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Plant life and growth forms (shortened to 'plant forms') represent key functional strategies of plants in relation to their environment and provide important insights into the ecological constraints acting on the distribution of biodiversity. Despite their functional importance, how the spectra of plant forms contribute to global gradients of plant diversity is unresolved. Using a novel dataset comprising > 295 000 species, we quantify the contribution of different plant forms to global gradients of vascular plant diversity. Furthermore, we establish how plant form distributions in different biogeographical regions are associated with contemporary and paleoclimate conditions, environmental heterogeneity and phylogeny. We find a major shift in representation of woody perennials in tropical latitudes to herb-dominated floras in temperate and boreal regions, following a sharp latitudinal gradient in plant form diversity from the tropics to the poles. We also find significant functional differences between regions, mirroring life and growth form responses to environmental conditions, which is mostly explained by contemporary climate (18-87%), and phylogeny (6-62%), with paleoclimate and heterogeneity playing a lesser role (< 23%). This research highlights variation in the importance of different plant forms to diversity gradients world-wide, shedding light on the ecological and evolutionary pressures constraining plant-trait distributions.
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Evolução Biológica , Traqueófitas , Filogenia , Biodiversidade , Clima , Plantas , Clima TropicalRESUMO
Sustainability science needs new approaches to produce, share, and use knowledge because there are major barriers to translating research into policy and practice. Multiple actors hold relevant knowledge for sustainability including indigenous and local people who have developed over generations knowledge, methods, and practices that biodiversity and ecosystem assessments need to capture. Despite efforts to mainstream knowledge coproduction, less than 3% of the literature on nature's contributions to people (NCP) integrates indigenous and local knowledge (ILK). Approaches and tools to better integrate scientific and ILK knowledge systems in NCP assessments are urgently needed. To fill this gap, we conducted interviews with ILK experts from Abancay and Tamburco, Peru, and convened focus groups and workshops during which participatory mapping, a serious game, a Bayesian belief network based on ILK were introduced. We inventoried 60 medicinal plants used to treat different illnesses, and analyzed the spatial distribution of the 7 plants that contribute the most to a good quality of life, and delineated their nonmedicinal uses. Based on the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services conceptual framework, we defined dimensions of a good quality of life according to indigenous and local worldviews. Medicinal plants contributed strongly to health and household security, among other contributions. Climate change and overexploitation were the main perceived threats to medicinal plants, despite the existence of formal and customary institutions to regulate trade. Our approach was flexible enough to integrate diverse forms of knowledge, as well as qualitative and quantitative information from, for example, the Bayesian belief network.
Coproducción de conocimiento para mejorar la evaluación de las contribuciones de la naturaleza para las personas Resumen La ciencia de la sostenibilidad necesita nuevos enfoques para producir, compartir y utilizar los conocimientos, ya que existen grandes obstáculos para trasladar la investigación a la política y la práctica. Varios actores poseen conocimientos relevantes para la sostenibilidad, incluidos los pueblos originarios y locales que han desarrollado conocimientos, métodos y prácticas a lo largo de generaciones, que deben reflejarse en las evaluaciones de la biodiversidad y los ecosistemas. A pesar de los esfuerzos por integrar la coproducción de conocimientos, <3% de la bibliografía sobre las contribuciones de la naturaleza a las personas (CNP) integra los conocimientos autóctonos y locales (CAL). Se necesitan urgentemente enfoques y herramientas para integrar mejor los sistemas de conocimiento científico y los conocimientos autóctonos y locales en las evaluaciones de los CNP. Para llenar este vacío, realizamos entrevistas con expertos en CAL de Abancay y Tamburco, Perú, y convocamos grupos focales y talleres durante los cuales se introdujeron el mapeo participativo, un juego serio y una red de creencia bayesiana basada en CAL. Inventariamos 60 plantas medicinales utilizadas para tratar diferentes enfermedades y analizamos la distribución espacial de las siete especies de plantas que más contribuyen a una buena calidad de vida y delineamos sus usos no medicinales. A partir del marco conceptual de la Plataforma Intergubernamental Científico-Normativa sobre Diversidad Biológica y Servicios de los Ecosistemas, definimos las dimensiones de una buena calidad de vida según las cosmovisiones autóctonas y locales. Las plantas medicinales contribuían en gran medida a la salud y a la seguridad de los hogares, entre otras aportaciones. El cambio climático y la sobreexplotación fueron las principales amenazas percibidas para las plantas medicinales a pesar de la existencia de instituciones tradicionales que regulan el mercado. Nuestra estrategia fue lo suficientemente flexible para integrar el conocimiento diverso, así como la información cualitativa y cuantitativa, como por ejemplo la red de creencia bayesiana.
