RESUMO
Narrowing the communication and knowledge gap between producers and users of scientific data is a longstanding problem in ecological conservation and land management. Decision support tools (DSTs), including websites or interactive web applications, provide platforms that can help bridge this gap. DSTs can most effectively disseminate and translate research results when producers and users collaboratively and iteratively design content and features. One data resource seldom incorporated into DSTs are species distribution models (SDMs), which can produce spatial predictions of habitat suitability. Outputs from SDMs can inform management decisions, but their complexity and inaccessibility can limit their use by resource managers or policy makers. To overcome these limitations, we present the Invasive Species Habitat Tool (INHABIT), a novel, web-based DST built with R Shiny to display spatial predictions and tabular summaries of habitat suitability from SDMs for invasive plants across the contiguous United States. INHABIT provides actionable science to support the prevention and management of invasive species. Two case studies demonstrate the important role of end user feedback in confirming INHABIT's credibility, utility, and relevance.
Assuntos
Conservação dos Recursos Naturais/métodos , Espécies Introduzidas/estatística & dados numéricos , Dispersão Vegetal/fisiologia , Tomada de Decisões , Técnicas de Apoio para a Decisão , Ecossistema , Internet , Plantas/classificação , Software , Estados UnidosRESUMO
Ximenia americana is one of the most valuable wild edible plants in the world. In different countries, it is utilized as food, medicine, an essential oil source, and the industrial component to other products. In Ethiopia, it was one of the most known and very important plants for a long period of time. It was utilized as food, a medicinal plant, and animal feed. It was also one of the most economically important and culturally valuable plants. But nowadays, it is not adequately available in the country due to deforestation problem in the years. In addition, its economic importance, current status, and medicinal roles are not well documented and understood. As for research studies, it is concluded that unless a collective effort is taken, the existence of this plant is under severe threat and needs to have some measures. This review article is aimed at addressing the abovelined topics in detail and to pinpoint and explain the importance and status of Ximenia americana.
Assuntos
Olacaceae , Plantas Comestíveis , Plantas Medicinais , Ração Animal/economia , Ração Animal/provisão & distribuição , Animais , Conservação dos Recursos Naturais , Espécies em Perigo de Extinção , Etiópia , Etnobotânica , Frutas/economia , Frutas/provisão & distribuição , Humanos , Medicinas Tradicionais Africanas , Olacaceae/química , Olacaceae/crescimento & desenvolvimento , Fitoterapia/economia , Dispersão Vegetal , Plantas Comestíveis/crescimento & desenvolvimento , Plantas Medicinais/crescimento & desenvolvimentoRESUMO
Urban grasslands are usually managed as short-cut lawns and have limited biodiversity. Urban grasslands with low-intensity management are species rich and can perform numerous ecosystem services, but they are not accepted by citizens everywhere. Further, increasing and/or maintaining a relatively high level of plant species richness in an urban environment is limited by restricted plant dispersal. In this study, we examined the connectivity of urban grasslands and prioritized the grassland patches with regard to their role in connectivity in an urban landscape. We used high-resolution data from a land use system to map grassland patches in Wroclaw city, Silesia, southwest Poland, Central Europe, and applied a graph theory approach to assess their connectivity and prioritization. We next constructed a model for several dispersal distance thresholds (2, 20, 44, 100, and 1000 m), reflecting plants with differing dispersal potential. Our results revealed low connectivity of urban grassland patches, especially for plants with low dispersal ability (2-20 m). The priority of patches was correlated with their area for all dispersal distance thresholds. Most of the large patches important to overall connectivity were located in urban peripheries, while in the city center, connectivity was more restricted and grassland area per capita was the lowest. The presence of a river created a corridor, allowing plants to migrate along watercourse, but it also created a barrier dividing the system. The results suggest that increasing the plant species richness in urban grasslands in the city center requires seed addition.
