ARPHA OAI-PMH Endpoint
Not a member yet
49206 research outputs found
Sort by
Functional trait interactions drive seed buoyancy and dispersal strategies in Echinocystis lobata
No full textHydrochory (water dispersal) is a major driver of plant invasions in riparian landscapes but both the diaspore traits that determine flotation and the contribution of water-mediated transport to the colonization success of non-native species remain insufficiently understood. Echinocystis lobata, an alien vine widely naturalized along European rivers, provides a suitable model for testing how seed morphology governs buoyancy and, consequently, hydrochorous dispersal potential. The main aim of this study was to examine how functional traits influence the buoyancy of E. lobata seeds, which can be classified as normal seeds, freely released from fruits, and trapped seeds, retained within fruits. We investigated three hypotheses under controlled laboratory conditions: (H1) seed mass, particularly in interaction with thickness, determines sinking probability; (H2) surface area affects flotation mainly through interactions with mass; and (H3) trapped seeds differ functionally from normally released seeds. Using a generalized linear mixed-effects model, we demonstrated that buoyancy is governed by non-linear interactions among mass, thickness, and surface area, with distinct patterns for trapped versus normal seeds. Thin normal seeds floated longer as mass increased, whereas in trapped seeds higher mass accelerated sinking. Surface area influenced flotation only when combined with mass and trapping status. Normal seeds remained buoyant for up to 14 days, while trapped seeds sank sooner (≤11 days). These findings highlight that variability in diaspore traits generates a broad spectrum of dispersal outcomes, supporting both local deposition and long-distance hydrochoric transport. Understanding how trait-vector interactions shape dispersal enhances invasion risk prediction and informs management strategies, such as removing reproductive plants near waterways before fruit maturation. Overall, our results demonstrate that hydrochory, amplified by diaspore heteromorphism, may be a key driver increasing the invasiveness of E. lobata in European river valleys
Sedum qingyuanense (Crassulaceae), a new species from Qingyuan, Guangdong, China
No full textThis study describes a new species of Sedum (Crassulaceae), Sedum qingyuanense sp. nov. discovered in Qingyuan City, Guangdong Province, China. Morphologically, S. qingyuanense resembles S. alfredii and S. emarginatum. The new species may have previously been misidentified as S. alfredii. However, the new species can be readily distinguished from S. alfredii by its creeping sterile stems, opposite leaves, emarginate leaf apices, and smaller sepals. Compared to S. emarginatum, it is differentiated by its creeping sterile stems, smaller sepals, and conspicuous pseudopetioles. Phylogenetic analysis based on the nuclear ribosomal DNA internal transcribed spacer (ITS) region revealed that the new species forms a sister clade to S. emarginatum within Sedum sect. Sedum, supported by moderate to strong bootstrap support (> 80%). Integrating both morphological evidence and the phylogenetic tree, we establish it as an independent lineage
From conflicts to coexistence? Exploring the dynamics of human-wildlife conflicts in a mosaic forest-savanna transition area of Mbam et Djerem National Park, Central Cameroon
No full textHuman-wildlife conflict (HWC) has been recognized to significantly affect both human livelihoods and wildlife conservation around protected areas, including the Mbam et Djerem National Park (MDNP) in central Cameroon. However, little is known about the dynamics of these conflicts, including types of conflict, species involved, crops raided, animals attacked, financial losses incurred, and existing mitigation techniques. This hampers effective mitigation strategies and policy interventions. To help fill this knowledge gap, the study aims to explore the dynamics of HWC around the MDNP, including local mitigation strategies employed. Using a stratified sampling approach and a structured questionnaire, data were collected from 280 respondents across 10 villages and diverse vegetation types.Overall, 98% of respondents experienced HWC, with crop raiding (98%) and domestic animal attacks (58%) being the primary conflict types. Cane rats, porcupines, and squirrels were recognized as the principal crop raiders, primarily targeting cassava (90%), maize (51%) and groundnuts (29%). Hawks (69%), civets (62%) and falcons (29%) predominantly attacked chicks. Conflicts were reported to occur year-round, peaking during the rainy season (88%). Financial losses due to crop raiding ranged from XAF 0 to 3,400,000 (mean = XAF 454,999 ± XAF 603,232.2), influenced by farm and raided plot sizes, while losses from domestic animal attacks ranged from XAF 5,000 to XAF 500,000 (mean = XAF 93,323 ± 105,285.3), affected by seasons and distance from the village to the park. Farm surveillance (59%), trapping (42%), and fencing (35%) were the major mitigation measures employed by respondents but were reported to be largely ineffective. The study emphasizes the need to support the local communities with alternative livelihood strategies, effective compensation systems, and improved mitigation measures to reduce human-wildlife conflict, enhance their well-being, and ensure their support for the protection of the MDNP
