Jairo Lizandro Schmitt

Composição e distribuição vertical de pteridófitas epifíticas sobre Dicksonia sellowiana Hook. (Dicksoniaceae), em floresta ombrófila mista no sul do Brasil

Dicksonia sellowiana Hook., a tree fern species, is illegally extracted from the Mixed Ombrophylous Forest of southern Brazil, what changes the vegetation structure and reduces the availability of micro-habitats for epiphytic species. The composition and the vertical distribution of epiphytic pteridophytes were studied on D. sellowiana. The study was carried out in a Mixed Ombrophylous Forest area, at the Parque Municipal da Ronda in the State of Rio Grande do Sul, Brazil. One hundred and sixty four phorophytes were selected and their caudices were divided at intervals of 1 m, from the ground. At each interval the occurrence of pteridophyte species was recorded, and the frequency by phorophyte and by interval was calculated. Twenty species were recorded, from 13 genera and seven families, and habitual holoephiphytes predominated. The largest specific richness was found in Aspleniaceae (6) and in the Asplenium L. genus (6). The species with the highest relative frequency on the phorophytes were Trichomanes angustatum Carmich., Blechnum binervatum (Poir.) C.V. Morton & Lellinger and Vittaria lineata (L.) Sm.. Considering a sub-sample of 60 phorophytes, T. angustatum and B. binervatum had decreasing frequency of occurrence from the ground up to 4 m. The average richness was higher in the first three intervals. The richness found over the caudices of D. sellowiana represented 67% of the total epiphytic pteridophytes found in Mixed Ombrophylous Forest area, at the Parque Municipal da Ronda and this shows the importance of this host plant for the maintenance of epiphytic species in the forest environment.

Aspectos ecológicos de Alsophila setosa Kaulf. (Cyatheaceae, Pteridophyta) no Rio Grande do Sul, Brasil

Alsophila setosa Kaulf. is a tree fern occurring in the primary and secondary forest formations in South and Southeastern Brazil. The present study discusses population structure, architecture of the underground parts as well as herbivory of fronds and epiphytic species. Fieldwork was performed in two secondary forest tracts in the municipalities of Morro Reuter and Sapiranga in the state of Rio Grande do Sul, Brazil. Contiguous 100 m2 plots were surveyed as to the occurrence of A. setosa and plants sizes. Two samples, of 45 plants in Morro Reuter and 48 in Sapiranga, were examined throughout a full year cycle as to herbivory on their fronds. Five plants were uprooted for the study of the underground structures. The epiphytic plants on the caudexes were recorded and sampled. The underground structure is complex, with caulinar branches that may form new plants, leading to an increase of the number of individuals in a stand and to an aggregate spatial distribution. A larger number of smaller plants was recorded. Herbivory damage was observed on 28.88% of the plants in Morro Reuter and 35.41% in Sapiranga. As to vascular epiphytes, 16 species were found, with a predominance of holoepiphytes. This role as phorophyte is of special importance for the conservation of some the epiphytic species.

Estrutura populacional e desenvolvimento da fase esporofítica de Cyathea delgadii Sternb. (Cyatheaceae, Monilophyta) no sul do Brasil

Cyathea delgadii Sternb. is a tree fern that grows in primary and secondary forests from Norhteastern to Southern Brazil. This study discusses the population structure and development of the sporophytic phase (caudex growth, frond production, phenology of spore production) of C. delgadii in a secondary forest in the State of Rio Grande do Sul, Brazil, based on observations of 41 plants during a 13 month period. The species had an aggregated spatial distribution pattern and higher frequency of smaller individuals, indicating high potential for population regeneration. On average, the caudex of plants grew 4.65 cm year-1, and the highest growth rates were recorded for taller plants. The similar frond production rate (5.75 fronds year-1) and senescence rate (4.92 fronds year1) reflect the capacity to maintain a stable number of fronds. Only a few plants formed fertile fronds, while spore production and liberation occur in an asynchronous pattern.

Spore germination and gametophyte development of Cyathea atrovirens (Langsd. & Fisch.) Domin (Cyatheaceae) under different pH conditions

Cyathea atrovirens (Langsd. & Fisch.) Domin, an intensely exploited tree fern, is found inside forests in several succession stages, as well as in swamps, roadsides and unused fields in the Rio dos Sinos basin, in the state of Rio Grande do Sul, southern Brazil. This study evaluated the in vitro germination and gametophyte development of C. atrovirens under different pH conditions, as well as spore viability after different storage times at 7 ºC. The lowest germination rate of spores was obtained at pH 7.0. At pH 5.0 to 6.5, laminar gametophyte development started at 20 to 30 days of culture. Antheridia and archegonia were first observed at 35 and 128 days, respectively. Storage at 7 ºC did not affect germination rates. The capability of germination at different pH levels may explain the occurrence of the species in a wide range of habitats. The present study contributes to the understanding of the full life-cycle of C. atrovirens and to the analysis of the influence of abiotic components, providing information for the cultivation, management and conservation of the species.

Growth Rates and Age Estimates of Alsophila setosa Kaulf. in Southern Brazil

ABSTRACT The tree fern Alsophila setosa, occurs in primary and secondary forests of southern and southeastern Brazil. Two populations in secondary forest formations in the northeastern part of the State of Rio Grande do Sul, in the municipalities of Morro Reuter (45 plants) and Sapiranga (48 plants), were studied to estimate the ages of the plants. Two approaches were tested, one based on the total length in relation to the yearly growth rate of the caudex, and the second on the total number of scars and remains of stipe bases along the caudex in relation to the yearly frond production. Estimates based on growth rates and total length did not agree with the information and records of the past land use, whereas frond production over a longer time period presented acceptable estimates. The development of a new plant formed through vegetative reproduction was observed during three years. A brief discussion of the problems of age estimates in tree ferns is presented.

