Refine
Year of publication
Document Type
- Article (14)
- Part of Periodical (1)
Has Fulltext
- yes (15)
Is part of the Bibliography
- no (15)
Keywords
- Afroriccardia gen. nov. (1)
- Aneuraceae (1)
- Riccardia (1)
- liverworts (1)
- phylogeny (1)
The Guianas (French Guiana, Suriname, Guyana) are probably one of the last areas of the world covered largely by virgin lowland rain forest. Species diversity of epiphytic bryophytes was investigated in dry evergreen forest and mixed forest using mountaineering techniques to ascend into the canopy. The results indicate that the lowland rain forest is richer in species than previously believed due to neglect of the canopy flora, which may hold more than 50% of the local species. The mixed forest holds the richest flora and on one single forest tree up to 67 bryophyte species were found (50 on average); 28 trees yielded 154 species. A species/area curve indicates that epiphytic bryophyte species are usually commonly distributed in the forest and a few trees may yield much of the local flora. A recent checklist of the Guianas includes over 600 species of bryophytes: 375 Hepaticae and 234 Musci. As the region lacks in altitude (except on Mt. Roraima) the general character of the bryophyte flora of the Guianas is typically lowland neotropical. Over 80% of the species are rather widespread in tropical America (Amazonian species included), and the remaining are Guayana Highlands, northern Amazonian or Caribbean elements. Endemism is very low: 2.5 %.
A floristic and ecological study of bryophytes and macrolichens in different lowland rain forest types around Mabura Hill, Guyana, South America, yielded 170 species: 52 mosses, 82 liverworts and 36 macrolichens. Lejeuneaceae account for about 30% of the species and are the dominant cryptogamic family of the lowland rain forest. Special attention was paid to the flora of the forest canopy, by using mountaineering techniques. It appeared that 50% of the bryophyte species and 86% of the macrolichens occurred exclusively in the canopy. Dry evergreen 'walaba' forest on white sand is particularly rich in lichens whereas the more humid 'mixed' forest on loamy soil is characterized by a rather rich liverwort flora. More species are exclusive to the mixed forest than to dry evergreen forest due to the 'canopy effect', i.e. the occurrence of xerophytic species in the outer canopy of both dry and humid forests. Furthermore, canopy species have wider vertical distributions on trees in the dry evergreen forest than in the mixed forest, due to the more open canopy foliage of the dry evergreen forest.
A survey of the literature and collections in the Monteverde Cloud Forest Preserve and adjacent pastureland yielded a total of 198 epiphytic bryophyte taxa (120 species of hepatics in 50 genera, 77 species of moss in 48 genera, and 1 hornwort): 178 in the primary forest, 63 in the secondary forest, and 84 in the pastureland.
A brief account of the geography and floristic regions of Panamá is complemented with an historical account of the liverwort studies of this country. This is followed by an annotated checklist of 289 taxa, including 93 new for Panamá. Among these are four hornwort taxa that represent the first anthocerotes reported. Each checklist entry comprises proper taxon citation, collection data and/or bibliographic references.
A bryological inventory of the Upper Mazaruni District, Guyana (former British Guiana) yielded almost three hundred species, including 2 genera and 11 species new to science and 130 species new to the Guianas. The densely forested and very humid north slope of Mount Roraima (500-2300 m.) proved to be the richest area for bryophytes and most of the novelties were found there. The present paper provides an enumeration of the species collected with a brief characterization of their habitat. The following species are described as new: Haesselia acuminata Gradst., Plagiochila gymnocalyx Inoue, Radula gradsteinii Yamada, Radula guyanensis Yamada, Radula mazarunensis Yamada and Stenorrhipis grollei Gradst. Anastrophyllum subg. Vanaea Inoue & Gradst. from Mount Roraima is elevated to generic rank.
