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1.
Sci Data ; 8(1): 52, 2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33563993

RESUMO

In plants, secondary metabolite profiles provide a unique opportunity to explore seasonal variation and responses to the environment. These include both abiotic and biotic factors. In field experiments, such stress factors occur in combination. This variation alters the plant metabolic profiles in yet uninvestigated ways. This data set contains trait and mass spectrometry data of thirteen grassland species collected at four time points in the growing season in 2017. We collected above-ground vegetative material of seven grass and six herb species that were grown in plant communities with different levels of diversity in the Jena Experiment. For each sample, we recorded visible traits and acquired shoot metabolic profiles on a UPLC-ESI-Qq-TOF-MS. We performed the raw data pre-processing in Galaxy-W4M and prepared the data for statistical analysis in R by applying missing data imputation, batch correction, and validity checks on the features. This comprehensive data set provides the opportunity to investigate environmental dynamics across diverse neighbourhoods that are reflected in the metabolomic profile.


Assuntos
Pradaria , Metaboloma , Plantas/metabolismo , Estações do Ano , Biodiversidade , Cromatografia Líquida , Alemanha , Espectrometria de Massas , Plantas/classificação
2.
Nat Commun ; 12(1): 354, 2021 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-33441560

RESUMO

The mega-diversity of herbivorous insects is attributed to their co-evolutionary associations with plants. Despite abundant studies on insect-plant interactions, we do not know whether host-plant shifts have impacted both genomic adaptation and species diversification over geological times. We show that the antagonistic insect-plant interaction between swallowtail butterflies and the highly toxic birthworts began 55 million years ago in Beringia, followed by several major ancient host-plant shifts. This evolutionary framework provides a valuable opportunity for repeated tests of genomic signatures of macroevolutionary changes and estimation of diversification rates across their phylogeny. We find that host-plant shifts in butterflies are associated with both genome-wide adaptive molecular evolution (more genes under positive selection) and repeated bursts of speciation rates, contributing to an increase in global diversification through time. Our study links ecological changes, genome-wide adaptations and macroevolutionary consequences, lending support to the importance of ecological interactions as evolutionary drivers over long time periods.


Assuntos
Borboletas/genética , Ecossistema , Evolução Molecular , Genoma de Inseto/genética , Animais , Borboletas/classificação , Borboletas/fisiologia , Estudo de Associação Genômica Ampla/métodos , Geografia , Interações Hospedeiro-Parasita , Filogenia , Plantas/classificação , Plantas/parasitologia , Especificidade da Espécie , Fatores de Tempo
3.
Nat Commun ; 12(1): 516, 2021 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-33483517

RESUMO

Understanding how biological and environmental factors interactively shape the global distribution of plant and animal genetic diversity is fundamental to biodiversity conservation. Genetic diversity measured in local populations (GDP) is correspondingly assumed representative for population fitness and eco-evolutionary dynamics. For 8356 populations across the globe, we report that plants systematically display much lower GDP than animals, and that life history traits shape GDP patterns both directly (animal longevity and size), and indirectly by mediating core-periphery patterns (animal fecundity and plant dispersal). Particularly in some plant groups, peripheral populations can sustain similar GDP as core populations, emphasizing their potential conservation value. We further find surprisingly weak support for general latitudinal GDP trends. Finally, contemporary rather than past climate contributes to the spatial distribution of GDP, suggesting that contemporary environmental changes affect global patterns of GDP. Our findings generate new perspectives for the conservation of genetic resources at worldwide and taxonomic-wide scales.