Assuntos
Biodiversidade , Planejamento de Cidades/métodos , Pradaria , Dispersão Vegetal , Polônia , RiosRESUMO
We measured 34 years of plant community change in a degraded oak woodland undergoing ecological management. Management included regular prescribed fire, control of white-tailed deer populations, repeated sowing of a diverse seed mix, and removal of invasive plants. We tracked change with several conservation metrics. Time series analysis showed no significant changes over time in either plant species richness or the Shannon-Weiner diversity index. Floristic Quality Assessment measures-the Floristic Quality Index (FQI), Cover-weighted FQI, and the Mean Coefficient of Conservatism (Mean C)-all increased dramatically over time, such that their values now surpass those of the highest quality representative of this habitat in the region. Cover-weighted FQI had the added benefit of being quick to respond (negatively and positively) to short-term management changes during the study. This sensitivity highlights its utility for adaptive management, enabling timely, data-driven changes to ongoing management regimes. Plant community composition showed striking changes during the study period, as species of high conservation value replaced weedier species. As a group, conservative woodland species are notoriously slow to recover from degradation, making this flora's recovery particularly notable. A mid-study cessation of management immediately stalled the woodland's recovery according to Floristic Quality metrics, but the restoration quickly returned to its positive trajectory with the resumption of management treatments. These results illustrate that impressive plant biodiversity restoration can be achieved, even in highly degraded contemporary oak ecosystems, if ecological management is comprehensive and if it is sustained over time.
Assuntos
Florestas , Quercus , Desenvolvimento Sustentável , Distribuição Animal , Animais , Cervos , Incêndios , Illinois , Espécies Introduzidas , Dispersão VegetalRESUMO
Recent expansion of croplands in the United States has caused widespread conversion of grasslands and other ecosystems with largely unknown consequences for agricultural production and the environment. Here we assess annual land use change 2008-16 and its impacts on crop yields and wildlife habitat. We find that croplands have expanded at a rate of over one million acres per year, and that 69.5% of new cropland areas produced yields below the national average, with a mean yield deficit of 6.5%. Observed conversion infringed upon high-quality habitat that, relative to unconverted land, had provided over three times higher milkweed stem densities in the Monarch butterfly Midwest summer breeding range and 37% more nesting opportunities per acre for waterfowl in the Prairie Pothole Region of the Northern Great Plains. Our findings demonstrate a pervasive pattern of encroachment into areas that are increasingly marginal for production, but highly significant for wildlife, and suggest that such tradeoffs may be further amplified by future cropland expansion.
Assuntos
Animais Selvagens , Conservação dos Recursos Naturais , Custos e Análise de Custo/estatística & dados numéricos , Produção Agrícola/tendências , Produtos Agrícolas/economia , Animais , Biodiversidade , Borboletas , Produção Agrícola/economia , Produção Agrícola/estatística & dados numéricos , Dispersão Vegetal , Análise Espaço-Temporal , Estados UnidosRESUMO
Expanding the network of protected areas is a core strategy for conserving biodiversity in the face of climate change. Here, we explore the impacts on reserve network cost and configuration associated with planning for climate change in the USA using networks that prioritize areas projected to be climatically suitable for 1460 species both today and into the future, climatic refugia and areas likely to facilitate climate-driven species movements. For 14% of the species, networks of sites selected solely to protect areas currently climatically suitable failed to provide climatically suitable habitat in the future. Protecting sites climatically suitable for species today and in the future significantly changed the distribution of priority sites across the USA-increasing relative protection in the northeast, northwest and central USA. Protecting areas projected to retain their climatic suitability for species cost 59% more than solely protecting currently suitable areas. Including all climatic refugia and 20% of areas that facilitate climate-driven movements increased the cost by another 18%. Our results indicate that protecting some types of climatic refugia may be a relatively inexpensive adaptation strategy. Moreover, although addressing climate change in conservation plans will have significant implications for the configuration of networks, the increased cost of doing so may be relatively modest. This article is part of the theme issue 'Climate change and ecosystems: threats, opportunities and solutions'.
