The black fly genus Simulium includes medically and ecologically important species, characterized by a wide variation of ecological niches largely determining their distributional patterns. In a ...rapidly changing environment, species-specific niche characteristics determine whether a species benefits or not. With aquatic egg, larval and pupal stages followed by a terrestrial adult phase, their spatial arrangements depend upon the interplay of aquatic conditions and climatic-landscape parameters in the terrestrial realm. The aim of this study was to enhance the understanding of the distributional patterns among Simulium species and their ecological drivers. In an ecological niche modelling approach, we focused on 12 common black fly species with different ecological requirements. Our modelling was based on available distribution data along with five stream variables describing the climatic, land-cover, and topographic conditions of river catchments. The modelled freshwater habitat suitability was spatially interpolated to derive an estimate of the adult black flies' probability of occurrence. Based on similarities in the spatial patterns of modelled habitat suitability we were able to identify three biogeographical groups, which allows us to confirm old assessments with current occurrence data: (A) montane species, (B) broad range species and (C) lowland species. The five veterinary and human medical relevant species Simulium equinum, S. erythrocephalum, S. lineatum, S. ornatum and S. reptans are mainly classified in the lowland species group. In the course of climatic changes, it is expected that biocoenosis will slightly shift towards upstream regions, so that the lowland group will presumably emerge as the winner. This is mainly explained by wider ecological niches, including a higher temperature tolerance and tolerance to various pollutants. In conclusion, these findings have significant implications for human and animal health. As exposure to relevant Simulium species increases, it becomes imperative to remain vigilant, particularly in investigating the potential transmission of pathogens.
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•Three ecological groups were identified based on distributional patterns.•Old assessments were confirmed with the latest occurrence data.•For each group, we derived different population trends in times of global change.•Global change elevates importance of vector-borne diseases.•Our results serve as base for effective Simuliidae monitoring.
•The improved monthly runoff frequency method (IMRF) was proposed.•The guarantee degree of ecological flow based on the ecological requirements of fish (EFG) was proposed.•The quantity, timing, and ...quality of water required by fish were considered in EFG.•Practical safeguard for river ecosystems and standard for water resources allocation.
Human activities have altered the natural flow regime and exacerbated the consumption of water resources, leading to increasingly acute conflict between domestic and production water demands and ecological water demands. Scientific quantification of ecological flow and its guarantee degree under hydrological variation is an important topic for water resources allocation research. A comprehensive study of ecological flow and its guarantee degree is currently lacking. Thus, the improved monthly runoff frequency method (IMRF) and the guarantee degree of ecological flow based on the ecological requirements of fish (EFG) were proposed in this study. The quantity, timing, and quality of water required by fish during the migration period, spawning and feeding period, and overwintering period were considered in EFG. Taking the Jinsha River Basin as the study area, the results demonstrated that the annual runoff series was mutated in 1986, the overall hydrological alteration degree was 32.7 % and the ecological risk based on DHRAM was moderate in the basin. The suitable and basic ecological flows for each month were reliable and could serve as reasonable water quantity standards for the quantification of EFG. EFG of typical years (wet, normal, dry, and withered years) for the pre-change period were 86 %, 82 %, 67 %, and 63 %, respectively; and 79 %, 81 %, 73 %, and 71 % for typical years during the post-change period, respectively. The differences in EFG for the pre- and post-change periods were closely related to the variations in the hydrological regime of the river. The findings can provide a valuable reference for ecological protection and water resource management in the Jinsha River Basin, and may also be instructive for similar studies in other cases.
Climatic history and ecology are considered the most important factors moulding the spatial pattern of genetic diversity. With the advent of molecular markers, species' historical fates have been ...widely explored. However, it has remained speculative what role ecological factors have played in shaping spatial genetic structures within species. With an unprecedented, dense large-scale sampling and genome-screening, we tested how ecological factors have influenced the spatial genetic structures in Alpine plants. Here, we show that species growing on similar substrate types, largely determined by the nature of bedrock, displayed highly congruent spatial genetic structures. As the heterogeneous and disjunctive distribution of bedrock types in the Alps, decisive for refugial survival during the ice ages, is temporally stable, concerted post-glacial migration routes emerged. Our multispecies study demonstrates the relevance of particular ecological factors in shaping genetic patterns, which should be considered when modelling species projective distributions under climate change scenarios.