Diplasiolejeunea involuta Winkler, a species formerly known only from El Salvador, was collected from shrubs in a non pure Sphagnum - Blechnum bog in Costa Rica. The plant is easily recognized by its large leaves, very convex lobes and very large lobules with obviously involute apex; the species has 3-7 oil bodies of the Jungermannia type per cell. Most characteristics of D. involuta fit with those of the subgenus Austrolejeuneopsis, the size of the underleaves are like those of the subgenus Diplasiolejeunea and the stout lobule covers up to 85% of the lobe, as in the subgenus Physolejeunea.
A synopsis is provided of 88 species in 17 genera currently recognized in Lejeuneaceae subfamily Ptychanthoideae sensu lato (including Nipponolejeunea) of Asia. Taxonomic novelties include Thysananthus flavescens (Hatt.) comb. nov. (for Mastigolejeunea flavescens (Hatt.) Mizut.), Spruceanthus macrostipulus (Steph.) comb. nov. (for Archilejeunea macrostipula (Steph.) Verd.) and the reduction of Platylejeunea Mizut. to synonymy under Lopholejeunea.
Tropical deforestation, inevitably, leads to the local loss of bryophyte species. Recent studies show that the degree of species loss may vary considerably and depends on the scale or amount of habitat change that has occurred. Predictably, the shade epiphytes are most seriously affected by disturbance. An estimated 10% of the bryophyte species of neotropical rain forests are under threat. Based on data from recent monographs, a first list of 19 endangered and 27 rare species of these forests is presented. Critical areas for threatened species include Costa Rica and Panama, the Greater Antilles, the Chocó, southeastern Brazil, and parts of Amazonia. Protection of as much as possible of the remaining natural rain forest area seems the best approach to the conservation of the tropical bryophyte flora.
This paper presents data on morphology, ecology and distribution of 16 species of bryophytes collected in Pernambuco, Brazil, that are interesting floristic records. Notothylasorbicularis (Schwein.) Sull. is new to Brazil, 11 species are new to the Northeast region of Brazil and 4 species are new to Pernambuco.
A bryophyte inventory along an altitudinal gradient on Cerro Pirre (1200 m), Darién National Park, Panama, demonstrates that the different rain forest types along the gradient (inundatedlowland, hillside-lowland, submontane, montane elfin forest) have very different species assemblages. The montane forest has the largest number of exclusive species and the largest bryophyte biomass. Species richness is greatest in the submontane forest. The bryophyte flora of Cerro Pirre is not exceedingly rich in species owing to the rather low elevation of the mountain and the seasonal climate in the adjacent coastal plain. Nevertheless, the distinct altitudinal diversification and the occurrence of a considerable number of rare hepatic taxa, demonstrate the importance of Darién National Park as an area of plant conservation. Forty hepatic species are reported as new to Panama.
Seven species of Radula are reported from the Galapagos Islands, including Radula santacruziana spec. nov. The majority of the species are common and widespread in the neotropics; two (including the new species) are endemic to the Galapagos. R. cornucopiae Spruce and R. mollis Lindenb. et Gott. are reduced to synonymy, resp. under R. episcia Spruce and R. quadrata Gott. et al.
With 280 accepted species, the genus Riccardia S.F.Gray (Aneuraceae) is one of the most speciose genera of simple thalloid liverworts. The current classification of this genus is based on morphological and limited-sampling molecular studies. Very few molecular data are available and a comprehensive view of evolutionary relationships within the genus is still lacking. A phylogeny focusing on relationships within the large genus Riccardia has not been conducted. Here we propose the first worldwide molecular phylogeny of the genus Riccardia, based on Bayesian inference and parsimony ratchet analyses of sequences from three plastid regions (psbA-trnH, rps4, trnL-F). The results support the monophyly of Riccardia and a new monospecific genus, Afroriccardia Reeb & Gradst. gen. nov., is described based on molecular and morphological evidence. The results indicate that several currently recognized infrageneric divisions and a few species are not monophyletic, suggesting that further analyses are needed to arrive at a proper understanding of the phylogeny of the genus. Although evidence for an Andean clade was found, most of the species appear scattered in different clades without clear geographical segregation. Broader sampling and further analyses are necessary in order to improve our understanding of the phylogeny of this poorly known liverwort genus.