Dysosma xishuiensis (Berberidaceae), a new species from Guizhou, China, based on morphological and molecular evidence
No full textDysosma xishuiensis Y. B. Yang, M. T. An & C. H. Yang is described and illustrated as a new species from Xishui County in northern Guizhou Province, China. This species is morphologically similar to D. versipellis, but differs by its glabrous abaxial leaf surface, pedicels, and sepals; inflorescences bearing more flowers (8–20 vs. 5–8); larger obovate–oblong petals (2.8–3.4 × 1.5–2.0 cm vs. 2.5 × 0.8 cm); and an obpyriform ovary (vs. ellipsoid). The phylogenetic relationships reconstructed using ITS, matK, and rbcL sequences further confirm that it is a new species within Dysosma. This species is currently known only from the Xishui National Nature Reserve in Guizhou. According to IUCN criteria (B2, D), due to its limited distribution and low population numbers, D. xishuiensis is assessed as Endangered (EN)
Four new species of Microdochium (Microdochiaceae, Xylariales) from Hainan, China
No full textMicrodochium has been reported worldwide as a plant pathogen, endophyte, or saprotroph. This study utilized four genetic loci (ITS, LSU, rpb2, and tub2) along with morphological characteristics, employing maximum likelihood and Bayesian inference analyses to identify and establish the taxonomic status of four new species from two host plants (Bambusaceae sp. and Phragmites australis) in Hainan Province, China. We propose four new species, Microdochium australiana sp. nov., M. baishamenense sp. nov., M. bambusina sp. nov., and M. bambusarum sp. nov. We provide detailed descriptions and micrographs of these species and compare them with other Microdochium species
A new species of the Cymbasoma longispinosum species-group (Copepoda, Monstrilloida) from the northern South China Sea
No full textA new monstrilloid copepod species, Cymbasoma stricturum sp. nov., is described and illustrated on the basis of adult females from the Pearl River estuary, northern South China Sea. The new species is closest to C. morii Sekiguchi, 1982, C. sinopense Üstün, Terbiyik & Suárez-Morales, 2014, and C. jinigudira Suárez-Morales & McKinnon, 2016, but it can be distinguished by a combination of characters including strongly protuberant, straight oral papilla; a cephalothorax that is distinctly constricted at the anterior two-fifths in both dorsal and lateral views; and two pairs of well-developed nipple-like processes on anterior dorsal surface, among other diagnostic traits. This is the ninth nominal species known in the Cymbasoma longispinosum species-group. We provide an updated dichotomous key for females and a revised worldwide distribution map of the species-group
Biogeography of tropical dry forest soils
No full textThe tropical dry forest is a tropical biome characterized by prolonged dry seasons, and harbors an exceptionally rich floristic biodiversity. Yet it is among the most threatened biomes and its belowground diversity remains poorly documented. Here, we analyzed the soil environmental DNA with metabarcoding to quantify the belowground diversity and composition of 11 tropical dry forest sites across four biogeographic regions in Colombia, and we provide a comparative analysis of the biogeographic drivers of soil biodiversity, including soil properties, climate, and spatial factors. We found that the soil microbial communities of tropical dry forests had high proportions of taxa associated with dry conditions, such as Actinomycetota, Glomeromycetes, and Amoebozoa, compared to other tropical forests. Soil mesofauna consisted mainly of ants, termites, and earthworms, with few enchytraeids. The soil microbial alpha and beta diversity were primarily driven by soil physicochemical and climatic drivers, bacteria being more sensitive to aridity than fungi. Macroorganisms exhibited patterns of diversity that were less well explained by the tested predictors. Rather, most of their variation was associated with the sampled region, reflecting a marked biogeographic structure and suggesting that macroorganisms are more prone to isolation-by-distance than microorganisms. Overall, the prevalence of drought-associated microbial taxa and the specific composition of soil mesofauna indicate that tropical dry forests harbour a distinctive belowground biota. These findings provide an important baseline for understanding soil biodiversity in tropical dry forests and support conservation and restoration efforts at the biome scale
Dive into the Italian PONDY dataset: Pond vegetation data and water physico-chemical parameters
