Southern Locations Research Articles

Modeling drought stress impacts under current and future climate for peanut in the semiarid pampas region of Argentina

In the semiarid pampas region of Argentina, peanut ( Arachis hypogaea L.) crop undergoes frequent and unpredictable drought stress periods, with high probability of occurrence under future climate change projections. However, the overall frequency of occurrence and timing of different drought stress patterns under current and future climates has not been well investigated for the main peanut region in central Argentina. The aims of this study were to: (i) define the main peanut drought stress patterns and their occurrence (frequency) during the peanut growing season, via a crop growth modeling approach, (ii) test seed yield stability of the formerly defined (in i) drought stress patterns under future climate scenarios, and (iii) analyze the effect of sowing dates on peanut seed yield as a management strategy to mitigate the impact of future climate scenarios for peanut seed yield in the semiarid pampas region of Argentina. The APSIM-peanut growth model was calibrated and validated for local genotypes and production environments. Our study simulated seasonal drought stress patterns at five representative locations across the region under current and future climate scenarios, and tested six sowing dates as a practice to mitigate the impact of climate change. Clustering analysis identified two contrasting environment types (ETs). The high stress ET showed greater frequency of occurrence (>50%) at the southern locations. Future climate conditions increased the frequency of high stress ET by roughly 6% and reduced peanut seed yield by 12%, as average across locations. For both current and future climates, earlier sowing dates maximized peanut seed yield, regardless the locations. Changing sowing date was not an effective practice to mitigate the negative impact of climate change on peanut seed yield. The defined ETs allowed identifying a target population of environments (TPE) having implications for optimizing peanut breeding and management strategies. The projected increase in the frequency of drought stress for all tested locations provides a challenging scenario for sustaining peanut productivity in this region. • The aims were to determine drought patterns under current and future climate, and to test sowing date as a mitigation tool • The defined drought stress patterns changed the frequency across locations, identifying a target population of environments • ·Future climate increased the frequency of drought stress by ~6% and reduced peanut seed yield by ~12% • Sowing date did not mitigate climate change impact. • This study provides insights to optimize breeding and management, and assists policy makers to address climate change.

Diet composition and overlap for adult walleye, lake whitefish, and yellow perch in Green Bay, Lake Michigan

Interspecific interactions among walleye Sander vitreus, lake whitefish Coregonus clupeaformis, and yellow perch Perca flavescens in Green Bay could influence the population status of each species, but potential trophic interactions are poorly understood. Our objectives were to determine if diet assemblages for each species and diet overlap among species varied spatially and temporally within Green Bay. Adult walleye (≥381 mm total length (TL); N = 981), lake whitefish (≥432 mm TL; N = 1507), and yellow perch (≥150 mm TL; N = 1174) were collected during May-October of 2018 and 2019 from multiple locations in southern and northern Green Bay. Diet assemblages of each species varied between northern and southern Green Bay, but walleye diets were more temporally variable (among months within zones and between years) than diets of lake whitefish or yellow perch. Lake whitefish represented a seasonally important prey item for walleye in southern Green Bay, composing 10 % and 41 % of walleye diets by weight in May and June, respectively. Yellow perch generally composed <15 % of walleye diets by weight but were consumed at a broader spatiotemporal scale than lake whitefish. Diet overlap between walleye and both lake whitefish and yellow perch was generally weak or moderate, whereas diet overlap between whitefish and perch was generally strong. Our assessment of adult trophic interactions suggests that changes in the population status of one species could influence fisheries for all three, and we identify additional research questions to address potential population-level effects of these trophic interactions.