Background:
Active restoration is necessary to enhance the recovery of Ostrea
edulis
reefs, which contribute to many ecosystem services. Restoration can be integrated within aquaculture practices, ...bringing positive environmental changes while maximising space utilisation. The restoration project MAREA (MAtchmaking Restoration Ecology and Aquaculture) aims to bring back
O. edulis
in the North-West Adriatic addressing the feasibility of its cultivation. Both successful restoration and sustainable aquaculture require a thorough understanding of the ecological needs, as the requirements of both activities need to be harmonized. Therefore, one of the preliminary activities before embarking on the pilot was the completion of a thorough literature review to identify research directions and gaps required for ‘restorative aquaculture’, aiming to gather the most up to date O
. edulis
knowledge on a global and local scale.
Methods:
Internet (Web of Science, Scopus, Google scholar) and physical resources (libraries) were searched for all available global and local knowledge on O
. edulis. Bibliometrix
was used to identify the main research topics using keywords, titles, and abstracts analyses. Studies were then manually screened and summarised to extract knowledge specific to restoration and aquaculture.
Results:
While restoration studies are recent, evidence for the loss of this species and potential causes (and solutions) have been discussed since the end of the 19
th
century. While diseases were a leading cause for reef loss, substratum limitation appears to be one of the leading limiting factors for both restoration and aquaculture of O
. edulis
, and was already mentioned in the early texts that were found.
Conclusions:
The review highlighted that restoration success and aquaculture feasibility depend upon the crucial stage of settlement. The project ‘MAREA’ will therefore increase its focus on this stage, both in terms of timing, location, and materials for settlement plates placement.
•Insect biomass alone cannot predict biodiversity metrics across contrasting habitats.•Biodiversity metrics other than biomass or insect abundance should be mainstreamed.•Patterns of phylogenetic ...diversity (PD) are consistent using different trees.•Species identification is key for conservation tailored to the targeted organisms.
Recent studies have reported on dramatic cases of aerial insect population declines by focusing on the measure of the total biomass of caught insects. However, there is currently no consensus about how biomass patterns among sites and habitats might consistently capture the subtleties of changes in aerial insect community structure. Here, we investigated the relationship between the total biomass of wild bees collected using pan traps in urban, agricultural, and semi-natural habitats on one hand, and a spectrum of biodiversity metrics on the other hand, particularly species richness (SR), alpha diversity, functional diversity (FD) and three different forms of phylogenetic diversity (PD). Our results indicate that although biomass is significantly and highly correlated with the abundance of wild bees, it is generally significantly but only moderately and non-linearly correlated to the various facets of wild bee diversity among habitats. By contrast, we also found that all three measures of PD used are consistent across habitats, suggesting that a taxonomic hierarchy based on Linnaean classification could be used as a proxy for the measurement of PD in wild bees, particularly in other well-studied areas such as Western Europe where a multi-gene molecular phylogeny is unavailable as yet. Collectively, our results illustrate the clear limitations of biodiversity monitoring through measures of trapped insects biomass. We advocate for more robust measures of biodiversity trends in wild bees, requiring both standardized surveys, and the identification of caught specimens down to the species level to capture the subtleties of species, traits-based and phylogeny-based community changes across habitats or time. Scaling out this approach is an essential prerequisite for more global conservation planning tailored to the ecological requirements of the targeted insect species.
Summary
Species absent from a community but with the potential to establish (dark diversity) are an important, yet rarely considered component of habitat‐specific species pools. Quantifying this ...component remains a challenge as dark diversity cannot be observed directly and must be estimated. Here, we empirically test whether species ecological requirements or species co‐occurrences provide accurate estimates of dark diversity.
We used two spatially nested independent datasets, one comprising 3033 samples of coastal grassland vegetation from 4 m2 and 200 m2 plots from Scotland, UK, and another comprising 780 samples of forest vegetation plots from 30 m2 and 500 m2 plots from Switzerland. Dark diversity for each of the smaller scaled plots was estimated through investigating the degree of (i) similarity in ecological requirements (measured as Ellenberg values); and (ii) co‐occurrence likelihood. Estimates were validated using species from the larger spatial scales. Estimates were further validated using observations from all larger scale plots surrounding a focal assemblage within a 2 km (Scottish grassland) and 10 km (Swiss forest) radius.
The co‐occurrence method was shown to be more accurate resulting in far fewer negative mismatches (i.e. species observed but not predicted), as well as higher proportions of observed and predicted species, relative to the Ellenberg method. Of the species observed in the large‐scale samples, 18% were estimated as part of the smaller scale dark diversity via the co‐occurrence approach relative to 8% for the Ellenberg method for both the Scottish and Swiss data, respectively. These values increased to 67% & 60% and 32% & 35%, respectively, across all observations within a 2 km (Scottish grasslands) and 10 km (Swiss forests) radius.