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Ecossistema , Plantas Medicinais , Humanos , Qualidade de Vida , Teorema de Bayes , Conservação dos Recursos NaturaisRESUMO
Climate change over the past decades has significantly altered global hydrothermal conditions and caused an evident shift in species distribution. Predicting species distribution patterns and identifying their influencing factors will be essential in developing coping strategies to prevent species extirpation and extinction. Yet, environmental factors affecting the distribution of woody species in Central Asia remain largely unknown. Here, I used the MaxEnt model to predict the current distributions and future distribution under three SSP-RCP scenarios of six common woody species in Central Asia. The results indicated a good performance of the MaxEnt model. Precipitation of driest month and annual mean temperature were the dominant factors affecting species distribution. For the species with wide ecological niches, i.e., Acer negundo and Rosa chinensis, the suitable areas showed an evident expansion trend under future scenarios. In addition, a trend toward higher elevation was found for the species that grew at high altitudes (1600-3200 m). However, the average elevation of suitable area for A. negundo and R. chinensis firstly increased but then decreased under future scenarios. Even though the areas with high species diversity increased from 0.59% under the current situation to 0.82% and 0.81% under ssp245 in 2021-2040 and 2041-2060, respectively, species diversity showed an apparent loss in parts of the northwest and southeast areas under ssp370 and ssp585. This study can guide susceptible habitat protections under climate change.
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Mudança Climática , Ecossistema , Temperatura , Previsões , ÁsiaRESUMO
For many species, climate change leads to range shifts that are detectable, but often insufficient to track historical climatic conditions. These lags of species range shifts behind climatic conditions are often coined "climatic debts", but the demographic costs entailed by the word "debt" have not been demonstrated. Here, we used opportunistic distribution data for c. 4000 European plant species to estimate the temporal shifts in climatic conditions experienced by these species and their occupancy trends, over the last 65 years. The resulting negative relationship observed between these two variables provides the first piece of evidence that European plants are already paying a climatic debt in Alpine, Atlantic and Boreal regions. In contrast, plants appear to benefit from a surprising "climatic bonus" in the Mediterranean. We also find that among multiple pressures faced by plants, climate change is now on par with other known drivers of occupancy trends, including eutrophication and urbanisation.
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Mudança Climática , Ecossistema , Plantas , UrbanizaçãoRESUMO
Climate change impacts on the structure and function of ecosystems will worsen public health issues like allergic diseases. Birch trees (Betula spp.) are important sources of aeroallergens in Central and Northern Europe. Birches are vulnerable to climate change as these trees are sensitive to increased temperatures and summer droughts. This study aims to examine the effect of climate change on airborne birch pollen concentrations in Central Europe using Bavaria in Southern Germany as a case study. Pollen data from 28 monitoring stations in Bavaria were used in this study, with time series of up 30 years long. An integrative approach was used to model airborne birch pollen concentrations taking into account drivers influencing birch tree abundance and birch pollen production and projections made according to different climate change and socioeconomic scenarios. Birch tree abundance is projected to decrease in parts of Bavaria at different rates, depending on the climate scenario, particularly in current centres of the species distribution. Climate change is expected to result in initial increases in pollen load but, due to the reduction in birch trees, the amount of airborne birch pollen will decrease at lower altitudes. Conversely, higher altitude areas will experience expansions in birch tree distribution and subsequent increases in airborne birch pollen in the future. Even considering restrictions for migration rates, increases in pollen load are likely in Southwestern areas, where positive trends have already been detected during the last three decades. Integrating models for the distribution and abundance of pollen sources and the drivers that control birch pollen production allowed us to model airborne birch pollen concentrations in the future. The magnitude of changes depends on location and climate change scenario.
