Mike Hopkins

New Brazilian Floristic List Highlights Conservation Challenges

A comprehensive new inventory of Brazilian plants and fungi was published just in time to meet a 2010 Convention on Biological Diversity target and offers important insights into this biodiversitys global significance. Brazil is the home to the worlds richest flora (40,989 species; 18,932 endemic) and includes two of the hottest hotspots: Mata Atlântica (19,355 species) and Cerrado (12,669 species). Although the total number of known species is one-third lower than previous estimates, the absolute number of endemic vascular plant species is higher than was previously estimated, and the proportion of endemism (56%) is the highest in the Neotropics. This compilation serves not merely to quantify the scale of the challenge faced in conserving Brazils unique flora but also serves as a key resource to direct action and monitor progress. Similar efforts by other megadiverse countries are urgently required if the 2020 targets of the Convention on Biological Diversity and the Global Strategy for Plant Conservation are to be attained.

Amazon vegetation: how much don’t we know and how much does it matter?

SummaryIn spite of the existence of a vast body of information on the plant diversity of the Amazon, there remain significant obstacles to informed decision-making and management for conservation. Species distributions are poorly understood and the relationships between diversity and composition of vegetation, ecosystem services and resilience to climatic fluctuations are insufficiently clear. The geographic distribution of phylogenetic diversity in relation to current protected areas is unexplored and very little is known about intraspecific genetic variability and its practical significance. Interpretation of vegetation differentiation and distribution remains relatively simplistic; there are still large parts of the basin for which few or no botanical data exist, and many rare and sparsely distributed species remain undiscovered. Improved understanding of the ecological roles, dynamics and associations of the species of greatest importance for the maintenance of sustainable livelihoods and ecosystem services, habitat restoration and adaptation to climate change is a high priority. In many cases these are common and widespread species. Some of these issues are explored by looking at the Cristalino region in northern Mato Grosso as a case-study. Effective integration, quality assessment, synthesis and application of existing data on the plant diversity of the Amazon will help to address these issues. However, more targeted information is needed from the ground. Future prioritisation of research effort will require a careful and pragmatic balance between the ‘traditional’ focus on rare and endemic species and species-rich communities, and the growing need to understand the key ‘framework’ elements that will determine the future of the Amazon environment. Similar situations are faced elsewhere in the tropics: for botanical research institutes in the 21st century this demands an urgent re-evaluation of core activities and concerted engagement with the issues and challenges facing conservation in a context of rampant population growth, climate change and environmental destruction.ResumoApesar da existência de um grande volume de informação a respeito da diversidade vegetal da Amazônia, uma série de obstáculos ainda dificulta a tomada de decisões devidamente informadas sobre conservação e manejo sustentável da região. Falta conhecimento com relação à distribuição das espécies, e às interações entre diversidade e composição da vegetação, aos serviços do ecossistema e sua adaptabilidade e resistência às flutuações climáticas. A distribuição da diversidade filogenética das espécies em relação às áreas atualmente protegidas ainda é desconhecida, e muito pouco é sabido sobre o significado prático da variabilidade intraespecífica. A interpretação dos diferentes tipos de vegetação permanece extremamente simplificada, com grandes áreas da bacia para as quais não há dados botânicos disponíveis ou os mesmos são insuficientes, e muitas espécies raras ou esparsamente distribuídas ainda aguardam descobrimento. Uma melhor compreensão dos papéis ecológicos, da dinâmica e das associações das espécies mais importantes para a manutenção de estilos de vida sustentáveis e dos serviços do ecossistema, recuperação de áreas degradadas e adaptabilidade às mudanças climáticas, são as grandes prioridades. Em muitos casos essas espécies são comuns e amplamente distribuídas. Alguns desses temas são explorados utilizando a região do Cristalino, no norte do Mato Grosso, como um estudo de caso. A integração efetiva, o controle da qualidade, a síntese e a aplicação dos dados existentes da diversidade vegetal da Amazônia serão fundamentais para a solução dessas questões. No entanto, ainda é necessário gerar a informação relevante a partir do estudo da área. A priorização das pesquisas futuras requer um equilíbrio cuidadoso e prático entre o foco ‘tradicional’, interessado em espécies raras e endêmicas e nas comunidades ricas em termos de espécies e a necessidade crescente de compreender os elementos da ‘estrutura’ que irá determinar o futuro do bioma amazônico. Situações semelhantes estão sendo enfrentadas nos trópicos como um todo: os institutos botânicos do século 21 precisam reavaliar urgentemente as suas principais atividades e engajar-se de modo coordenado para incluir os tópicos e desafios causados pelo crescimento populacional desordenado, mudanças climáticas e destruição ambiental.

