCS was investigated using an array comprising 27 current- and pressure-recording inverted echo sounders. Over 400 days of measurements from June 2018 to July 2019 showed a narrow and strong (∼70 km, ∼2.3 cm s−1 at 2500 dbar) northward current near the steep eastern boundary, while a wide and weak (∼180 km, ∼1.5 cm s−1 at 2500 dbar) southwestward current lies along the subdued western boundary. The circulation showed conspicuous cyclonic patterns with a volume transport of ∼1.21 ± 0.93 Sv (1 Sv ≡ 106 m3 s−1) and ∼1.59 ± 0.95 Sv below 2500 dbar along the eastern and western boundaries, respectively. The current near the LS was strong in late autumn and early winter but weak in late winter and spring, following the seasonal variation of LS deep-water overflow. However, the southwestward current in the interior SCS was stronger in summer and early autumn but weaker in late winter and early spring. The different seasonal patterns identified near the LS and the interior SCS are attributed to the propagation of seasonal variation. The weak current along the western boundary in August 2018 and February 2019 was dominated by LS deep-water overflow with a time lag of ∼7.5 months. Although eddies in the upper ocean may also contribute to such variation through pressure work, the effect is minor. Significance Statement Cyclonic circulation in the deep South China Sea (SCS) largely contributes to water renewal, energy budget, and sedimentary processes and influences the transport of dissolved elements, minerals, and pollutants. As an important part of the SCS throughflow, an in-depth analysis of the SCS abyssal circulation may also contribute to understanding Indonesian Throughflow and global climate change. The three-dimensional abyssal circulation west of the Luzon Strait was investigated using large-scale data from June 2018 to July 2019, which provided unprecedented coverage of abyssal circulation in the northeast SCS. The study provides important observational evidence for the existence of SCS abyssal cyclonic circulation. Detailed spatiotemporal structure of abyssal circulation and its variations are presented, and related dynamic processes are discussed.

Impact of the Plant-Based Natural Supplement Imмunostart Herb on Honey Bee Colony Performance

Abstract Winter is the season that poses the greatest challenges for honey bee colonies. Therefore, the main approach in beekeeping practice is aimed mainly at providing sufficient quality food supplies for bee colonies in early autumn. We conducted the present study to test the influence of the natural plant extract IMМUNOSTART HERB on population strength, stored pollen area, capped worker brood area, and honey yield. The experimental groups were supplied with IMМUNOSTART HERB 4 times at 7-day intervals, whereas sugar syrup was given to the control groups. The obtained results showed that the applied supplemental diet affected all investigated biological parameters, with the most noticeable effect after the second application. In all measurements, the honey bee colony parameters in the treated groups showed higher values in comparison to the control groups. These results highlight the potential of herbal supplements to effectively improve bee colonies’ development during the period of scarce bee forage, as well as to provide suitable conditions for successful overwintering.

ASSESSMENT OF THE SUCCESS OF MICRO GRAFTING CLEMENTINE TIMING ON SOUR ORANGE

This study was carried out at three locations (Laboratory of Plant Tissue Culture, Fields of the College of Agriculture, University of Diyala and one of the private nursery at the city of Baqubah. The applied experiments included two separate experiments on the scion Mandarin Clementine micro grafted on Sour orange rootstock. The first micro grafting experiment aimed to develop a method of vegetative propagation of Clementine and transferring the micro grafts from a laboratory to the field and comparing grafting dates (spring, early autumn, late autumn) with the laboratory grafting after treating grafting region with different concentrations of gibberellin (0, 0.3 or 0.4 mg. L-1). The effect of grafting dates on the percentages of success of grafted plants after one month of acclimatization. The experiment was carried out according to completely randomized design (CRD) as a factorial experiment with two factors and three replications for the first one, and as a single factor experiment with three replicates for the second experiment. Results showed a decline in the percentage of success of the grafting and a slight success correlated with increased gibberellin concentration in the aforementioned experiment at early fall grafting. A second field experiment, was conducted with the aim of studying the success of maintained micro propagated plants during summer season and the effect of foliar spray with salicylic acid (0, 200 or 400 mg. L-1) and marine algae extract (0, 5 or 10 g. L-1) on some characteristics of vegetative growth and some chemical characteristics. The experiment was carried out according to the Randomized Complete Block Design (RCBD), as a factorial experiment with two factors and three replications. No significant effect for both factors was recorded in most vegetative characteristics, while chemical composition was significantly affected caused by the two factors.

