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Abstract The Ibitipoca Mountains occur in southeastern Minas Gerais state, Southeast Brazil, and includes a mosaic of different vegetation types, as part of the Atlantic Forest domain. Such heterogeneity results in the occurrence of several ecotones in the region, considered essential buffer zones for maintaining biodiversity and structure among adjacent ecosystems. Given the importance of these environments for biodiversity conservation, floristic surveys are important to catalogue plant richness in natural areas, where species and landscapes have been destroyed, especially over the last decades. To contribute to increase the knowledge on the vascular Flora in the Ibitipoca Mountains, a floristic inventory was undertaken in private properties located in the boundaries of "Parque Estadual do Ibitipoca" (Ibitipoca State Park). Relevant findings of the present study include: characterization of the different vegetation types, 17 new records for the Flora of Minas Gerais, collection of 288 species never recorded in the state park (80% dissimilarity - especially due to the occurrence and size of different phytophysiognomies between these areas) and presence of 31 threatened species. In addition, discussions about conservation efforts and public policies are presented.
Resumo A Serra do Ibitipoca ocorre no sudeste do estado de Minas Gerais, sudeste do Brasil, e inclui um mosaico de diferentes tipos de vegetação, como parte do domínio da Mata Atlântica. Tal heterogeneidade é resultado da ocorrência de diversos ecótonos na região, considerados áreas de amortecimento essenciais para manutenção da biodiversidade e estrutura de ecossistemas adjacentes. Dada a importância destes ambientes para conservação da biodiversidade, inventários florísticos são importantes para catalogar a riqueza de plantas em áreas naturais, onde espécies e paisagens têm sido destruídas, especialmente nas últimas décadas. Para contribuir com o aumento do conhecimento sobre a Flora vascular na Serra do Ibitipoca, um inventário florístico foi conduzido em áreas privadas adjacentes ao Parque Estadual do Ibitipoca. As descobertas mais relevantes do presente estudo incluem: caracterização dos diferentes tipos de vegetação, 17 novos registros para a Flora de Minas Gerais, coleta de 288 espécies nunca registradas para o parque (80% de dissimilaridade - especialmente devido à ocorrência e tamanho de diferentes fitofisionomias entre as áreas) e presença de 31 espécies ameaçadas. Além disso, discussões sobre esforços para conservação e políticas públicas são apresentadas.
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Bromeliaceae display many water-use strategies, from leaf impounding tanks to Crassulacean acid metabolism (CAM) photosynthesis and absorbing trichomes. Recent studies show that trichomes in inflorescences of bromeliads can exude viscous secretions, protecting against various stresses, including excessive water loss. In light of this, and considering the knowledge gap regarding inflorescence trichomes in bromeliads, we aimed to investigate the presence, source and chemical nature of inflorescence secretions in species of the Tillandsioideae (Bromeliaceae) and to describe the anatomy of their floral bracts focusing on trichome structure and position. We conducted a prospection of secretory activity and anatomy in floral bracts in 52 species of Tillandsioideae and 1 early divergent Bromeliaceae species. We used histochemical tests to investigate the presence and nature of secretion combined with standard light microscopy methods. Secretion appears in all studied species of tribe Vrieseeae, in Guzmania species, Wallisia cyanea, Tillandsia streptopylla (Tillandsieae) and Catopsis morreniana (Catopsideae). It is absent in Vriesea guttata (Vrieseeae), Racinaea crispa and various Tillandsia species (Tillandsieae). Secretion is produced by peltate trichomes on the adaxial surface of young bracts and comprises hydrophilic and lipophilic substances. Bract anatomy revealed an internal mucilage-secreting tissue with wide distribution within the subtribe Vrieseinae. Our results point to a broad occurrence of secretion associated with bracteal scales in inflorescences of Tillandsioideae. Secretory function is strongly related to trichomes of the adaxial surface, whereas the indumentum of the abaxial side is lacking or likely associated with water absorption; the latter case is especially related to small, xeric plants. Exudates might engage in colleter-like roles, protecting against desiccation, high-radiation and herbivores. Directions for future research are presented.
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Nectar plays important roles in the relationship between plants and other organisms, both within pollination systems and as a defense mechanism. In the latter case, extranuptial nectaries (ENNs) usually attract patrolling arthropods that reduce herbivory. ENNs have been frequently reported within the "xeric clade" of Bromeliaceae, but their occurrence in other groups of bromeliads is largely unexplored, especially considering their position, secretory activity and structure. After observing the presence of ants constantly patrolling the inflorescences of Pitcairnia burchellii Mez, we searched for the presence, secretory activity, and structure of ENNs in this species. We also provide a brief review of the occurrence ENNs in Bromeliaceae. The distribution of nectaries was assessed using ant-exclusion experiments, while structural analysis was performed using standard methods for light and scanning electron microscopy. The presence of sugars in the secretion was assessed by thin-layer chromatography and glucose strip tests. Nectaries in P. burchelli are non-structured glands on the adaxial surface of floral bracts and sepals. Bracts and sepals are distinct spatial units that act over time in the same strategy of floral bud protection. Literature data reveals that ENNs might be more common within Bromeliaceae than previously considered, comprising a homoplastic feature in the family. Future perspectives and evolutionary and taxonomic implications are discussed.
