Ruy José Válka Alves

Can campo rupestre vegetation be floristically delimited based on vascular plant genera

A number of floristic and vegetation studies apply the terms campo rupestre, campo de altitude (or Brazilian páramo), and Tepui to neotropical azonal outcrop and montane vegetation. All of these are known to harbor considerable numbers of endemic plant species and to share several genera. In order to determine whether currently known combinations of vascular plant genera could help circumscribe and distinguish these vegetation types, we selected 25 floras which did not exclude herbs and compiled them into a single database. We then compared the Sørensen similarities of the genus–assemblages using the numbers of native species in the resulting 1945 genera by multivariate analysis. We found that the circumscription of campo rupestre and other Neotropical outcrop vegetation types may not rely exclusively on a combination of genera.

Orchidaceae do Parque Estadual de Ibitipoca, MG, Brasil

ABSTRACT – (Orchidaceae of Ibitipoca State Park, Minas Gerais State, Brazil). Ibitipoca State Park (PEIB) is located in southeasternMinas Gerais, in Santa Rita de Ibitipoca and Lima Duarte municipalities (21o40’-21o44’S; 43o52’-43o55’W). It has a variety of v egetationtypes, with a predominance of “campo rupestre” (rocky grasslands) mixed with forests. This work aimed to survey Orchidaceae spe ciesgrowing at PEIB. One-hundred-and-eighteen taxa belonging to 47 genera were found. The largest genera are Pleurothallis sensu lato (13 spp.), Oncidium (12 spp. and one probable hybrid), Epidendrum (10 spp.), and Maxillaria (9 spp.). Four species are new recordsfor the flora of Minas Gerais state. Compared to other areas of “campos rupestres”, PEIB is one of the most species-rich sites, in spiteof having a relatively small area. Key words : “ campo rupestre ”,Atlantic rain forest, cloud forest, biogeography Introducao O Parque Estadual de Ibitipoca (PEIB) estasituado no sudeste do Estado de Minas Gerais, entreos municipios de Santa Rita de Ibitipoca e LimaDuarte. Apresenta em sua area um mosaico deformacoes vegetais, das quais o campo rupestre ocupaa maior extensao. E a menor unidade de conservacaodo estado que tem o campo rupestre como sua principalformacao, sendo tambem uma das unidades deconservacao mais visitadas no Brasil (Salimena-Pires1997; Rodela 1998; Vitta 2002). Na segunda edicaodo Atlas para a conservacao da biodiversidade noestado de Minas Gerais, a Serra de Ibitipoca figuraentre as areas prioritarias para a conservacao da florano Estado, citada na categoria de importância biologicaespecial, o nivel mais alto adotado (Drummond

Angiosperm disjunction "Campos rupestres - restingas": a re-evaluation

A disjunct distribution pattern between the extrazonal formations of the campos rupestres (rocky grasslands) in the Espinhaco mountain range and the restingas (coastal strand vegetation) in Brazil has been proposed repeatedly for several flowering-plant species. In order to validate this distribution pattern, available data from the literature and major herbaria were compiled and evaluated. Some of these species also occur in campos rupestres on mountain ranges in Goias state, campos de altitude (high altitude grasslands) of the Serra do Mar, and on geologically homologous rocky formations of the Guyana shield. Species that were also recorded for distinct zonal formations like cerrado, caatinga and forests were excluded from the pattern. The campo rupestre-restinga disjunction proved valid for 9 of 56 investigated species (16%). Explanations put forth by different authors for this unusual disjunction pattern are compared in the light of geological and climatological evidence.

Summit vascular flora of Serra de São José, Minas Gerais, Brazil

The campos rupestres form a mosaic of rocky savannas concentrated mainly along the Espinhaco chain, on the Brazilian shield. Though the Serra de Sao Jose lies over 100 km to the south of the Espinhaco chain, the campo rupestre flora of this small range harbors several endemic plant taxa. The provided checklist is the result of two decades of floristic research complemented with data from herbaria and literature. The flora is compared with the results of several other pertinent surveys. A total of 1,144 vascular plant species, representing 50.3 species/km2, were documented to date in the Sao Jose range, representing a species-richness per unit area over five times greater than other known campo rupestre floras. The most species-rich families were the Asteraceae (126 species), Orchidaceae (106), Melastomataceae (63), Leguminosae (60), Cyperaceae (45), Poaceae (41), Rubiaceae (37), Myrtaceae (28), Bromeliaceae (27), Eriocaulaceae (23), Lamiaceae (23), and Malpighiaceae (22).