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Betula , Mudança Climática , Alérgenos , Ecossistema , PólenRESUMO
Neotropical fruit species once dispersed by Pleistocene megafauna have regained relevance in diversifying human diets to address malnutrition. Little is known about the historic interactions between humans and these fruit species. We quantified the human role in modifying geographic and environmental ranges of Neotropical fruit species by comparing the distribution of megafauna-dispersed fruit species that have been part of both human and megafauna diets with fruit species that were exclusively part of megafauna diets. Three quarters of the fruit species that were once dispersed by megafauna later became part of human diets. Our results suggest that, because of extensive dispersal and management, humans have expanded the geographic and environmental ranges of species that would otherwise have suffered range contraction after extinction of megafauna. Our results suggest that humans have been the principal dispersal agent for a large proportion of Neotropical fruit species between Central and South America. Our analyses help to identify range segments that may hold key genetic diversity resulting from historic interactions between humans and these fruit species. These genetic resources are a fundamental source to improve and diversify contemporary food systems and to maintain critical ecosystem functions. Public, private, and societal initiatives that stimulate dietary diversity could expand the food usage of these megafauna-dispersed fruit species to enhance human nutrition in combination with biodiversity conservation.
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Dieta , Ecossistema , Fósseis , Frutas/química , Mamíferos , Dispersão Vegetal , Animais , Biodiversidade , Frutas/classificação , HumanosRESUMO
In natural grasslands, C4 plant dominance increases with growing season temperatures and reflects distinct differences in plant growth rates and water use efficiencies of C3 vs. C4 photosynthetic pathways. However, in lawns, management decisions influence interactions between planted turfgrass and weed species, leading to some uncertainty about the degree of human vs. climatic controls on lawn species distributions. We measured herbaceous plant carbon isotope ratios (δ13 C, index of C3 /C4 relative abundance) and C4 cover in residential lawns across seven U.S. cities to determine how climate, lawn plant management, or interactions between climate and plant management influenced C4 lawn cover. We also calculated theoretical C4 carbon gain predicted by a plant physiological model as an index of expected C4 cover due to growing season climatic conditions in each city. Contrary to theoretical predictions, plant δ13 C and C4 cover in urban lawns were more strongly related to mean annual temperature than to growing season temperature. Wintertime temperatures influenced the distribution of C4 lawn turf plants, contrary to natural ecosystems where growing season temperatures primarily drive C4 distributions. C4 cover in lawns was greatest in the three warmest cities, due to an interaction between climate and homeowner plant management (e.g., planting C4 turf species) in these cities. The proportion of C4 lawn species was similar to the proportion of C4 species in the regional grass flora. However, the majority of C4 species were nonnative turf grasses, and not of regional origin. While temperature was a strong control on lawn species composition across the United States, cities differed as to whether these patterns were driven by cultivated lawn grasses vs. weedy species. In some cities, biotic interactions with weedy plants appeared to dominate, while in other cities, C4 plants were predominantly imported and cultivated. Elevated CO2 and temperature in cities can influence C3 /C4 competitive outcomes; however, this study provides evidence that climate and plant management dynamics influence biogeography and ecology of C3 /C4 plants in lawns. Their differing water and nutrient use efficiency may have substantial impacts on carbon, water, energy, and nutrient budgets across cities.
