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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Le Cénomanien de Tunisie centrale : étude paléoecologique, stratigraphique, micropaléontologique et paléogeographique

Gargouri Razgallah, Saloua 22 December 1983 (has links) (PDF)
L'objectif de cet ouvrage est d'établir un schéma d'évolution paléogéographique de la plate-forme cénomanienne permettant de replacer géographiquement les différents domaines sédimentologiques. Tracer le paysage de Tunisie centrale au cours du Cénomanien, n'est autre qu'une analyse et une compréhension des faciès et de l'environnement. Il a fallu d'abord tenter, dans la mesure du possible, d'esquisser une biozonation basée non seulement sur les foraminifères benthiques et planctoniques, mais aussi les ammonites et les ostracodes. Cette biozonation appelait à son tour une étude systématique. C'est dans cette direction que s'est engagée la présente recherche
12

Trends in evolutionary morphology : a case study in the relationships of angel sharks and batoid fishes

Claeson, Kerin Michele 20 October 2010 (has links)
Chondrichthyans are cartilaginous fishes that include the extant chimaeras, sharks, and batoids, and their extinct relatives. In this dissertation, I examined the growth, development, and relationships of extinct and extant chondrichthyans. I reexamined the skeleton of fossil and fetal specimens of the angel sharks (Squatiniformes) and reanalyzed the current morphologically based hypothesis of chondrichthyan evolution, which conflicts with the current molecular based hypothesis. I did this by including extinct taxa and new characters based on dentition, and the ethmoid, occipital, pectoral, and vertebral skeleton. My results supported the pre-existing morphological hypothesis that angel sharks, saw sharks, and batoids form a clade. However, some of my new characters, particularly those based on the vertebral morphology, indicate that fetal and juvenile angel sharks do not share as many apomorphies with batoids as previously hypothesized from the examination of adults. I also examine the relationships of major groups within batoids, beginning with the construction of a hypothesis of the evolutionary history of electric rays (Torpediniformes). My results are consistent with previous rank-based classifications. However, they deviate from previous classifications depending on the criteria used to generate the hypothesis and on which taxon, or combination of taxa, were used to root the ingroup phylogeny. Because pectoral and vertebral morphology are so critical to morphological hypotheses, I also examined the growth and development of the synarcual cartilage in batoid fishes, with particular emphasis on the synarcual of skates (Rajiformes). My results demonstrate that calcification and chondrification do not proceed in the same order, temporally and spatially. Finally, I redescribe the extinct batoid †Cyclobatis, known only from the Cretaceous, and evaluate its phylogenetic position. My results indicate that †Cyclobatis, the oldest known rajid, is also the sister taxon to a clade of all known extant members of Rajidae. Furthermore, the inclusion of new characters, mainly derived from the synarcual, help to resolve the interrelationships of Rajidae. / text
13

Introducing Explorer of Taxon Concepts with a case study on spider measurement matrix building

Cui, Hong, Xu, Dongfang, Chong, Steven S., Ramirez, Martin, Rodenhausen, Thomas, Macklin, James A., Ludäscher, Bertram, Morris, Robert A., Soto, Eduardo M., Koch, Nicolás Mongiardino 17 November 2016 (has links)
Background: Taxonomic descriptions are traditionally composed in natural language and published in a format that cannot be directly used by computers. The Exploring Taxon Concepts (ETC) project has been developing a set of web-based software tools that convert morphological descriptions published in telegraphic style to character data that can be reused and repurposed. This paper introduces the first semi-automated pipeline, to our knowledge, that converts morphological descriptions into taxon-character matrices to support systematics and evolutionary biology research. We then demonstrate and evaluate the use of the ETC Input Creation - Text Capture - Matrix Generation pipeline to generate body part measurement matrices from a set of 188 spider morphological descriptions and report the findings. Results: From the given set of spider taxonomic publications, two versions of input (original and normalized) were generated and used by the ETC Text Capture and ETC Matrix Generation tools. The tools produced two corresponding spider body part measurement matrices, and the matrix from the normalized input was found to be much more similar to a gold standard matrix hand-curated by the scientist co-authors. Special conventions utilized in the original descriptions (e.g., the omission of measurement units) were attributed to the lower performance of using the original input. The results show that simple normalization of the description text greatly increased the quality of the machine-generated matrix and reduced edit effort. The machine-generated matrix also helped identify issues in the gold standard matrix. Conclusions: ETC Text Capture and ETC Matrix Generation are low-barrier and effective tools for extracting measurement values from spider taxonomic descriptions and are more effective when the descriptions are self-contained. Special conventions that make the description text less self contained challenge automated extraction of data from biodiversity descriptions and hinder the automated reuse of the published knowledge. The tools will be updated to support new requirements revealed in this case study.
14