The origins and molecular evolution of SARS-CoV-2 lineage B.1.1.7 in the UK.

The first SARS-CoV-2 variant of concern (VOC) to be designated was lineage B.1.1.7, later labelled by the World Health Organization as Alpha. Originating in early autumn but discovered in December 2020, it spread rapidly and caused large waves of infections worldwide. The Alpha variant is notable for being defined by a long ancestral phylogenetic branch with an increased evolutionary rate, along which only two sequences have been sampled. Alpha genomes comprise a well-supported monophyletic clade within which the evolutionary rate is typical of SARS-CoV-2. The Alpha epidemic continued to grow despite the continued restrictions on social mixing across the UK and the imposition of new restrictions, in particular, the English national lockdown in November 2020. While these interventions succeeded in reducing the absolute number of cases, the impact of these non-pharmaceutical interventions was predominantly to drive the decline of the SARS-CoV-2 lineages that preceded Alpha. We investigate the only two sampled sequences that fall on the branch ancestral to Alpha. We find that one is likely to be a true intermediate sequence, providing information about the order of mutational events that led to Alpha. We explore alternate hypotheses that can explain how Alpha acquired a large number of mutations yet remained largely unobserved in a region of high genomic surveillance: an under-sampled geographical location, a non-human animal population, or a chronically infected individual. We conclude that the latter provides the best explanation of the observed behaviour and dynamics of the variant, although the individual need not be immunocompromised, as persistently infected immunocompetent hosts also display a higher within-host rate of evolution. Finally, we compare the ancestral branches and mutation profiles of other VOCs and find that Delta appears to be an outlier both in terms of the genomic locations of its defining mutations and a lack of the rapid evolutionary rate on its ancestral branch. As new variants, such as Omicron, continue to evolve (potentially through similar mechanisms), it remains important to investigate the origins of other variants to identify ways to potentially disrupt their evolution and emergence.

Fruit Fly in a Challenging Environment: Impact of Short-Term Temperature Stress on the Survival, Development, Reproduction, and Trehalose Metabolism of Bactrocera dorsalis (Diptera: Tephritidae).

Simple SummaryBactrocera dorsalis (Hendel) is a widespread and economically important insect pest, infesting various fruits and vegetables. Due to the instability of climate change in early spring and autumn, extreme cold and hot temperatures were developed in a short period of time. Exposure to sudden short-term high or low temperatures may affect the reproduction, development, and physiological changes of B. dorsalis. In this study, we determined the effects of short-term temperature treatments on the growth, development, fecundity, and trehalose metabolism of B. dorsalis. The results showed that development and reproduction of the flies were negatively affected when temperature was below 10 °C; or more than 31 °C, even causing permanent sterility at extreme temperatures. The changes of glucose, glycogen, trehalose, and trehalose-6-phosphate synthase level had a correlation with the population dynamics of the fruit flies. Our present study can provide a scientific basis for population monitoring, prediction, and comprehensive prevention of the fruit fly.An understanding of physiological damage and population development caused by uncomfortable temperature plays an important role in pest control. In order to clarify the adaptability of different temperatures and physiological response mechanism of B. dorsalis, we focused on the adaptation ability of this pest to environmental stress from physiological and ecological viewpoints. In this study, we explored the relationship between population parameters and glucose, glycogen, trehalose, and trehalose-6-phosphate synthase responses to high and low temperatures. Compared with the control group, temperature stress delayed the development duration of all stages, and the survival rates and longevity decreased gradually as temperature decreased to 0 °C and increased to 36 °C. Furthermore, with low temperature decrease from 10 °C to 0 °C, the average fecundity per female increased at 10 °C but decreased later. Reproduction of the species was negatively affected during high-temperature stresses, reaching the lowest value at 36 °C. In addition to significantly affecting biological characteristics, temperature stress influenced physiological changes of B. dorsalis in cold and heat tolerance. When temperature deviated significantly from the norm, the levels of substances associated with temperature resistance were altered: glucose, trehalose, and TPS levels increased, but glycogen levels decreased. These results suggest that temperature stresses exert a detrimental effect on the populations’ survival, but the metabolism of trehalose and glycogen may enhance the pest’s temperature resistance.