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Ecossistema , Poaceae , Cidades , Humanos , Fotossíntese , Dispersão Vegetal , Estados UnidosRESUMO
BACKGROUND: Predicting a list of plant taxa most likely to be observed at a given geographical location and time is useful for many scenarios in biodiversity informatics. Since efficient plant species identification is impeded mainly by the large number of possible candidate species, providing a shortlist of likely candidates can help significantly expedite the task. Whereas species distribution models heavily rely on geo-referenced occurrence data, such information still remains largely unused for plant taxa identification tools. RESULTS: In this paper, we conduct a study on the feasibility of computing a ranked shortlist of plant taxa likely to be encountered by an observer in the field. We use the territory of Germany as case study with a total of 7.62M records of freely available plant presence-absence data and occurrence records for 2.7k plant taxa. We systematically study achievable recommendation quality based on two types of source data: binary presence-absence data and individual occurrence records. Furthermore, we study strategies for aggregating records into a taxa recommendation based on location and date of an observation. CONCLUSION: We evaluate recommendations using 28k geo-referenced and taxa-labeled plant images hosted on the Flickr website as an independent test dataset. Relying on location information from presence-absence data alone results in an average recall of 82%. However, we find that occurrence records are complementary to presence-absence data and using both in combination yields considerably higher recall of 96% along with improved ranking metrics. Ultimately, by reducing the list of candidate taxa by an average of 62%, a spatio-temporal prior can substantially expedite the overall identification problem.
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Plantas/classificação , Biodiversidade , AlemanhaRESUMO
Contents Summary 366 I. Introduction 366 II. Testing ecological theory: effects of the environment on lianas 369 III. A unified explanation for liana distribution and the maintenance of liana diversity 370 IV. Testing ecological theory: effects of lianas on the environment 373 V. Theoretical effects of lianas on forest diversity 375 VI. Lianas and trophic interactions in forests 375 VII. Unresolved challenges in liana ecology 376 VIII. Conclusions 377 Acknowledgements 377 References 377 SUMMARY: Lianas constitute a diverse polyphyletic plant group that is advancing our understanding of ecological theory. Specifically, lianas are providing new insights into the mechanisms that control plant distribution and diversity maintenance. For example, there is now evidence that a single, scalable mechanism may explain local, regional, and pan-tropical distribution of lianas, as well as the maintenance of liana species diversity. The ability to outcompete trees under dry, stressful conditions in seasonal forests provides lianas a growth advantage that, over time, results in relatively high abundance in seasonal forests and low abundance in aseasonal forests. Lianas may also gain a similar growth advantage following disturbance, thus explaining why liana density and diversity peak following disturbance at the local, forest scale. The study of ecology, however, is more than the effect of the environment on organisms; it also includes the effects of organisms on the environment. Considerable empirical evidence now indicates that lianas substantially alter their environment by consuming resources, suppressing tree performance, and influencing emergent properties of forests, such as ecosystem functioning, plant and animal diversity, and community composition. These recent studies using lianas are transcending classical tropical ecology research and are now providing novel insights into fundamental ecological theory.