A erradicação das cabras ferais e seu impacto sobre a biodiversidade vegetal – um marco na história da Ilha da Trindade, Brasil

Os recentes sinais de recuperacao da flora nativa e endemica da Ilha da Trindade, Brasil, sao atribuidos a erradicacao de vertebrados introduzidos no seculo XVIII. Tres seculos de devastacao resultaram no desaparecimento de especies vegetais endemicas e na reducao drastica da cobertura florestal e das populacoes de aves marinhas. Em 2005 a Marinha do Brasil conclui a erradicacao das cabras ferais, resultando no inicio da expansao da cobertura vegetal em areas previamente nuas. Os unicos vertebrados invasores remanescentes sao os camundongos. Esse fato representa um marco na historia natural de Trindade e deve incentivar novos trabalhos de conservacao na ilha.

Zizyphus mauritiana Lam. (Rhamnaceae) and the chemical composition of its floral fecal odor

When in blossom, jujube (Zizyphus mauritiana Lam., Rhamnaceae) emanates a strong fecal odor. The substances responsible for this scent were analysed by headspace solid-phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS) associated to standard co-injection and retention indexes, which showed benzaldehyde as major constituent. Minor benzenoids, aliphatic carboxylic acids, aldehydes, hydrocarbons and oxygenated monoterpenes were also observed. Olfactometric evaluation of the SPME using GC-sniffing port indicated skatole (3-methyl-indole) as responsible for the fecal odor and vanillin for the sweety odor.

The Orchidaceae of Itacolomi State Park in Minas Gerais, Brazil

This paper compares the partial Orchidaceae floras of Itacolomi State Park in Ouro Preto, Minas Gerais, Brazil, in two different periods. The first is represented by all colections prior to 1980, while the second comprises those of the past five years. Floral analyses document the recent collections.

Topossequência de solos na ilha da trindade, atlântico sul

The Brazilian Oceanic islands are unique environments which have received increasing attention from the scientific community due to their environmental importance. This study aimed to provide a first characterization of soils of the Trindade Island, considering mainly the chemical and physical properties in the different geoenvironments. Another objective was to contribute to a deeper undestanding of the pedogeomorphological relationships, allowing a preliminary identification of soils along a typical toposequence. A total of 10 soil profiles representing all geoenvironments were sampled. These soils were the result of lithological, topographical and vegetation influences, frequently in close association. Soil chemical, morphological and physical analyses were performed and the results indicate the ocurrence of unique features that suggest an endemic character. The pedodiversity on Trindade is primarily related to the parent material and topographical variations. Soils generally have high fertility, particularly in terms of Ca and P contents associated with bird excreta inputs. On the southern side of the island, with a cooler and wetter climate, narrow valleys and steep slopes shelter a more exuberant vegetation of giant ferns, with accumulation of fibrous organic material even on steep slopes, forming atypical Histosols. Soils at an altitude of over 400 m are more acid and nutrient-poor, but P contents are still very high, which was attributed to bird activity. On the northern side of the island, semi-arid to tropical dry climates prevail, and soils are shallower, nutrient-rich and highly eroded, with dominance of Litholic or Regolitic Neosols. Some pedological features of Trindade soils prevent an appropriate fitting by the Brazilian Soil Classification System, calling for adaptations at various classification levels for an adequate classification.

Constituintes químicos voláteis das flores e folhas do pau-brasil (Caesalpinia echinata, Lam.)

The volatile constituents obtained from a static cryogenic headspace of Caesalpinia echinata Lam. (Leguminosae) showed E-b-ocimene as the major compound (57.2%), beside other monoterpenes, C6 derivatives like n-hexanal and (E)-2-hexenal and nitrogen compounds such as indole and methyl anthranilate. From the essential oil of the leaves obtained by hydrodistillation in a Clevenger apparatus, (E)-3-hexen-1-ol was identified as the major constituent while phenolic compounds were the most representative class of secondary metabolites.

Longevity of the Brazilian underground tree Jacaranda decurrens Cham.

Underground trees are a rare clonal growth form. In this survey we describe the branching pattern and estimate the age of the underground tree Jacaranda decurrens Cham. (Bignoniaceae), an endangered species from the Brazilian Cerrado, with a crown diameter of 22 meters. The mean age calculated for the individual was 3,801 years, making it one of the oldest known living Neotropical plants.