Comparative population dynamics of two sympatric Palaemon shrimps (Palaemon adspersus Rathke, 1836 and Palaemon elegans Rathke, 1836) from the Southeast Caspian Sea

This study provides comparative information about population dynamics for the Palaemon adspersus Rathke, 1836 and P. elegans Rathke, 1836 shrimps on the southeastern coast of the Caspian Sea. Specimens were collected on a monthly basis between April 2019 and May 2020. A total of 9,643 specimens (8,478 P. adspersus and 1,165 P. elegans) were captured and examined. The highest abundance of both shrimps was observed in autumn. The male P. elegans ranged between 16.80 and 61.99 mm in total length and the females between 16.80 and 61.99 mm. The total length for male and female P. adspersus ranged from 21.46 to 69.29 mm and 18.24 to 75.46 mm, respectively. The mean ( ± SD) total length for the males and females of P. elegans was 33.65 ± 4.12 and 40.81 ± 6.59, whereas that of P. adspersus was 48.41 ± 6.27 for males and 54.68 ± 9.90 for females. Based on the b-value of LWR, the growth type of P. adspersus is positively allometric. Likewise, the relationships of female and pooled-sexes P. elegans was positively allometric, while that of male P. elegans was negatively allometric. The estimation of the VBGF parameters resulted as Total Length∞ (TL∞)=71.93 mm, K=0.72 y-1, and t0=-0.176 for males, and TL∞=78.23 mm, K=0.64 y-1, and t0=-0.194 for the females of P. adspersus, while for P. elegans as TL∞=56.13 mm, K=0.91 y-1, and t0=-0.147 for males and TL∞=65.63 mm, K=0.87 y-1, and t0=-0.148 for females. The size-frequency analysis showed that both shrimps were made up of two age groups. The recruitment pattern of the shrimps was continuous with a unimodal pulse for both males and females and showed that P. adspersus is mainly recruited during the autumn and early winter while for P. elegans, during mid-summer and early autumn. The estimated maximum age was 3.35/year for the males and 2.66/year for the females of P. adspersus and 3.78/year for the males and 3.33/year for the females of P. elegans. Therefore, in this case, P. elegans shrimp is more sensitive to death than P. adspersus. The findings point to the underlying notable differentiation of the growth of the shrimps governing the processes of population dynamics. We assume that these differences result from the contrasting life-history strategies of these two Palaemon shrimps.

Daily, Seasonal and Inter-Annual Variation in Activity Within a Common Pipistrelle Swarming Site and Hibernaculum

Seasonal swarming by bats in underground sites in late summer and early autumn is increasingly understood to play a vital role in their life-cycle, relating both to nuptial activity and to the use of swarming sites as hibernacula. The common pipistrelle (Pipistrellus pipistrellus) is a largely commensal species in which seasonal swarming often occurs in built structures, which have been hypothesised to serve as mass hibernacula during the coldest part of the winter. A number of detailed studies of P. pipistrellus swarming sites have recorded year-round patterns of activity, as well as the demographic make-up of the visiting bats, but there has been relatively little study of overnight patterns of activity, or how swarming interacts with weather conditions at a variety of scales. This study uses auditory monitoring data, recorded continuously over a 27 month period in a P. pipistrellus swarming site within a built structure in northern England, to derive a detailed phenology of bat activity within the site, and uses generalised additive modelling to explain daily variation in activity in terms of seasonal trends modified by fluctuating weather conditions. Results suggest that cool conditions delay the onset of swarming in spring and late summer, and can suppress swarming behaviour even at the height of the swarming period, leading to a pronounced pulse of activity when temperatures rise, and the extension of activity into mid-Autumn. Roosting also occurred at the study site during the swarming period, and was associated with significant flying during the day in warm temperatures, which may reflect a search for cooler roosting locations. Overnight activity occurred throughout the hibernation period, but little evidence emerged for an influx of bats to a mass hibernaculum at the start of the winter.