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Fenômenos Ecológicos e Ambientais , Modelos Teóricos , Árvores/fisiologia , Biodiversidade , FlorestasRESUMO
Plant-soil feedbacks and interspecific competition are ubiquitous interactions that strongly influence the performance of plants. Yet few studies have examined whether the strength of these interactions corresponds with the abundance of plant species in the field, or whether feedbacks and competition interact in ways that either ameliorate or exacerbate their effects in isolation. We sampled soil from two intermountain grassland communities where we also measured the relative abundance of plant species. In greenhouse experiments, we quantified the direction and magnitude of plant-soil feedbacks for 10 target species that spanned a range of abundances in the field. In soil from both sites, plant-soil feedbacks were mostly negative, with more abundant species suffering greater negative feedbacks than rare species. In contrast, the average response to competition for each species was unrelated with its abundance in the field. We also determined how competitive response varied among our target species when plants competed in live vs. sterile soil. Interspecific competition reduced plant size, but the strength of this negative effect was unchanged by plant-soil feedbacks. Finally, when plants competed interspecifically, we asked how conspecific-trained, heterospecific-trained, and sterile soil influenced the competitive responses of our target species and how this varied depending on whether target species were abundant or rare in the field. Here, we found that both abundant and rare species were not as harmed by competition when they grew in heterospecific-trained soil compared to when they grew in conspecific-cultured soil. Abundant species were also not as harmed by competition when growing in sterile vs. conspecific-trained soil, but this was not the case for rare species. Our results suggest that abundant plants accrue species-specific soil pathogens to a greater extent than rare species. Thus, negative feedbacks may be critical for preventing abundant species from becoming even more abundant than rare species.
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Fenômenos Fisiológicos Vegetais , Plantas , Solo , Microbiologia do Solo , Especificidade da EspécieRESUMO
BACKGROUND AND AIMS: Although plant distribution patterns are well documented, our understanding of the ecophysiological mechanisms that control the geographical ranges of plant species remains poor. We used a largely ignored method, the performance of the male gametophyte in vitro, to assess whether the thermal range of pollen germination and tube growth controls species distribution ranges, in this case along an elevational gradient. METHODS: Using in vitro pollen germination experiments, we obtained cardinal temperatures (minimal, optimal and maximal) of pollen germination and pollen tube growth for 25 herbaceous species along a mean annual temperature gradient of about 5 °C. These temperatures were correlated with temperatures of the sites where the species were collected. The presence of a phylogenetic signal in the data set as well as an effect of species flowering phenology were also estimated. KEY RESULTS AND CONCLUSIONS: We found a strong positive relationship between temperature conditions at our collection sites and the minimum temperature for both pollen germination and pollen tube growth. In addition, a significant correlation between maximum temperature of pollen tube growth and temperature of flowering month was apparent. We conclude that the restriction of pollen germination and growth by low temperatures is an important contributor to the climatic restriction of plant species distributions. Improved knowledge of this thermal precursor to seed production could, from a functional perspective, enhance our understanding of species distributions along climatic gradients and our ability to predict how anthropogenic climate change might affect plant community composition.
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Germinação/fisiologia , Pólen/fisiologia , Ecossistema , Flores/fisiologia , Alemanha , Filogenia , Tubo Polínico/crescimento & desenvolvimento , Especificidade da Espécie , TemperaturaRESUMO
PREMISE OF THE STUDY: Understanding the evolutionary and ecological factors that determine plant distributions is of primary importance in botanical research. These factors may vary in predictable ways across different spatial scales, and thus, we can leverage scale to reveal the underlying processes limiting plant distributions. METHODS: We review various research considerations across local and geographic scales, including the investigation of dispersal and habitat limitation, evolutionary factors, abiotic and biotic factors, and research logistics. We also present two case studies, slender monkeyflower (Mimulus leptaleus) and cut-leaf monkeyflower (Mimulus laciniatus), in the California Sierra Nevada. KEY RESULTS: At a local spatial scale (within 50 m), no seeds were produced from plants sown at sites located just beyond known patches of M. leptaleus, but within the species' geographic range. At a much broader spatial scale (kilometers), at the highest and lowest elevations of the species' range, we found greatly reduced abundance and fecundity in plants sown outside of the geographic range limits of M. laciniatus. CONCLUSIONS: These cases illustrate two contrasting spatial scales, yet agree in their illustration of strong habitat limitation. We end by discussing future avenues of research and by suggesting ways botanical researchers can frame their studies to maximize information gained on species requirements, distribution limits, and conservation among varying spatial scales.
