The time of fruiting of Ulota Bruchii Hornsch. and U. crispa Brid.

Abstract

For obscure reasons, sporophytes of the dioicous Hamatocaulis vernicosus are currently unknown in France. With the aim of understanding this failure of sporophyte production we investigated (1) sexual phenology, (2) sex ratio pattern at different spatial scales, (3) limitation of sporophyte formation by the availability of only one sex, (4) limitation of sporophyte formation caused by the distance between male and female, (5) location of sporophytes and (6) the consevation implications of this failure of sporophyte production. Principal results show that phenology cannot explain the failure of sporophyte production. At the regional scale, sporophyte formation is prevented by the fact that several mountain ranges have single-sex populations. The production of spore capsules relies on a strict combination of factors at the local scale: occurrence of sexually expressed mixed-sex colonies, a short distance between male and female individuals and favourable environmental factors (light grazing, high water table). In the Massif Central of France spore production is unlikely because of current unfavourable conditions. Fertility patterns appeared useful in a conservation context.     

Fine‐scale variation within urban landscapes affects marking patterns and gastrointestinal parasite diversity in red foxes

1. Urban areas are often considered to be a hostile environment for wildlife as they are highly fragmented and frequently disturbed. However, these same habitats can contain abundant resources, while lacking many common competitors and predators. The urban environment can have a direct impact on the species living there but can also have indirect effects on their parasites and pathogens. To date, relatively few studies have measured how fine‐scale spatial heterogeneity within urban landscapes can affect parasite transmission and persistence.
2. Here, we surveyed 237 greenspaces across the urban environment of Edinburgh (UK) to investigate how fine‐scale variation in socio‐economic and ecological variables can affect red fox (Vulpes vulpes) marking behavior, gastrointestinal (GI) parasite prevalence, and parasite community diversity.
3. We found that the presence and abundance of red fox fecal markings were nonuniformly distributed across greenspaces and instead were dependent on the ecological characteristics of a site. Specifically, common foraging areas were left largely unmarked, which indicates that suitable resting and denning sites may be limiting factor in urban environments. In addition, the amount of greenspace around each site was positively correlated with overall GI parasite prevalence, species richness, and diversity, highlighting the importance of greenspace (a commonly used measure of landscape connectivity) in determining the composition of the parasite community in urban areas.
4. Our results suggest that fine‐scale variation within urban environments can be important for understanding the ecology of infectious diseases in urban wildlife and could have wider implication for the management of urban carnivores.

     

Local grassland restoration affects insect communities

1. It is hypothesised that ecological restoration in grasslands can induce an alternative stable state shift in vegetation. The change in vegetation influences insect community assemblages and allows for greater functional redundancy in pollination and refuge for native insect species. 2. Insect community assemblages at eight coastal California grassland sites were evaluated. Half of these sites had undergone restoration through active revegetation of native grassland flora and half were non‐restored. Insects were collected from Lupinus bicolor (Fabaceae) within 2 × 2‐m² plots in spring 2017. Lupinus bicolor is a common native species that is used in California restoration projects, and home and state landscaping projects. 3. Ordination demonstrated that insect community assemblages were different between restored and non‐restored sites. These differences were seen in insect functional groups as well as taxa‐specific differences and were found to be driven by environmental characteristics such as non‐native forb cover. 4. Functional redundancy of herbivores decreased at restored sites, while pollinators became more redundant compared with non‐restored sites. The assemblages of the common species found at restoration sites contained more native insects than those found at non‐restored sites, including species such as Bombus vosnesenskii. 5. Local grassland restoration has the potential to induce an alternative stable state change and affect insect community assemblages. Additionally, it was found that grassland restoration can be a potential conservation tool to provide refugia for bumblebees (Bombus), but additional studies are required to fully understand its broader applicability.     

格网尺度下典型旅游城市生态服务价值估算和时空分异特征——以三亚为例

以典型旅游城市三亚市为案例地，利用2006-2018年4期Landsat遥感影像数据，借助ENVI、ArcGIS平台定量识别土地利用演变特征，在1km×1km格网尺度下估算旅游地生态系统服务价值，并结合空间探索性数据分析揭示生态系统服务价值时空分异特征及其与旅游地发展的时空耦合关系。结果表明：（1）2006-2018年间，三亚市生态系统服务价值总量呈逐年下降趋势，由6.73×10⁹元降至5.76×10⁹元，累计减少9.78×10⁸元；（2）空间格局上，三亚市呈"南低北高"空间分异格局，2006-2018年增值区域连片分布于崖州区、天涯区、吉阳区南部区域，且呈逐年减少趋势，减值区域集聚于天涯区东北部、海棠区；（3）空间集聚上，生态系统服务价值截面各年份均呈显著空间正相关且相关性先降后增。高高集聚区位于天涯区北部区域，低低集聚区分布于沿海、海湾地区；（4）旅游发展与生态系统服务价值时空演化特征关联性较强。三亚市天涯区北部林地生态环境良好，生态系统服务价值略有下降但绝对数值稳定，是生态系统服务价值主要来源；旅游发展较为迅速的三亚湾、崖州湾以及海棠湾，相对增值区域较多，但绝对生态系统服务价值损失显著，严重滞后于其他区域。     

Does re-creation of extensive pasture-forest mosaics provide an economically sustainable way of nature conservation in Sweden''s forest dominated regions?