Aspectos cariogen?micos em esp?cies marinhas de Haemulidae (Perciformes) e Labridae (Labriformes): uma perspectiva evolutiva

Motta Neto, Cl?vis Coutinho da 29 September 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-03-21T13:09:14Z No. of bitstreams: 1 ClovisCoutinhoDaMottaNeto_TESE.pdf: 24405489 bytes, checksum: f4b763bedf2b803da39f795bc3d80ff3 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-03-23T15:58:48Z (GMT) No. of bitstreams: 1 ClovisCoutinhoDaMottaNeto_TESE.pdf: 24405489 bytes, checksum: f4b763bedf2b803da39f795bc3d80ff3 (MD5) / Made available in DSpace on 2018-03-23T15:58:48Z (GMT). No. of bitstreams: 1 ClovisCoutinhoDaMottaNeto_TESE.pdf: 24405489 bytes, checksum: f4b763bedf2b803da39f795bc3d80ff3 (MD5) Previous issue date: 2017-09-29 / O Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A S?rie Percomorpha ? maior divis?o entre os vertebrados, constituindo o maior e mais derivado clado de peixes tele?steos. Dentre suas Ordens, Perciformes e Labriformes constituem modelos adequados ? investiga??o do conservadorismo e diversifica??o cromoss?mica. Em Perciformes o conservadorismo cromoss?mico ? representado por cari?tipos basais com 2n=48 acroc?ntricos, extensivamente compartilhados por uma parcela consider?vel de esp?cies. As causas e extens?o do conservadorismo cariot?pico em v?rias fam?lias desta Ordem n?o s?o inteiramente claras. Diante da diversidade de esp?cies em Labriformes, aspectos mais detalhados de sua evolu??o cariot?pica ou mesmo status taxon?mico de algumas esp?cies merecem particular aten??o. Com vistas a contribuir com novas informa??es sobre essas quest?es foram implementadas an?lises cromoss?micas convencionais (colora??o convencional com Giemsa, bandamento C e Ag-RONs, fluocrocromos base-espec?ficos) e citomoleculares (hibridiza??o in situ com sondas DNAr 18S, DNAr 5S). Oito esp?cies dos g?neros Anisotremus e Haemulon da fam?lia Haemulidae (Perciformes) foram analisadas, incluindo amostras de diferentes ?reas do Atl?ntico, como modelo de evolu??o conservativa. Em 2 esp?cies do g?nero Bodianus da fam?lia Labridae (Labriformes), foram analisados tamb?m aspectos da evolu??o de sequ?ncias repetitivas particulares (DNAr 18S, DNAr 5S, Alu e Tol2) nos cromossomos por hibridiza??o com 5 metilcitosina (5mC). Adicionalmente, foram realizadas compara??es filogen?ticas, utilizando sequ?ncias de DNA mitocondrial (COI e 16S) e nuclear (Rodopsina) para verificar o status taxon?mico da esp?cie Bodianus insularis, end?mica das ilhas Meso-Atl?nticas. Todas as esp?cies de Haemulidae apresentaram 2n=48a, s?tios Ag-RONs simples e heterocromatina centrom?rica reduzida, al?m de consider?vel compartilhamento de s?tios de DNAr 5S e 18S, confirmando a ocorr?ncia de estase cariot?pica na fam?lia. Os padr?es cariot?picos das popula??es de A. virginicus e H. chrysargyreum entre o Caribe e Atl?ntico Sul n?o revelaram varia??es cromoss?micas decorrentes da barreira dos des?gues dos rios Amazonas/Orinoco. Em Bodianus, as an?lises identificaram uma not?vel regi?o descondensada em um par cromoss?mico subteloc?ntrico, denominada regi?o BOD. Entre suas caracter?sticas constitutivas e funcionais particulares, se mostram DAPI-, argentof?lica (Ag+), marcantemente hipometilada e saturada de elementos transpon?veis, sugerindo que a participa??o destes elementos m?veis pode ter contribu?do para sua g?nese e din?mica epigen?tica complexa. Quanto a esp?cie end?mica B. insularis, sua diverg?ncia gen?tica ? muito inferior ? apresentada por esp?cies diferenciadas sugerindo que embora represente um grupo geograficamente isolado, constitua