Assuntos
Distribuição Animal , Biodiversidade , Mudança Climática , Conservação dos Recursos Naturais/métodos , Parques Recreativos/economia , Dispersão Vegetal , Refúgio de Vida Selvagem , Mudança Climática/economia , Conservação dos Recursos Naturais/economia , Estados UnidosRESUMO
Global patterns of species and evolutionary diversity in plants are primarily determined by a temperature gradient, but precipitation gradients may be more important within the tropics, where plant species richness is positively associated with the amount of rainfall. The impact of precipitation on the distribution of evolutionary diversity, however, is largely unexplored. Here we detail how evolutionary diversity varies along precipitation gradients by bringing together a comprehensive database on the composition of angiosperm tree communities across lowland tropical South America (2,025 inventories from wet to arid biomes), and a new, large-scale phylogenetic hypothesis for the genera that occur in these ecosystems. We find a marked reduction in the evolutionary diversity of communities at low precipitation. However, unlike species richness, evolutionary diversity does not continually increase with rainfall. Rather, our results show that the greatest evolutionary diversity is found in intermediate precipitation regimes, and that there is a decline in evolutionary diversity above 1,490 mm of mean annual rainfall. If conservation is to prioritise evolutionary diversity, areas of intermediate precipitation that are found in the South American 'arc of deforestation', but which have been neglected in the design of protected area networks in the tropics, merit increased conservation attention.
Assuntos
Biodiversidade , Evolução Biológica , Chuva , Árvores , Clima Tropical , Mudança Climática , Conservação dos Recursos Naturais , Cadeias de Markov , Filogenia , Dispersão Vegetal , América do Sul , Especificidade da EspécieRESUMO
In an era of climate change, biological invasions by alien species represent one of the main anthropogenic drivers of global environmental change. The present study, using an ensemble modelling approach, has mapped current and future global distribution of the invasive Leucanthemum vulgare (Ox-eye Daisy) and predicted the invasion hotspots under climate change. The current potential distribution of Ox-eye Daisy coincides well with the actual distribution records, thereby indicating robustness of our model. The model predicted a global increase in the suitable habitat for the potential invasion of this species under climate change. Oceania was shown to be the high-risk region to the potential invasion of this species under both current and future climate change scenarios. The results revealed niche conservatism for Australia and Northern America, but contrastingly a niche shift for Africa, Asia, Oceania and Southern America. The global distribution modelling and risk assessment of Ox-eye Daisy has immediate implications in mitigating its invasion impacts under climate change, as well as predicting the global invasion hotspots and developing region-specific invasion management strategies. Interestingly, the contrasting patterns of niche dynamics shown by this invasive plant species provide novel insights towards disentangling the different operative mechanisms underlying the process of biological invasions at the global scale.
Assuntos
Mudança Climática , Monitorização de Parâmetros Ecológicos/métodos , Espécies Introduzidas/tendências , Leucanthemum , Dispersão Vegetal , África , Ásia , Austrália , Simulação por Computador , Monitorização de Parâmetros Ecológicos/estatística & dados numéricos , Previsões/métodos , Modelos Estatísticos , América do Norte , Oceania , Medição de Risco/métodos , América do SulRESUMO
We analyze the optimal harvesting problem for an ecosystem of species that experience environmental stochasticity. Our work generalizes the current literature significantly by taking into account non-linear interactions between species, state-dependent prices, and species seeding. The key generalization is making it possible to not only harvest, but also 'seed' individuals into the ecosystem. This is motivated by how fisheries and certain endangered species are controlled. The harvesting problem becomes finding the optimal harvesting-seeding strategy that maximizes the expected total income from the harvest minus the lost income from the species seeding. Our analysis shows that new phenomena emerge due to the possibility of species seeding. It is well-known that multidimensional harvesting problems are very hard to tackle. We are able to make progress, by characterizing the value function as a viscosity solution of the associated Hamilton-Jacobi-Bellman equations. Moreover, we provide a verification theorem, which tells us that if a function has certain properties, then it will be the value function. This allows us to show heuristically, as was shown by Lungu and Øksendal (Bernoulli 7(3):527-539, 2001), that it is almost surely never optimal to harvest or seed from more than one population at a time. It is usually impossible to find closed-form solutions for the optimal harvesting-seeding strategy. In order to by-pass this obstacle we approximate the continuous-time systems by Markov chains. We show that the optimal harvesting-seeding strategies of the Markov chain approximations converge to the correct optimal harvesting strategy. This is used to provide numerical approximations to the optimal harvesting-seeding strategies and is a first step towards a full understanding of the intricacies of how one should harvest and seed interacting species. In particular, we look at three examples: one species modeled by a Verhulst-Pearl diffusion, two competing species and a two-species predator-prey system.
