Could the acid–base status of Antarctic sea urchins indicate a better‐than‐expected resilience to near‐future ocean acidification?

Increasing atmospheric carbon dioxide concentration alters the chemistry of the oceans towards more acidic conditions. Polar oceans are particularly affected due to their low temperature, low carbonate content and mixing patterns, for instance upwellings. Calcifying organisms are expected to be highly impacted by the decrease in the oceans' pH and carbonate ions concentration. In particular, sea urchins, members of the phylum Echinodermata, are hypothesized to be at risk due to their high‐magnesium calcite skeleton. However, tolerance to ocean acidification in metazoans is first linked to acid–base regulation capacities of the extracellular fluids. No information on this is available to date for Antarctic echinoderms and inference from temperate and tropical studies needs support. In this study, we investigated the acid–base status of 9 species of sea urchins (3 cidaroids, 2 regular euechinoids and 4 irregular echinoids). It appears that Antarctic regular euechinoids seem equipped with similar acid–base regulation systems as tropical and temperate regular euechinoids but could rely on more passive ion transfer systems, minimizing energy requirements. Cidaroids have an acid–base status similar to that of tropical cidaroids. Therefore Antarctic cidaroids will most probably not be affected by decreasing seawater pH, the pH drop linked to ocean acidification being negligible in comparison of the naturally low pH of the coelomic fluid. Irregular echinoids might not suffer from reduced seawater pH if acidosis of the coelomic fluid pH does not occur but more data on their acid–base regulation are needed. Combining these results with the resilience of Antarctic sea urchin larvae strongly suggests that these organisms might not be the expected victims of ocean acidification. However, data on the impact of other global stressors such as temperature and of the combination of the different stressors needs to be acquired to assess the sensitivity of these organisms to global change.     

Reconstructing the diets of Greek Byzantine populations (6th-15th centuries AD) using carbon and nitrogen stable isotope ratios

Documentary evidence and artistic representations have traditionally served as the primary sources of information about Byzantine diet. According to these sources, Byzantine diet was based on grain (primarily wheat and barley), oil, and wine, supplemented with legumes, dairy products, meat, and marine resources. Here, we synthesize and compare the results of stable isotope ratio analyses of eight Greek Byzantine populations (6th-15th centuries AD) from throughout Greece. The δ(13) C and δ(15) N values are tightly clustered, suggesting that all of these populations likely consumed a broadly similar diet. Both inland and coastal Byzantine populations consumed an essentially land-based C(3) diet, significant amounts of animal protein, and possibly some C(4) plants, while no evidence of a general dependence on low-δ(15) N legumes was observed. One interesting result observed in the isotopic data is the evidence for the consumption of marine protein at both coastal sites (a reasonable expectation given their location) and for some individuals from inland sites. This pattern contrasts with previous isotopic studies mainly on prehistoric Greek populations, which have suggested that marine species contributed little, or not at all, to the diet. The possibility that fasting practices contributed to marine protein consumption in the period is discussed, as are possible parallels with published isotope data from western European medieval sites.     

Taxonomic notes on the genus Otoptera (Phaseoleae, Fabaceae) in southern Africa

A taxonomic study of the genus Otoptera (tribe Phaseoleae) is presented. This distinct genus consists of two species, O. burchellii in southern Africa (Namibia, Botswana, South Africa and Zimbabwe) and O. madagascariensis endemic to Madagascar. The two species differ in the shape and size of leaflets, size and orientation of the spur located at the base of the wing petal, and also by size of the pod. A key to the two species is provided. This study focuses mainly on the southern African O. burchellii DC., which is described and illustrated. The species name is lectotypified and the known geographical distribution is recorded for the first time.     