uma sinon?mia de B. pulchellus. A diverg?ncia nos ritmos de diversifica??o cariot?pica entre Haemulidae e Labridae ? aqui discutida ? luz de caracter?sticas cariot?picas intr?nsecas que podem favorecer o tamponamento e a fixa??o de mudan?as cromoss?micas e aspectos biol?gicos das esp?cies que contribuem para as condi??es particulares de evolu??o cariot?pica desses dois grupos de peixes marinhos. / Percomorpha series is the largest division among vertebrates, constituting the largest and most derived clade of teleostean fishes. Among its Orders, Perciformes and Labriformes constitue adequated models for the investigation of conservatism and chromosomal diversification. In Perciformes the chromosomal conservatism is represented by basal karyotypes with 2n = 48 acrocentric, extensively shared by a considerable portion of species. The causes and extent of the karyotypic conservatism in various families of this Order are not entirely clear. In front of the diversity of species in Labriformes, more detailed aspects of its karyotype evolution or even the taxonomic status of some species deserve particular attention. In order to contribute with new information on these issues, it was implemented conventional chromosome analysis (conventional staining with Giemsa, C-banding and Ag- NORs, base-specific fluochromes) and cytomolecular (in situ hybridization with 18S rDNA, 5S rDNA) probes were implemented. Eight species of the genera Anisotremus and Haemulon of the family Haemulidae (Perciformes) were analyzed, including samples from different areas of the Atlantic, as a model of conservative evolution. In 2 species of the Bodianus genus Labridae (Labriformes), it was also analyzed aspects of the evolution of particular repetitive sequences (DNAr 18S, DNAr 5S, Alu and Tol2) in the chromosomes by hybridization with 5 methylcytosine (5mC). Additionally, phylogenetic comparisons were performed using mitochondrial (COI and 16S) and nuclear (Rhodopsin) DNA sequences to verify the taxonomic status of the Bodianus insularis species, endemic to the Meso-Atlantic islands. All Haemulidae species presented 2n = 48a, single Ag-NORs sites and reduced centromeric heterochromatin, besides considerable sharing of rDNA 5S and 18S sites, confirming the occurrence of karyotype stasis in the family. The karyotypic patterns of the populations of A. virginicus and H. chrysargyreum between the Caribbean and the South Atlantic did not reveal chromosomal variations due to the barrier of the discharges of the Amazonas / Orinoco rivers. In Bodianus, the analyzes identified a remarkable decondensed region in a subtelocentric chromosomal pair, denominated BOD region. Among its particular constitutive and functional characteristics, it is DAPI-, Argentof?lica (Ag +), markedly hypomethylated and saturated with transposable elements, suggesting that the participation of these mobile elements may have contributed to its genesis and complex epigenetic dynamics. In relation to the endemic species B. insularis its genetic divergence is much inferior to that presented by differentiated species suggesting that although it represents a geographically isolated group, it constitutes a synonym of B. pulchellus. The divergence in the rates of karyotype diversification between Haemulidae and Labridae is discussed here in the light of intrinsic karyotype characteristics that may favor the buffering and the fixation of chromosomal changes and biological aspects of the species that contributes to particular conditions of karyotype evolution of these two groups of marine fish.
15