Assuntos
Agricultura/métodos , Conservação dos Recursos Naturais/métodos , Ecossistema , Modelos Biológicos , Modelos Econômicos , Agricultura/economia , Animais , Conservação dos Recursos Naturais/economia , Análise Custo-Benefício , Humanos , Cadeias de Markov , Dispersão Vegetal , Plantas , Densidade Demográfica , Dinâmica Populacional , Processos EstocásticosRESUMO
Arabica coffee (Coffea arabica) is a key crop in many tropical countries and globally provides an export value of over US$13 billion per year. Wild Arabica coffee is of fundamental importance for the global coffee sector and of direct importance within Ethiopia, as a source of harvestable income and planting stock. Published studies show that climate change is projected to have a substantial negative influence on the current suitable growing areas for indigenous Arabica in Ethiopia and South Sudan. Here we use all available future projections for the species based on multiple general circulation models (GCMs), emission scenarios, and migration scenarios, to predict changes in Extent of Occurrence (EOO), Area of Occupancy (AOO), and population numbers for wild Arabica coffee. Under climate change our results show that population numbers could reduce by 50% or more (with a few models showing over 80%) by 2088. EOO and AOO are projected to decline by around 30% in many cases. Furthermore, present-day models compared to the near future (2038), show a reduction for EOO of over 40% (with a few cases over 50%), although EOO should be treated with caution due to its sensitivity to outlying occurrences. When applying these metrics to extinction risk, we show that the determination of generation length is critical. When applying the International Union for Conservation of Nature's Red list of Threatened Species (IUCN Red List) criteria, even with a very conservative generation length of 21 years, wild Arabica coffee is assessed as Threatened with extinction (placed in the Endangered category) under a broad range of climate change projections, if no interventions are made. Importantly, if we do not include climate change in our assessment, Arabica coffee is assessed as Least Concern (not threatened) when applying the IUCN Red List criteria.
Assuntos
Mudança Climática , Coffea/fisiologia , Espécies em Perigo de Extinção , Extinção Biológica , Dispersão Vegetal , Modelos Biológicos , Medição de RiscoRESUMO
Carbon capturing coastal and marine habitats around the world are decreasing in extent every year, habitats found in abundance in Small Island Developing States' territories. However, these habitats are under threat by increased levels of economic activities and extreme weather events. Consequently, as those ecosystems become scarce their value is expected to increase. In this paper the "value of information", the increase in knowledge that renders a system or a function more valuable, from marine habitat mapping is presented through the (monetary) valuation of one regulating service provided by the newly mapped habitats. Mapping a section of a channel with a multibeam echosounder revealed more seagrass resources than in previous studies. Using values for both the Social Cost of Carbon and Abatement Cost methods, from the literature we estimate the value of the carbon sequestration and storage service these seagrass meadows provide. The impacts of hurricanes in the newly mapped seagrasses were also investigated. Despite the costs of mapping, monitoring and of projected losses of ecosystem services provision due to hurricanes, net benefits over a time period of 50â¯years were considerably larger. The new information provided highlights carbon capturing habitats as more important, enabling the "value of information" to inform policymaking.