Assuntos
Biodiversidade , Clima , Ecossistema , Variação Genética , Plantas/genética , Algoritmos , Distribuição Animal , Animais , Evolução Molecular , Genética Populacional , Geografia , Traços de História de Vida , Modelos Teóricos , Filogenia , Dispersão Vegetal , Plantas/classificação
4.
Ecotoxicol Environ Saf ; 208: 111697, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396028

RESUMO

Owing to the unique properties and useful applications in numerous fields, nanomaterials (NMs) received a great attention. The mass production of NMs has raised major concern for the environment. Recently, some altered growth patterns in plants have been reported due to the plant-NMs interactions. However, for NMs safe applications in agriculture and medicine, a comprehensive understanding of bio-nano interactions is crucial. The main goal of this review article is to summarize the results of the toxicological studies that have shown the in vitro and in vivo interactions of NMs with plants. The toxicity mechanisms are briefly discussed in plants as the defense mechanism works to overcome the stress caused by NMs implications. Indeed, the impact of NMs on plants varies significantly with many factors including physicochemical properties of NMs, culture media, and plant species. To investigate the impacts, dose metrics is an important analysis for assaying toxicity and is discussed in the present article to broadly open up different aspects of nanotoxicological investigations. To access reliable quantification and measurement in laboratories, standardized methodologies are crucial for precise dose delivery of NMs to plants during exposure. Altogether, the information is significant to researchers to describe restrictions and future perspectives.


Assuntos
Ecotoxicologia/normas , Poluentes Ambientais/toxicidade , Nanoestruturas/toxicidade , Plantas/efeitos dos fármacos , Agricultura , Ecotoxicologia/tendências , Poluentes Ambientais/química , Humanos , Nanoestruturas/química , Desenvolvimento Vegetal/efeitos dos fármacos , Plantas/classificação , Plantas/metabolismo , Especificidade da Espécie , Estresse Fisiológico/efeitos dos fármacos
5.
Methods Mol Biol ; 2222: 39-55, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33301086

RESUMO

This chapter presents an overview of the major plant DNA sequences and molecular methods available for plant taxonomy. Guidelines are provided for the choice of sequences and methods to be used, based on the DNA compartment (nuclear, chloroplastic, mitochondrial), evolutionary mechanisms, and the level of taxonomic differentiation of the plants under survey.


Assuntos
Código de Barras de DNA Taxonômico , Plantas/classificação , Plantas/genética , Código de Barras de DNA Taxonômico/métodos , Código de Barras de DNA Taxonômico/normas , Variações do Número de Cópias de DNA , DNA de Cloroplastos , DNA Mitocondrial , DNA de Plantas , Evolução Molecular , Genoma de Planta , Genômica/métodos , Sequências Repetitivas de Ácido Nucleico
6.
Methods Mol Biol ; 2222: 1-38, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33301085

RESUMO

Taxonomy is the science that explores, describes, names, and classifies all organisms. In this introductory chapter, we highlight the major historical steps in the elaboration of this science, which provides baseline data for all fields of biology and plays a vital role for society but is also an independent, complex, and sound hypothesis-driven scientific discipline.In a first part, we underline that plant taxonomy is one of the earliest scientific disciplines that emerged thousands of years ago, even before the important contributions of the Greeks and Romans (e.g., Theophrastus, Pliny the Elder, and Dioscorides). In the fifteenth-sixteenth centuries, plant taxonomy benefited from the Great Navigations, the invention of the printing press, the creation of botanic gardens, and the use of the drying technique to preserve plant specimens. In parallel with the growing body of morpho-anatomical data, subsequent major steps in the history of plant taxonomy include the emergence of the concept of natural classification , the adoption of the binomial naming system (with the major role of Linnaeus) and other universal rules for the naming of plants, the formulation of the principle of subordination of characters, and the advent of the evolutionary thought. More recently, the cladistic theory (initiated by Hennig) and the rapid advances in DNA technologies allowed to infer phylogenies and to propose true natural, genealogy-based classifications.In a second part, we put the emphasis on the challenges that plant taxonomy faces nowadays. The still very incomplete taxonomic knowledge of the worldwide flora (the so-called taxonomic impediment) is seriously hampering conservation efforts that are especially crucial as biodiversity has entered its sixth extinction crisis. It appears mainly due to insufficient funding, lack of taxonomic expertise, and lack of communication and coordination. We then review recent initiatives to overcome these limitations and to anticipate how taxonomy should and could evolve. In particular, the use of molecular data has been era-splitting for taxonomy and may allow an accelerated pace of species discovery. We examine both strengths and limitations of such techniques in comparison to morphology-based investigations, we give broad recommendations on the use of molecular tools for plant taxonomy, and we highlight the need for an integrative taxonomy based on evidence from multiple sources.