Floristický průzkum části povodí řeky Oslavy mezi obcemi Velké Meziříčí a Vaneč / Floristic research of part of catchment area of Oslava river between villages Velke Mezirici and Vanec

BORŮVKOVÁ, Zuzana January 2008 (has links)
The study deals with a description of vegetation of part of catchment area of Oslava river between villages Velke Mezirici and Vanec. The search had been realised during the vegetation seasons of the years 2006 and 2007. There are characterised geological-petrographical, soil, climatic, hydrographic ratios and basic phytogeographical characteristics of this area in the form of a search. Selected genera of the observed plants was characterised and their incidence is figured in the schematic maps of the area. There were found out 327 kinds of plants there. In the annex there are attached schematic maps with places of occurence of the plant genera and photographic documentation.
16

Statistické vyhodnocení fylogeneze biologických sekvencí / Statistic evaluation of phylogeny of biological sequences

Zembol, Filip January 2013 (has links)
The topic of my diploma thesis is the statistical evaluation of biological sequences with the help of phylogenic trees. In the theoretical part we will create a literary recherche of estimation methodology concerning the course of phylogeny on the basis of the similarity of biological sequences (DNA and proteins) and we will focus on the inaccuracies of the estimation, their causes and the possibilities of their elimination. Afterwards, we will compare the methods for the statistical evaluation of the correctness of the course of phylogeny. In the practical part of the thesis we will suggest algorithms that will be used for testing the correctness of the phylogenic trees on the basis of bootstrapping, jackknifing, OTU jackknifing and PTP test which are able to the capture phylogenic tree with the method neighbor joining from the biological sequences in FASTA code. It is also possible to change the distance model and the substitution matrix. To be able to use these algorithms for the statistical support of phylogenic trees we have to verify their right function. This verification will be evaluated on the theoretical sequences of the amino acids. For the verification of the correct function of the algorithms, we will carry out single statistical tests on real 10 sequences of mammalian ubiquitin. These results will be analysed and appropriately discussed.
17

The Genus Milnesium (Tardigrada: Eutardigrada: Milnesiidae) in the Great Smoky Mountains National Park (North Carolina and Tennessee, USA), With the Description of Milnesium Bohleberi sp. Nov.

Bartels, Paul J., Nelson, Diane R., Kaczmarek, Łukasz, Michalczyk, Łukasz 30 June 2014 (has links)
For many decades the genus Milnesium was thought to consist of a single, cosmopolitan species: Milnesium tardigradum Doyere, 1840. However, recently the genus has been re-evaluated, and numerous new species have been described. Cur-rently, over twenty extant species and one fossil are recognised, and most appear to have very narrow geographic ranges. It is doubtful that M. tardigradum sensu stricto is truly cosmopolitan, but to evaluate this hypothesis, specimens previously identified as M. tardigradum must be re-examined using newly proposed taxonomic characters. As part of the All Taxa Biodiversity Inventory (ATBI) we collected Milnesium specimens from various locations in the Great Smoky Mountains National Park (GSMNP). Two Milnesium species have been evaluated, and one of them, Milnesium bohleberi sp. nov., is new to science. The new species is most similar to M. eurystomum but differs by shorter claws and a shorter, narrower, and more cylindrical buccal tube. The other Milnesium species, very rare in our collection, is morphologically indistin-guishable from Milnesium granulatum Ramazzotti 1962, which was previously known only from Chile, Italy and Roma-nia. Based on the recently revised description of M. tardigradum sensu stricto, this nominal species for the genus has not been found in the GSMNP samples.
18

Chimères, données manquantes et congruence : validation de différentes méthodes par simulations et application à la phylogénie des mammifères

Campbell, Véronique January 2009 (has links)
Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.
19

Revis?o taxon?mica das esp?cies brasileiras de Alternanthera Forssk (Amaranthaceae Juss.)

