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1.
Science ; 378(6623): eabf0869, 2022 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-36454829

RESUMO

Madagascar's biota is hyperdiverse and includes exceptional levels of endemicity. We review the current state of knowledge on Madagascar's past and current terrestrial and freshwater biodiversity by compiling and presenting comprehensive data on species diversity, endemism, and rates of species description and human uses, in addition to presenting an updated and simplified map of vegetation types. We report a substantial increase of records and species new to science in recent years; however, the diversity and evolution of many groups remain practically unknown (e.g., fungi and most invertebrates). Digitization efforts are increasing the resolution of species richness patterns and we highlight the crucial role of field- and collections-based research for advancing biodiversity knowledge and identifying gaps in our understanding, particularly as species richness corresponds closely to collection effort. Phylogenetic diversity patterns mirror that of species richness and endemism in most of the analyzed groups. We highlight humid forests as centers of diversity and endemism because of their role as refugia and centers of recent and rapid radiations. However, the distinct endemism of other areas, such as the grassland-woodland mosaic of the Central Highlands and the spiny forest of the southwest, is also biologically important despite lower species richness. The documented uses of Malagasy biodiversity are manifold, with much potential for the uncovering of new useful traits for food, medicine, and climate mitigation. The data presented here showcase Madagascar as a unique "living laboratory" for our understanding of evolution and the complex interactions between people and nature. The gathering and analysis of biodiversity data must continue and accelerate if we are to fully understand and safeguard this unique subset of Earth's biodiversity.


Assuntos
Biodiversidade , Evolução Biológica , Humanos , Biota , Florestas , Madagáscar , Filogenia
2.
Science ; 378(6623): eadf1466, 2022 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-36454830

RESUMO

Madagascar's unique biota is heavily affected by human activity and is under intense threat. Here, we review the current state of knowledge on the conservation status of Madagascar's terrestrial and freshwater biodiversity by presenting data and analyses on documented and predicted species-level conservation statuses, the most prevalent and relevant threats, ex situ collections and programs, and the coverage and comprehensiveness of protected areas. The existing terrestrial protected area network in Madagascar covers 10.4% of its land area and includes at least part of the range of the majority of described native species of vertebrates with known distributions (97.1% of freshwater fishes, amphibians, reptiles, birds, and mammals combined) and plants (67.7%). The overall figures are higher for threatened species (97.7% of threatened vertebrates and 79.6% of threatened plants occurring within at least one protected area). International Union for Conservation of Nature (IUCN) Red List assessments and Bayesian neural network analyses for plants identify overexploitation of biological resources and unsustainable agriculture as the most prominent threats to biodiversity. We highlight five opportunities for action at multiple levels to ensure that conservation and ecological restoration objectives, programs, and activities take account of complex underlying and interacting factors and produce tangible benefits for the biodiversity and people of Madagascar.


Assuntos
Biodiversidade , Espécies em Perigo de Extinção , Animais , Humanos , Teorema de Bayes , Biota , Madagáscar , Mamíferos , Plantas
4.
Sci Rep ; 11(1): 9585, 2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-33953271

RESUMO

Recent studies have leveraged large datasets from plot-inventory networks to report a phenomenon of hyperdominance in Amazonian tree communities, concluding that few species are common and many are rare. However, taxonomic hypotheses may not be consistent across these large plot networks, potentially masking cryptic diversity and threatened rare taxa. In the current study, we have reviewed one of the most abundant putatively hyperdominant taxa, Protium heptaphyllum (Aubl.) Marchand (Burseraceae), long considered to be a taxonomically difficult species complex. Using morphological, genomic, and functional data, we present evidence that P. heptaphyllum sensu lato may represent eight separately evolving lineages, each warranting species status. Most of these lineages are geographically restricted, and few if any of them could be considered hyperdominant on their own. In addition, functional trait data are consistent with the hypothesis that trees from each lineage are adapted to distinct soil and climate conditions. Moreover, some of the newly discovered species are rare, with habitats currently experiencing rapid deforestation. We highlight an urgent need to improve sampling and methods for species discovery in order to avoid oversimplified assumptions regarding diversity and rarity in the tropics and the implications for ecosystem functioning and conservation.