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Evolução Biológica , Clima , Ecossistema , Mimulus/fisiologia , Dispersão Vegetal , California , Meio Ambiente , GeografiaRESUMO
Although grass pollen is widely regarded as the major outdoor aeroallergen source in Australia and New Zealand (NZ), no assemblage of airborne pollen data for the region has been previously compiled. Grass pollen count data collected at 14 urban sites in Australia and NZ over periods ranging from 1 to 17 years were acquired, assembled and compared, revealing considerable spatiotemporal variability. Although direct comparison between these data is problematic due to methodological differences between monitoring sites, the following patterns are apparent. Grass pollen seasons tended to have more than one peak from tropics to latitudes of 37°S and single peaks at sites south of this latitude. A longer grass pollen season was therefore found at sites below 37°S, driven by later seasonal end dates for grass growth and flowering. Daily pollen counts increased with latitude; subtropical regions had seasons of both high intensity and long duration. At higher latitude sites, the single springtime grass pollen peak is potentially due to a cooler growing season and a predominance of pollen from C3 grasses. The multiple peaks at lower latitude sites may be due to a warmer season and the predominance of pollen from C4 grasses. Prevalence and duration of seasonal allergies may reflect the differing pollen seasons across Australia and NZ. It must be emphasized that these findings are tentative due to limitations in the available data, reinforcing the need to implement standardized pollen-monitoring methods across Australasia. Furthermore, spatiotemporal differences in grass pollen counts indicate that local, current, standardized pollen monitoring would assist with the management of pollen allergen exposure for patients at risk of allergic rhinitis and asthma.
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Projections of spatial biodiversity dynamics under climate warming are often based on models including only climate variables, and when non-climatic factors (e.g. soil) are included, data are often at much coarser spatial resolutions than those experienced by plants. Field studies along elevation gradients permit the gathering of detailed soil data, while still covering a wide climatic gradient. Here, an intensive field survey of four spring forest herbs along an elevation gradient showed that soil properties had substantial impacts on the occurrence/abundance of all species, and that soil effects were more pronounced at higher elevations. For Trillium erectum and Claytonia caroliniana, very infrequent occurrences at high elevation were strongly associated with rare microsites with high pH or nutrients. In a seven-year transplant experiment with T. erectum, we found that individuals grew to much smaller sizes at high than low elevation, suggesting that environmental factors rather than dispersal limitation constrain the species' upper range limit, despite substantial warming in recent decades. Our study demonstrates that soil factors interact strongly with climate to determine plant range limits along climatic gradients. Unsuitable soils for plants at high elevations or latitudes may represent an important constraint on future plant migration and biodiversity change. This article is part of the theme issue 'Ecological novelty and planetary stewardship: biodiversity dynamics in a transforming biosphere'.
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Plantas , Solo , Humanos , Solo/química , Florestas , Biodiversidade , Dispersão VegetalRESUMO
The artificial structures can influence wetland topology and sediment properties, thereby shaping plant distribution and composition. Macrobenthos composition was correlated with plant cover. Previous studies on the impact of artificial structures on plant distribution are scarce in incorporating time-series data or extended field surveys. In this study, a machine-learning-based species distribution model with decade-long observation was analyzed to investigate the correlation between the shift in the distribution of B. planiculmis, artificial structure-induced elevation changes and the expansion of other plants, as well as their connection to soil properties and crab composition dynamics under plants in Gaomei Wetland. Long short-term memory model (LSTM) with Shapley additive explanations (SHAP) was employed for predicting the distribution of B. planiculmis and explaining feature importance. The results indicated that wetland topology was influenced by both artificial structures and plants. Areas initially colonized by B. planiculmis were replaced by other species. Soil properties showed significant differences among plant patches; however, principal component analysis (PCA) of sediment properties and niche similarity analysis showed that the niche of plants was overlapped. Crab composition was different under different plants. The presence probability of B. planiculmis near woody paths decreased according to LSTM and field survey data. SHAP analysis suggested that the distribution of other plants, historical distribution of B. planiculmis and sediment properties significantly contributed to the presence probability of B. planiculmis. A sharp decrease in SHAP values with increasing NDVI at suitable elevations, overlap in PCA of sediment properties and niche similarity indicated potential competition among plants. This decade-long time-series field survey revealed the joint effects of artificial structure and vegetation on the topology and soil properties dynamics. These changes influenced the plant distribution through potential plant competition. LSTM with SHAP provided valuable insights in the underlying the mechanisms of artificial structure effects on the plant zonation process.