Assuntos
Plantas/classificação , Biodiversidade , Evolução Biológica , Código de Barras de DNA Taxonômico , Fenótipo , Plantas/anatomia & histologia
7.
Methods Mol Biol ; 2222: 69-88, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33301088

RESUMO

With the expansion of molecular techniques, the historical collections have become widely used. The last boom started with using next- and second-generation sequencing in which massive parallel sequencing replaced targeted sequencing and third-generation technology involves single molecule technology. Studying plant DNA using these modern molecular techniques plays an important role in understanding evolutionary relationships, identification through DNA barcoding, conservation status, and many other aspects of plant biology. Enormous herbarium collections are an important source of material especially for taxonomic long-standing issues, specimens from areas difficult to access or from taxa that are now extinct. The ability to utilize these specimens greatly enhances the research. However, the process of extracting DNA from herbarium specimens is often fraught with difficulty related to such variables as plant chemistry, drying method of the specimen, and chemical treatment of the specimen. The result of these applications is often fragmented DNA. The reason new sequencing approaches have been so successful is that the template DNA needs to be fragmented for proper library building, and herbarium DNA is exactly that. Although many methods have been developed for extraction of DNA from herbarium specimens, the most frequently used are modified CTAB and DNeasy Plant Mini Kit protocols. Nine selected protocols in this chapter have been successfully used for high-quality DNA extraction from different kinds of plant herbarium tissues. These methods differ primarily with respect to their requirements for input material (from algae to vascular plants), type of the plant tissue (leaves with incrustations, sclerenchyma strands, mucilaginous tissues, needles, seeds), and further possible applications (PCR-based methods, microsatellites, AFLP or next-generation sequencing).


Assuntos
Código de Barras de DNA Taxonômico/métodos , Plantas/classificação , Plantas/genética , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Fracionamento Químico/métodos , DNA de Plantas/genética , DNA de Plantas/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala , Repetições de Microssatélites , Especificidade de Órgãos , Folhas de Planta/genética , Reação em Cadeia da Polimerase , Kit de Reagentes para Diagnóstico , Análise de Sequência de DNA
8.
Methods Mol Biol ; 2222: 107-118, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33301090

RESUMO

Size, structure, and sequence content lability of plant mitochondrial genome (mtDNA) across species has sharply limited its use in taxonomic studies. Historically, mtDNA variation has been first investigated with RFLPs, while the development of universal primers then allowed studying sequence polymorphisms within short genomic regions (<3 kb). The recent advent of NGS technologies now offers new opportunities by greatly facilitating the assembly of longer mtDNA regions, and even full mitogenomes. Phylogenetic works aiming at comparing signals from different genomic compartments (i.e., nucleus, chloroplast, and mitochondria) have been developed on a few plant lineages, and have been shown especially relevant in groups with contrasted inheritance of organelle genomes. This chapter first reviews the main characteristics of mtDNA and the application offered in taxonomic studies. It then presents tips for best sequencing protocol based on NGS data to be routinely used in mtDNA-based phylogenetic studies.


Assuntos
Código de Barras de DNA Taxonômico , Genoma Mitocondrial , Genômica , Plantas/classificação , Plantas/genética , Genômica/métodos , Filogenia , Filogeografia , Polimorfismo Genético , Recombinação Genética , Análise de Sequência de DNA
9.
Methods Mol Biol ; 2222: 167-178, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33301094

RESUMO

Genotyping-by-sequencing (GBS) is a method to discover and genotype simultaneous genome-wide high-throughput single nucleotide polymorphisms (SNPs). GBS is based on reducing genome complexity with restriction enzymes. Here we describe a method developed by Elshire et al. for constructing simplified GBS libraries and recent bioinformatic approaches developed to analyze the large volume of polymorphism data generated by this method. GBS approach is suitable for population studies, taxonomic and phylogenic studies, germplasm characterization, and breeding and trait mapping for a wide range of organisms, including plants with complex genomes.