Assuntos
Evolução Biológica , Burseraceae/genética , Ecossistema , Filogenia , Floresta Úmida
5.
Genes (Basel) ; 10(5)2019 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-31121954

RESUMO

Plants in the Burseraceae are globally recognized for producing resins and essential oils with medicinal properties and have economic value. In addition, most of the aromatic and non-aromatic components of Burseraceae resins are derived from a variety of terpene and terpenoid chemicals. Although terpene genes have been identified in model plant crops (e.g., Citrus, Arabidopsis), very few genomic resources are available for non-model groups, including the highly diverse Burseraceae family. Here we report the assembly of a leaf transcriptome of Protium copal, an aromatic tree that has a large distribution in Central America, describe the functional annotation of putative terpene biosynthetic genes and compare terpene biosynthetic genes found in P. copal with those identified in other Burseraceae taxa. The genomic resources of Protium copal can be used to generate novel sequencing markers for population genetics and comparative phylogenetic studies, and to investigate the diversity and evolution of terpene genes in the Burseraceae.


Assuntos
Burseraceae/genética , Folhas de Planta/genética , Terpenos/metabolismo , Transcriptoma/genética , Burseraceae/metabolismo , Genômica , Anotação de Sequência Molecular , Óleos Voláteis/metabolismo , Extratos Vegetais/genética , Extratos Vegetais/metabolismo , Folhas de Planta/metabolismo
6.
Acta amaz ; 43(3): 261-290, set. 2013. ilus, tab
Artigo em Português | LILACS-Express | LILACS, VETINDEX | ID: biblio-1455148

RESUMO

The purpose of this study was to describe the richness, structure and diversity of tree species occurring in seasonally dry forests and some ecotone areas (Seasonal Forest/Ombrophilous Forest) in the state of Tocantins (Brazil). We aimed to provide information for conservation, management, environmental compensation and restoration strategies, and discuss their phytogeography identities in relation to other Brazilian forests. We selected 22 areas in 18 hydrogeographic basins and performed an inventory of all trees species (DHB > 5 cm) occurring in 477 plots of 400 m². We conducted a classification analysis of the vegetation using the TWINSPAN method in two different scales. The first assessed the beta diversity among plots within the state of Tocantins, and the second analysed similarities between these forests and other forests ecosystems in the Cerrado ecoregion and related ecotones in Central Brazil. A wide variation of species richness (33 to 243 species), density (486 to 1179 trees.ha-1), basal area (14.04 to 37.49 m². ha-1), diversity indexes (H’ = 2.75 to 4.59) and evenness (J’ = 0.72 to 0.86) across the sites was found. Based on floristic and structural aspects, classification analyses identified four major forests types: Seasonal Deciduous Forest, Seasonal Semi-deciduous Forest, and two ecotones Seasonal Semideciduous Forest/Ombrophilous Forest and ecotone Seasonal Deciduous Forest / Ombrophilous Forest. In order to maintain plant and habitat diversity in the Amazon/Cerrado transition zone, the creation of conservation areas should be intensified using biogeographical patterns as site selection criteria.


O objetivo deste estudo foi descrever a riqueza, estrutura e diversidade de espécies arbóreas em áreas de Floresta Estacional e ecótono (Floresta Estacional/Floresta Ombrófila) no estado do Tocantins, buscando subsídios para a conservação, manejo florestal, compensação de reserva legal e recuperação ambiental, além de discutir as identidades fitogeográficas em comparação com outras florestas do Brasil. Em 18 bacias hidrográficas, conduziu-se amostragem da vegetação arbórea (DAP > 5 cm) de 22 áreas (amostras) por meio do inventário de 477 parcelas de 400 m². Foram elaboradas análises de classificação pelo método TWINSPAN, em duas escalas distintas. A primeira avaliou a diversidade beta entre as parcelas amostradas no estado do Tocantins e a segunda buscou analisar a similaridade das florestas do Tocantins em relação a outras florestas do bioma Cerrado e suas áreas de tensão ecológica. As florestas amostradas apresentaram ampla variação em termos de riqueza (33 a 243 espécies), densidade (486 a 1.179 ind.ha-1), área basal (14,04 e 37,49 m².ha-1), índices de diversidade (H´ = 2,75 a 4,59) e de equabilidade (J´= 0,72 a 0,86). As análises de classificação convergiram para resultados comuns, identificando quatro ambientes dissimilares em termos florísticos e estruturais no estado do Tocantins: Floresta Estacional Decidual, Floresta Estacional Semidecidual, ecótono Floresta Estacional Semidecidual/Floresta Ombrófila e ecótono Floresta Estacional Decidual/Floresta Ombrófila. A fim de manter a diversidade de plantas e de ambientes na região de transição Floresta Amazônica e Cerrado, sugere-se que o processo de criação de unidades de conservação no estado do Tocantins deva ser intensificado e tenha como base para seleção das áreas critérios biogeográficos.

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