Crescimento do cáudice e fenologia de Dicksonia sellowiana Hook. (Dicksoniaceae) no sul do Brasil

In Southern and Southeastern Brazil, the tree fern Dicksonia sellowiana Hook. still is illegally extracted from remnants forests for the use of its fibrous caudex cover, as well as for cultivation as an ornamental plant. In the present study the caudex growth, frond production, expansion and senescence as well as the formation and release of spores have been studied based on the observation of 37 plants. During an observation period of one year, the caudexes grew at an average of 5.65 cm year-1 and the growth rate presented a strong correlation with the height of the plants. Similar frond production rate (10.86 fronds year-1) and senescence (10.54 fronds year-1) evidenced the capacity of maintaining a stable number of fronds throughout the year. Only 14 individuals developed fertile fronds, most of them producing spores during the summer and liberating them during the winter. Production and release of spores were influenced more by temperature and photoperiod rather than by rainfall.

Integrated Environmental Assessment of streams in the Sinos River basin in the state of Rio Grande do Sul, Brazil.

The deterioration of environmental quality in the Sinos River basin is directly associated with the impacts of intense industrialization and urbanization. An integrated environmental assessment (IEA) was conducted in July and September of 2012, in areas along the sources of the EstânciaVelha/Portão, Pampa and Schmidt streams using physical, chemical and biological methods. The water in the three sampling sites was not proper for human consumption, presented a low toxic contamination index (TCI) and mesotrophic characteristics. One site was included in Class 4, and two, in Class 3, according to current legislation. The rapid assessment protocol (RAP) indicated a natural environmental condition for habitat diversity and environmental impact in the three sites. The Tradescantia pallida (Rose) D.R. Hunt var. purpurea Boom biomarker showed water genotoxicity in two of the sites. The integrated diagnosis of water quality in these streams is fundamentally important to ensure the sustainable management of water resources and their multiple uses, as well to estimate their contribution to pollution in this river basin.

Fenologia de três espécies de Myrsine l. em floresta secundária semidecídua no Sul do Brasil

RESUMO – Eventos vegetativos e reprodutivos de Myrsine lorentziana (Mez.) Arechav., M. guianensis (Aubl.) Kuntze e M. coriacea (Sw.) R. Br. foram avaliados por dois anos, em Floresta Estacional Semidecidual secundaria, no Parque Municipal Henrique Luis Roessler, Novo Hamburgo, RS, Brasil. Os eventos fenologicos foram relacionados a variaveis climaticas, e observou-se correlacao negativa com a temperatura e o fotoperiodo em M. guianensis e M. coriaceae, na fenofase floracao, enquanto na frutificacao essa correlacao ocorreu em M. lorentziana e M. coriaceae. M. guianensis foi a unica especie que apresentou correlacao negativa da fenofase de frutos maduros com o fotoperiodo e a temperatura. Floracao e frutos maduros constituiram eventos sazonais nas tres especies, que em conjunto fornecem alimento para a avifauna durante o ano todo. A presenca de frutos imaturos, queda foliar e brotamento demonstrou ser um evento continuo ao longo do ano. Nenhum evento fenologico se correlacionou com a precipitacao, resultado esperado em ambientes sem periodos secos regulares.

Phenology, caudex growth and age estimation of Cyathea corcovadensis (Raddi) Domin (Cyatheaceae) in a subtropical forest in southern Brazil

Cyathea corcovadensis (Raddi) Domin occurs in northeastern, southeastern and southern Brazil, being widely distributed in the last. This was a three-year study, conducted from August 2008 to July 2011, in which we evaluated C. corcovadensis in a subtropical forest in southern Brazil. For the first year (August 2008 to July 2009), we monitored 30 plants on a monthly basis in order to analyze phenological events (vegetative and reproductive) and caudex growth. We also estimated the ages of the plants. Except in June and July of 2009, monthly leaf emergence and senescence were continuous and irregular, which prevented total leaf abscission, during that first year. Leaf emergence, senescence and fertility correlated with photoperiod, temperature and plant height, whereas rainfall was not a good predictor of C. corcovadensis phenophase. Within the forest fragment studied, the high proportion of fertile individuals (63.3%) indicated that the population has the potential to increase in size. The mean annual caudex growth rate was 4.66-8.23 cm and was statistically equivalent among the three years evaluated. The number of leaves per plant remained stable throughout the study period. Among plants that were 4 m tall, the mean estimated age was 60.3 years when calculated on the basis of overall height and mean annual growth rate, compared with only 46.9 years when calculated on the basis of the number of total leaf scars or petiole remains on the caudex and mean annual leaf production.

Richness, coverage and concentration of heavy metals in vascular epiphytes along an urbanization gradient

Richness, coverage and concentration of heavy metals in vascular epiphytes were analyzed in isolated trees along an urbanization gradient in Southern Brazil. A total of 20 phorophytes were sampled in the main street of each site. Concentrations of chromium, cadmium, lead, manganese, nickel and zinc were measured in the leaves of Tillandsia recurvata L. using Graphite Furnace Atomic Absorption Spectrophotometry. A decreasing gradient of epiphyte richness and coverage was observed as urbanization increased. Vehicle fleet and demographic density were the parameters most correlated with the reduction of epiphytic diversity. In T. recurvata, significantly higher values of cadmium, lead and zinc were recorded in the most urbanized areas, and were strongly related to the vehicle fleet and to the demographic density in these sites. The results demonstrated that these parameters could be applied to the diagnosis of environmental quality in urban areas, allowing standardized analyses in other regions.