Search Results (367)

Murundus fields (wetland earth-mounds) represent a relatively understudied physiognomy in the Cerrado biome. This study aimed to evaluate the composition, life history, phytosociology, endemism, and conservation status of woody plant species in murundus fields in a forestry-dominated landscape in the Brazilian savanna. We established 40 plots, each measuring 50 × 20 m, where all live shrub-arboreal plants with a trunk diameter at the base of ≥1 cm and a height > 0.5 m were identified. Using these data, we calculated the absolute and relative values of density, dominance, and frequency, as well as the importance value index. In addition, we estimated Shannon’s and Simpson’s diversity indices and Pielou’s equability index. Our findings included 155 species, 69 genera, and 38 families in the study area. The invasive exotic species Pinus caribaea Morelet showed the highest importance value, followed by Jacaranda caroba (Vell.) DC., Miconia albicans (Sw.) Steud., Erythroxylum suberosum A.St.-Hil., and Miconia fallax DC. The pronounced presence of P. caribaea is a matter of concern and highlights the need for control measures, given its potential to hinder the regeneration of native species. We identified species occurring in various Cerrado phytophysiognomies, suggesting that murundus fields function as transitional habitats. This study underscores the importance of conserving species within the inadequately studied Cerrado physiognomy. Full article

Sweetpotato genotypes, often known by regional names, are easily propagated via cuttings, which can lead to mixing and misidentification of cultivars. This complicates traceability and commercialization. Accurate characterization of common genotypes would support their formal registration and strengthen the sweetpotato value chain. Sweetpotato is a staple crop in Brazil, and in this study, four states, representing different geographic regions in Brazil, were selected. A total of 37 samples were collected in these states, and the samples were evaluated by SSR molecular markers and morphological traits. The samples were cleaned of virus and compared to the global sweetpotato collection held at the International Potato Center under the International Treaty on Plant Genetic Resources for Food and Agriculture. SSR markers effectively distinguished among accessions. The genotype locally known as “Canadense” matched closely both genetically and morphologically to the CIP accession ‘Blesbok’. This alignment paves the way for formalizing cuttings and root production of “Canadense”/‘Blesbok’ for commercial use. In contrast, several accessions marketed in Sergipe as “white skin sweetpotato” did not correspond to any known CIP accession, suggesting that they may be unique regional genotypes or acquired from other sources, since sweetpotato is an exotic crop in Brazil. Overall, the research identified key genotypes, supporting their official registration with Brazil’s Ministry of Agriculture, Livestock, and Supply, thereby enhancing the legal commercialization of cuttings and roots. Additionally, the clear molecular and trait-based classification will assist sweetpotato crop improvement programs in selecting appropriate parent lines for future crosses. Full article

Spontaneous plants are plants that occur in urban environments such as pavement gaps or cracks in walls without cultivation and are not remnants of historic native habitats. They are critical components of urban road green space vegetation, and their distribution is affected by multiple factors. Heavy traffic and frequent human disturbances on urban roads exacerbate exotic spontaneous plant invasions. Exploring the diversity of their distributions, adaptation mechanisms of these exotic plants and their relationship with native ones is vital for focused control of harmful invasives. Based on field surveys, this study analyzed the distribution of exotic spontaneous plants across habitat types, urbanization gradients and disturbance intensities in road green spaces, and their interactions with native counterparts. Our results indicated: (1) 425 spontaneous species were recorded (234 exotic, 191 native), with 71.8% cosmopolitan and 74.7% monotypic genera. (2) The spontaneous exotic plant community achieves extensive resource preemption by forming a structure dominated by a single super-dominant species (Setaria viridis) and characterized by a broader overall niche breadth. (3) Different habitats sustain a similar number of exotic spontaneous plant species (i.e., $\alpha$-diversity), but their species compositions are highly differentiated, with such differences driven almost entirely by species turnover. At the urban scale, spontaneous exotic plants adapt to regional environments with varying urbanization intensities by maintaining extensive similarity in community composition and making only extremely weak adjustments to the pattern of individual distribution among species. (4) The spontaneous plant community exhibits a pattern dominated by weak interspecific associations and random assemblages, where ecological interactions among species are weak, and the community structure is more consistent with the stochastic processes described by the Neutral Theory. At the regional environmental gradient scale, the diversity of spontaneous native and exotic plants exhibited coordinated variation. The study provides a scientific basis for urban biological invasion control and biodiversity management. Full article