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Hormigas , Bromeliaceae/fisiología , Néctar de las Plantas , Animales , Artrópodos/fisiología , Bromeliaceae/ultraestructura , Cromatografía en Capa Delgada , Mecanismos de Defensa , Herbivoria , Microscopía Electrónica de Rastreo , Néctar de las Plantas/química , Polinización/fisiologíaRESUMEN
Changes in phenological events have been vastly documented in face of recent global climate change. These studies are concentrated on temperate plants, and the responses of tropical species are still little understood, likely due to the lack of long-term phenological records in the tropics. In this case, the use of herbarium specimens to gather phenological data over long periods and wide geographic areas has emerged as a powerful tool. Here, we used four Melastomataceae species endemic to the Brazilian Atlantic Forest to evaluate phenological patterns and alterations as responses to recent climate changes. Phenological data were gathered from Reflora Virtual Herbarium specimens collected between 1920 and 2018, and analyzed with circular statistics applied to the intervals 1920-1979, 1980-1999, and 2000-2018. The effects of temperature range, average temperature, precipitation, and photoperiod on flowering and fruiting of each species were tested using multiple linear regressions. Through circular statistics, we detected changes, mostly delays, in the flowering of Miconia quinquedentata, Pleroma clavatum and P. trichopodum, and in the fruiting of M. acutiflora, P. clavatum and P. trichopodum. We also found that flowering and fruiting occurrence were related to local climatic conditions from months prior to the collections. We found marked phenological variations over the decades and also that these variations are associated to global climate change, adding up to the large body of evidence from higher latitudes. Our results also support herbarium collections as an important source for long-term tropical phenological studies. The lack of consistent patterns of responses among the four species (e.g. fruiting delayed two months in P. clavatum and advanced one month in M. acutiflora) suggests that climate change has unequal effects across tropical forests. This highlights the urgent need for further research to understand and forecast the ecological implications of these changes in global ecosystems processes.
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Cambio Climático , Ecosistema , Melastomataceae , Flores , Frutas , Reproducción , TemperaturaRESUMEN
Bromeliad scales have been investigated extensively due to their recognition as a key ecological and evolutionary feature of Bromeliaceae. However, much remains unknown about such trichomes and only recently mucilage exudation was described for them in a species of the subfamily Bromelioideae. The present study aimed to investigate the secretion present in inflorescences of Tillandsia cyanea Linden ex K. Koch (Tillandsioideae) to determine whether the scales of this species also produce and release secretions. Samples of young and mature portions of inflorescences were collected and prepared according to standard methods for light and electron microscopy. Anatomical and ultrastructural results indicate that the secretion is produced by the wing portion of typical peltate trichomes on the adaxial surface of bracts. The secretory activity begins in the early stages of trichome expansion and characteristically occurs in cells exhibiting a porous cuticle and dense cytoplasm with numerous mitochondria and dictyosomes. Histochemical tests confirmed mucilage secretion and revealed proteins in the exudate. These data comprise the first record of mucilage exudation by trichomes within Tillandsioideae and indicate that this capacity may be more relevant to bromeliad biology than previously considered. Functional aspects and colleter-like activity are also discussed.
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BACKGROUND: This paper provides a quantitative and general description of the Rio de Janeiro Botanical Garden herbarium (RB) dataset. Created over a century ago, the RB currently comprises ca. 750,000 mounted specimens, with a strong representation of Brazilian flora, mainly from the Atlantic and Amazon forests. Nearly 100% of these specimens have been entered into the database and imaged and, at present, about 17% have been geo-referenced. This data paper is focused exclusively on RB's exsiccatae collection of land plants and algae, which is currently increasing by about twenty to thirty thousand specimens per year thanks to fieldwork, exchange and donations. Since 2005, many national and international projects have been implemented, improving the quality and accessibility of the collection. The most important facilitating factor in this process was the creation of the institutional system for plants collection and management, named JABOT. Since the RB is continuously growing, the dataset is updated weekly on SiBBr and GBIF portals. NEW INFORMATION: The most represented environments are the Atlantic and Amazon forests, a biodiversity hotspot and the world's largest rain forest, respectively. The dataset described in this article contains the data and metadata of plants and algae specimens in the RB collection and the link to access the respective images. Currently, the RB data is publicly available online at several biodiversity portals, such as our institutional database JABOT, the Reflora Virtual Herbarium, the SiBBr and the GBIF portal. However, a description of the RB dataset as a whole is not available in the literature.
