140 research outputs found
Micromorfologia da superfície do aquênio em Bulbostylis Kunth (Cyperaceae)
(Micromorfologia da superfície do aquênio em Bulbostylis Kunth (Cyperaceae)) Bulbostylis possui
aproximadamente 150 espécies, distribuídas nas regiões tropicais e subtropicais de ambos os hemisférios. Caracteres
morfológicos da superfície do aquênio, em microscopia eletrônica de varredura, foram utilizados para diferenciar 38 das 45
espécies de Bulbostylis Kunth (Cyperaceae) ocorrentes no Brasil, permitindo o reconhecimento de três padrões de
ornamentação da superfície do aquênio: tuberculado, reticulado e transversalmente rugoso. Além destes, outros caracteres
de interesse taxonômico foram observados, tais como a variação na escultura primária do aquênio, a ornamentação das
paredes anticlinais, a presença ou ausência de corpos silicosos e o contorno das células epidérmicas. _________________________________________________________________________________________ ABSTRACT: Bulbostylis comprises approximately 150 species distributed in the tropics and subtropics of both hemispheres. The morphology of the achene surface, using scanning electron microscopy, was used to differentiate 38 species of Bulbostylis Kunth (Cyperaceae) and revealed the presence of three patterns of ornamentation on the achene surface: tuberculate, reticulate, and transversely rugose. Other characters of taxonomic interest were also observed, including the primary sculpturing, the ornamentation of the anticlinal cell walls of the epidermis, the presence or absence of silica bodies, and the shape of the epidermal cells
VEGETAÇÃO E FLORA NO CARIRI PARAIBANO
A study of the flora and vegetation of the Cariri Region of Paraíba was carried out in order to support strategies for conservation and sustainable use of the region's caatinga. For the floristic survey, the whole Cariri region was considered, but for the study of vegetation structure, two areas in different states of preservation were chosen: a well-preserved site, the Fazenda Almas private reserve (RPPN; 7°2815”S, 36°53'51”W), and a significantly altered site, the São João do Cariri Experimental Station (7º23'48”S and 36º31'55”W). In the floristic survey 396 species were observed, with the family Leguminosae being the most diverse. In São João do Cariri, 26 species of trees or shrubs were observed with the dominants being Caesalpinia pyramidalis, Croton sonderianus, Combretum leprosum and Jatropha mollissima. In Fazenda Almas, 67 species of trees or shrubs were found, with the most prominent being Croton sonderianus, Caesalpinia pyramidalis, and also Manihot catingae. The low diversity found at the São João de Caririri site was reflected in all the structural parameters of the vegetation, indicating a degradation of the local vegetation which has been used for years for grazing goats. The species diversity in the Fazenda Almas RPPN was much higher than that observed in São João do Cariri or other areas of caatinga in Paraíba.Realizou-se um estudo da flora e da estrutura da vegetação no Cariri Paraibano com o objetivo de subsidiar estratégias para conservação e uso sustentável da caatinga na região. No levantamento florístico considerouse toda a área do Cariri, mas para os estudos de estrutura foram selecionadas duas localidades em diferentes estádios de conservação: a RPPN Fazenda Almas (7°2815”S, 36°53'51”W), Cariri Ocidental, área mais preservada, e a Estação Experimental de São João do Cariri (7º23'48”S e 36º31'55”W), Cariri Oriental, com vegetação bastante alterada. No levantamento florístico foram observadas 396 espécies, sendo a família Leguminosae a mais diversa. Em São João do Cariri foram observadas 26 espécies arbóreo-arbustivas e a dominância de Caesalpinia pyramidalis, Croton sonderianus, Combretum leprosum e Jatropha mollissima. Na Fazenda Almas registraram-se 67 espécies arbóreo-arbustivas, destacando-se também Croton sonderianus e Caesalpinia pyramidalis e ainda Manihot catingae. A baixa diversidade florística encontrada na EE São João do Cariri refletiu-se em todos os parâmetros estruturais de vegetação analisados indicando a degradação da vegetação local, que há anos é utilizada para pastoreio de caprinos. A diversidade na RPPN Fazenda Almas foi bastante superior à observada em São João do Cariri e em outras áreas de caatinga na Paraíba
Diversity of cyperaceae in Brazil
The purpose of this catalogue was to combine the available data from
publications, theses, databases, and herbarium specimens from around 120 Herbaria, and colections sampled
in Brazilian vegetation during the last 15 years to produce the most complete list, as possible as, of Cyperaceae
species for Brazil. We catalogued ca. 1,700 names for 678 species in 42 genera occurring in Brazil. These
values represent ca. 15 percent of the species and 40 percent of the genera found in the world. Both subfamilies
of Cyperaceae are found in Brazil with Cyperoideae being the most diverse at both generic and specific levels.