Assuntos
Alismatales/fisiologia , Sequestro de Carbono , Conservação dos Recursos Naturais , Ecossistema , Dispersão Vegetal , Ilhas Virgens Britânicas , Conservação dos Recursos Naturais/economiaRESUMO
The state-dependent speciation and extinction (SSE) models have recently been criticized due to their high rates of "false positive" results. Many researchers have advocated avoiding SSE models in favor of other "nonparametric" or "semiparametric" approaches. The hidden Markov modeling (HMM) approach provides a partial solution to the issues of model adequacy detected with SSE models. The inclusion of "hidden states" can account for rate heterogeneity observed in empirical phylogenies and allows for reliable detection of state-dependent diversification or diversification shifts independent of the trait of interest. However, the adoption of HMM has been hampered by the interpretational challenges of what exactly a "hidden state" represents, which we clarify herein. We show that HMMs in combination with a model-averaging approach naturally account for hidden traits when examining the meaningful impact of a suspected "driver" of diversification. We also extend the HMM to the geographic state-dependent speciation and extinction (GeoSSE) model. We test the efficacy of our "GeoHiSSE" extension with both simulations and an empirical dataset. On the whole, we show that hidden states are a general framework that can distinguish heterogeneous effects of diversification attributed to a focal character.
Assuntos
Extinção Biológica , Especiação Genética , Modelos Teóricos , Geografia , Cadeias de Markov , Filogenia , Dispersão Vegetal , Traqueófitas/classificação , Traqueófitas/fisiologiaRESUMO
A survey of the ecological variability within 52 populations of Schoenoplectus californicus (C.A. Mey.) Soják across its distributional range revealed that it is commonly found in nitrogen (N) limited areas, but rarely in phosphorus limited soils. We explored the hypothesis that S. californicus supplements its nitrogen demand by bacterial N2-fixation processes associated with its roots and rhizomes. We estimated N2-fixation of diazotrophs associated with plant rhizomes and roots from several locations throughout the species' range and conducted an experiment growing plants in zero, low, and high N additions. Nitrogenase activity in rhizomes and roots was measured using the acetylene reduction assay. The presence of diazotrophs was verified by the detection of the nifH gene. Nitrogenase activity was restricted to rhizomes and roots and it was two orders of magnitude higher in the latter plant organs (81 and 2032 nmol C2H4 g DW-1 d-1, respectively). Correspondingly, 40x more nifH gene copies were found on roots compared to rhizomes. The proportion of the nifH gene copies in total bacterial DNA was positively correlated with the nitrogenase activity. In the experiment, the contribution of fixed N to the plant N content ranged from 13.8% to 32.5% among clones from different locations. These are relatively high values for a non-cultivated plant and justify future research on the link between N-fixing bacteria and S. californicus production.
Assuntos
Cyperaceae/metabolismo , Fixação de Nitrogênio , Nitrogênio/metabolismo , Raízes de Plantas/metabolismo , Rizoma/metabolismo , Áreas Alagadas , Proteínas de Bactérias/metabolismo , Cyperaceae/microbiologia , Nitrogênio/química , Nitrogenase/metabolismo , América do Norte , Oxirredutases/metabolismo , Fósforo/química , Fósforo/metabolismo , Dispersão Vegetal , Proteínas de Plantas/metabolismo , Rizoma/microbiologia , Solo/química , América do Sul , Especificidade da EspécieAssuntos
Sequestro de Carbono , Mudança Climática , Atividades Humanas , Agricultura/economia , Agricultura/métodos , Agroquímicos/toxicidade , Carbono/análise , China , Mudança Climática/economia , Mudança Climática/estatística & dados numéricos , Conservação dos Recursos Naturais/economia , Conservação dos Recursos Naturais/legislação & jurisprudência , Conservação dos Recursos Naturais/estatística & dados numéricos , Ecossistema , Poluição Ambiental/economia , Poluição Ambiental/legislação & jurisprudência , Poluição Ambiental/prevenção & controle , Poluição Ambiental/estatística & dados numéricos , Humanos , Dispersão VegetalRESUMO