Phenotypic differences are not explained by pre-zygotic reproductive barriers in sympatric varieties of the Humiria balsamifera complex (Humiriaceae)

Biosystematic studies addressing mechanisms of speciation in widespread, phenotypically variable Neotropical plant taxa are scarce. In Viruá National Park, Roraima State, Brazil, we demonstrate that nine phenotypic variables measured from sympatric populations of two varieties within the Humiria balsamifera complex (Humiriaceae) are sharply discontinuous for both vegetative and floral characters. However, these differences were not explained by either phenological separation in anthesis, suppressed reproductive success in experimental inter-varietal crosses, or pollinator preferences, suggesting that pre-zygotic reproductive mechanisms do not contribute to the demonstrable phenotypic differences. Post-zygotic barriers such as reduced germination success in crosses, balancing selection at fine scales, or historical factors such as recent contact among formally isolated populations may account for the maintenance of phenotypic variation among these sympatric varieties. Future studies relating genetic structure with phenotypic variation may shed light on the mechanisms which promote and maintain large Neotropical species complexes such as in this case.

An interactive key (Lucid) for the identifying of the genera of seed plants from the Ducke Reserve, Manaus, AM, Brazil

A identificacao de plantas da Amazonia e ainda muito dificil devido a muitos fatores, como por exemplo grandes lacunas de coleta. Em consequencia do conhecimento ainda preliminar da flora dessa grande regiao, muitas publicacoes taxonomicas (revisoes ou tratamentos floristicos) tornam-se ultrapassadas em poucos anos. A publicacao on-line de trabalhos taxonomicos foi sugerida como desejavel nesse contexto, por permitir a constante atualizacao dos dados, embora esse tipo de publicacao deva ser mais valorizada pela comunidade cientifica. Para a area da Reserva Ducke (Manaus, AM), foi publicado um excelente guia de campo ilustrado, baseado exclusivamente em caracteres vegetativos. Entretanto, a presenca de estruturas reprodutivas no material coletado nao facilita sua identificacao com esse tipo de guia de campo. Alem disso, como em qualquer chave impressa, o texto nao pode ser atualizado, a nao ser em uma nova edicao. Para exemplificar uma maneira de facilitar a identificacao das plantas da Amazonia, foi elaborada uma chave interativa de entradas multiplas para os generos de fanerogamas que ocorrem na Reserva Ducke, com o auxilio do programa Lucid 3.5. Essa chave inclui caracteres vegetativos, reprodutivos e muitas ilustracoes e esta disponivel on-line. Sao discutidas as vantagens e peculiaridades desse tipo de publicacao eletronica.

Independent evolution of pouched flowers in the Amazon is supported by the discovery of a new species of Lesia (Gesneriaceae) from Serra do Aracá tepui in Brazil

We describe and illustrate Lesia tepuiensis, a new species of subshrub from rock outcrops of the Serra do Aracá tepui in Amazonas, Brazil. Phylogenetic analyses based on 7219-aligned base pairs of the plastid and nuclear DNA sequences recovered the new species as sister to Lesia savannarum, the type species of Lesia, a genus recently described as monotypic. The new species is readily distinguished from L. savannarum by having a red, pouched corolla tube, lanceolate calyx lobes, a hirsute to tomentose leaf indument and a rupicolous habit. Phylogenetic analyses of the relationships of Lesia with other genera in the subtribe Columneinae indicated that Lesia and Codonanthopsis form a monophyletic group sister to a clade endemic to the Brazilian Atlantic forest formed by Nematanthus and Codonanthe. The pouched corolla tube found in the genera Lesia and Nematanthus appears to have evolved independently in these two lineages. Ecological and distributional data, as well as a key to the species of Lesia and related genera, are also provided.

Passiflora fissurosa, uma nova espécie de Passifloraceae para o Amazonas, Brasil

Passiflora fissurosa M.A.D. Souza sp. nov., presently known only from the Adolpho Ducke Forest Reserve in Amazonian Brazil, is described and illustrated. P. fissurosa belongs in the subgenus Passiflora, Supersection Passiflora, Section Laurifoliae and Series Laurifoliae, with simple, entire leaves, a biglandular petiole, free foliaceous stipules larger than 1 cm, in the group of species with the outer two series of the corona sub-equal. Morphologically it resembles P. nitida, which differs by the horizontal curved with erect-divergent margin operculum, the presence of a nectariferous ring, vertical limen and glabrous ovary. The epithet is derived from the characteristic of the bark, which is corky and profoundly fissured, which is showed only by P. phellos of the Laurifoliae group which has the first series of the corona smaller than the second.