A new assemblage of fossil leaves and wood from The Aguja Formation (Upper Campanian) of West Texas: An interfluvial community in a volcanic landscape

A new assemblage of fossil leaves and wood is described from the uppermost Aguja Formation (upper Campanian) of Big Bend National Park, Texas, USA. While diverse leaf assemblages have been reported from Campanian through Maastrichtian strata in more northerly areas of North America, few have been so far described from southern localities. The leaf assemblage was found preserved within a lenticular tuff bed. The number of species (7) of leaves in the assemblage is low and includes one fern and six dicots. Most specimens represent taxa which have small leaves with entire margins, a morphology consistent with a dry, warm climate. Thin sections of several fossil wood samples found nearby at the same stratigraphic interval as the tuff reveals that the fossil woods represent conifers with irregularly-spaced growth rings. The assemblage may represent shrubby vegetation within an open, conifer-dominated woodland which developed within a periodically dry environment. However, the assemblage may also represent early successional species that grew in areas that had been previously disturbed by deposition of pyroclastic material. A comparison of two localities in the uppermost Aguja Formation reveal the occurrence of two types of vegetational communities – one exemplified by presumably riparian, evergreen angiosperm woodlands and another exemplified by interfluvial conifer forest with an associated herbaceous community. Given that both sites preserve very similar depositional facies, it seems that observed differences involving fossil wood taxonomy and structure are likely related to the local availability of water.

The Observed Impact of the South Asian Summer Monsoon on Land-Atmosphere Heat Transfers and Its Inhomogeneity over the Tibetan Plateau

To promote Tibetan meteorological research, the third Tibetan Plateau (TP) Experiment for atmospheric sciences (TIPEX III) has been carried out over the plateau region since 2014, with near-surface heat fluxes measured at different sites. Using the observational data of near-surface heat fluxes measured at 8 plateau stations in TIPEX III, as well as the ECMWF ERA Interim reanalysis data, the land-atmosphere heat transfers over different regions of TP and their responses to the South Asian summer monsoon (SASM) during active/break periods were investigated. Inhomogeneity was found in the land-atmosphere heat transfers over the plateau, with large differences among plateau stations. During the observation period, the daily averaged total heat transfer (the sum of sensible and latent heat flux) varied from 70.2 to 101.2 Wm−2 among the 8 plateau stations, with the sensible heat flux from 18.8 to 60.1 Wm−2 and the latent heat flux from 10.1 to 74.7 Wm−2. These heat transfers were strongly affected by the SASM evolution, but with strong inhomogeneities over the plateau stations. Overall, the more southern station locations exhibited more SASM impacts. The land-atmosphere heat transfers (the total, sensible and latent heat fluxes) were greatly weakened/strengthened during the SASM active/break period at Namco (southeast plateau), Baingoin (central plateau), Lhari (central plateau), and Nagqu (central plateau), which were closely related to the weakened/strengthened radiation conditions. However, the SASM impacts were quite small or even negligible for the other plateau stations, which complicated our conclusions, and further investigations are still needed.

지역빈도해석을 이용한 남해안 지역의 극치풍속 추정

We performed the regional frequency analysis to estimate the extreme wind speed in southern coastal region of Korea using annual maximum wind speed (AMWS) and linear-moments method proposed by Hosking. Data at all station is found to be accordance. It is confirmed that all data could represent one homogeneous region through the heterogeneity test. Generalized Normal (GNO) and Generalized Extreme Value (GEV) distributions were selected as probability distributions representing the southern coastal region from the goodness-of-fit tests. The stability of the two distributions was evaluated using the relative error (RB) and the root mean square error (RRMSE). It is found that the GNO distribution is more stable than the GEV distribution. Finally, the extreme wind speed of the stations is estimated use the quantile representing the southern coast region, the average, median value, and location parameters of each station. The regional frequency analysis is effective to estimate the extreme wind speed at station where data are insufficient or not measured.