Although younger generations are not always given a prominent role in ethnobotanical surveys, studying intergenerational knowledge transfer should still be a primary interest, in the context of traditions’ erosion, globalization, disinterest and plant blindness. Our study was designed to describe the situation of knowledge transfer and to find potential solutions to counteract erosion by involving the children. This ethnobotanical survey involved students from primary and secondary schools of Valle Imagna (Bergamo, Italy) through different meetings and structured questionnaires to record their traditional knowledge on medicinal plants. The children were then asked to become an active part of the project by interviewing their families. All data recorded were archived in a database for statistical analysis. Students (number = 112) reported 41 plant species, with 36% reporting at least 3 species each. Forty percent of their use reports were related to exotic species or purchased plant material. The most reported species were Matricaria chamomilla L. and Camellia sinensis (L.) Kuntze with common preparations such as infusions from commercial products. Parents (n = 96) reported 76 species and grandparents (n = 35) 52. Statistical analysis showed correlation between traditional knowledge and age/gender, with older generations and female gender correlated to deeper knowledge. Our results suggest deep erosion and a clear lack of intergenerational knowledge transfer. However, our project serves as evidence of the concrete role ethnobotany holds in safeguarding the remaining cultural heritage of a territory, fostering preservation from the outset with the participation of younger generations. Full article

Cities host a heterogeneous composition of native and exotic plants, yet the spatial distribution of plant richness and its drivers remain poorly understood. We evaluated the influence of the center-edge gradient, along the environmental gradient from the historic city center to the urban edge, and habitat type, reflecting local conditions, on plant richness in Santiago, Chile. Sidewalks, parks, and vacant lots (n = 234 per habitat type) were randomly sampled across varying distances from the historic center and urban edge, recording neighborhood socioeconomic level and municipality. Four richness metrics were analyzed using generalized linear mixed models (GLMMs): total richness, richness by origin (native or exotic), and richness by life form (trees, shrubs, or herbs), considering habitat type, socioeconomic level, and distances as fixed effects and municipality as a random effect. We recorded 699 species (13% native and 87% exotic; 23% trees, 20% shrubs, and 56% herbs). Distances to the city center and urban edge had no significant effect, whereas habitat type emerged as the primary determinant: sidewalks exhibited higher total, native, and exotic richness with more trees and shrubs, whereas vacant lots were dominated by herbs. These patterns indicate that floristic richness is distributed in a mosaic, independent of urban gradients. Given the importance of Santiago’s Mediterranean region as a biodiversity hotspot, the low representation of native species is concerning. Increasing their presence and associated ecosystem services requires tailored interventions for each habitat type. Full article

Charcoal rot, a destructive disease of soybean roots, has limited control options, and the development of resistant cultivars is the most effective, economical, and sustainable strategy. However, tropical cultivars are generally susceptible, while exotic resistant accessions are poorly adapted to tropical conditions. This study represents the initial step toward developing tropical soybean cultivars combining resistance and agronomic performance. We evaluated the agronomic performance of progenies derived from crosses between exotic lines partially resistant to Macrophomina phaseolina (PI 594302 and PI 567562A) and three commercial tropical cultivars with high yield potential (relative maturity groups (RMGs) 5.5, 6.2, and 6.9). Populations were advanced to the F₆ generation and assessed for yield, plant height, first pod insertion, and agronomic value using a partial diallel design. Grain yield ranged from 18.5 to 33.2 g·plant⁻¹ across generations. The combining ability analysis revealed predominance of additive genetic effects, highlighting PI 594302 and VMAX RR (RMG 6.2) as key parents for plant height, agronomic value, and grain yield and exhibited the greatest potential for superior progeny across generations. These results identify promising lines with high agronomic performance and adaptation, which will undergo resistance confirmation in subsequent studies, supporting the long-term goal of developing tropical soybean cultivars that combine productivity, sustainability, and tolerance to charcoal rot. Full article