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Aprendizado de Máquina , Áreas Alagadas , Braquiúros , Monitoramento Ambiental/métodos , Solo/química , China , Plantas , AnimaisRESUMO
Vernonia cinerea (L.) Less. is a perennial herbaceous plant found mainly in tropical areas, particularly in Southeast Asia, South America, and India. Various parts of V. cinerea have traditionally been used in folk medicine to treat several diseases, such as malaria, fever, and liver diseases. V. cinerea has so far yielded about 92 secondary metabolites. The majority of these are sesquiterpene lactones, but triterpenes, flavonoids, steroids, phenolics, and other compounds are present as well. V. cinerea crude extracts reportedly exhibit anti-inflammatory, antiprotozoal, antidiabetic, anticancer, antimicrobial, antioxidant, and renoprotective activities. This study aims to provide the latest up-to-date information on the botanical characterization, distribution, traditional uses, phytochemistry, and pharmacological activity of V. cinerea. Information on V. cinerea was thoroughly reviewed. The literature published between 1950 and 2024 was compiled through online bibliographic databases, including SciFinder, Web of Science, Google Scholar, PubMed, ScienceDirect, Springer Link, Wiley, and the MDPI online library. The keywords used for the literature search included Vernonia cinerea (L.) Less. and the synonyms Cyanthillium cinereum (L.) H.Rob., Conyza cinerea L., and various others.
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Medicina Tradicional , Compostos Fitoquímicos , Extratos Vegetais , Vernonia , Vernonia/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Humanos , Compostos Fitoquímicos/farmacologia , Fitoterapia , Animais , América do Sul , Sudeste AsiáticoRESUMO
PREMISE OF THE STUDY: Plants that invest in large, heavy seeds and colorful, fleshy fruits or analogous structures seem adapted for dispersal by large vertebrates. Some such plants, like Australian cycads in the genus Macrozamia, do not disperse well, which could be explained by seed-dispersal relationships with megafauna that are rare or extinct in contemporary ecosystems. Such plants provide an opportunity to investigate the ecological consequences of low seed-dispersal distances. ⢠METHODS: We investigated seed dispersal of Macrozamia miquelii in Central Queensland by tracking the fate of marked seeds, identifying the dispersal fauna and quantifying population demography and spatial structure. ⢠KEY RESULTS: We found that 70-100% of marked seeds remained within 1 m of maternal females (cycads are dioecious). Of the 812 seeds recovered (from 840 originally marked) only 24 dispersed >1 m from maternal females, the greatest observed dispersal being 5 m. We found an average of 2.2 seedlings and 0.7 juveniles within 1.5 m of mature females, which suggests that most seeds that remain in the vicinity of maternal females perish. Within-stand densities ranged between 1000 and 5000 plants/ha. The brushtail possum Trichosurus vulpecula was the only animal observed to move the seeds. ⢠CONCLUSIONS: Macrozamia are adapted for dispersal by megafauna that are rare or absent in contemporary ecosystems. We argue that Macrozamia are "grove forming" plants that derive ecological benefit from existing as high-density, spatially discrete populations, the function of megafaunal dispersal adaptations being the infrequent dispersal of seeds en masse to establish new such groves in the landscape.