The study demonstrates that dark diversity for a community can be successfully estimated using readily available data, through exploring species co‐occurrence patterns. This work substantiates that habitat‐specific species pools can be accurately quantified and should prove valuable for understanding underlying community processes and improving our knowledge of the mechanisms governing species co‐existence.
On the one hand, the European beech (
a L.) is the tree of the future due to ongoing climate changes, on the other hand, there are questions about its expansion and economic use as a replacement for ...the declining Norway spruce (
L. Karst.). This literature review examines 140 studies summarizing basic research on beech in the context of climate change. As a climax tree species, beech is becoming dominant again in parts of its original range at the middle and higher altitudes of Central Europe, following spruce. It is a shade-loving species that can thrive in various types of mixed forest stands. To cultivate beech, close-to-nature methods, shelterwood, or selection management are optimal. The occurrence of the beech seed year is influenced by factors such as precipitation, temperature, drought, and air pollution. Although beech is generally considered resistant to abiotic and biotic factors, it often needs protection against hoofed game browsing in the earliest stages of development. As climate change progresses, it is essential to cultivate beech in areas rich in precipitation and nutrients where it can thrive even under more extreme conditions. In optimal conditions, beech has shown intensive regeneration in recent years, aggressively displacing other tree species. However, with insufficient precipitation and prolonged periods of drought, beech loses its vigor, production, and ability to compete. For adaptation to climate change, it is recommended to select appropriate beech provenance, promote natural regeneration, and cultivate structurally differentiated stands through positive-selection thinning from above.
Zulkarnaen RN, Garvita RV, Wawangningrum, H, Tyas KN. 2020. Population ecology size and habitat preference of the ghost orchid Didymoplexis pallens in Bogor Botanic Gardens, Indonesia. Biodiversitas ...21: 2056-2061. Didymoplexis pallens is a terrestrial orchid that has leafless characteristics. The population ecology of D. pallens is still not widely known because it only grows in certain areas and at certain times. This study aims to know the population ecology and habitat preference of D. pallens. The study was conducted in Bogor Botanic Gardens where D. pallens occurred naturally. The research method uses purposive sampling by establishing observation plots around bamboo collections in the garden. The results showed that D. pallens had a large population around specific bamboos, such as Gigantochloa verticillate, Gigantochloa atroviolacea and Dendrocalamus giganteus. In addition, the presence of D. pallens populations was strongly influenced by the presence of other plants that compete around it and light intensity. The Principal Component Analysis revealed there are two components of the abiotic factor that influenced the existence of D. pallens, i.e. the first component consisting of coverage, air humidity, temperature, and soil humidity. The second component consisting of litter thickness and soil pH.
The poor understanding of the spread conditions and the geographical patterns of the exotic freshwater snail Physa acuta in sub-Saharan Africa urban streams makes it difficult to design and implement ...sustainable management tools, especially in deteriorating global and local environments. This study aimed to determine the ecological preferences and the major environmental variables associated with P. acuta abundance, occurrence and distribution in Douala urban streams-system using modelling approaches based on discriminant factor analysis, canonical Spearman correlation and random forest tree models. We inductively define four clusters for snail’s distribution along a geographical and upstream–downstream pollution gradient. Snail’s specimens were collected monthly over a 13-month period in two forest and ten urban sites using a long-handled net (30x30cm side, 400-µm mesh). Meanwhile, measurements of the physicochemical properties of water and streambed sediment were taken. In addition, ten metal contents were determined in P. acuta tissues to assess its ability of bioaccumulation of heavy metals. Results revealed that urban streams of Douala are adversely impaired, especially downstream of industrial effluents. Discriminant factor analysis and random forest regression trees model showed that dissolved oxygen, biochemical oxygen demand, alkalinity, salinity, pH, water depth, wetted width, zinc, iron, cadmium, encumbrance rate of the sediment and sediment types (high sandy mud, sandy mud and muddy sand) were the major environmental variables responsible for structuring P. acuta distribution. Abundances decline drastically following pollution gradient, with great decrease observed in juvenile size classes. High contents of metals were detected in P. acuta tissues, especially downstream of industrial effluents. This study highlights that P. acuta spread in Douala urban-streams system is structured by key environmental variables related to an upstream–downstream pollution gradient. Therefore management plans should emphasize on proper disposal ways of industrial wastes, and stakeholders should take responsible actions in water pollution control and implement the polluter-payer principle.
•Dynamic trend of the invasive snail P. acuta was assessed using modelling approach.•P. acuta abundances decrease significantly following stream flow pollution profile.•DFA and RDF models showed a tight P. acuta dynamic-sediment properties relationship.•P. acuta is sensitive to long-term chemical pollution & juveniles are more affected.•Using P. acuta as model to monitor pollution and heavy metals disposal is relevant.
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