Urban and peri-urban farmers in Malawi increasingly use treated and untreated wastewater for vegetable production, but little is known about the extent of heavy metal accumulation in both exotic and indigenous vegetables, particularly with respect to differences between edible tissues (leaves vs. stems). This study addresses this gap by measuring the concentrations of cadmium (Cd), chromium (Cr), lead (Pb), zinc (Zn), and copper (Cu) in wastewater, soils, and six vegetables including three exotic and three indigenous irrigated with effluent from the Soche Wastewater Treatment Plant in Blantyre. Metal concentrations were determined using Atomic Absorption Spectrophotometry. Wastewater contained Zn (0.01 ± 0.001 mg/L) and Cu (0.02 ± 0.018 mg/L), both below World Health Organization (WHO) and Malawi Bureau of Standards (MBS) limits (Zn: 0.2 mg/L; Cu: 2 mg/L), while Cd, Cr, and Pb were below detection limit. In soils, Zn reached 56.4 ± 0.5 mg/kg, exceeding the WHO limit of 36 mg/kg; other metals remained within WHO permissible values. Vegetables showed species- and tissue-specific variation in metal accumulation: Cr reached 4.65 mg/kg in Cucurbita moschata stems, Cd up to 0.31 mg/kg in Amaranthus retro-flexus leaves, and Pb up to 4.09 mg/kg in Brassica rapa stems—all above FAO/WHO permissible limits (2.3, 0.2, and 0.3 mg/kg, respectively). Duncan’s post hoc analysis confirmed significant differences (p < 0.05) across matrices and plant parts, with leaves generally accumulating more Zn and Cu than stems. Principal component analysis (PCA) revealed that Zn, Cu, Cr, and Pb in the wastewater-soil-vegetable system largely share a common source, likely wastewater effluent and historical soil contamination, while Cd showed a more sporadic distribution, highlighting differential accumulation pathways. Health risk assessments revealed high Health Risk Index (HRI) values, with Brassica rapa stems (HRI = 92.3) and Brassica rapa subsp. chinensis leaves (HRI = 82.2) exceeding the safe threshold (HRI > 1), indicating potential chronic risks. This study reveals potential health risks associated with wastewater irrigation due to heavy metal accumulation in edible vegetables, and therefore recommends further research on metal speciation, seasonal variation, and bioaccumulation at different crop growth stages. Full article

Green roofs have increasingly been used in urban contexts to increase thermal insulation, provide habitat for species, and increase urban biodiversity. Here, we provide the results of a monitoring experiment to document (1) the survival rate of planted species of a green roof with no maintenance and (2) the natural colonization by new species of the same roof. Each month for one year, we conducted floristic and vegetation surveys, identifying the species of colonizers and monitoring the cover of both planted and wild species. We conducted various statistical tests to determine the driving factors of spontaneous plants’ colonization of the unattended green roof. Among the planted species, several Mediterranean species thrived despite the lack of irrigation, and among these, Thymus serpyllum L. (a prostrate shrub) maintained the highest cover. The spontaneous colonization involved 62 species, including Mediterranean (38%) and exotic species (15%), primarily annual ruderals. The difficult climatic and pedological conditions (i.e., solar irradiation, soil structure) of the green roof have driven the colonization process and the survival of the colonizers. Research on dynamic colonization processes can contribute to designing green roofs with greater biodiversity, a more sustainable approach to long-term management, enhanced urban climate adaptation, and greater aesthetic appeal. Full article

Human-driven land use change and intensification is a major threat to global biodiversity. High levels of land management intensity may reduce species diversity, change the composition and structure of plant and animal communities and disrupt ecological processes. However, there is still scarce information on the impacts of land management intensity on island pollinator communities and their interactions with plants. Here, we aim to assess how different land use types (natural vegetation, semi-natural pastures, and intensive pastures), representing a gradient of grazing intensification, influence pollinator diversity and plant–pollinator interactions on Terceira Island (Azores). We surveyed 30 sites (10 per land use) and recorded 1453 visits by 41 pollinator species. Alpha diversity did not differ among land uses, but grazing intensification reduced the abundance of several native species while favoring some exotics, such as the honeybee. Network analyses showed changes in structural properties and declines in interactions between native species with increasing grazing disturbance. Introduced species, particularly the honeybee, dominated interactions in intensively managed habitats, replacing native species from key ecological roles. Our findings highlight the vulnerability of island ecosystems to grazing intensification and emphasize the need for conservation measures in the Azores, namely the reduction in grazing intensity, restoration of habitat connectivity, and implementation of pollinator-friendly agri-environmental schemes to enhance native biodiversity and sustain ecosystem services. Full article