Souza, Luisa Ramos Senna 10 January 2015 (has links)
Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2017-10-09T21:51:42Z No. of bitstreams: 1 TESE_LUISA RAMOS.pdf: 12171909 bytes, checksum: dfd039e3c7457072b9d4c4c178c30162 (MD5) / Made available in DSpace on 2017-10-09T21:51:42Z (GMT). No. of bitstreams: 1 TESE_LUISA RAMOS.pdf: 12171909 bytes, checksum: dfd039e3c7457072b9d4c4c178c30162 (MD5) Previous issue date: 2015-01-10 / Amaranthaceae is a family of about 180 genera and 2,500 species, divided in 8 subfamilies, and distributed in tropical and temperate areas of both hemispheres. It represents the most species-rich lineage within the Caryophyllales. For Brazil are recognized 158 species in 27 genera, with three endemic, and most of them included in Gomphrenoideae.This subfamily includes two major Brazilian genera,Gomphrena with 45 species and Alternanthera with 36 species. Alternanthera is a monophyletic group of about 100 species of pantropical distribution, characterized by sessile or pedunculate axillaryinflorescences, with the partial inflorescence unit reduced to a single flower. Flowers are sessile or pedicellate, protected by a bract and two bracteoles, bisexual, with (4-)5 tepals, (4-)5 stamens, with fused filaments forming a basal tube, free towards the tube end and alternating with pseudo-staminodes.The latest revision of Alternanthera for Brazil dates backto that of the Flora Brasiliensis,of more than 160 years ago, fully justifyinga new revision, the principal objective of our thesis. It isdivided into four chapters, followingan introduction. Chapter 1 includes a morphological study of the Alternanthera species in Brazil, using 107 characters, of which 99 were considered informative and have been evaluated using DELTA, resulting in a description of vegetative and floral organs of Alternanthera,with the focuson the most important of them for the group's taxonomy anda discussionof their terminology.Chapter 2 isa study of the Alternanthera brasiliana complex of five species, using the statistical exploratory analysis. Only four species in the complexwere recognized, with a proposalto synonymize Alternanthera ramosissimatoA. brasiliana.Chapter 3 is the text of a paperon the new species Alternanthera catingae, submitted for publication in Phytotaxa. Chapter 4 is a revision of the Brazilian species of Alternanthera, based on the study of 1,900 specimens deposited in 19 herbaria and using the adopted typological species concept.In addition to the traditional revisionary methodology, modernanalytic tools were used inthe evaluation of species occurring in Brazil. We recognized 35 species, with one, A.catingae, new to science, synonymizedsix species, and made one new combination. The work should be an important contributionto the study of the Brazilian Amaranthaceae, especially in terms of reaching the objective of making the Flora of Brazil go online in 2020. / As