Assuntos
Código de Barras de DNA Taxonômico , Técnicas de Genotipagem , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , Plantas/classificação , Plantas/genética , Biodiversidade , Biologia Computacional/métodos , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Fluxo de Trabalho
10.
Methods Mol Biol ; 2222: 149-166, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33301093

RESUMO

Molecular markers provide researchers with a powerful tool for variation analysis between plant genomes. They are heritable and widely distributed across the genome and for this reason have many applications in plant taxonomy and genotyping. Over the last decade, molecular marker technology has developed rapidly and is now a crucial component for genetic linkage analysis, trait mapping, diversity analysis, and association studies. This chapter focuses on molecular marker discovery, its application, and future perspectives for plant genotyping through pangenome assemblies. Included are descriptions of automated methods for genome and sequence distance estimation, genome contaminant analysis in sequence reads, genome structural variation, and SNP discovery methods.


Assuntos
Código de Barras de DNA Taxonômico , Técnicas de Genotipagem , Ensaios de Triagem em Larga Escala , Plantas/classificação , Plantas/genética , Biologia Computacional/métodos , Código de Barras de DNA Taxonômico/métodos , Código de Barras de DNA Taxonômico/normas , Contaminação por DNA , Evolução Molecular , Marcadores Genéticos , Genoma de Planta , Genômica/métodos , Genótipo , Ensaios de Triagem em Larga Escala/normas , Filogenia , Polimorfismo de Nucleotídeo Único
11.
Methods Mol Biol ; 2222: 219-247, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33301097

RESUMO

Understanding biology and genetics at molecular level has become very important for dissection and manipulation of genome architecture for addressing evolutionary and taxonomic questions. Knowledge of genetic variation and genetic relationship among genotypes is an important consideration for classification, utilization of germplasm resources, and breeding. Molecular markers have contributed significantly in this respect and have been widely used in plant science in a number of ways, including genetic fingerprinting, diagnostics, identification of duplicates and selection of core collections, determination of genetic distances, genome analysis, development of molecular maps, and identification of markers associated with desirable breeding traits. The application of molecular markers largely depends on the type of markers employed, distribution of markers in the genome, type of loci they amplify, level of polymorphism, and reproducibility of products. Among many DNA markers available, random amplified polymorphic DNA (RAPD) is the simplest, is cost-effective, and can be performed in a moderate laboratory for most of its applications. In addition, RAPDs can touch much of the genome and has the advantage that no prior knowledge of the genome under research is necessary. The recent improvements in the RAPD technique like arbitrarily primed polymerase chain reaction (AP-PCR), sequence characterized amplified region (SCAR), DNA amplification fingerprinting (DAF), sequence-related amplified polymorphism (SRAP), cleaved amplified polymorphic sequences (CAPS), random amplified microsatellite polymorphism (RAMPO), and random amplified hybridization microsatellites (RAHM) can complement the shortcomings of RAPDs and have enhanced the utility of this simple technique for specific applications. Simple protocols for these techniques are presented along with the applications of RAPD in genetic diversity analysis, mapping, varietal identification, genetic fidelity testing, etc.


Assuntos
Código de Barras de DNA Taxonômico , Plantas/classificação , Plantas/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Mapeamento Cromossômico , Cruzamentos Genéticos , Impressões Digitais de DNA , Evolução Molecular , Variação Genética , Genética Populacional , Genoma de Planta , Genômica/métodos , Filogenia , Melhoramento Vegetal
12.
Methods Mol Biol ; 2222: 187-218, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33301096

RESUMO

AFLP or amplified fragment length polymorphism is a PCR-based molecular technique that uses selective amplification of a subset of digested DNA fragments from any source to generate and compare unique fingerprints of genomes. It is more efficient in terms of time, economy, reproducibility, informativeness, resolution, and sensitivity, compared to other popular DNA markers. Besides, it requires very small quantities of DNA and no prior genome information. This technique is widely used in plants for taxonomy, genetic diversity, phylogenetic analysis, construction of high-resolution genetic maps, and positional cloning of genes, to determine relatedness among cultivars and varietal identity, etc. The review encompasses in detail the various applications of AFLP in plants and the major advantages and disadvantages. The review also considers various modifications of this technique and novel developments in detection of polymorphism. A wet-lab protocol is also provided.