Physiological characterisation of the calcified alga Corallina officinalis (Rhodophyta) from the leading to trailing edge in the Northeast Atlantic

Intertidal macroalgae are exposed to many biotic and abiotic stressors, including significant fluctuations in environmental parameters such as salinity, temperature, pH and solar radiation. This study characterized populations of the intertidal calcifying red alga Corallina officinalis across its geographic distribution in the North-east Atlantic. Processes examined included primary production, respiration, light and dark calcification, photosynthesis-irradiance, and calcification-irradiance evolution. Results confirmed significant differences in the physiology of C. officinalis between latitudes with a clear north-to-south gradient. Compared with central and southern populations of this species, northern populations appeared to be the most robust, showing potential for local physiological adaptation in response to increased variability in environmental factors present within their habitat. Conversely, southern populations displayed a distinct lack of local adaptation compared with northern populations. This is possibly due to southern populations being located within an environment at the upper limit of their stress tolerance, therefore restricting the species’ ability to adapt. As a result, future permanent decline, or even disappearance, of C. officinalis within southern locations of the North-east Atlantic could occur, a process that is likely to be accelerated by predicted future climatic changes. Furthermore, given the essential role these ecosystem engineers play within their habitat, any loss of C. officinalis is also expected to have a strongly negative impact on the surrounding environment. HIGHLIGHTS Decoupled photosynthesis and calcification in Corallina. officinalis show complex relationships, not direct dependencies. Most physiological characteristics in northern C. officinalis populations differ significantly from those in central and southern locations. Species adaptation is predominantly to lower light and temperature conditions.

Genetic identification and diversity of stocks of the African bonytongue, Heterotis niloticus (Osteoglossiformes: Arapaiminae), in Nigeria, West Africa

Inland fisheries are an important source of protein and income for people in Africa. Their sustainable management can greatly benefit from identification of regional genetic stocks and characterization of their genetic diversity, but such information is lacking for most African freshwater fisheries. The African bonytongue, Heterotis niloticus, is an important component of inland fisheries in West Africa. Nigeria has the largest fishery for African bonytongues, representing ~ 86% of the global total. Recent declines in yields at some Nigerian locations, however, suggest current levels of exploitation may be unsustainable. Habitat degradation also may be impacting some stocks. Despite its commercial and nutritional importance, the African bonytongue has been the subject of scant genetic research to support management. We examined patterns of genetic diversity in natural populations of H. niloticus at four locations in Nigeria, including Kainji Lake, a reservoir on the Niger River in north-central Nigeria, and three southern localities (Ethiope River, Igbokoda River, and Epe Lagoon), as well fish from the Ouémé River delta near Porto Novo, Benin. Eighty-five specimens were genotyped for nine microsatellite-loci. Genetic diversity estimates were highest at Kainji Lake, and substantially lower at southern localities. High levels of genetic differentiation were detected between samples from Kainji Lake and those from southern localities. Low, yet significant FST values were observed among samples from southern Nigerian localities that were more differentiated from the sample from nearby coastal Benin. We thus recommend that African bonytongues from the five locations be considered distinct genetic stocks and managed accordingly.

Hydrothermal vent periphery invertebrate community habitat preferences of the Lau Basin

The Eastern Lau Spreading Center (ELSC), located between 19°20′S and 22°45′S, is a back-arc basin containing active hydrothermal vents, and is characterized by gradients of several geological and chemical variables that follow along the north – south axis. The northern section of the ELSC spreads faster than the southern section resulting in farther distance from the Tofua Arc and vent geology and chemistry more akin to mid-oceanic ridges. In the southern section, where distance from the arc is less, substrates are more heavily influenced by water resulting in andesitic substrates as opposed to the basaltic substrates in the north. There are also north to south biological patterns; vent peripheral zone communities in the northern area are dominated by anemones, and in the southern area, by sponges. This project used a replacement type experiment to test whether the anemone and sponge community distributions are due to substrate preferences (basalt or andesite) or location effects. In September 2006, 17 basalt and 18 andesite rock blocks were set out in the peripheral vent zone at three locations in the Lau Basin; 42 months later, in May 2009, the rocks were recovered. After rock block collection, communities that had colonized them were defined by identifying all invertebrates to lowest taxonomic level possible. As expected, basalt rock blocks were smoother than andesite rock blocks, but they were also smaller, though this was ameliorated by even distribution at experimental locations. Rock type did not affect the invertebrate community, but location did; the location specific effect that impacted the invertebrate community may have been sulfide concentration. The seafloor at southern locations was more brecciated, allowing sulfide to distribute farther laterally, which could result in enhanced primary productivity, and thus influence the observed community differences. We conclude that in peripheral vent habitats, energy availability for primary production and food availability are more important in structuring communities than the type of rock substrate.