Amaranthaceae constituem uma fam?lia com cerca de 180 g?neros e 2.500 esp?cies, com distribui??o nas faixas tropicais e temperadas dos dois hemisf?rios e representam a mais rica linhagem de esp?cies dentre as Caryophyllales. Inclui 8 subfam?lias . Para o Brasil s?o referidas 158 esp?cies distribu?das em 27 g?neros, dos quais tr?s s?o end?micos, grande parte desses g?neros s?o inclu?dos em Gomphrenoideae. Esta subfam?lia inclui os maiores g?neros representados no Brasil, Gomphrena com 45 esp?cies e Alternanthera com 36 esp?cies. Alternanthera ? um grupo monofil?tico com cerca de 100 esp?cies, possui distribui??o pantropical e ? caracterizado por apresentar infloresc?ncias axilares, s?sseis ou pedunculadas, com unidade parcial da infloresc?ncia reduzida a ?nica flor. As flores s?o s?sseis ou pediceladas, protegidas por uma br?ctea e duas bract?olas, bissexuadas, com (4?)5 t?palas, (4?)5 estames com filetes fundidos formando um tubo basal, livres acima do tubo e alternados com pseudo-estamin?dios. A ?ltima revis?o de Alternanthera para o Brasil foi elaborada para a Flora brasiliensis mais de 160 anos atr?s, justificando-se plenamente a nova revis?o proposta, que ? o principal objetivo desta tese. Os resultados obtidos encontram-se distribu?dos em quatro cap?tulos, que se seguem ap?s a Introdu??o. No Cap?tulo 1 ? apresentado o estudo morfol?gico das esp?cies de Alternanthera do Brasil, onde foram levantados 107 caracteres dos quais 99 foram considerado informativos e foram avaliados utilizando o Programa DeLTA. Como resultado, ? produzida uma descri??o dos ?rg?os vegetativos e florais de Alternanthera destacando os mais importantes para taxonomia do grupo, bem como uma discuss?o dos diferentes termos utilizados na morfologia do grupo. No Cap?tulo 2 ? apresentado o estudo do ?complexo Alternanthera brasiliana? composto por cinco esp?cies, atrav?s da abordagem de estat?stica explorat?ria. Como resultado foram reconhecidas apenas quatro esp?cies no grupo, com a proposta de sinonimiza??o de Alternanthera ramosissima em A. brasiliana. No Cap?tulo 3 ? inclu?do o texto original da nova esp?cie Alternanthera catingae, enviado para publica??o na revista Phytotaxa. No Cap?tulo 4 ? apresentada a revis?o das esp?cies brasileiras de Alternanthera realizada a partir da an?lise de mais de 1900 esp?cimes do g?nero, depositados em 19 herb?rios, com a utiliza??o do conceito tipol?gico de esp?cies. Al?m da metodologia tradicional utilizada em trabalhos de revis?o, foram utilizadas tamb?m ferramentas diferenciadas para an?lise e avalia??o das esp?cies que ocorrem no Brasil. Foram reconhecidas 35 esp?cies, das quais uma nova para a ci?ncia, A.catingae, seis sin?nimos de esp?cies cujos tipos s?o do p?is, e uma nova combina??o. O trabalho aqui apresentado se constitui um importante avan?o para o estudo das Amaranthaceae brasileiras, especialmente visando a flora do Brasil on line para 2020.
20