China's croplands have experienced drastic changes in management practices, such as fertilization, tillage, and residue treatments, since the 1980s. There is an ongoing debate about the impact of these changes on soil organic carbon (SOC) and its implications. Here we report results from an extensive study that provided direct evidence of cropland SOC sequestration in China. Based on the soil sampling locations recorded by the Second National Soil Survey of China in 1980, we collected 4,060 soil samples in 2011 from 58 counties that represent the typical cropping systems across China. Our results showed that across the country, the average SOC stock in the topsoil (0-20 cm) increased from 28.6 Mg C ha-1 in 1980 to 32.9 Mg C ha-1 in 2011, representing a net increase of 140 kg C ha-1 year-1 However, the SOC change differed among the major agricultural regions: SOC increased in all major agronomic regions except in Northeast China. The SOC sequestration was largely attributed to increased organic inputs driven by economics and policy: while higher root biomass resulting from enhanced crop productivity by chemical fertilizers predominated before 2000, higher residue inputs following the large-scale implementation of crop straw/stover return policy took over thereafter. The SOC change was negatively related to N inputs in East China, suggesting that the excessive N inputs, plus the shallowness of plow layers, may constrain the future C sequestration in Chinese croplands. Our results indicate that cropland SOC sequestration can be achieved through effectively manipulating economic and policy incentives to farmers.
Assuntos
Agricultura/métodos , Sequestro de Carbono , Carbono/análise , Conservação dos Recursos Naturais/legislação & jurisprudência , Compostos Orgânicos/análise , Políticas , Solo/química , Agricultura/economia , Agroquímicos/química , China , Compostagem , Conservação dos Recursos Naturais/economia , Conservação dos Recursos Naturais/estatística & dados numéricos , Produtos Agrícolas/química , Fazendas , Atividades Humanas , Humanos , Dispersão Vegetal , Raízes de Plantas/química , Caules de Planta/química , Plantas/química , Mudança Social , Microbiologia do SoloRESUMO
This work is devoted to studying the dynamics of a structured population that is subject to the combined effects of environmental stochasticity, competition for resources, spatio-temporal heterogeneity and dispersal. The population is spread throughout n patches whose population abundances are modeled as the solutions of a system of nonlinear stochastic differential equations living on [Formula: see text]. We prove that r, the stochastic growth rate of the total population in the absence of competition, determines the long-term behaviour of the population. The parameter r can be expressed as the Lyapunov exponent of an associated linearized system of stochastic differential equations. Detailed analysis shows that if [Formula: see text], the population abundances converge polynomially fast to a unique invariant probability measure on [Formula: see text], while when [Formula: see text], the population abundances of the patches converge almost surely to 0 exponentially fast. This generalizes and extends the results of Evans et al. (J Math Biol 66(3):423-476, 2013) and proves one of their conjectures. Compared to recent developments, our model incorporates very general density-dependent growth rates and competition terms. Furthermore, we prove that persistence is robust to small, possibly density dependent, perturbations of the growth rates, dispersal matrix and covariance matrix of the environmental noise. We also show that the stochastic growth rate depends continuously on the coefficients. Our work allows the environmental noise driving our system to be degenerate. This is relevant from a biological point of view since, for example, the environments of the different patches can be perfectly correlated. We show how one can adapt the nondegenerate results to the degenerate setting. As an example we fully analyze the two-patch case, [Formula: see text], and show that the stochastic growth rate is a decreasing function of the dispersion rate. In particular, coupling two sink patches can never yield persistence, in contrast to the results from the non-degenerate setting treated by Evans et al. which show that sometimes coupling by dispersal can make the system persistent.
