Topographic heterogeneity lengthens the duration of pollinator resources

The availability of sufficient and diverse resources across time is important for maintenance of biodiversity and ecosystem functioning. In this study, we examine the potential for variation in environmental conditions across topographic gradients to extend floral resource timing. Flowering time on a landscape may vary across topography due to differences in abiotic factors, species turnover, or genotypic differences. However, the extent to which this variation in phenology affects overall flowering duration on a landscape, and the components of diversity that influence flowering duration, are unexplored. We investigate whether differences in flowering time due to topography yield an overall extension in duration of flowering resources in a northern California grassland. We recorded flowering time of pollinator resource species across four successive spring growing seasons (2015–2018) on paired north and south aspects. Flowering time differences were evaluated both at the community level and within species present on both paired aspects. The role of plasticity was examined in an experimental case study using genotypes of Lasthenia gracilis. We found that aspect is a strong determinant of phenology, with earlier flowering on warmer south‐facing slopes. Aspect differences resulted in complementarity in timing of flowering resources across sites, as aspects that started flowering earlier also ended earlier. Complementarity between north and south aspects served to extend the flowering time of pollinator resources by an average of 4–8 days (8%–15%), depending on the year. This extension can be attributed to both within‐species responses to aspect differences and species turnover. Flowering of L. gracilis genotypes was distinct across aspects, demonstrating that plasticity can drive the extension of flowering duration. Our findings indicate that heterogeneous topography can extend overall flowering time of pollinator resources, which may support pollinator biodiversity. Extension was most pronounced at the community level, which incorporates species turnover as well as plastic and genotypic differences within species.     

Land masses and oceanic currents drive population structure of Heritiera littoralis,a widespread mangrove in the Indo‐West Pacific

Phylogeographic forces driving evolution of sea‐dispersed plants are often influenced by regional and species characteristics, although not yet deciphered at a large spatial scale for many taxa like the mangrove species Heritiera littoralis. This study aimed to assess geographic distribution of genetic variation of this widespread mangrove in the Indo‐West Pacific region and identify the phylogeographic factors influencing its present‐day distribution. Analysis of five chloroplast DNA fragments’ sequences from 37 populations revealed low genetic diversity at the population level and strong genetic structure of H. littoralis in this region. The estimated divergence times between the major genetic lineages indicated that glacial level changes during the Pleistocene epoch induced strong genetic differentiation across the Indian and Pacific Oceans. In comparison to the strong genetic break imposed by the Sunda Shelf toward splitting the lineages of the Indian and Pacific Oceans, the genetic differentiation between Indo‐Malesia and Australasia was not so prominent. Long‐distance dispersal ability of H. littoralis propagules helped the species to attain transoceanic distribution not only across South East Asia and Australia, but also across the Indian Ocean to East Africa. However, oceanic circulation pattern in the South China Sea was found to act as a barrier creating further intraoceanic genetic differentiation. Overall, phylogeographic analysis in this study revealed that glacial vicariance had profound influence on population differentiation in H. littoralis and caused low genetic diversity except for the refugia populations near the equator which might have persisted through glacial maxima. With increasing loss of suitable habitats due to anthropogenic activities, these findings therefore emphasize the urgent need for conservation actions for all populations throughout the distribution range of H. littoralis.     

Culture Independent Diversity of Bacterial Communities Indigenous to Lower Altitude at Laohugou Glacial Environment

Abstract

High-throughput sequencing approach of the 16S rRNA gene was employed to evaluate the bacterial diversity inhabit in melted water, snow, soil, and rocks samples at the lower altitudes of the Laohugou glacial environment. Bioinformatics tools were used to process millions of Illumina reads for alpha and beta diversities of bacterial communities. The diversity indices such as Chao, Shannon, and Simpson were different in the collected samples and solid samples (soil and rocks) showed higher taxon richness and evenness. Taxonomic diversity was unexpectedly higher and the major portion of sequences was assigned to Proteobacteria, Actinobacteria, and Acidobacteria. Higher variation in community structure was reported at the class level and Alphaproteobacteria was dominant. The solid niches were occupied by a higher number of phyla compared with liquid. The physicochemical variables acted as spatial gradients and associated with the bacterial structural communities of the glacial ecosystem. Findings showed that both Proteobacteria and Actinobacteria in solid samples influenced the bacterial community structure in downstream liquid samples. Interestingly, the metagenomic biomarkers were higher in liquid samples. This study provides precious datasets to understand the bacterial community in a better way under the influence of spatial, physical and environmental factors.     

AAI to DDD pacing mode inappropriate switches in a dual chamber pacemaker due to ventricular blanking period

A 90-year-old woman received a dual chamber pacemaker (PM) for a sick sinus syndrome. The PM was programmed with SafeR AAI-DD pacing mode at 60 bpm. During a standard follow up, some memorized electrograms (EGMs) were found in SafeR diagnostics, with atrial pacing (Ap) not followed by any ventricular sensing/pacing event, due to simultaneous junctional activity falling into ventricular blanking period during Ap and, for this reason, unsensed by the PM. Blanking periods can affect PM functioning if not revealed and adjusted.     