Influence of site conditions and land management on Quercus suber L. population dynamics in the southern Iberian Peninsula

During recent decades, tree mortality and dieback have been reported in forest ecosystems across global biomes. Although numerous forest species, including those of the genus Quercus, have been affected by hotter and drier conditions in the Mediterranean Basin during the last decades, there is scarce information regarding the interactive role of past management and climate across large areas of south-western Europe. Here, we examined the influence of several climatic factors (mean annual temperature, annual precipitation) over the last 3 decades, latitude, land management and site conditions on the cork oak (Quercus suber L.) population dynamics given their high ecological and economic relevance. We sampled 20 plots across contrasting environmental conditions in SW Iberian Peninsula with different land property (public vs. private) to characterize cork oak tree size, stand density, mortality ratio and regeneration. We observed widespread effects of latitude (8.9% at northern vs. 15.6% at southern plots) and land property (6.9% in private properties vs. 13.9% in public ones) on tree mortality. Tree density and basal area differed with latitude, with higher values (307.2 trees ha-1 and 38.4 m2 ha-1, respectively) at northern populations. In addition, the more intense cork-focused productive management resulted in higher tree sizes in private (mean DBH = 47.3 cm) than in public (mean DBH = 37.8 cm) plots. Tree regeneration was higher in northern forests (94.9 ± 25.2 vs. 26.0 ± 6.1 saplings ha-1 for the southern location), being this difference more pronounced in public plots. These findings highlight the importance of sustainable forest management in public and private forests for further reduction of mortality processes, as well as for enhancing the regeneration aimed to the conservation of cork oak under forecasted drier conditions of these economically invaluable Mediterranean forests.

Spatial Distribution of Heavy Metals in Near-Shore Marine Sediments of the Jeddah, Saudi Arabia Region: Enrichment and Associated Risk Indices

Red Sea coastal development has rapidly accelerated in recent decades that has led to a rise in the anthropogenic heavy metal levels in sediments. A total of 80 surficial sediment samples were collected from the shallow waters along the eastern Red Sea coast near Jeddah, Saudi Arabia. These samples were collected from three locations, designated as North, Middle and South of Jeddah, to assess the concentrations of six heavy metals: chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), and lead (Pb). The results showed that the concentrations (mg/kg) of these metals in the studied sediments follow this order: Pb (77.34 ± 150.59) &gt; Mn (36.52 ± 37.72) &gt; Zn (18.02 ± 23.94) &gt; Cr (9.56 ± 5.81) &gt; Cu (9.18 ± 13.67) &gt; Ni (3.68 ± 4.54). The majority of the polluted sediments were recorded in the Middle and South locations. Pollution and enrichment indices such as Geo-accumulation indices (Igeo), Enrichment Factors (Ef), Contamination Factors (Cf), Pollution Load Indices (PLI), Potential Ecological Risk Indices (PERI) and Potential Toxicity Response Indices (RI) were calculated from the measured metals to establish baselines for the region and assess specific metal enrichments by location along the Jeddah coastline. The Igeo values showed that 30% of the Southern location stations are considered moderately to highly polluted. The Ef for all the studied sediments followed this order: Pb (extremely severe enrichment) &gt; Zn &gt; Cu &gt; Cd &gt; Cr (severe enrichment) &gt; Ni (moderate enrichment).

Variation in White spruce needle respiration at the species range limits: A potential impediment to Northern expansion.