There is a major risk that many of the remaining semi-natural pastures in Swedish forest dominated regions will lose their grazing in the near future with lost biodiversity as a result. The reason is the high costs of grazing small pastures with cattle from generally small herds. The approaching decoupling of the present EU income support per head of cattle will increase the risk. Calculations based on economies of scale in beef production and opportunity cost of forest and arable land suggest that re-creating extensive pasture-forest mosaics consisting of existing semi-natural pastures and adjacent arable fields and forests can secure economically sustainable grazing. The risk of local extinction of grassland species due to habitat isolation is also lower in large mosaics than in small, scattered pastures.     

Association of the colistin resistance gene mcr-1 with faecal pollution in water environments in Hanoi,Vietnam

Colistin is one of the antibiotics of last resort for human health. However, the dissemination of the plasmid-mediated colistin resistance gene mcr-1 is of great concern globally. In the One Health framework, the environment is an important component for managing antimicrobial resistance. However, little information is available concerning the prevalence of mcr-1 in water environments. We aimed to reveal the prevalence of mcr-1 in different water environments in Hanoi, Vietnam. Quantitative PCR was applied to detect mcr-1 in four urban drainages receiving untreated domestic wastewater, three rivers, five lakes and two groundwater samples. Urban drainages contained higher concentrations of mcr-1, suggesting that urban residents carry the gene. The class 1 integron-integrase gene was identified as a good surrogate of antibiotic resistance genes including mcr-1. A significant correlation was found between the levels of mcr-1 and the human-specific cross-assembly phage, which is an indicator of human faecal pollution. These results indicated that the primary source of mcr-1 in urban water environments is human faeces, which is consistent with the fact that most domestic wastewater is untreated in Hanoi. The control of untreated wastewater is critical for alleviating the spread of mcr-1 in water environments in Vietnam.     

Sexual dimorphism in scales of marbled flounder Pseudopleuronectes yokohamae (Pleuronectiformes: Pleuronectidae), with comments on the relevance to their spawning behaviour

Variation of scales on the blind side of Pseudopleuronectes yokohamae in relation to sex, maturity and body size was examined. Immature males often have cycloid scales, while mature males have mostly ctenoid scales. Large females also often have ctenoid scales (but with fewer spines compared with males), and small females have mostly cycloid scales. The number of spines (ctenii) on the blind‐side scale increases with body size in both sexes, indicating an ontogenetic change in scale morphology. As P. yokohamae spawn demersal eggs with males positioning themselves above the females on the ocular side, it is hypothesized that ctenoid scales on the blind side in mature males function for maintaining contact with females during spawning.     

Settling-site selection and survival of two scale insects,Ceroplastes rubens andC. ceriferus,on citrus trees

We studied settling-site selection and the resulting survival of two sessile scale insects, Ceroplastes rubens and C. ceriferus, in the citrus tree, Citrus unshiu, in central Japan. C. rubens preferred 0-year-old twigs most as a settling-site; the density of nymphs settling on 0-year-old twigs was significantly higher than those on ≥1-year-old twigs, and few nymphs settled on ≥3-year-old twigs. The mean survival rates from settling until reproduction in the next year were significantly higher on more preferred twigs than on less preferred ones. In C. ceriferus, nymphs significantly preferred 1- and 2-year-old twigs to 0- and ≥3-year-old ones, and the mean survival rates on the more preferred 1- and 2-year-old twigs were significantly higher than those on less preferred ≥3-year-old twigs. However, the survival rate on less preferred 0-year-old twigs was slightly higher than those on 1- and 2-year-old ones. Thus, in both species of scale, it was the preferred twigs which were more profitable sites for survival after settling, except for less preferred 0-year-old twigs for C. ceriferus. In both scale species, most mortality was due to growth cessation, which is believed to be related to the twig quality as a food source. Predators and parasitoids were minor mortality factors. Both species showed constant survival rates until the density of settled nymphs exceeded double the “upper-limit” density, whereupon they decreased drastically. Nymphs of C. rubens settling on twigs of high scale density showed a spacing-out distribution, those of C. ceriferus did not. In C. rubens, an increase in preference for originally less profitable twigs at the later stage of the settling season was observed, but not in C. ceriferus. Accordingly, individuals of C. rubens showed a stronger tendency to avoid conspecifics than did C. ceriferus. Although nymphs of the two scales clearly preferred more profitable sites, their settling-site selection did not agree with the predictions from the ideal free distribution theory (Fretwell and Lucas, 1970). The discrepancies were (1) frequent settling on less profitable sites at the early stage of the settling season, (2) insufficient utilization of the most profitable twigs, and (3) virtually 100% mortality on overcrowded twigs under conditions where unoccupied profitable twigs still remained. These discrepancies are thought due to the limited dispersal time of nymphs.