Les sépultures italiennes du Paléolithique supérieur. Reconstitutions du régime alimentaire

The identification of dietary habits is increasingly seen as a fundamental aspect for studying the ancient human populations. Accordingly, several projects aiming to identify Paleolithic individuals’ dietary patterns were developed to analyze the organic component of bone tissue and identify isotopic markers to reconstruct the food typology. Bone fragments from six individuals were selected for carbon and nitrogen stable isotopes analysis. The interpretation of human isotopic data was framed through a dataset of twenty-one Italian Paleolithic individuals. The isotopic data generated for the Paleolithic individuals agree with the information already provided by the archaeological record concerning the Italian hunter and gatherer communities. Their subsistence economy was essentially grounded upon the exploitation of high protein foods, either from terrestrial fauna resources or inland lacustrine or riverine species.     

不同组织分离期对大圆头蛹虫草菌种性能的影响

为明确大圆头蛹虫草组织分离最佳分离时期,以大圆头蛹虫草优良母种为母本,采用组织分离法制备子代母种,以优良母种为对照,通过对不同组织分离期（35、40、45、50 d）子代母种平板培养、液体培养及栽培实验,考察不同组织分离期对子代母种培养性状及子实体形成能力的影响。结果表明,不同组织分离期大圆头蛹虫草子代母种培养性状存在较大的差异,其子实体形成能力与子代母种培养性状具有显著相关性,以组织分离期为40 d的子代母种性能表现最优,优良菌种筛选率最高（48%）,45 d次之（44%）,50 d最低（32%）。 明确大圆头蛹虫草优良菌种选育组织分离最佳时期为40 d,试验结果为大圆头蛹虫草优质菌种选育、复壮提供参考。     

Germination response of four pasture species to temperature,light, and post-harvest period

Abstract

The purpose of this research was to explore the effect of temperature, light, and post-harvest period, and their interactions, on seed germination ecology of four common pasture species in the Mediterranean environment. Mature seeds of Diplotaxis erucoides, Hirschfeldia incana, Hyoseris scabra (Mediterranean distribution) and Sonchus oleraceus (cosmopolitan distribution) were subjected to seven constant temperatures (10–40°C, at intervals of 5°C) under continuous darkness, or a 12 h/12 h light/dark photoperiod at 30, 150 and 270 days after harvest (DAH). Cumulative germination and germination speed were determined. In all the tested species, except S. oleraceus, light significantly enhanced germination. S. oleraceus seeds maintained germination values over 90%, in a wide range of temperatures (10–35°C), in the dark as well as in light. Seeds of H. incana germinated well soon after seed dispersal. In D. erucoides and H. scabra, germination increased with storage period, while in S. oleraceus there was no effect of seed age. In all the species, moreover, no germination was recorded at 40°C. Temperature, light, and post- harvest requirement may be regarded as an adaptation strategy to ensure optimal conditions for seedling development and survival in Mediterranean species, while the species with a cosmopolitan distribution germinates under almost all tested conditions.     

The plant landscape as inferred from a basket of the Roman town of Privernum (Latium,central Italy)

Abstract

Privernum was a rich Roman colony located 70 km southwest of Rome (southern Latium, central Italy). The archaeobotanical investigations focused on the garden and related structures of the luxury domus della Soglia nilotica. They are archaeologically and radiocarbon dated to the second half of the 1st century AD. The remains of a charred basket were found in the filling of the euripus, an ornamental water basin of the garden. The weaving was made with twisted strands of the leaves of Ampelodesmos mauritanicus (Poir.) T. Durand and Schinz; for the bottom and the handle/s of the basket, wood of evergreen oaks and ash and/or elm, respectively were probably used. The basket contained Pinus pinea seeds and cone scales, and Prunus persica endocarps, which were probably burnt in summer. The sediment in the drainage system and in the kitchen was processed for macro- and microremains. The results indicate the presence of spontaneous ruderal and weed flora elements, typical of human settlement areas, and crops.     

Forecasting range expansion into ecological traps: climate‐mediated shifts in sea turtle nesting beaches and human development

Some species are adapting to changing environments by expanding their geographic ranges. Understanding whether range shifts will be accompanied by increased exposure to other threats is crucial to predicting when and where new populations could successfully establish. If species overlap to a greater extent with human development under climate change, this could form ecological traps which are attractive to dispersing individuals, but the use of which substantially reduces fitness. Until recently, the core nesting range for the Critically Endangered Kemp's ridley sea turtle (Lepidochelys kempii) was ca. 1000 km of sparsely populated coastline in Tamaulipas, Mexico. Over the past twenty‐five years, this species has expanded its range into populated areas of coastal Florida (>1500 km outside the historical range), where nesting now occurs annually. Suitable Kemp's ridley nesting habitat has persisted for at least 140 000 years in the western Gulf of Mexico, and climate change models predict further nesting range expansion into the eastern Gulf of Mexico and northern Atlantic Ocean. Range expansion is 6–12% more likely to occur along uninhabited stretches of coastline than are current nesting beaches, suggesting that novel nesting areas will not be associated with high levels of anthropogenic disturbance. Although the high breeding‐site fidelity of some migratory species could limit adaptation to climate change, rapid population recovery following effective conservation measures may enhance opportunities for range expansion. Anticipating the interactive effects of past or contemporary conservation measures, climate change, and future human activities will help focus long‐term conservation strategies.