White spruce (Picea glauca) spans a massive range, yet the variability in respiratory physiology and related implications for tree carbon balance at the extremes of this distribution remain as enigmas. Working at both the most northern and southern extents of the distribution range more than 5000 km apart, we measured the short-term temperature response of dark respiration (R/T) at upper and lower canopy positions. R/T curves were fit to both polynomial and thermodynamic models so that model parameters could be compared among locations, canopy positions, and with previously published data. Respiration measured at 25°C (R25 ) was 68% lower at the southern location than at the northern location, resulting in a significantly lower intercept in R/T response in temperate trees. Only at the southern location did upper canopy leaves have a steeper temperature response than lower canopy leaves, likely reflecting canopy gradients in light. At the northern range limit respiration is nearly twice that of the average R25 reported in a global leaf respiration database. We predict that without significant thermal acclimation, respiration will increase with projected end-of-the-century warming and will likely constrain the future range limits of this important boreal species.

Third and fourth year biomass yields of Miscanthus x giganteus, switchgrass, big bluestem, and prairie cordgrass in southern Manitoba, Canada: Latitude of origin affects biomass yield among native grasses

Warm season perennial grasses that use C4 photosynthesis can provide a reliable supply of bioenergy and biomaterials, achieving the greatest annually harvestable biomass of any crop in most temperate regions. Short growing seasons bookended by cold temperatures and snow cover challenge the productivity of C4 perennial grasses at high latitudes. Cultivars from higher latitudes also often flower and senesce before fully realizing the late summer and fall growing season, compounding the productivity limitations of a shorter growing season. In contrast, cultivars from southern locations planted at higher latitudes may flower later in the growing season, extending their vegetative growth and productivity. At a common field site in southern Manitoba, Canada we compare first-, third-, and fourth-year biomass yields of Miscanthus x giganteus, and cultivars of switchgrass, prairie cordgrass, and big bluestem, spanning latitudes from southern Manitoba to Illinois/Indiana, USA. In addition, we compared spring canopy closure, plant height, and reproductive development during the fourth growing season. Miscanthus x giganteus (M114) and cultivars Sunburst (switchgrass) and Prairie View (big bluestem) consistently achieved ≥10 Mg ha−1 in their third and fourth years, with M114 achieving 13 Mg ha−1 both years. Both prairie cordgrass cultivars (Red River and IL-102) also achieved ≥10 Mg ha−1 the third year, but their yields were halved in the drier fourth growing season. Among native North American grasses, cultivars originating from higher latitudes showed more vigorous spring growth, but flowered earlier, thus reducing their biomass yields compared to cultivars originating further south of our field site.

Genetic differentiation in the threatened soft coral Dendronephthya australis in temperate eastern Australia

AbstractThe endangered soft coral Dendronephthya australis faces substantial population decreases in central eastern Australian waters. Despite uncertainty about the cause of these declines, the population genetics of the species has not been investigated. Genetic analysis suggests that D. australis is a single species within the family Nephtheidae, confirming identifications based on morphological characteristics only. Soft coral colonies were distributed from Seahorse Gardens in Port Stephens to Jervis Bay in temperate Australian waters, a distance of some 400 km. Genetic differentiation was observed along this distribution using SNP genotyping. Relatively high levels of genetic differentiation were observed between Jervis Bay and the other sites, indicating limited gene flow between this location and others. Moreover, the genetic distinctiveness, low diversity and heterozygote excess at this southern location suggested that it was subjected to a recent population decline and genetic bottleneck. Colonies at Seahorse Gardens and Ettalong, approximately 150 km south of Seahorse Gardens, displayed greater genetic diversity, making these sites more likely to host ancestral populations and to have acted as refugia. Recent substantial decreases in population sizes at these locations are particularly concerning, and these locations require immediate conservation attention.

Comparing the emergence of Echinochloa crus‐galli populations in different locations. Part I: Variations in emergence timing and behaviour of two populations

