Kátia Cavalcanti Pôrto

Hepáticas (Marchantiophyta) de um fragmento de Mata Atlântica na Serra da Jibóia, Município de Santa Teresinha, BA, Brasil

This paper provid the results of the survey of hepatics at Serra da Jiboia, remaining Atlantic Forest, Santa Teresinha Municipality, Bahia. Seventy especies were recorded belonging to 41 genera and 14 families: Aneuraceae (2), Bryopteridaceae (2), Calypogeiaceae (1), Cephaloziaceae (2), Geocalycaceae (2), Herbertaceae (1), Jubulaceae (4), Lejeuneaceae (37), Lepidoziaceae (4), Metzgeriaceae (2), Pallaviciniaceae (2), Plagiochilaceae (8), Radulaceae (2), Trichocoleaceae (1). The family Lejeuneaceae were represents for 52,9% of the species. Three substrates were colonized: living trunks (67%), trunks in decomposition (14%) and leaves (33%). Five growth-forms were found: mat (69%), thallose (9%), carpet (19%), pendent (3%) and turf (1%). The results are similar to these found in tropical rainforest lower montane and submontane.

Sex ratio, spatial segregation, and fertilization rates of the epiphyllous moss Crossomitrium patrisiae (Brid.) Müll.Hal. in the Brazilian Atlantic rainforest

Abstract In order to investigate which mechanisms the epiphyllous moss Crossomitrium patrisiae employs to overcome the typical constraints of dioicy in light of its spatially isolated habitat, we tested the predictions that high fertilization rates are achieved due to (1) high rates of sexual expression, (2) balanced sex ratios, and (3) high co-occurrence of both sexes in the same colony (leaf). Seven hundred and ninety-seven ramets were studied for total length, presence, and number of gametoecia and number of fertilized perichaetia in the female according to spatial segregation at leaf- and shrub-scales. High rates of sexual expression (76%) were confirmed. The other two predictions, however, were not upheld as C. patrisae exhibited a strong male bias (0·43 ♀∶1 ♂ at ramet level, n = 604). Despite considerable spatial segregation (co-occurrence of sexes was seen in 36·7% of shrubs and 12·8% of colonies), this species revealed one of the highest fertilization rates ever reported for a dioicous bryophyte at three spatial scales: nearly 90% of the mixed colonies bore sporophytes, 40% of all female ramets, and 74% of female ramets occurring in mixed colonies bore sporophytes. Thus, the relative rareness of females may be a phenotypic response due to heavy investment in sporophyte maturation as demonstrated by the high fertilization success of females. High rates of sexual expression and the occurrence of fertilization in nearly all cases of coincidence of sexes in common colonies, with low levels of abortion, contribute to the sexual reproductive success and, subsequently, the long-term survival of this species.

Spatial structure of bryophyte communities along an edge-interior gradient in an Atlantic Forest remnant in Northeast Brazil

Abstract The species richness and diversity of epiphytic and epiphyllous bryophytes were investigated along an edge-interior gradient in a large Atlantic Forest remnant in Northeast Brazil. Bryophyte samples were collected at 60 geographically randomised points, which were distributed among five zones located at different distances in from the forest edge. In each site the altitude was recorded and a hemispherical photograph was taken to determine the degree of canopy opening and light transmittance. There was no statistically significant variation of species-richness and diversity in relation to the forest edge, even at 1084 m from the edge. Instead, among the microenvironment variables studied, only altitude supported the most diverse bryophyte floras, especially epiphyllous and shade-tolerant species that are sensitive to disturbance. Besides this, the degree of canopy cover was also relevant, albeit with less significance. These results show that bryophytes respond better to scattered and unique conditions, within moderate microclimates, in the remnant itself than they do to the edge-interior gradient distances alone.

Reproductive phenology of the moss Sematophyllum subpinnatum in a tropical lowland forest of north-eastern Brazil

Abstract Sematophyllum subpinnatum (Brid.) E.Britton is an autoicous species of moss with a pantropical distribution. Two populations of S. subpinnatum from a Tropical Lowland Forest remnant were sampled monthly over a period of 2 years. The results were similar in the two populations. The average number of antheridia produced per perigonium ranged from eight to 20, and of archegonia per perichaetium from three to 26. Antheridial and archegonial initiation, maturation and fertilized archegonia occur throughout the year, but increased in frequency during the rainy season. The initial stages of sporophyte development were most common between the months of June and September, indicating that, although S. subpinnatum produces gametangia all year round, the rainy season is the most favourable period for fertilization.

Reproductive phenology of Octoblepharum albidum (Bryopsida, Leucobryaceae) in a tropical lowland forest of north-eastern Brazil

Abstract The seasonality of maturation of gametangia and development of sporophytes of the autoicous moss Octoblepharum albidum Hedw. was investigated in a remnant of the Atlantic Forest in Pernambuco State, Brazil. Two populations of this species were sampled monthly for a period of 2 years. The results obtained were similar in both populations and are presented together. The average number of antheridia produced per perigonium was 13.4 and of archegonia per perichaetium was 6.7. The frequency of juvenile, immature and mature gametangia was considerably greater during the rainy season, when there was also an increase in fertilized archegonia. Sporophytes began their development during the rainy season and continued into the dry season, when the spores were dispersed. The reproductive pattern of this species presented a marked seasonality,apparently greatly influenced by rainfall.