Melon has great economic importance in Brazil, and flower development is the basis for fruit and seed production. The objective of this study was to elucidate the variability of flowering characteristics and to compare qualitative and quantitative reproductive variations in relation to pollen viability and stigmatic receptivity in 21 genotypes, which includes 15 Brazilian accessions. In addition, we evaluated the influence of time on the growth of the pollen tube and its arrival at the ovule in vivo at different intervals (1 h, 2 h, 3 h) after hand pollination in three commercial varieties, one exotic accession, and two intervarietal hybrids, by epifluorescence technique. Three groups were distributed by the clustering method of Scott–Knott at 5% probability; group III included only commercial varieties for the flower width descriptor. C. melo germplasm presented 81% andromonoecious plants and 19% trimonoecious plants. Through the multivariate strategy, these 21 genotypes were distributed into six groups with distinct reproductive characteristics, and male flowering was accelerated compared to female flowering. Regarding pollen viability, it was greater than 95% according to staining methods. Pollen germination rate in vivo was affected by time, with an almost 12.5% increase between 1 h and 3 h after hand pollination, and the in vivo pollen germination in hybrids was lower than in commercial varieties. Brazilian accessions, despite stability in pollen viability and stigma receptivity, have great differences in reproductive terms, such as variations in the quantitative and qualitative characteristics of floral pieces and flowering. This work contributes to the knowledge on varieties, hybrids, exotic accession, and Brazilian melon germplasm by characterizing some of their main agricultural traits, such as reproduction floral biology, and opens up prospects for yield evaluation in plant breeding programs. Full article

In tropical regions, the establishment of large-scale exotic plantations has addressed the demand for timber resources but has also disrupted the structural stability of native vegetation and altered soil nutrient cycling, thereby impairing ecosystem functions. Identifying effective restoration strategies for these plantations is crucial for sustainable forest management and ecological security. This study examined Acacia mangium Willd., Cunninghamia lanceolata (Lamb.) Hook., and Pinus caribaea Morelet. plantations in Hainan Tropical Rainforest National Park under three treatments: plantation control, girdling, and natural secondary forest. Vegetation surveys and soil analyses were conducted to explore the relationships between community structure, soil physicochemical properties, and enzyme activities. Diversity indices, Pearson correlations, and redundancy analysis were used to assess plant–soil relationships. The results showed that girdling significantly accelerated succession in C. lanceolata and P. caribaea plantations, increased species diversity, and enhanced the dominance of native species. Shrub-layer diversity indices (H_shrub, D_shrub, E_shrub) were the main drivers of soil properties and enzyme activities, while tree-layer effects were weaker. Girdling regulated soil nutrients and biological activity primarily via changes in community structure. These findings highlight the importance of optimizing shrub-layer structure and enhancing diversity for tropical plantation restoration. Combining forest type conversion with moderate interventions can promote coordinated plant–soil development over time. Full article

Rising biological invasions continue to threaten biodiversity conservation worldwide. To protect native ecosystems and biodiversity, improve resilience against invasions, and lower ecological management costs, it is crucial to identify native plant species that can endure the competitive pressures from invasive plants. This greenhouse study examined the competition between Solidago canadensis and 32 native plant species to identify key functional traits of these native plant species that influence their competitive effects on and responses to S. canadensis. The results indicated that S. canadensis seedlings were unable to suppress the growth of most of the native species studied, while most native species could significantly suppress growth of S. canadensis, reducing its biomass by 12–92%. The suppression effects by native plants were closely related to their root functional traits. Specifically, annuals with higher root–shoot ratio, specific root lengths, stem biomass, plant height by day 10, and smaller number of root tips showed stronger inhibition of S. canadensis. On the other hand, perennials with smaller average root diameter, or greater root biomass and plant heights by day 60, were also more inhibitory towards S. canadensis. This study concluded that the competitive effect of seedlings of S. canadensis have weaker competitive impacts compared to most the studied native plants. Root traits are essential in the competition between native plants and S. canadensis, potentially aiding in the identification of native plant species with high resistance to invasion. Full article