浙江武义2009年南方水稻黑条矮缩病的毒源地分析

2009年, 浙江省境内首次出现南方水稻黑条矮缩病毒(Southern rice black streaked dwarf virus, SRBSDV), 且仅武义县有发病现象。因为该病毒病是一种虫媒病毒, 且白背飞虱Sogatella furcifera (Horváth)是主要传毒介体, 所以本文通过白背飞虱灯下诱虫情况调查、 迁飞轨迹模拟、 天气学背景分析以及毒源地分析, 阐释了2009年浙江省武义县发现的南方水稻黑条矮缩病的供毒源地分布情况, 以及白背飞虱携毒的传递路径, 并讨论了轨迹模拟中各生物学参数的设定方法, 从而为剖析该病毒的宏观流行规律奠定科学基础。结果显示：(1) 通过对白背飞虱迁入武义的主要虫源地与经鉴定的南方水稻黑条矮缩病发病区域的叠加分析, 明确了浙江武义的可能毒源地分布于两广、 闽南、 赣南四省区境内; (2) 西南低空急流及偏南气流是白背飞虱将我国南方的病毒远距离传送到武义县境内的动力源; (3) 白背飞虱随下沉气流和降雨在武义境内的集中降落是南方水稻黑条矮缩病在当地暴发的触发条件。     

Bucking the trend: the African Black Oystercatcher as a recent conservation success story

The African Black Oystercatcher Haematopus moquini is a charismatic, southern African near-endemic, wader species, that is often seen as a flagship species for coastal bird conservation, as it was recently down-listed regionally to Least Concern on the IUCN Red List of Threatened Species. To celebrate this rare conservation success story, BirdLife South Africa named it the 2018 Bird of the Year and ran a year-long programme in collaboration with the Nature’s Valley Trust highlighting aspects of the species’ biology, current threats, and conservation success. We used data collected by the Southern African Bird Atlas Project (SABAP1 and SABAP2) to examine changes in the species’ range and relative abundance, both in the records between the two projects, as well as trends within the SABAP2 sampling period (2008–2017). This case study enabled us to assess whether such metrics can accurately reflect abundance and distributional changes in a species. We found increases in the reported range and the reporting rates between the two Atlas projects, and that the SABAP2 reporting rate was stable. Regionally, across four coastal categories, the reporting rate was lowest in KwaZulu-Natal, though this region also showed an increase in the probability of reporting during the SABAP2 period. While corroborating the recent change in the species’ conservation status, we also provide good evidence that the long-term SABAP data can be used successfully to assess population trends and range changes over time.     

Landscape‐scale lidar analysis of aboveground biomass distribution in secondary Brazilian Atlantic Forest

Secondary forests account for more than half of tropical forests and represent a growing carbon sink, but rates of biomass accumulation vary by a factor of two or more even among plots in the same landscape. To better understand the drivers of this variability, we used airborne lidar to measure forest canopy height and estimate biomass over 4529 ha at Serra do Conduru Park in Southern Bahia, Brazil. We measured trees in 30 georeferenced field plots (0.25‐ha each) to estimate biomass using allometry. Then we estimated aboveground biomass density (ABD) across the lidar study area using a statistical model developed from our field plots. This model related the 95th percentile of the distribution of lidar return heights to ABD. We overlaid this map of ABD on a Landsat‐derived forest age map to determine rates of biomass accumulation. We found rapid initial biomass regeneration (~6 Mg/ha yr), which slowed as forests aged. We also observed high variability in both height and biomass across the landscape within forests of similar age. Nevertheless, a regression model that accounted for spatial autocorrelation and included forest age, slope, and distance to roads or open areas explained 62 and 77 percent of the landscape variation in ABD and canopy height, respectively. Thus, while there is high spatial heterogeneity in forest recovery, and the drivers of this heterogeneity warrant further investigation, we suggest that a relatively simple set of predictor variables is sufficient to explain the majority of variance in both height and ABD in this landscape.     