AbstractEchinochloa crus‐galli (L.) P. Beauv. is one of the most important weeds. It is distributed worldwide and has adapted to diverse habitats and climatic conditions. This study aimed to compare the emergence patterns of two populations of E. crus‐galli from different environments at 11 locations across Europe and the Middle East. Seeds of the two populations were collected from maize in Italy and from spring barley in Norway and were then buried in soil in autumn 2015. In the spring of 2016, the soil was disturbed around the usual seedbed preparation date in each location and emergence was recorded. The soil was again disturbed a year later and emergence was recorded for a second season. Total emergence, the times of onset, end and to 50% emergence and the period between 25% and 75% of emergence were analysed by two‐way ANOVA and principal components analysis. The Italian population showed a higher emergence than the Norwegian population in Southern locations, while the ranking was reversed in Northern locations. In almost all locations, a tendency to emerge earlier was recorded for the Norwegian population, but the periods from 25% to 75% emergence were similar for both populations. Total emergence, and the times of onset and end of emergence seemed to be mainly under genotypic (plus maternal) control, suggesting there were different temperature thresholds for seedling emergence in each population. Conversely, the duration of emergence seemed to be mainly under environmental control. This research confirms the high variability between populations and suggests the need to continue identifying key characteristics for the development of efficient models for seedling emergence in specific climates and/or latitudes.

Characteristics of individual surface waves measured by moored buoys in the coastal waters of the eastern Arabian Sea

In this study, the characteristics of the individual surface waves in the eastern Arabian Sea over one year are examined based on the measured time-series data using Waverider buoys at four locations covering ∼500 km of the western Indian coastline. At all locations, the number of waves is high during the non-monsoon compared to the monsoon period (June–September). Number of waves in a year is higher in the northern location (∼6,417,657) than in the southern locations (∼5,497,168) since comparatively more short-period waves are observed in the north. Maximum wave height varied from 7.0 to 7.6 m, and the steepness of the largest waves varies from 0.056 to 0.082 at different locations and is much smaller than the wave breaking limit. Number of short-period waves observed is higher than the long-period waves at all locations except in the monsoon, when a significant number of intermediate-period waves are present. The mean wave steepness of the 30-min record is ∼22% higher than the conventionally reported significant wave steepness based on mean wave period. Hilbert–Huang transform method is used to detect the freak wave and analyze the abnormal wave group structure. It is observed that freak wave occurrence is high during the monsoon.

Strip cutting management in Scots pine stands on peatlands – a financial comparison to rotation forestry

ABSTRACT Even-aged management (rotation forestry, RF) involves ditch network maintenance (DNM) operations in peatlands. Although the DNM operations contribute tree growth, they have negative environmental effects on watercources. To avoid DNM, a strip cutting (SC) management has been proposed. SC management in peatlands relies on natural regeneration by trees growing on the edge stand next to a clear-cut strip. The width of a cut strip varies, and here 20, 35 and 50 m strip width were applied in three locations in Finland: Akaa (southern), Kuopio (central), and Oulu (northern Finland). Tree growth of an edge stand and sapling stand was modeled with a stand-level model which accounted for the effect of dominant height of the edge stand and variation of shading among alternative strip widths. In southern location, RF financially outperformed SC management with interest rates 2–4%, but with a 5% interest rate and strip with of 35 or 50 m SC management was more beneficial than RF. In central and northern locations RF was better only with a 2% interest rate and with a 20 m strip width. Our results demonstrate that SC management is a financially valid option to apply in pine-dominated peatlands, particularly in northern regions.

Effects of Weak- and Semi-Winter Cultivars of Wheat on Grain Yield and Agronomic Traits by Breaking through Traditional Area Planting