Climatic Mechanism of Delaying the Start and Advancing the End of the Growing Season of Stipa krylovii in a Semi-Arid Region from 1985–2018

Plant phenological variations depend largely on temperature, but they cannot be explained by temperature alone in arid and semi-arid regions. To reveal the response mechanisms of grassland phenology to climate change, the effects of temperature, moisture and light at the start (SOS), peak (POS) and end (EOS) of the growing season for Stipa krylovii (S. krylovii) in Inner Mongolian grassland was analysed from 1985–2018 with partial least squares (PLS) regression. The results showed that the SOS was significantly delayed at a rate of 5.4 d/10a (change over 10 years), while POS and EOS were insignificantly advanced, which were inconsistent with the existing understanding that climate warming advances the SOS and delays the EOS. The vapor pressure deficit (VPD) in July, maximum air temperature (Tmax) in September of the previous year, diurnal temperature range (DTR) from mid-February to mid-March, and Tmax from late March to mid-April of the current year were the critical factors and periods triggering the SOS, which contributed to 68.5% of the variation in the SOS. Additionally, the minimum air temperature (Tmin) occurred from mid-December to late December, and precipitation (PRE) occurred from mid-June to late July for POS, which could explain 52.1% of POS variations. In addition, Tmax from late August to early September influenced the EOS with an explanation of 49.3%. The results indicated that the phenological variations in S. krylovii were the result of the combined effects of climatic conditions from the previous year and the current year. Additionally, an increase in the preseason DTR delayed the SOS, and excessive summer precipitation induced an earlier POS, while warming in early autumn induced an earlier EOS, reflecting the adaptation mechanism of the perennial dense-cluster herbaceous plants in semi-arid regions to climate change. These findings could enrich the understanding of plant phenology in response to climate change.

Loliginid paralarvae from the Southeastern Gulf of Mexico: Abundance, distribution, and genetic structure

Global commercial catches of squid have increased greatly in the last few years. However, approximately a quarter of the squid catches are still unidentified. In the southeastern Gulf of Mexico (SGoM), the squid catches are not recorded most of the time and are unidentified. This lack of knowledge limits the evaluation of the populations and prevents the establishment of conservation strategies. In this study, we used morphological and molecular (DNA barcoding– cytochrome c oxidase subunit I gene) identification tools to analyze the species composition of the family Loliginidae based on their paralarvae (PL), their abundance distribution by size class, and their genetic structure on the Yucatan Shelf, SGoM. A total of 134 PL were also collected from three oceanographic cruises held in 2015, 2016, and 2018. A total of 56 adults were collected from three ports of Yucatan. Both adults and PL were identified as Doryteuthis pleii (Blainville, 1823). The highest abundances of PL were detected from the West and the Central zones of the Yucatan Shelf at 50- and 15-m depth isobaths at 163 and 21 km from the coastline, respectively. The abundance was higher (316 PL•1,000 m-3) in the early summer (June 2018), medium (213 PL•1,000 m-3) at the end of summer and early autumn, and very low (24 PL•1,000 m-3) in late autumn. A high haplotype and nucleotide diversity (Hd= 0.77; π= 0.002) with no structured population (Fst < 0) was also found, suggesting a continuous gene flow throughout the Yucatan Shelf. This information establishes the basis for a future comprehensive understanding of their biological cycle and population dynamics.