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The cataloging of the vascular plants of the Americas has a centuries-long history, but it is only in recent decades that an overview of the entire flora has become possible. We present an integrated assessment of all known native species of vascular plants in the Americas. Twelve regional and national checklists, prepared over the past 25 years and including two large ongoing flora projects, were merged into a single list. Our publicly searchable checklist includes 124,993 species, 6227 genera, and 355 families, which correspond to 33% of the 383,671 vascular plant species known worldwide. In the past 25 years, the rate at which new species descriptions are added has averaged 744 annually for the Americas, and we can expect the total to reach about 150,000.
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A National Forest Inventory (NFI) encompassing the entire territory of Brazil is in progress. It is coordinated and promoted by the Brazilian Forest Service of the Ministry of Environment. In each state, the NFI collaborates with local herbaria by receiving collected plant material and performing species identification. Consultants are hired by the NFI and work at the local herbaria under the supervision of a curator. In exchange for curatorial assistance, the NFI provides equipment and consumables for the herbarium. Other public projects collaborating with NFI are Reflora and the Brazilian Biodiversity Information System (SiBBr). Both projects have online platforms that seek to connect herbaria and make all their data freely available, including high quality digital images of specimens. Through inter-institutional collaboration, the joint interests of NFI, Reflora, SiBBr and local herbaria have improved collections, expanded the online Reflora database, and provided the NFI with verified species lists. These strategic uses of public funding are positively affecting Botany, particularly during a period of economic crisis and cuts in research. Here, we illustrate the increase in floristic knowledge through the improvement of a herbarium collection in Rio Grande do Norte (RN) - the Brazilian state with the lowest levels of plant richness. We report 71 new occurrences of vascular plants for RN, belonging mainly to the Poaceae, Fabaceae and Malvaceae. Most of the species with new occurrences have a Neotropical distribution (21 spp.) and only seven are restricted to the Brazilian Northeast. Our findings highlight previous gaps in RN's floristic knowledge. The partnership NFI, Reflora, SiBBr and the UFRN herbarium improved herbarium curation, digital collection, and quality of data. Finally, a fellowship provided by Reflora and SiBBr allowed improving curation by distributing duplicates and incorporating the Herbarium of Câmara Cascudo Museum.
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We present a new record to the Brazilian territory (i.e. Tradescantia boliviana), the rediscovery of a species exclusively known from the cultivated type collection (i.e. T. valida), the description of a new taxon (i.e. T. chrysophylla), synonyms for T. crassula and T. boliviana, correct the typification of T. crassula, and designation of a lectotype for T. ambigua and T. ambigua var. pilosula. Furthermore, we present illustrations, comments, distribution maps, and identification keys for the studied taxa.
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The Atlantic Forest in southern Bahia State, Brazil, has high levels of diversity and vascular plant endemism. There have been few floristic surveys of the mountain forests there, however, especially those focusing on herbs and canopy plants, with studies of Atlantic Forest epiphytes having been limited to the southern and southeastern region of that country. The present study therefore surveyed the epiphytic angiosperms in the Serra das Lontras National Park (SLNP), the distribution of their species among genera and families, and their biogeographical patterns. Fieldwork was performed between February 2011 and March 2012. Collections were made along roads and trails and phorophytes were occasionally climbed and fallen trees and branches examined in order to sample canopy species. The study site demonstrated high epiphyte richness (256 spp.), one of the highest recorded in the Atlantic Forest. The richest families are Orchidaceae, Bromeliaceae, and Araceae, reaffirming the patterns reported in previous major reviews on epiphytes. The species exhibit high degrees of endemism (45%) to the Atlantic Forest, especially among the Bromeliaceae and Orchidaceae. One new occurrence to Brazil, four to the Atlantic Forest and 30 to Bahia state are registered. The SLNP shares more species with areas of southern and southeastern Brazil than with other northeastern states.
A Floresta Atlântica do sul da Bahia apresenta elevados níveis de diversidade e endemismo de plantas vasculares. No entanto, poucos levantamentos florísticos foram realizados em áreas de floresta montana, especialmente para ervas e plantas de dossel. Estudos com epífitas estão concentrados principalmente em áreas do Sul e Sudeste do Brasil. Desta forma, o presente estudo realizou o levantamento das angiospermas epífitas do Parque Nacional da Serra das Lontras (PNSL) e verificou a distribuição das espécies pelas famílias e gêneros e seus padrões biogeográficos. As coletas foram realizadas entre fevereiro de 2011 e março de 2012 nas trilhas e estradas de acesso. Alguns forófitos foram escalados e árvores e ramos caídos foram examinados com o intuito de coletar espécies restritas ao dossel. A área de estudo apresentou alta diversidade de epífitas (256 spp.), uma das maiores já registradas para a Floresta Atlântica. As famílias com maior riqueza são Orchidaceae, Bromeliaceae e Araceae, reafirmando os padrões encontrados anteriormente em revisões do tema. As espécies apresentam alto grau de endemismo (45%) è Floresta Atlântica, especialmente em Bromeliaceae e Orchidaceae. São registradas uma nova ocorrência para o Brasil, quatro para a Floresta Atlântica e 30 para a Bahia. O PNSL possui mais espécies em comum com o Sul e o Sudeste do que com a região Nordeste.