Musgos (Bryophyta) de um fragmento de Mata Atlântica na Serra da Jibóia, município de Santa Terezinha, BA, Brasil

This work presents the results of an inventory of mosses carried out in an Atlantic Forest fragment in the Jiboia Mountains, Santa Terezinha, Bahia State, Brazil. A total of 61 moss species distributed in 23 families and 46 genera were found. The families Sematophyllaceae (seven spp.), Orthotrichaceae (six spp.), Pilotrichaceae (five spp.), Calymperaceae (five spp.), Leucobryaceae (five spp.) and Meteoriaceae (four spp.) had higher species richness. Actinodontium integrifolium (Broth.) Churchill and Calymperes venezuelanum (Mitt.) Pitt. are new records for Brazil. Ectropothecium leptochaeton (Schwaegr.) W.R. Buck., Eulacophyllum cultelliforme (Sull.) W.R. Buck & Ireland, Fissidens santa-clarensis Ther., Mittenothamnium reptans (Hedw.) Card., Orthostichella pentasticha (Brid.) Buck, Pilotrichella flexilis (Hedw.) Angstr., Lepidopilidium portoricense (Mull. Hal.) Crum & Steere, and Thuidium tomentosum Schimp. are new records for Bahia. As regards geografic distribuition, neotropical taxa predominate, while in relation to communities, corticicolous (70%) and epixilous species (23%) predominate. The local flora was considered rich for including 24% of the bryophytes that occur in Bahia State.

Novas ocorrências de hepáticas (Marchantiophyta) para o estado da Bahia, Brasil

In Serra da Jiboia were recorded 13 species of new ocurrence wich are eight species from region Northeastern: Bazzania aurescens Spruce, Calypogeia peruviana Nees & Mont., Cephalozia crassifolia (Lindenb. & Gottsche) Fulford, Lepidozia cupressina (Sw.) Lindenb., Pallavicinia lyellii (Hook.) S.F. Gray, Plagiochilla diversifolia Lindenb. & Gottsche, Radula kegelli Gottsche ex Steph. and Riccardia fucoidea (Sw.) Schiffin., and five are recorded for the first time from Bahia, State: Metzgeria albinea Spruce, Plagiochila gymnocalycina (Lehm. & Lindenb.) Mont., P. simplex (Sw.) Lindenb., Riccardia amazonica (Spruce) S.W. Arnell and Symphyogyna aspera Steph. from Bahia, State. For each specie are provided taxonomics and ecological comments, geographical general and in Brazil distribution, and indication of literature with description and ilustration. Some species were ilustrated.

REPRODUÇÃO SEXUADA EM MUSGOS ACROCÁRPICOS DO ESTADO DE PERNAMBUCO, BRASIL

The frequency of sexual reproduction in acrocarpous mosses collected in Pernambuco State, and subsequently deposited in the UFP Herbarium, was determined based on sporophyte production. Each voucher was observed under a dissecting microscope for recording the presence of the sporophyte and its developmental stage. The data obtained from literature was also registered. 770 voucher, distributed in 11 families and 59 species, were examined. 26 species have a monoecious reproductive system, 27 a dioicous one, and the six remaining ones have an unknown breeding system. The rate of fruiting specimens was higher in monoicous (3:1) than dioicous ones. Sporophytes were found in 88% of the best represented species. The frequency of fruiting specimens of dioicous species is either occasional or rare. The analysis of the developmental stages of sporophyte throughtout the year demonstrated that the production of sporophytes mainly occurs during the rainy season. Finally, humidity and self-fertilization play an important rule in the sexual reproduction of the acrocarpous mosses.

Beta-diversity: Effect of geographical distance and environmental gradients on the rocky outcrop bryophytes

Abstract The rocky outcrops are indeed islands amidst a “sea” of soil and thus their floristic composition and species diversity are influenced by stochasticity. Our discovery was settled to regional level, mainly from the Mantel tests (rM = 0.41, p = 0.01) and partial Mantel (rM = 0.41, p = 0.03), significant when contrasting the floristic x geographical distances and floristic x geographical distances with environment distance weighted, respectively. At the local level, clustering by Group mean (UPGMA) did not show a general pattern for the geographical distance, suggesting that in outcrops stochastic processes are the major actors at the regional scale while the local level need to be more intensely studied in order to reach better conclusions.

Species richness and distribution of bryophytes within different phytophysiognomies in the Chapada Diamantina region of Brazil

The Chapada Diamantina ecoregion is within the caatinga (shrublands) biome of Brazil. Environmental factors determine the phytophysiognomies that distinguish the ecoregion from the surrounding areas. This study aimed to investigate the distribution of bryophyte flora in this ecoregion, by phytophysiognomy and elevational zone. Analyzing specimens we collected from five municipalities in the region, together with specimens (previously collected from the region) in herbaria, we identified 400 taxa. The phytophysiognomies that presented the highest species richness and the greatest numbers of exclusive taxa were forests and campos rupestres (dry, rocky grasslands), which respectively accounted for 51% and 40% of the taxa, compared with only 5% and 4%, respectively, for the caatinga and cerrado (savanna). Species richness and the numbers of exclusive taxa were highest in the lower and upper montane zones. There was a predominance of neotropical taxa and a significant number of disjunct species found in Brazil and in the Andes region. We conclude that the Chapada Diamantina region is an important center of bryophyte diversity, harboring not only a great number of species overall but also a considerable number of species exclusive to the region, primarily in forests and campos rupestres at elevations above 800 m.