Assuntos
Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Plantas/classificação , Plantas/genética , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados/métodos , Código de Barras de DNA Taxonômico , Impressões Digitais de DNA , Epigenômica/métodos , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Variação Genética , Transcriptoma
13.
PLoS One ; 15(12): e0243923, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33332382

RESUMO

A lack of sufficient training data, both in terms of variety and quantity, is often the bottleneck in the development of machine learning (ML) applications in any domain. For agricultural applications, ML-based models designed to perform tasks such as autonomous plant classification will typically be coupled to just one or perhaps a few plant species. As a consequence, each crop-specific task is very likely to require its own specialized training data, and the question of how to serve this need for data now often overshadows the more routine exercise of actually training such models. To tackle this problem, we have developed an embedded robotic system to automatically generate and label large datasets of plant images for ML applications in agriculture. The system can image plants from virtually any angle, thereby ensuring a wide variety of data; and with an imaging rate of up to one image per second, it can produce lableled datasets on the scale of thousands to tens of thousands of images per day. As such, this system offers an important alternative to time- and cost-intensive methods of manual generation and labeling. Furthermore, the use of a uniform background made of blue keying fabric enables additional image processing techniques such as background replacement and image segementation. It also helps in the training process, essentially forcing the model to focus on the plant features and eliminating random correlations. To demonstrate the capabilities of our system, we generated a dataset of over 34,000 labeled images, with which we trained an ML-model to distinguish grasses from non-grasses in test data from a variety of sources. We now plan to generate much larger datasets of Canadian crop plants and weeds that will be made publicly available in the hope of further enabling ML applications in the agriculture sector.


Assuntos
Agricultura/classificação , Aprendizado Profundo , Processamento de Imagem Assistida por Computador , Plantas/classificação , Algoritmos , Canadá , Humanos , Aprendizado de Máquina , Desenvolvimento Vegetal , Plantas/anatomia & histologia
14.
PLoS One ; 15(9): e0239183, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32941518

RESUMO

The boundary between the boreal and arctic biomes in northwest Europe has been a matter of debate for many years. Some authors consider that the boundary is marked by the northern limit of tree growth in the northernmost Norwegian mainland. In this study we have collected air and soil temperature data from 37 heath stands from northern Finnmark (71°N), the northernmost part of the Norwegian mainland, through Bear Island (74°N) in the Barents sea, to Adventsdalen (78)°N (in Spitsbergen) in Svalbard archipelago. In Finnmark, plots both south and north of the treeline were investigated. Vegetation and soil chemistry analyses were performed on the plots in Finnmark and Svalbard. Significant decreasing south-north trends in air and soil temperatures were observed from Finnmark to Spitsbergen. Soils in Finnmark were acidic and rich in organic matter, while those on Adventsdalen were basic and poor in organic matter. Vegetational analysis identified five communities: three in Finnmark and two on Adventsdalen. The communities in Finnmark had marked mutual similarities but were very different from those on Adventsdalen. No significant ecological differences between heaths south and north of the treeline in Finnmark were observed. Air and soil temperature variables in Finnmark were outside the recognized range for the arctic biome and inconsistent with the presence of permafrost both south and north of the treeline. A major difference between Finnmark and Spitsbergen was amount of soil frost and length of the growing season. Our results suggest that the boreal biome extends all the way to the north coast of mainland Norway; and previously used division of heaths in Finnmark into boreal, alpine and arctic biomes is not justified.