Melastomataceae na Marambaia, Rio de Janeiro, Brasil: diversidade taxon?mica, aspectos flor?sticos e estado de conserva??o

Silva, Kelly Cristina da 30 March 2011 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-08-29T11:54:58Z No. of bitstreams: 1 2011- Kelly Cristina da Silva.pdf: 7307607 bytes, checksum: 8d84ec46e5af2c80b3625d586980819b (MD5) / Made available in DSpace on 2016-08-29T11:54:58Z (GMT). No. of bitstreams: 1 2011- Kelly Cristina da Silva.pdf: 7307607 bytes, checksum: 8d84ec46e5af2c80b3625d586980819b (MD5) Previous issue date: 2011-03-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The Atlantic Forest is one of the world's biodiversity hotspots because of the diversity and high degrees of endemism and threat. Melastomataceae is a plant family typical of this biome, and it is represented by more than 500 species that occur from restingas (sandy coastal plain habitats) to the upper montane forests and high-altitude grasslands. Despite this broad representation, there are few taxonomic studies of this family for this biome, and especially of the flora of Rio de Janeiro state. The present study aims to survey the Melastomataceae at Marambaia, an island included in the Atlantic Forest biome, as well as taxonomic and floristic similarity studies. It has significant ecological importance as a natural refuge for several plant species of the Tropical Moist Forest and for the preservation of genetic heritage. The vegetation types are Submontane Tropical Moist Forest and restinga, and the Melastomataceae is represented by seven genera and 25 species, of which 13 (52%) represent new records for the area. Miconia is the largest genus with 10 species, followed by Tibouchina (6 spp.), Leandra (4 spp.), Clidemia (2spp.) and Huberia, Marcetia and Ossaea (1 sp. each). Descriptions, illustrations, and a key to identify the taxa are provided. Morphological characteristics of leaves, inflorescences, buds, petals, hypanthium, stamens, indumentum, fruits, and seeds are diagnostic to distinguish the taxa. Comments on morphological peculiarities of species and geographical, phenological, and conservation status data are also presented. Three species are cited on the list of endangered species of Rio de Janeiro municipality. Among the vegetation formations, the Submontane Tropical Moist Forest has the highest species richness (23 species), while in restingas the richness is lower, with eight species in forest formations, five species in shrubby formations, and only two species in herbaceous formations. Similarity between the vegetation formations of Marambaia was low, ranging between 4.2% and 40%. Despite the strong relationship between these formations and their physical proximity, the four areas at Marambaia have low species similarity. Key words: Atlantic / A Floresta Atl?ntica ? um dos hotspots mundiais de biodiversidade devido ? elevada diversidade e graus de endemismo e amea?a. Dentre as fam?lias vegetais t?picas desse bioma est? Melastomataceae, com mais de 500 esp?cies e que ocorrem desde as restingas at? as florestas altomontanas e campos de altitude. Apesar dessa numerosa representatividade, poucos s?o os estudos taxon?micos sobre esta fam?lia na flora fluminense. Desse modo, o presente estudo tem como objetivo realizar o levantamento flor?stico da fam?lia Melastomataceae na Marambaia, uma regi?o insular integrada no bioma Floresta Atl?ntica, bem como estudos taxon?micos e de similaridade flor?stica. Ela desempenha significativa import?ncia ecol?gica como um ref?gio natural para diversas esp?cies de plantas da Mata Pluvial e atua na preserva??o do patrim?nio gen?tico. Nessa regi?o insular, onde a cobertura vegetal ? de Floresta Ombr?fila Densa Submontana e Restinga, a representatividade da fam?lia Melastomataceae mostra-se expressiva, constitu?da de sete g?neros e 25 esp?cies, das quais 13 correspondem a novos registros para a ?rea. Miconia ? o g?nero mais numeroso, com 10 esp?cies, seguido por Tibouchina (6 spp.), Leandra (4 spp.), Clidemia ( 2spp.) e Huberia, Marcetia e Ossaea (1 sp. cada). S?o apresentadas descri??es, ilustra??es e chaves para identifica??o dos t?xons. Caracter?sticas morfol?gicas das folhas, infloresc?ncias, ?pice dos bot?es florais e p?talas, hipanto, estames, tipos de indumento, frutos e sementes mostram-se diagn?sticas para a identifica??o dos t?xons. Coment?rios sobre particularidades morfol?gicas das esp?cies e dados geogr?ficos, fenol?gicos e sobre o estado de conserva??o das esp?cies, tamb?m s?o apresentados. Tr?s esp?cies s?o citadas na lista das esp?cies amea?adas de extin??o para o munic?pio do Rio de Janeiro. Dentre as forma??es vegetais analisadas, a Floresta Ombr?fila Densa Submontana apresentou a maior riqueza de esp?cies (23 esp?cies), enquanto nas restingas a riqueza foi menor, com oito esp?cies nas Forma??es Florestais, cinco esp?cies nas Forma??es Arbustivas e apenas duas esp?cies nas Forma??es Herb?ceas. A similaridade entre as forma??es vegetais da Marambaia foi baixa, variando entre 4,2% e 40%. Apesar da elevada rela??o entre essas forma??es e suas proximidades f?sicas na Marambaia, as quatro ?reas guardam poucas semelhan?as na composi??o de esp?cies

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