Impact of Black Summer 2019/20 Wildfires on True Bug Priority Species (Insecta: Hemiptera: Heteroptera) in the Northeast Forests of New South Wales

ABSTRACT This study examined the impact of the Black Summer 2019/20 wildfires in the Northeast Forests of New South Wales for seven priority heteropteran (= true bug) species, across a range of vegetation classes and host plants. Our area of study spanned 104,000 km2, from the Queensland border to the Hunter Valley, and west towards Narrabri. We used data primarily from the Plant Bug Inventory database, inclusive of all phytophagous families of the suborder Heteroptera. We identified 122 survey sites based on their distribution in historical collection data and that of their known host plants. These sites were parsed into unburnt (69 locations) and burnt (53 locations), with the latter further categorised by fire severity. The 122 sites were surveyed in four field trips in the late summer early autumn and spring of 2021. One or more of the priority species were detected at thirty-three sites (22 unburnt and 11 burnt sites). The first three field trips (January–March) resulted in the discovery of only Woodwardiola ‘n.sp_LOMA’. The fourth field trip (November) resulted in the discovery of four additional species (Kirkaldyella rugosa, Setocoris ‘n.sp_BINA’, Epimixia vulturna and Eritingis trivirgata), as well as W. ‘n.sp_LOMA’. The two other priority species (Kirkaldyella schuhi and Myrmecoroides grossi) were not found. IUCN Red list methodology was employed to analyse the conservation status of the seven priority species. All seven priority species were found to be species of Least Concern for EEO and Data Deficient for AOO. The Data Deficient categorisation was decided based on insufficient sampling data plus expert opinion. Further sampling is required for all species but is critical for Kirkaldyella schuhi and Myrmecoroides grossi to determine whether their non-detection in this survey is due to sampling inadequacy or due to environmental factors.

Improving Salmonid Monitoring by Nocturnal Counting in Rivers

AbstractAccurate abundance estimates are crucial for evidence‐based fisheries management. In rivers, drift dive counting and electrofishing are commonly used for quantifying fish abundance. However, the likelihood that fish are detected by these counting methods is affected by a range of factors, with substantial potential implications for the outcomes. Fish behavior and distribution also differs with light intensity, yet diel variation in abundance estimates produced by common enumeration methods has received little attention. Here, we present a comparison of diurnal and nocturnal counts of the landlocked population of Atlantic SalmonSalmo salar, known as “småblank,” and Brown TroutSalmo truttain a Norwegian river. Six drift dive transects and 12 electrofishing sites were surveyed at day and night in early autumn. During drift dives, småblank were exclusively observed at night. Brown Trout were observed by snorkelers both day and night but in significantly higher numbers at night (six times more Brown Trout per 100 m at night versus in the day). Catch per unit effort of backpack electrofishing was significantly higher at night than at daytime for both småblank and Brown Trout older than age 0 (202% and 108% higher, respectively). We argue that differences in drift dive counts were mainly caused by fish hiding in the substrate during the day and being more active at night, resulting in diel differences in detection rate. Further studies are needed to determine whether differences in electrofishing catches were caused by diel fish migrations or higher catchability at night.

Variability of early autumn planktonic assemblages in the strait of Gibraltar: a regionalization analysis

The Strait of Gibraltar (SG) is the only connection of the Mediterranean Sea with the global circulation. The SG is an outstanding marine region to explore physical-biological coupling of pelagic communities due to its hydrodynamic complexity, including strong tidal forcing and marked spatial gradients and fronts. The authors have unravelled the role of the fortnightly tidal scale (spring and neap tides) and local processes (upwelling and tidal-topographic mixing) that shape planktonic assemblages in the Strait. To do so, an oceanographic cruise was taken in early autumn 2008 with a high-resolution grid sampling and spring/neap tidal conditions. The planktonic features were captured using different automatic and semi-automatic techniques of plankton analyses (flow cytometry, FlowCAM, LOPC and Ecotaxa) that allowed covering a wide range of sizes of the community from pico- to mesoplankton. The SG was sectorized into two clusters based on the biogeochemical and main water column properties. Cluster 1 (CL1) covered shallow productive areas around Cape Trafalgar (CT). CL1 presented higher concentrations of chlorophyll and nutrients, and phytoplankton was mostly represented by Synechococcus and coastal diatoms while zooplankton had the highest percentage of meroplankton (31%). In contrast, cluster 2 (CL2) covered open ocean waters and presented more oligotrophic features, i.e. nitrogen-depleted waters with lower chlorophyll concentrations and a picoplankton community dominated by Prochlorococcus and holoplankton predominance in mesozooplankton. Under early autumn conditions with overall nutrient-depleted and stratified waters, the CT area emerges as an ecosystem where the constant tidal mixing and nutrients supply is coupled with an active production also being favored by high residence times and finally shaping a plankton community with unique features in the area.