Assuntos
Biodiversidade , Clima , Pergelissolo/química , Fenômenos Fisiológicos Vegetais , Regiões Árticas , Ilhas , Noruega , Plantas/classificação
15.
PLoS One ; 15(9): e0238222, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32936803

RESUMO

The expansion of agriculture is a major driver of biodiversity loss worldwide, through changes generated in the landscape. Despite this, very little is still known about the complex relationships between landscape composition and heterogeneity and plant taxonomical and functional diversity in Mediterranean ecosystems that have been extensively managed during millennia. Although according to the Intermediate Disturbance Hypothesis (IDH) plant richness might peak at intermediate disturbance levels, functional diversity might increase with landscape heterogeneity and decrease with the intensity of disturbance. Here, we evaluated the associations of landscape composition (percentage of crops) and heterogeneity (diversity of land-cover classes) with plant taxonomical diversity (richness, diversity, evenness), local contribution to beta diversity, and functional diversity (functional richness, evenness, divergence and dispersion) in 20 wild Olea europaea communities appearing within agricultural landscapes of Mallorca Island (Western Mediterranean Basin). In accordance with the IDH, we found that overall plant richness peaked at intermediate levels of crops in the landscape, whereas plant evenness showed the opposite pattern, because richness peak was mainly related to an increase in scarce ruderal species. Plant communities surrounded by very heterogeneous landscapes were those contributing the most to beta diversity and showing the highest functional richness and evenness, likely because diverse landscapes favour the colonization of new species and traits into the communities. In addition, landscape heterogeneity decreased functional divergence (i.e., increased trait overlap of dominant species) which may enhance community resilience against disturbances through a higher functional redundancy. However, a large extent of agriculture in the landscape might reduce such resilience, as this disturbance acted as an environmental filter that decreased functional dispersion (i.e, remaining species shared similar traits). Overall, our study highlights the importance of considering several indices of taxonomical and functional diversity to deeply understand the complex relationships between ecosystems functions and landscape context.


Assuntos
Agricultura/métodos , Biodiversidade , Conservação dos Recursos Naturais/métodos , Produtos Agrícolas/crescimento & desenvolvimento , Ecossistema , Monitoramento Ambiental/métodos , Plantas/classificação , Humanos , Região do Mediterrâneo
16.
Nat Commun ; 11(1): 4721, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32948775

RESUMO

The importance of soil age as an ecosystem driver across biomes remains largely unresolved. By combining a cross-biome global field survey, including data for 32 soil, plant, and microbial properties in 16 soil chronosequences, with a global meta-analysis, we show that soil age is a significant ecosystem driver, but only accounts for a relatively small proportion of the cross-biome variation in multiple ecosystem properties. Parent material, climate, vegetation and topography predict, collectively, 24 times more variation in ecosystem properties than soil age alone. Soil age is an important local-scale ecosystem driver; however, environmental context, rather than soil age, determines the rates and trajectories of ecosystem development in structure and function across biomes. Our work provides insights into the natural history of terrestrial ecosystems. We propose that, regardless of soil age, changes in the environmental context, such as those associated with global climatic and land-use changes, will have important long-term impacts on the structure and function of terrestrial ecosystems across biomes.


Assuntos
Biota , Ecossistema , Solo/química , Bactérias/classificação , Biodiversidade , Biomassa , Clima , Fungos/classificação , Microbiota , Plantas/classificação , Fatores de Tempo
17.
PLoS One ; 15(8): e0238165, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32841269

RESUMO

Vegetation mapping is of considerable significance to both geoscience and mountain ecology, and the improved resolution of remote sensing images makes it possible to map vegetation at a finer scale. While the automatic classification of vegetation has gradually become a research hotspot, real-time and rapid collection of samples has become a bottleneck. How to achieve fine-scale classification and automatic sample selection at the same time needs further study. Stratified sampling based on appropriate prior knowledge is an effective sampling method for geospatial objects. Therefore, based on the idea of stratified sampling, this paper used the following three steps to realize the automatic selection of representative samples and classification of fine-scale mountain vegetation: 1) using Mountain Altitudinal Belt (MAB) distribution information to stratify the study area into multiple vegetation belts; 2) selecting and correcting samples through iterative clustering at each belt automatically; 3) using RF (Random Forest) classifier with strong robustness to achieve automatic classification. The average sample accuracy of nine vegetation formations was 0.933, and the total accuracy of the classification result was 92.2%, with the kappa coefficient of 0.910. The results showed that this method could automatically select high-quality samples and obtain a high-accuracy vegetation map. Compared with the traditional vegetation mapping method, this method greatly improved the efficiency, which is of great significance for the fine-scale mountain vegetation mapping in large-scale areas.