Assuntos
Ecossistema , Modelos Biológicos , Crescimento Demográfico , Biologia Computacional , Cadeias de Markov , Conceitos Matemáticos , Dinâmica não Linear , Dispersão Vegetal , Densidade Demográfica , Dinâmica Populacional , Análise Espaço-Temporal , Processos EstocásticosRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Cornus mas L. (cornelian cherry) fruits have been used for centuries as traditional cuisine and folk medicine in various countries of Europe and Asia. In folk medicines, the fruits and other parts of the plant have been used for prevention and treatment of a wide range of diseases such as diabetes, diarrhea, gastrointestinal disorders, fevers, rheumatic pain, skin and urinary tract infections, kidney and liver diseases, sunstroke, among others. This review provides a systematic and constructive overview of ethnomedicinal uses, chemical constituents and pharmacological activities of this plant as well as future research need for its commercial utilization as nutraceutical food supplement and medicine. MATERIALS AND METHODS: This review is based on available literature on ethnomedicinal uses, phytochemical, pharmacological, toxicity and clinical studies on Cornus mas L. (cornelian cherry) fruits and other organs that was collected from electronic (SciFinder, PubMed, Science Direct and ACS among others) and library searches of books and journals. RESULTS: Versatile ethnomedicinal uses of the plant in different European and Asian countries have been reported. Phytochemical investigations on different parts of this plant have resulted in the identification of 101 compounds, among which anthocyanins, flavonoids and iridoids are the predominant groups. The crude extracts of fruits and other parts of the plant and their pure isolates exhibit a broad spectrum of pharmacological activities such as anti-microbial, anti-diabetic, anti-atherosclerotic, cyto-, hepato-, neuro- and renalprotective, antiplatelet and antiglaucomic activities. Anthocyanins, flavonoids, iridoids and vitamin C are the major bioactive constituents of the fruits. Fruits are non-toxic and safe food on acute toxicity studies in rat and human models. Clinical trials in diabetic type2 and hyperlipidemic patients showed significant trends of amelioration in sugar level, insulin secretion in diabetic patients and amelioration of lipid profile, apolipoprotein status and vascular inflammation in hyperlipidemic patients. CONCLUSION: Based on our review, Cornus mas L. (cornelian cherry) fruits and leaves can be used mainly in the treatment of diabetes, obesity, atherosclerosis, skin diseases, gastrointestinal and rheumatic problems. Some indications from ethnomedicines have been validated by pharmacological activities of the fruits and its extracts/pure isolates. The reported data reveal that the fruits are a potential source for treatment of diabetes, obesity, hyperlipidemia and gastrointestinal disorders. Unfortunately, the pharmacological studies in these areas are still insufficient to substantiate these preventive effects in confirmatory trials on the mass-scale clinical settings. Future studies on mechanisms of action, bioavailability, pharmacokinetics and adverse effects of the extracts and their bioactive constituents as well as their effective doses and long term toxic effects in humans are needed for commercial applications of these extracts/isolates in modern medicines. The available literature showed that most of the activities of the extracts are due to their constituents, anthocyanins, flavonoids and other phenolics, iridoids and vitamins for their antioxidant and other properties.
Assuntos
Cornus/química , Indústria Farmacêutica/métodos , Frutas/química , Medicina Tradicional , Folhas de Planta/química , Preparações de Plantas/farmacologia , Ásia , Cornus/crescimento & desenvolvimento , Europa (Continente) , Dispersão Vegetal , Preparações de Plantas/isolamento & purificaçãoRESUMO
BACKGROUND AND AIMS: The settling velocity of diaspores is a key parameter for the measurement of dispersal ability in wind-dispersed plants and one of the most relevant parameters in explicit dispersal models, but remains largely undocumented in bryophytes. The settling velocities of moss spores were measured and it was determined whether settling velocities can be derived from spore diameter using Stokes' Law or if specific traits of spore ornamentation cause departures from theoretical expectations. METHODS: A fall tower design combined with a high-speed camera was used to document spore settling velocities in nine moss species selected to cover the range of spore diameters within the group. Linear mixed effect models were employed to determine whether settling velocity can be predicted from spore diameter, taking specific variation in shape and surface roughness into account. KEY RESULTS: Average settling velocity of moss spores ranged from 0·49 to 8·52 cm s(-1) There was a significant positive relationship between spore settling velocity and size, but the inclusion of variables of shape and texture of spores in the best-fit models provides evidence for their role in shaping spore settling velocities. CONCLUSIONS: Settling velocities in mosses can significantly depart from expectations derived from Stokes' Law. We suggest that variation in spore shape and ornamentation affects the balance between density and drag, and results in different dispersal capacities, which may be correlated with different life-history traits or ecological requirements. Further studies on spore ultrastructure would be necessary to determine the role of complex spore ornamentation patterns in the drag-to-mass ratio and ultimately identify what is the still poorly understood function of the striking and highly variable ornamentation patterns of the perine layer on moss spores.