Investigating lake chlorophyll-a responses to the 2019 European double heatwave using satellite remote sensing

Compounded weather events such as sequential heatwaves are likely to increasingly impact freshwater ecosystems in the future. Satellite-derived chlorophyll-a concentration estimates for 36 European lakes during a widespread double heatwave event in the summer of 2019 show that deep and medium depth lakes at higher latitudes displayed a synchronous chlorophyll-a increase with temperature, possibly as the result of an improved light climate resulting from increased stratification. Many deep or northern lakes had a notable response to the heatwaves. Warmer, southern shallow lakes had the most asynchronous response, tending to show a greater response to subsequent low pressure or storm events than to the heatwave itself. Chlorophyll-a peaks typically occurred five days after the peak of the heatwave for shallow lakes. For some shallow lakes, the sequential cycle of several heatwaves and low pressure events was found to punctuate the seasonal pattern of chlorophyll-a. Notably, in several of these nutrient-rich lakes the response to the heatwave was dwarfed by large algal blooms occurring later during the typical cyanobacterial bloom period in early autumn, underlining the importance of timing and phenology in response to heatwaves in addition to depth, latitude and trophic state.

Seed Dormancy and Seedling Ecophysiology Reveal the Ecological Amplitude of the Threatened Endemism Picris willkommii (Schultz Bip.) Nyman (Asteraceae).

Plant communities can undergo drastic changes in their composition if the ecosystem is severely altered by human actions or climate change. These changes endanger any vulnerable species, mainly if it lives in a small area, as is the case of Picris willkommii (Schultz Bip.) Nyman. Therefore, it is essential to know how an ecosystem alteration could affect the seasonal pattern of the life cycle, seed production, germination time, as well as both plant emergence and development. During three consecutive years, the growth phenology and seed morpho-physiological traits of Picris willkommii were assessed, as well as the environmental factors that affect them (light, temperature, substrate). Under natural conditions, germination is in early autumn (15–25 °C air temperature), flowering is in spring, and seed maturation in late spring. The species produces two types of seeds differentiated in the degree of dormancy and other morpho–physiological traits, which contributes to the dispersal and spreading capacity; it prefers fine-textured limestone substrates with high N and P availability; it does not tolerate frosts below −5 °C; and it is able to acclimatize to changing environmental conditions, but there is a risk of being replaced by other more aggressive species. All of this is useful for species conservation programs.

Measuring Fluorescence as a Means to Evaluate the Physiological Reaction to Growth Retardant Applied to Manage Turf

This paper presents the effects of the physiological reaction of the main cool-season grass species used for turf in a temperate climate: perennial ryegrass, Kentucky bluegrass, and tall fescue, on a twice-a-year trinexapac-ethyl (TE) application in late spring and early autumn, seasons of rapid turf growth. The fully established turf plots in the split-plot system of three replicates, with three cultivars/species, were treated by TE (1.5 and 4.5 g/100 m2). The 4.5 g/100 m2 was harmful to Kentucky bluegrass. The perennial ryegrass responded by dose-dependent growth inhibition; 30–60% in spring and 25–40% in autumn for lower and higher doses, respectively. Tall fescue responded by 50% growth inhibition independently of concentration and season. Plant physiological responses, visualized as graphs of fluorescence data, revealed the stress of Kentucky bluegrass upon high TE dose. Based on principal component analysis (PCA) analysis, three groups were distinguished: perennial ryegrass varieties from high and low TE treatments and Kentucky bluegrass varieties from high TE. TE-dependent growth reduction with no significant quality decrease benefits the environment by reducing carbon footprint machine operations (mowing). Utilizing fluorescence measurement may help to manage turf physiology.

