Evolutionary tendencies in African Marantaceae

Die Marantaceae (550 Arten) sind eine weltweit verbreitete Familie von Stauden und Lianen aus dem Unterwuchs tropischer Tieflandregenwälder. Der morphologisch-ökologische Vergleich des basal abzweigenden Sarcophrynium-Astes mit dem in abgeleiteter Position stehenden Marantochloa-Ast, soll beispielhaft evolutionäre Muster in der Familie beleuchten. So wird in der Doktorarbeit zum ersten Mal ein Überblick über die Blütenbiologie und Phylogenie von rund 30 der 40 afrikanischen Marantaceae Arten präsentiert. Die Analysen basieren auf Daten von drei mehrmonatigen Feldaufenthalten in Gabun jeweils zwischen September und Januar. Vier Blütentypen werden beschrieben, die jeweils mit einer spezifischen Bestäubergilde verbunden sind (kleine, mittlere, große Bienen bzw. Vögel). Bestäubungsexperimente belegen, dass 18 Arten selbstkompatibel, aber nur zwei Arten autogam sind, also keine Bestäubungsvermittler benötigen. Der Fruchtansatz ist generell gering (10 -30 %). Die komplexe Synorganisation der Blüte ermöglicht in den Marantaceae einen explosiven Bestäubungsmechanismus. Um dessen ökologische Funktionalität zu verstehen, werden die Blüten von 66 Arten, alle wichtigen Äste der Marantaceae abdeckend, unter einem morphologisch-funktionalen Gesichtspunkt untersucht. Es gibt große Übereinstimmungen zwischen allen untersuchten Arten im Zusammenspiel (Synorganisation) der wichtigsten Bauelemente (Griffel, Kapuzenblatt, Schwielenblatt), die eine präzise Pollenübertragung ermöglichen. Basierend auf Daten von nrDNA (ITS, 5S) und cpDNA (trnL-F) wird für ein nahezu komplettes Artenspektrum die Phylogenie der zwei afrikanischen Äste erstellt. Hierauf werden morphologische und ökologische Merkmale sowie geographischer Verbreitungsmuster nach dem Parsimonieprinzip rekonstruiert, um so deren evolutionäre Bedeutung für die Marantaceae abschätzen zu können. Die Ergebnisse weisen auf die Beteiligung einer Vielzahl verschiedener Artbildungsfaktoren hin.

Canopy gap colonization in the Atlantic Montane Rain Forest

Na Floresta Pluvial Atlântica Montana do Sudeste Brasileiro, foi realizado um estudo para descrever e avaliar a colonização de clareiras. A composição de clareiras foi levantada através da cobertura do solo para as espécies herbáceas enquanto que todos os indivíduos lenhosos maiores que um metro de altura foram mensurados e identificados. Também foram coletadas informações sobre a estrutura das clareiras (área da clareira, número e diâmetro das quedas), posição topográfica e vegetação circundante. Dois gêneros de Marantaceae apresentaram considerável freqüência e abundância nas clareiras. As espécies lenhosas mais freqüentes e abundantes pertenceram ao grupo não-pioneiro e as famílias mais ricas encontradas nas clareiras não diferiram quando comparado à floresta como um todo. Como para as variáveis do estrato herbáceo e da vegetação circundante, os resultados revelaram que efeitos diretos e indiretos da topografia são importantes na determinação da composição interna de clareiras por espécies lenhosas. Estes resultados sugerem que a colonização de clareiras é influenciada não apenas pelas variáveis de estrutura, mas também pela posição topográfica e pelos indivíduos pré-estabelecidos.

Four new species of Maranta L. (Marantaceae) from Brazil

Maranta is a neotropical genus, species of which are found in moist and shaded habitats in forests and in the cerrado. During the preparation of Maranta`s monograph for the Flora Neotropica, four new species were discovered and are now described: Maranta longiflora S.Vieira & V.C.Souza, Maranta coriacea S.Vieira & V.C.Souza, Maranta pulchra S.Vieira & V.C.Souza and Maranta purpurea S.Vieira & V.C.Souza. These species are found in dry habitats, frequently near watercourses or occasionally in humid and shaded places. Two, M. pulchra and M. purpurea, seem to be endemic to the state of Mato Grosso. (C) 2008 The Linnean Society of London.

Endangerment and Likeability of Wildlife Species: How Important are they for Payments Proposed for Conservation?

This paper examines empirically the relative influence of the degree of endangerment of wildlife species and their stated likeability on individuals' allocation of funds for their conservation. To do this, it utilises data obtained from the IUCN Red List, and likeability and fund allocation data obtained from two serial surveys of a sample of the Australian public who were requested to assess 24 Australian wildlife species from three animal classes: mammals, birds and reptiles. Between the first and second survey, respondents were provided with extra information about the focal species. This information resulted in the dominance of endangerment as the major influence on the allocation of funding of respondents for the conservation of the focal wildlife species. Our results throw doubts on the proposition in the literature that the likeability of species is the dominant influence on willingness to pay for conservation of wildlife species. Furthermore, because the public's allocation of fund for conserving wildlife species seems to be more sensitive to information about the conservation status of species than to factors influencing their likeability, greater attention to providing accurate information about the former than the latter seems justified. Keywords: Conservation of wildlife species; Contingent valuation; Endangerment of species; Likeability of species; Willingness to pay

Common And Endangered Species: How Does Society Allocate Support For Their Conservation

Examines how society allocates support for species’ conservation when numbers involved are large and resources are limited. Rational behaviour suggests that species in urgent need of conservation will receive more support than those species that are common. However, we demonstrate that in the absence of balanced knowledge common species will receive support more than they would otherwise receive despite society placing high existence values on all species. Twenty four species, both common and endangered and some with a restricted distribution, are examined. We demonstrate that balanced information is vital in order to direct more support for species that are endangered than those that are not. Implications for conservation stemming from the findings are discussed.

Electronic states of trans-polyacetylene, poly(p-phenylene vinylene) and sp-hybridised carbon species in amorphous hydrogenated carbon probed by resonant Raman scattering

Inclusions of sp-hybridised, trans-polyacetylene [trans-(CH)x] and poly(p-phenylene vinylene) (PPV) chains are revealed using resonant Raman scattering (RRS) investigation of amorphous hydrogenated carbon (a-C:H) films in the near IR – UV range. The RRS spectra of trans-(CH)x core Ag modes and the PPV CC-H phenylene mode are found to transform and disperse as the laser excitation energy ћωL is increased from near IR through visible to UV, whereas sp-bonded inclusions only become evident in UV. This is attributed to ћωL probing of trans-(CH)x chain inhomogeneity and the distribution of chains with varying conjugation length; for PPV to the resonant probing of phelynene ring disorder; and for sp segments, to ћωL probing of a local band gap of end-terminated polyynes. The IR spectra analysis confirmed the presence of sp, trans-(CH)x and PPV inclusions. The obtained RRS results for a-C:H denote differentiation between the core Ag trans-(CH)x modes and the PPV phenylene mode. Furthermore, it was found that at various laser excitation energies the changes in Raman spectra features for trans-(CH)x segments included in an amorphous carbon matrix are the same as in bulk trans-polyacetylene. The latter finding can be used to facilitate identification of trans-(CH)x in the spectra of complex carbonaceous materials.