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Sementes/fisiologia , Zamiaceae/fisiologia , Demografia , Ecossistema , Queensland , Reprodução/fisiologiaRESUMO
It is known that two-spotted spider mite (Tetranychus urticae), a major pest of strawberry, is difficult to manage. This study was conducted to determine the optimal sampling unit to increase management efficiency of T. urticae in strawberries. The sampling unit was determined by characterizing within-strawberry distribution of T. urticae and by comparing coefficient of variation (CV) and correlation coefficient (r2) among potential sampling units. There was a significant (p < 0.05) difference in densities within a strawberry according to the leaf age. However, there was no significant difference in its density within a trifoliate leaf. More T. urticae were found on young-fully-opened (moderately old) leaves than on young and old ones. Moreover, these leaves had lower CV and r2 values than others. More specifically, optimal sampling units of T. urticae were fifth, fifth or sixth, and sixth oldest leaves for motiles (immatures and adults), all stages (motiles and eggs), and eggs, respectively. The required sampling number should be determined depending on the density. However, for management purposes, one and two leaflets would be acceptable for eggs and motiles, respectively. By using this small number of suitable sampling unit, the sampling and management for T. urticae in strawberries could be more efficient than before.
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BACKGROUND: The Rybachy and the Sredny Peninsulas are the northernmost part of Murmansk Region in the European part of Russia. While the most part of the Region is covered by boreal forest, the Peninsulas are covered by tundra. The vegetation and flora of Murmansk Region are well studied at present. The Peninsulas were first studied in 1829 by a Finnish botanist Jacob Fellman. The most comprehensive research was conducted in the late 19th - early 20th century. Nevertheless, the species composition of the Peninsulas' flora has changed significantly over the past 100 years due to land use and climate change. The aim of this dataset is to make the data on species occurrences for this territory digitally available via GBIF. To date, more or less complete digital floristic data were provided only by the project for digitising the book "Flora of Murmansk Region" (1953-1966).The present dataset is a part of the project studying the vegetation of the territory. We recorded the information about species frequency and distribution using the relevé method. NEW INFORMATION: We present a dataset based on 991 relevés from all vegetation types, which includes 16,289 records of georeferenced plant occurrences that belong to 568 species. There are 23 species of lichens (Ascomycota), 142 species of mosses (Bryophyta), three species of liverworts (Marchantiophyta) and 400 species of vascular plants (Tracheophyta) in the present dataset. The taxonomic diversity and unevenness result from the vegetation sampling. The data were collected in 2008, 2009, 2011, 2014 and 2015. The dataset cannot be considered as a complete vegetation database or a flora checklist, but it contains the occurrences and frequencies of the species from all the vegetation types.
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Queiroziella gen. nov., a new genus of Psylloidea (Psyllidae, Ciriacreminae), is erected for five new species developing on the multipurpose tree Mimosa scabrella (Leguminosae, Caesalpinioideae, mimosoid clade): viz. Queiroziella erato sp. nov., Q. euterpe sp. nov., Q. melpomone sp. nov., Q. terpsichore sp. nov. and Q. thalia sp. nov. Another species from Paraguay, associated with an unidentified Mimosa species, is transferred to the new genus as Queiroziella borealis (Burckhardt, 1987), comb. nov., from Zonopelma (Aphalaroidinae). The new taxa are diagnosed, described and illustrated, and keys are provided for the identification of adults and immatures. Morphologically, Queiroziella resembles Heteropsylla which is also associated with mimosoid legumes and with which it may be closely related. As their host, the new species are restricted to Southern Brazil. Queiroziella euterpe, Q. melpomone and Q. terpsichore are reported from the states of Paraná, Rio Grande do Sul, Santa Catarina and São Paulo, Q. thalia from Paraná and São Paulo, and Q. erato from Paraná. No clear phenological patterns were found though it seems that high psyllid populations coincide with new flush of the host plants. Despite that the psyllids occur sometimes in very high numbers, no visible damage could be detected on host trees. On the other hand, the honeydew of the psyllids may provide a food source for honey-bees during non-flowering periods of Mimosa scabrella.