Assuntos
Briófitas/fisiologia , Dispersão Vegetal , Modelos Biológicos , Esporos , VentoRESUMO
A rich structural diversity in forests promotes biodiversity. Forests are dynamic and therefore it is crucial to consider future structural potential when selecting reserves, to make robust conservation decisions. We analyzed forests in boreal Sweden based on 17,599 National Forest Inventory (NFI) plots with the main aim to understand how effectiveness of reserves depends on the time dimension in the selection process, specifically by considering future structural diversity. In the study both the economic value and future values of 15 structural variables were simulated during a 100 year period. To get a net present structural value (NPSV), a single value covering both current and future values, we used four discounting alternatives: (1) only considering present values, (2) giving equal importance to values in each of the 100 years within the planning horizon, (3) applying an annual discount rate considering the risk that values could be lost, and (4) only considering the values in year 100. The four alternatives were evaluated in a reserve selection model under budget-constrained and area-constrained selections. When selecting young forests higher structural richness could be reached at a quarter of the cost over almost twice the area in a budget-constrained selection compared to an area-constrained selection. Our results point to the importance of considering future structural diversity in the selection of forest reserves and not as is done currently to base the selection on existing values. Targeting future values increases structural diversity and implies a relatively lower cost. Further, our results show that a re-orientation from old to young forests would imply savings while offering a more extensive reserve network with high structural qualities in the future. However, caution must be raised against a drastic reorientation of the current old-forest strategy since remnants of ancient forests will need to be prioritized due to their role for disturbance-sensitive species.
Assuntos
Conservação dos Recursos Naturais , Previsões , Agricultura Florestal/métodos , Florestas , Biodiversidade , Orçamentos , Mudança Climática , Conservação dos Recursos Naturais/economia , Análise Custo-Benefício , Custos e Análise de Custo , Agricultura Florestal/economia , Modelos Econômicos , Modelos Teóricos , Dispersão Vegetal , Especificidade da Espécie , Suécia , Fatores de Tempo , Árvores/crescimento & desenvolvimentoRESUMO
We present a gridded 8 km-resolution data product of the estimated composition of tree taxa at the time of Euro-American settlement of the northeastern United States and the statistical methodology used to produce the product from trees recorded by land surveyors. Composition is defined as the proportion of stems larger than approximately 20 cm diameter at breast height for 22 tree taxa, generally at the genus level. The data come from settlement-era public survey records that are transcribed and then aggregated spatially, giving count data. The domain is divided into two regions, eastern (Maine to Ohio) and midwestern (Indiana to Minnesota). Public Land Survey point data in the midwestern region (ca. 0.8-km resolution) are aggregated to a regular 8 km grid, while data in the eastern region, from Town Proprietor Surveys, are aggregated at the township level in irregularly-shaped local administrative units. The product is based on a Bayesian statistical model fit to the count data that estimates composition on the 8 km grid across the entire domain. The statistical model is designed to handle data from both the regular grid and the irregularly-shaped townships and allows us to estimate composition at locations with no data and to smooth over noise caused by limited counts in locations with data. Critically, the model also allows us to quantify uncertainty in our composition estimates, making the product suitable for applications employing data assimilation. We expect this data product to be useful for understanding the state of vegetation in the northeastern United States prior to large-scale Euro-American settlement. In addition to specific regional questions, the data product can also serve as a baseline against which to investigate how forests and ecosystems change after intensive settlement. The data product is being made available at the NIS data portal as version 1.0.