Characteristics of atmospheric black carbon and other aerosol particles over the Arctic Ocean in early autumn 2016: Influence from biomass burning as assessed with observed microphysical properties and model simulations

We conducted ship-based measurements of marine aerosol particles (number concentration, size distribution, black carbon (BC), autofluorescence property, and PM2.5 composition) and trace gases (ozone (O3) and carbon monoxide (CO)) during a cruise of the R/V Mirai (23 August to 4 October 2016) over the Arctic Ocean, Northwest Pacific Ocean, and Bering Sea. Over the Arctic Ocean at latitudes >70°N, the averaged BC mass concentration was 0.7 ± 1.8 ng/m3, confirming the validity of our previously-reported observations (~1 ng/m3) over the same region during September 2014 and September 2015. The observed levels over the Arctic Ocean need to be used as a benchmark when testing the atmospheric transport models over the ocean, while they are substantially lower than those reported at Barrow (Utqiaġvik), a nearby ground-based station. We identified events with elevated BC mass concentrations and CO mixing ratios over the Arctic Ocean and Bering Sea as influenced by biomass burnings, with evidences from elevated levoglucosan levels, mixing states of BC particles, and particle size distributions. With WRF-Chem model simulations, we confirmed Siberian Forest fire plumes traveled over thousands of kilometers and produced substantially high BC and CO levels over the Bering Sea. The ΔBC/ΔCO ratios during these periods were estimated as ~1 ng/m3/ppbv, which are lower than those values reported, indicating that the results might have been affected by the wet removal process during transportation and/or by emission in smoldering conditions.

Coping with drought? Effects of extended drought conditions on soil invertebrate prey and diet selection by a fossorial amphisbaenian reptile.

Arid climates are characterized by a summer drought period to which animals seem adapted. However, in some years, the drought can extend for unusually longer periods. Examining the effects of these current extreme weather events on biodiversity can help to understand the effects of climate change, as models predict an increase in drought severity. Here, we examined the effects of "unusual" extended drought on soil invertebrate prey availability and on diet composition (based on fecal contents) and diet selection of a fossorial amphisbaenian, the checkerboard worm lizard Trogonophis wiegmanni. Weather data show interannual variations in summer drought duration. The abundance and diversity of soil invertebrates in spring were high, and similar to those found in a "normal" early autumn, after some rain had ended with the summer drought. In contrast, in years with "unusual" extended drought, abundance, and diversity of soil invertebrates in early autumn were very low. Also, there were seasonal changes in amphisbaenians' diet; in autumn with drought, prey diversity, and niche breadth decreased with respect to spring and autumns after some rain had fallen. Amphisbaenians did not eat prey at random in any season, but made some changes in prey selection that may result from drought-related restrictions in prey availability. Finally, in spite that amphisbaenians showed some feeding flexibility, their body condition was lower in autumn than in spring, and much lower in autumn with drought. If extended drought became the norm in the future, amphisbaenians might suffer important negative effects for their health state.

Three-Dimensional Structural Anomalies of the Western Pacific Subtropical High Ridge and Its Relationship with Precipitation in China during August–September 2021

