Briófitas rupícolas de um trecho do rio Bethary, Iporanga, Estado de São Paulo

Foram encontradas 19 espécies de briófitas, sendo 14 espécies de musgos e 5 espécies de hepáticas, cobrindo uma maior extensão de rochas das margens que do centro do leito do rio. As rochas das margens do rio, bem üuminadas, porém sem receber luz direta do sol, apresentaram uma maior número de espécies, muito emaranhadas entre si. Já as rochas do centro do leito do rio, iluminadas pela luz direta do sol, apresentaram um menor número de espécies, formando tufos isolados ou pouco emaranhados entre si.

Corticolous green algae from tropical forest remnants in the northwest region of São Paulo State, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Corticolous cyanobacteria from tropical forest remnants in northwestern São Paulo State, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

COMPARISON OF 3 TECHNIQUES FOR ESTIMATING PERIPHYTON ABUNDANCE IN BEDROCK STREAMS

Three procedures (line transect, point intercept and quadrat) for estimating abundance of macroscopic components of periphyton (macroalgae and bryophytes) were compared in two bedrock streams from southeastern Brazil on the basis of frequency and percent cover. In addition, two quadrat sizes (25 and 50 cm) were tested for best size. Samplings were all made within a 10 m length stream reach. Differences were tested by means of analysis of variance, ANOVA - one way, Student's t test and Chi-square test, whereas associations among them were evaluated by Pearson's r correlation coefficient. Values of frequency and percent cover varied among the different techniques and periphyton species in both sites but ANOVA, t and Chi-square tests revealed no significant difference (p<0.05) for percent cover in the two sites. No consistent pattern was observed for the different procedures between sites. Values for quadrat (25 and 50 cm) percent cover were positively correlated among distinct periphyton species. Significant differences for frequency were found in only one site. Quadrats of 50 cm produced the highest frequency values, whereas point intercept the lowest in both sites. In terms of spatial variation within the stream segment, significant differences were generally observed among all procedures, except between quadrats. As a rule, highly significant correlations for percent cover were found among the different techniques along the stream reach. The strongest relationships were found for quadrats with the other procedures, whereas the weakest between Line and point. Pros and cons of the three techniques are fully discussed.

Leaf anatomical and molecular studies in Bulbophyllum section Micranthae (Orchidaceae) and their implications for systematics

Bulbophyllum section Micranthae comprises 12 species of rupicolous or epiphytic orchids occurring in forests or in open rocky fields in Cerrado/Atlantic Forest ecotones throughout South America. We examined the leaf anatomy of 14 species and compared them with molecular data (nrITS) in phylogenetic analyses. The leaves of Bulbophyllum section Micranthae are characterised by uniseriate epidermis, with periclinal external cell wall thicker than the internal, presence of epicuticular wax, stomata present only on the abaxial surface with suprastomatic chambers, and collateral vascular bundles associated with sclerenchyma fibres. Some of these characters are shared with other rupicolous Orchidaceae species, demonstrating adaptive convergence in xeromorphic habitats. We found some anatomical characteristics with phylogenetic value. Bulbophyllum section Micranthae can be separated into two lineages: those with needle-like leaves, or flat leaves. The analyses show that anatomical characters as well as molecular data may contribute to the development of phylogenetic hypotheses. © 2013 Botanical Society of Sao Paulo.

Crystalline rock outcrops in the Atlantic Forest of northeastern Brazil: Vascular flora, biological spectrum, and invasive species

We studied the vegetation of two crystalline rock outcrops in the Atlantic Forest of northeastern Brazil. We recorded typically rupicolous species, which are rare or classified as extremely endangered, such as Aechmea guainumbiorum, found exclusively in one of the study sites. In both areas there was a predominance of therophytes over other life-forms, in contrast to observations made in rock outcrops of the southern Atlantic Forest. Therophytes also stood out in other rock outcrops at similar latitudes as our study site, regardless of the surrounding vegetation. Plants of other life-forms had significantly lower richness and showed adaptations to drought, such as succulent stem, pseudobulbs, dense pilosity, and underground storage organs. Our results suggest that invasive species may modify the vegetation of crystalline rock outcrops, as they change the number of species of all life-forms in comparison between sites. Hence, our results present the biological identity of these rupicolous habitats, which are marginal to forests, and point to the need for conserving them, in order to protect the Atlantic Forest's biodiversity. © 2013 Botanical Society of Sao Paulo.

Efeitos da textura e heterogeneidade de substratos artificiais em função da velocidade da correnteza e da escala temporal sobre as comunidades de macroalgas de ambientes lóticos

Pós-graduação em Ciências Biológicas (Biologia Vegetal) - IBRC

Características fotossintéticas de produtores primários de ambientes lóticos

Pós-graduação em Ciências Biológicas (Biologia Vegetal) - IBRC

Diversidade de líquens em leguminosas da Reserva Biológica de Mogi-Guaçu, SP

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

MICROSATELLITE LOCI FOR ORTHOPHYTUM OPHIUROIDES (BROMELIOIDEAE, BROMELIACEAE) SPECIES ADAPTED TO NEOTROPICAL ROCK OUTCROPS

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito das relações bióticas sobre o estabelecimento de macroalgas de ecossistemas lóticos tropicais: interação com microalgas e pressão por herbivoria

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)