No full textPonds are widespread yet highly vulnerable freshwater habitats that support diverse aquatic and terrestrial plant communities influenced by land use and water characteristics. The PONDY (Pond vegetation data and water physico-chemical parameters) dataset integrates vegetation and water physico-chemical data that have been collected to understand the responses of vegetation to environmental parameters. The dataset comprises 575 plots, of which 232 are aquatic and 343 are terrestrial, derived from 115 ponds across continental and insular areas of Italy. The dataset includes 743 vascular plant taxa and 5 macroalgae encompassing 364 genera and 89 families. Terrestrial plots host 690 taxa belonging to 87 families, while aquatic plots host 117 taxa belonging to 36 families. The dataset includes 10 taxa belonging to the Italian Red List and 39 alien species. Moreover, 11% of the aquatic plots have been classified in a Habitats Directive 92/43/EEC habitat type, while 48% have been classified in a EUNIS habitat type. The dataset contains, for each plot, measurements of physico-chemical water variables such as dissolved oxygen, water depth, and temperature, pH, turbidity, conductivity, and nutrient concentration. The PONDY dataset provides comprehensive information on plant diversity and abundance, community composition, habitat types, and water chemistry in Italian ponds, serving as a key resource for studying plant–environment relationships, developing predictive models, and supporting freshwater conservation efforts
Use of Americium and Curium fractions of minor actinides for the production of heat sources for radioisotope thermoelectric generators
No full textThe article considers the possibility of using the mixed (Am, Cm)-fraction extracted from minor actinides (MA) for large-scale production of powerful heat sources for space radioisotope thermoelectric generators (RTG). Such a choice of the MA fraction removes the limitation on the proportion of 236Pu in plutonium and leaves only a limitation on the proportion of 238Pu (above 80%). The irradiation of the (Am, Cm) mixture and the separated Am-fraction of MA are considered and compared. The irradiated material was placed in the central assembly of the VVER-1000 light-water power reactor core. It is proposed to remove only fission products (FP) from the irradiated material and to use the remaining three-component (Pu, Am, Cm) mixture as a heat source in the RTG. It has been shown that the mixed (Am, Cm)-fraction of MA is a preferable starting material compared to the Am-fraction since it provides the higher specific heat release of the produced three-component (Pu, Am, Cm) mixture at comparable rates of plutonium production and its isotopic compositions
Ecosystem services across Europe. D4.2 Current and future natural capital and ecosystem services
No full textThe EU Biodiversity Strategy for 2030 aims to put biodiversity on the path to recovery by 2030. A key component of the Strategy is the development of a coherent Trans-European Nature Network (TEN-N), to increase the coherence of the existing network of Natura 2000 sites and other nationally designated protected areas by addressing gaps in the coverage of priority habitats and species. The NaturaConnect project supports the design of a TEN-N, amongst others by designing and developing a future-proof blueprint through spatial conservation prioritisation. In this context, it is key to consider multifunctionality, that is, to ensure that the TEN-N addresses not just ecological representativeness but also the ability of nature to meet societal needs or demands through the provisioning of ecosystem services (ES).The present deliverable of NaturaConnect (D4.2) provides a set of ES layers aligned with present and potential future land and climate conditions, designed for use in spatial conservation prioritisation. We generated layers for a selection of regulating and cultural ES, with a focus on climate change mitigation (carbon storage and sequestration) and adaptation (e.g., improving soil retention considering expected increases in the magnitude and frequency of heavy rainfall events), food security (crop pollination, pest control), as well as the capacity of nature to improve people’s mental and physical health by offering opportunities for recreation and experiencing nature. We quantified all ES based on common input data with regard to land systems and climate, to ensure compatibility. Where possible and relevant, we considered ES supply, demand and flow separately.We quantified carbon storage and sequestration according to a book-keeping approach, assigning typical values of the amounts of carbon stored (MgC/ha) and sequestred (MgC/ha/yr) to each land system. We considered only the supply of carbon storage and sequestration, reasoning that the demand for this service is global and considerably larger than the supply. The amounts of carbon stored and sequestered are based on values from the scientific literature and existing datasets which indicate how much carbon is stored and sequestered per land system, and how this would change if the land system underwent a transition (e.g. from forest to cropland). Output maps revealed that forests and wetlands, especially in northern Europe, are characterised by the highest carbon storage and sequestration rates. Croplands are characterised by negative sequestration rates, hence act as sources of