In August-September 2021, the western Pacific subtropical high (WPSH) showed significant anomalies, with some areas between the Yangtze and Yellow River basins in China suffering from heavy rainfall and flooding, while extreme heat occurred in Southern China. Using the 6 h reanalysis data of NCEP/NCAR and the daily precipitation observation data, this paper studied the abnormal characteristics and the thermal mechanism of the three-dimensional ridge of the WPSH during the seasonal transition from late summer to early autumn in August-September 2021, and explored its connection with the precipitation in the areas between the Yangtze and Yellow River basins in China during the same period. The results showed that, in August-September 2021, the three-dimensional ridge of the WPSH appeared to be southward at the lower troposphere and tilted northward with height. According to the diagnosis of the atmospheric heat source, it was found that the center of atmospheric cold source in the low latitudes at 850 hPa enhanced the surface high pressure, corresponding to the WPSH ridge shifting southward at the lower troposphere, which led to more water vapor convergence and more precipitation between the Yangtze and Yellow River basins. The latent heat of condensation released by the increased precipitation between the Yangtze and Yellow River basins in China heated the middle and upper troposphere, increasing the intensity of the high pressure in the upper troposphere, corresponding to the WPSH ridge northward at the upper troposphere. This anomalous tilt of the WPSH ridge in August-September 2021 and the intense precipitation processes between the Yangtze and Yellow River basins in China during the same period established a reciprocal feedback mechanism through diabatic heating. Further studies also showed that the anomalous tilt of the WPSH ridge is one of the important modes of its three-dimensional structural anomalies, and that, in years when the ridge tilts from south to north with height anomalously in August-September, the areas between the Yangtze and Yellow River basins are characterized by high precipitation.

Observations on the biology of the Flores weevil, Floresianus sordidus Hustache in northern New Zealand

ABSTRACT Flores weevil (Floresianus sordidus Hustache, 1939 (Coleoptera, Curculionidae)) is now common in northern areas of the North Island of New Zealand. Historic records and new field data were investigated to learn more of the biology, seasonality, and likely pest status of the weevil. Laboratory studies were undertaken on its feeding preferences and the impact of host plant on oviposition and survival. Flores weevil adults were found to be absent in pastures from November to February and started emerging in early autumn (March), with peak emergence in April and May. Adults preferred feeding on broad-leaved plants and did not feed on perennial ryegrass (Lolium perenne L.). Mean longevity of field-collected adults in the laboratory ranged from 20 days, when provided ryegrass, to 62 days on plantain (Plantago lanceolata L.). Eggs were laid in batches of up to 20 eggs. Most eggs were laid by weevils feeding on red clover (Trifolium pratense L.) and the least by those provided ryegrass. Dissections showed ryegrass-fed weevils retained mature eggs in their ovaries. First instar larvae were found to feed on soil organic matter, whereas second and third instar larvae fed on roots. Host plant had no significant effect on larval survival or development of these stages.

Time Shift in the Exploitation of Fish Stocks by Great Cormorants Phalacrocorax carbo at Lake IJsselmeer: How Wintering Birds began Competing for Fish with Breeding Conspecifics

Monthly aerial bird counts showed a strong increase in the number of wintering Great Cormorants Phalacrocorax carbo sinensis since the late 1990s at Lake IJsselmeer but not at Lake Markermeer-IJmeer. Compared to the 1980–1990s, breeding numbers also increased in this part of the system. The resulting increased exploitation of fish stocks was thought to have been possible because of a long-term increase in the stock of Ruffe Gymnocephalus cernuus, despite a clear overall decline of total estimated fish biomass in the lake during the same period. The most likely cause of these shifts was thought to be the intensive commercial fishing regime, removing the large predatory fish first, followed by a strong reduction of stocks of large Bream Abramis brama, in turn paving the way for increases in the stocks of Ruffe. Increased predation by Cormorants on the enhanced stocks of small fishes was possible because of ameliorated underwater visibility in Lake IJsselmeer. Starting in 2000, there was a strong shift in both temporal habitat use and associated fish consumption by Cormorants towards the winter period. The local breeding birds, exploiting the same age- and size-structured community of fishes in the spring, thus face an already-depleted food resource. Compared to the 1980–1990s, fish consumption by Cormorants in winter increased by a factor of ten, whereas that by breeders did so by a factor of 1.6. Our calculations showed that the actual harvest of available fish stock by wintering and breeding Cormorants together was c. 5% in 1985–2000 and c. 15% in 2001–2015. The disproportionate division of the overall consumption (‘harvest’) of the fish stock towards the wintering birds is a strong argument for direct competition with their conspecifics breeding locally. In conclusion, we calculate that because of the increased winter exploitation initiated by the activities of an intensive commercial fishery, the fish consumption in summer and early autumn by breeding Cormorants and their offspring was suppressed by a factor of six.