Although lower species were recorded for the tribes Cryptangieae, Sclerieae, and Trilepideae, these tribes
represent a much higher percentage of the world’s totals for genera and species. The most diverse genera are
Rhynchospora (157 spp.), Cyperus (101 spp.), Scleria (82 spp.) and Eleocharis (69 spp.). Fifteen genera have
one species in Brazil, although five of them are monospecific. The most species-rich regions in Brazil are the
North and Southeast. There are no genera endemic to Brazil. There are, however, around 200 endemic species,
of which 40 are in the genus Rhynchospora. Taxonomic and nomenclatural problems found are pointed under
the species. For each catalogued species, the principal synonyms, bibliographic references, distribution
within Brazil’s five regions, vegetation type, and citation of selected material examined are provided
Viable Reserve Networks Arise From Individual Landholder Responses To Conservation Incentives
Abstract Conservation in densely-settled biodiversity hotspots areas often requires setting up reserve networks that maintain sufficient contiguous habitat to support viable species populations. Because it is difficult to secure landholder compliance with an tightly constrained reserve network design, attention has shifted to voluntary incentive mechanisms, such as purchase of conservation easements by reverse auction or through a fixed-price offer. These mechanisms carry potential advantages of transparency, simplicity, and low cost. But uncoordinated individual response to these incentives has been assumed to be incompatible with conservation goals of viability (which depends on contiguous habitat) and biodiversity representation. We model such incentives for southern Bahia in the Brazilian Atlantic Forest, one of the biologically richest and most threatened global biodiversity hotspots. Here, forest cover is spatially autocorrelated and associated with depressed land values, a situation that may be characteristic of longsettled areas with forests fragmented by agriculture. We find that in this situation, a voluntary incentive system can yield a reserve network characterized by large, viable patches of contiguous forest, and representation of subregions with distinct vegetation types and biotic assemblages -without explicit planning for those outcomes
A new classification of Cyperaceae (Poales) supported by phylogenomic data
Cyperaceae (sedges) are the third largest monocot family and are of considerable economic and ecological importance. Sedges represent an ideal model family to study evolutionary biology because of their species richness, global distribution, large discrepancies in lineage diversity, broad range of ecological preferences, and adaptations including multiple origins of C4 photosynthesis and holocentric chromosomes. Goetghebeur’s seminal work on Cyperaceae published in 1998 provided the most recent complete classification at tribal and generic level, based on a morphological study of Cyperaceae inflorescence, spikelet, flower and embryo characters plus anatomical and other information. Since then, several family‐level molecular phylogenetic studies using Sanger sequence data have been published. Here, more than 20 years after the last comprehensive classification of the family, we present the first family‐wide phylogenomic study of Cyperaceae based on targeted sequencing using the Angiosperms353 probe kit sampling 311 accessions. Additionally, 62 accessions available from GenBank were mined for overlapping reads and included in the phylogenomic analyses. Informed by this backbone phylogeny, a new classification for the family at the tribal, subtribal and generic levels is proposed. The majority of previously recognized suprageneric groups are supported, and for the first time we establish support for tribe Cryptangieae as a clade including the genus Koyamaea. We provide a taxonomic treatment including identification keys and diagnoses for the 2 subfamilies, 24 tribes and 10 subtribes and basic information on the 95 genera. The classification includes five new subtribes in tribe Schoeneae: Anthelepidinae, Caustiinae, Gymnoschoeninae, Lepidospermatinae and Oreobolinae. This article is protected by copyright. All rights reserved
The future of botanical monography : report from an international workshop, 12–16 March 2012, Smolenice, Slovak Republic
Monographs are fundamental for progress in systematic botany. They are the vehicles for circumscribing and naming
taxa, determining distributions and ecology, assessing relationships for formal classification, and interpreting long-term and
short-term dimensions of the evolutionary process. Despite their importance, fewer monographs are now being prepared by the
newer generation of systematic botanists, who are understandably involved principally with DNA data and analysis, especially
for answering phylogenetic, biogeographic, and population genetic questions. As monographs provide hypotheses regarding
species boundaries and plant relationships, new insights in many plant groups are urgently needed. Increasing pressures on
biodiversity, especially in tropical and developing regions of the world, emphasize this point. The results from a workshop (with
21 participants) reaffirm the central role that monographs play in systematic botany. But, rather than advocating abbreviated
models for monographic products, we recommend a full presentation of relevant information. Electronic publication offers
numerous means of illustration of taxa, habitats, characters, and statistical and phylogenetic analyses, which previously would
have been prohibitively costly. Open Access and semantically enhanced linked electronic publications provide instant access
to content from anywhere in the world, and at the same time link this content to all underlying data and digital resources used
in the work. Resources in support of monography, especially databases and widely and easily accessible digital literature
and specimens, are now more powerful than ever before, but interfacing and interoperability of databases are much needed.
Priorities for new resources to be developed include an index of type collections and an online global chromosome database.
Funding for sabbaticals for monographers to work uninterrupted on major projects is strongly encouraged. We recommend
that doctoral students be assigned smaller genera, or natural portions of larger ones (subgenera, sections, etc.), to gain the necessary expertise for producing a monograph, including training in a broad array of data collection (e.g., morphology, anatomy,
palynology, cytogenetics, DNA techniques, ecology, biogeography), data analysis (e.g., statistics, phylogenetics, models), and
nomenclature. Training programs, supported by institutes, associations, and agencies, provide means for passing on procedures
and perspectives of challenging botanical monography to the next generation of young systematists.Appreciation is expressed to: the Andrew W. Mellon Foundation
for financial support that allowed the workshop to be convened; the
International Association for Plant Taxonomy (IAPT) for additional
financial support for the workshop.http://www.botanik.univie.ac.at/iapt/s_taxon.phpam201
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