emission.We quantified the supply of soil retention based on the ability of vegetation to prevent soil erosion induced by heavy rainfall events, using the universal soil loss equation (RUSLE) to assess soil erosion. Specifically, we quantified the soil retention service (t/ha/yr) based on how much soil loss is prevented by the current vegetation cover, defined per land system, as compared to a counterfactual situation without vegetation. We also quantified the potential additional prevention of soil loss (t/ha/yr) if the vegetation were restored from its current state to a maximum cover. We defined soil retention demand based on the amount of soil loss to be prevented in order to ensure that losses would not exceed the natural soil formation rate. Output maps revealed hotspots of actual and potential additional soil retention demand, supply and flow mainly in mountainous regions, reflecting the key role of terrain slope in determining erodibility as well as the importance of vegetation for reducing it.We modelled the supply of crop pollination based on the potential of pollinator habitat to provide pollinators and the demand based on the presence of nearby cropland in need of pollination. Using observational data from scientific literature and existing databases, we first established a quantitative relationship that estimates wild pollinator abundance in pollinator-dependent cropland (n/m2) based on various ecologically relevant covariates, including the proportion of pollinator habitat within 3 km from the cropland cell. We used this relationship to map pollinator abundance in croplands across Europe, which we subsequently attributed to the cells with pollinator habitat (i.e., the service-providing units) within 3 km from each focal cropland cell, to facilitate application of the model results in spatial conservation prioritisation. Output maps reveal high pollinator abundance values for habitat cells located in areas dominated by cropland, as these habitat cells serve multiple cropland cells, and low values when multiple habitat cells surround a single cropland cell.To assess forest recreational potential, we developed a spatial model based on people’s preferences for forests with different structural characteristics, expressed through the willingness-to-travel (WTT) indicator. Using data from a large-scale visual choice experiment conducted in 12 European countries, we estimated WTT as a function of forest management classes, combined with spatial data on canopy height and tree species diversity. The result is the first Europe-wide map of forest recreational potential, revealing particularly high values in regions with taller, more diverse, and structurally complex forests.We modelled landscape recreational potential based on the recreational opportunities associated with the land systems surrounding each grid cell. We quantify supply based on the number and diversity of land systems that provide recreational opportunities within a given distance from each focal grid cell, and the demand based on the number of potential beneficiaries within a certain distance. Well-supplied areas encompass, among others, the western Iberian peninsula (Portugal) and the Pyrenees, the Auvergne, Rhone-Alpes, and the Provence-Alpes-Cote d’Azur in France, Ireland, Scotland, the Alps and Dinarides as well as the Baltics (Estonia, Latvia), and large parts of the Scandinavian Peninsula and Finland. Demand is particularly high for the European megacities and the various conurbations and metropolitan areas.Finally, we modelled nine regulating and five cultural species-based ecosystem services provided by terrestrial vertebrate species, including, among others, carrion removal, control of pest species (bark beetles, mosquitoes) and evolutionary heritage. For each service, we modelled supply based on the number of specific vertebrate species able to provide a certain service and demand based on the land system in a grid cell assumed to be in need of the service. Resulting maps show distinct patterns for the different ES, revealing the richness of provider species in areas with demand for each service.The ES layers described in this report were primarily developed to support broad-scale spatial conservation or restoration prioritisation efforts, i.e., efforts to identify and rank planning units (in this case grid cells) based on features considered in need of conservation or restoration. In the NaturaConnect project, the ES layers will be used together with layers of other relevant variables, such as biodiversity features, habitat connectivity and the costs of conservation, to identify pan-European conservation priorities. Beyond NaturaConnect, we expect our layers to be useful in particular for national and sub-national governmental and non-state authorities responsible for land planning, as our maps can help in identifying sites where ES supply or flow are high (indicating a need for conservation) or where demand is high yet supply is low (indicating a need for restoration). This way, we expect the layers and underlying code to be useful for informing land management and conservation planning also beyond the project