Assuntos
Altitude , Ecossistema , Plantas/classificação , Imagens de Satélites , Algoritmos , China , Análise por Conglomerados , Bases de Dados Factuais , Monitoramento Ambiental/estatística & dados numéricos , Processamento de Imagem Assistida por Computador , Redes Neurais de Computação , Tecnologia de Sensoriamento Remoto/estatística & dados numéricos , Imagens de Satélites/estatística & dados numéricos
18.
Nat Commun ; 11(1): 4180, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32826915

RESUMO

Ecologists have long argued that higher functioning in diverse communities arises from the niche differences stabilizing species coexistence and from the fitness differences driving competitive dominance. However, rigorous tests are lacking. We couple field-parameterized models of competition between 10 annual plant species with a biodiversity-functioning experiment under two contrasting environmental conditions, to study how coexistence determinants link to biodiversity effects (selection and complementarity). We find that complementarity effects positively correlate with niche differences and selection effects differences correlate with fitness differences. However, niche differences also contribute to selection effects and fitness differences to complementarity effects. Despite this complexity, communities with an excess of niche differences (where niche differences exceeded those needed for coexistence) produce more biomass and have faster decomposition rates under drought, but do not take up nutrients more rapidly. We provide empirical evidence that the mechanisms determining coexistence correlate with those maximizing ecosystem functioning.


Assuntos
Biodiversidade , Biomassa , Ecossistema , Modelos Biológicos , Fenômenos Fisiológicos Vegetais , Desenvolvimento Vegetal , Plantas/classificação , Dinâmica Populacional , Espanha
19.
Nat Commun ; 11(1): 3999, 2020 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-32778648

RESUMO

Land use change, by disrupting the co-evolved interactions between plants and their pollinators, could be causing plant reproduction to be limited by pollen supply. Using a phylogenetically controlled meta-analysis on over 2200 experimental studies and more than 1200 wild plants, we ask if land use intensification is causing plant reproduction to be pollen limited at global scales. Here we report that plants reliant on pollinators in urban settings are more pollen limited than similarly pollinator-reliant plants in other landscapes. Plants functionally specialized on bee pollinators are more pollen limited in natural than managed vegetation, but the reverse is true for plants pollinated exclusively by a non-bee functional group or those pollinated by multiple functional groups. Plants ecologically specialized on a single pollinator taxon were extremely pollen limited across land use types. These results suggest that while urbanization intensifies pollen limitation, ecologically and functionally specialized plants are at risk of pollen limitation across land use categories.


Assuntos
Ecologia , Fenômenos Fisiológicos Vegetais , Pólen , Polinização , Animais , Abelhas , Bases de Dados Factuais , Ecossistema , Filogenia , Plantas/classificação , Urbanização
20.
PLoS One ; 15(8): e0237645, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32814345

RESUMO

In this research, an efficient scheme to identify leaf types is proposed. In that scheme, the leaf boundary points are fitted in a continuous contour using Radial Basis Function Neural Networks (RBFNN) to calculate the centroid of the leaf shape. Afterwards, the distances between predetermined points and the centroid were computed and normalized. In addition, the time complexity of the features' extraction algorithm was calculated. The merit of this scheme is objects' independence to translation, rotation and scaling. Moreover, different classification techniques were evaluated against the leaf shape features. Those techniques included two of the most commonly used classification methods; RBFNN and SVM that were evaluated and compared with other researches that used complex features extraction algorithms with much higher dimensionality. Furthermore, a third classification method with an optimization technique for the SVM using Salp Swarm Algorithm (SSA) was utilized showing a significant improvement over RBFNN and SVM.


Assuntos
Algoritmos , Redes Neurais de Computação , Folhas de Planta/anatomia & histologia , Plantas/anatomia & histologia , Plantas/classificação , Máquina de Vetores de Suporte
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