Global warming has changed the suitability of areas traditionally planted with crops, raising concerns about cereal security. To investigate the possibilities and constraints of increasing yields by breaking through traditional area plantings of wheat cultivars, a two-year field experiment was conducted in southern and northern locations in the Yangtze River basin (YRB), China (separated by approximately 180 km), with seven weak-winter types and six semi-winter types, respectively, bred for the two regions. The movement of weak-winter-type cultivars to the north increased or did not change grain yield and their grain yields were not significantly higher than those of local semi-winter-type cultivars. The movement of semi-winter-type cultivars to the south significantly decreased their yields. Thus, breaking through traditional area plantings did not significantly increase grain yields compared with those of local wheat cultivars. Grain yield of wheat planted in the northern YRB was higher by 5 to 20% than that in the southern YRB because of an increase in spikes that resulted from a longer spike formation phase. In addition, the post-anthesis leaf area declined more slowly in the northern YRB because of higher main stem and tiller survival. High-yielding cultivars always had more spikes and larger photosynthetic areas after anthesis than those of low-yielding cultivars regardless of the planting locations, which led to increases in post-anthesis biomass. However, the grain yield of different cultivars was highly variable under different environmental conditions. The coefficient of variation (CV) of grain yield in different cultivars was significantly positively correlated with the CV of spike number and post-anthesis biomass, implying that flexibility spike number and post-anthesis biomass in response to environmental changes can maximize release of yield potential. Therefore, improving main stem and tiller survival can increase spike number and maintain post-anthesis photosynthetic areas and help to establish a large, highly stable, and productive population with a high level of suitability and production through effectively utilizing the resources during the late growth phase. Valuable suggestions for breeding high-yield and -stability cultivars and confirming their planting range in the future are given.

Late Devonian (Frasnian–Famennian) palynomorphs from the Padeha and Bahram Formations of Shahzadeh Mohammad section, northwest of Kerman, Iran

A diverse and well-preserved microphytoplankton assemblage is reported from a measured section of Frasnian–Famennian (Upper Devonian) Padeha and Bahram Formations in Shahzadeh Mohammad area, northwestern Kerman, southeast Iran. The palynoflora assemblage contains 17 genera and 23 species of acritarchs, chitinozoa, scolecodont and rich miospore taxa. 57 species (25 genera) of miospores were identified and 5 assemblage biozones were defined from the Shahzadeh Mohammad section. The miospore composition is similar to neighboring localities in Southern and Northern Iran, but it shows significant similarities with palynoflora from more distant localities, e.g. Saudi Arabia, Western Australia or Algeria. This implies a close relationship between the Iranian platform and other areas of the Northern Gondwana and southern Laurentia Domain during the late Devonian. The investigated section was deposited in a shallow marine environment with tropical conditions during the Frasnian-Famennian period.

The ‘other’ epidemic: canine ehrlichiosis in Australia

Canine monocytic ehrlichiosis (Ehrlichia canis infection) is a serious tick-transmitted disease of dogs that was considered exotic to Australia until recently. The disease was first reported across northern and central Australia in 2020, with significant canine morbidity and mortalities observed at indigenous communities where dog numbers are high, ticks are superabundant, and tick prevention is scant. The date and location of the incursion are unknown, yet comparative genomic analysis suggest the Australian E. canis may have originated from Asia or the Middle East. Veterinarians nationwide are on alert for this notifiable disease since cases have been reported in southern locations as a consequence of moving infected dogs from endemic areas. Acute infections in dogs respond favourably to doxycycline therapy, however chronic disease results in bone marrow failure and death. Tick prophylaxis is key to preventing canine ehrlichiosis and is best achieved using products that repel and kill ticks before they attach. Although reports exist of E. canis as a zoonosis, there is no evidence that the strain involved in the current Australian outbreak poses risk to humans.

A climatology of short-period temperature variations at Australian observation sites

The expansion over the last decade of observations in Australia with 1-min temporal resolution allows an assessment of temperature variations over very short periods, using data from 75 stations between 2012 and 2020. The mean difference between the highest and lowest temperatures within 1 min is greatest in the middle of the day, and greater in summer than winter at most locations, except in the northern tropics where it peaks towards the end of the dry season in spring. At noon in summer, the mean 1-min difference exceeds 0.4°C at numerous locations in semi-arid and arid regions, but is near 0.2°C at a range of southern and coastal locations. At night, it is between 0.05 and 0.10°C, with little seasonal variation, at most locations, although slightly higher in some areas subject to local topographically forced influences such as katabatic winds. There is evidence at some locations of daytime 1-min variations being larger (smaller) when antecedent conditions are abnormally dry (wet), indicating a possible role for the land surface in amplifying or dampening short-period temperature variations. In addition to any inherent interest, these results have applications in data quality control, and in assessing the confidence level that can be applied to estimated maximum and minimum temperatures on days with some missing observations.