Exotic invasive plant species can cause biodiversity loss by outcompeting and replacing native species. Herbicides are commonly used to control invasive plants owing to their low cost and high efficiency. However, herbicide use can have unintended effects on co-occurring native plant species by altering the competitive balance. We studied how herbicide application modifies the competition between an invasive and a native species. We examined the effects of applying glyphosate on the mortality, photosynthetic capacity, and growth of Solidago canadensis, an aggressive invasive species, and Imperata cylindrica, a native species that commonly co-occurs with S. canadensis. We also studied how applying glyphosate affected the competition between these species. Various glyphosate concentrations were applied to the two species grown either together or separately. The mortality rate increased while the photosynthetic capacity and growth decreased with increasing glyphosate concentration. Increasing the glyphosate concentration more negatively affected the parameters of I. cylindrica than those of S. canadensis. Plant growth, especially that of I. cylindrica, was more restricted by intraspecific competition than by interspecific competition as the glyphosate concentration increased. Furthermore, the relative competitive potential of the native species decreased with increasing glyphosate concentration. S. canadensis is more tolerant of glyphosate, which enhances its competitive advantage and hinders the proliferation, reintroduction, and success of native plant species. Future studies should focus on developing techniques to mitigate the negative impacts of invasive plant species, for example, via optimizing methods of spraying herbicides. Full article

Anthropogenic environments are increasingly recognised for their potential to support pollinator diversity, especially through the strategic selection of ornamental plant species. This study investigated the ecological role of Salvia yangii (formerly Perovskia atriplicifolia) in supporting solitary bees, particularly species of the genus Anthidium, within urban green spaces in Milan (Italy). Field observations were conducted in both urban and rural sites to assess pollinator visitation rates, bee abundance, and plant traits relevant to nesting and foraging. S. yangii attracted a diverse assemblage of bee genera, with Anthidium spp. consistently recorded as dominant visitors. This preference is likely driven by the short corolla tube, which facilitates the access to nectar, and its dense coverage of trichomes, which may serve as essential nesting materials. The interaction was found to be stable across environments, suggesting that S. yangii provides reliable floral and structural resources. These findings highlight the potential of specific ornamental plants to contribute meaningfully to urban pollinator conservation. While the use of exotic species warrants caution, we propose that S. yangii may be suitable for inclusion in pollinator-friendly planting guidelines under controlled horticultural conditions, offering a promising model for enhancing urban biodiversity through informed plant selection. Full article

Priority effects—the phenomenon where early-arriving species influence the establishment, growth, and reproduction of later-arriving species during community assembly—play a critical role in determining the invasion success of exotic species. However, how priority effects are influenced by nitrogen (N) availability remains understudied. The invasive species Bidens frondosa has rapidly expanded its range in China over the past few years. Yet it remains unclear how priority effects in B. frondosa versus native species may mediate invasion success, as well as how nutrient levels may alter these effects. Addressing these questions is essential for understanding the mechanisms driving B. frondosa invasion and for developing effective management strategies. In a greenhouse experiment, we manipulated the planting order of B. frondosa and its native congener B. biternata, then measured the growth and competitiveness of B. frondosa and B. biternata in both control and N addition treatments. Planting order greatly impacted the growth and competitiveness of both B. frondosa and B. biternata. Early arrival had more positive effects on B. frondosa than B. biternata, while late arrival more strongly inhibited B. frondosa than B. biternata. For B. frondosa, priority effects lessened with nitrogen addition, but the opposite occurred for B. biternata. Thus, priority effects may favor B. frondosa invasion, while late arrival, particularly under nitrogen addition, may curb its spread. As such, sowing early-germinating native species represents a useful management strategy for controlling B. frondosa invasions. Full article