Prevalence of Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency among Malaria Patients in Southern Thailand: 8 Years Retrospective Study

Erythrocytes deficient in glucose-6-phosphate dehydrogenase (G6PD) is more susceptible to oxidative damage from free radical derived compounds. The hemolysis triggered by oxidative agents such as primaquine (PQ) is used for the radical treatment of hypnozoites of P. vivax. Testing of G6PD screening before malaria treatment is not a common practice in Thailand, which poses patients at risk of hemolysis. This retrospective study aimed to investigate the prevalence of G6PD in malaria patients who live in Southern Thailand. Eight hundred eighty-one malaria patients were collected for 8-year from 2012 to 2019, including 785 (89.1%) of P. vivax, 61 (6.9%) of P. falciparum, 27 (3.1%) of P. knowlesi, and 8 (0.9%) of mixed infections. The DiaPlexC genotyping kit (Asian type) and PCR-RFLP were employed to determine the G6PD variants. The result showed that 5 different types of G6PD variants were identified in 26 cases (2.9%); 12/26 (46.2%) had Mahidol (487G>A) and 11/26 (42.3%) had Viangchan (871G>A) variants, while the rest had Kaiping (1388G>A), Union (1360C>T), and Mediterranean (563C>T) variants. G6PD Songklanagarind (196T>A) variant was not found in the study. Our result did not show a significant difference in the malaria parasite densities in patients between G6PD-deficient and G6PD-normal groups. According to our findings, testing G6PD deficiency and monitoring the potential PQ toxicity in patients who receive PQ are highly recommended.     

PHYLOGENYAND HISTORICAL ECOLOGY OF THE DESMARESTIACEAE (PHAEOPHYCEAE) SUPPORT A SOUTHERN HEMISPHERE ORIGIN1

Phylogenetic relationships in the Desmarestiales (Phaeophyceae) were inferred among the monotypic Arthrocladia (Arthrocladiaceae) and 27 isolates from Desmarestiaceae, representing 17 taxa of Desmarestia and the monotypic Antarctic genera Himantothallus and Phaeurus. Phaeurus and Arthrocladia were used as outgroups. Parsimony analyses of nuclear ribosomal DNA internal transcribed spacer (ITS1 and ITS2) sequences, in which gaps were both included and excluded, yielded well-resolved trees with a consistent general branching pattern. A parallel analysis of nine morphological and life-history characters and three ecological characters yielded a similar tree but provided little resolution in the terminal clades. The position of the monotypic Arthrocladia villosa within the Desmarestiales is consistent with monophyly for the order, but its position as the most primitive desmarestialean is not resolvable from the molecular data set. The basal position of Phaeurus, the Antarctic Desmarestia species, and Himantothallus is consistent with the hypothesis of a Southern Hemisphere origin for the family Desmarestiaceae. The more recent Northern Hemisphere “aculeata” clade evolved from an Antarctic ancestor. A “D. aculeata-like” species was ancestral to a lineage characterized by annual sporophytes with high sulfuric acid content, which radiated into many species, widely distributed in both hemispheres. Mapping of morphological and ecological characters onto the molecular tree confirm the informativeness of sulfuric acid-containing vacuoles and unilocular sporangial types. There is good congruence between phylogenetic tree topology and temperature impints in relation to biogeographic distribution, supporting the theory that temperature tolerance is a conservative trait.     

闽南丘陵山地引种栽培树木的物候期与抗寒力调查

本试验以厦门同安祥溪国有林场为试验点,进行为期30多年的引种驯化试验。对35种主要树种的物候观测表明,引种树木叶芽及幼叶的生长集中在每年3月,花期集中在2~6月,果熟期集中在7~10月。寒害调查结果表明,引种保存的117个树种中,未受寒害或受寒害轻、能在同安正常越冬的有83种,占70.9%;中度冻害的有八宝树、石笔木等16种,占13.7%;而受冻严重和地上部分冻死的有柚木、白格等18种,占15.4%。绝大部分树种均可顺利渡夏,90多种已开花结实;无病虫害或危害轻微不影响生长发育的有109种,占93.2%;病虫影响严重的有桔红、细子龙等8种,占6.8%;造林成活率大于80%的有110种,占93.8%。试验结果表明,闽南丘陵山地收集保存的树种种质资源的生态适应性是多样的,这些树种在生长发育和适应性等方面表现出较大的差异性。