Márcia C. M. Marques

Phenological patterns among plant life-forms in a subtropical forest in southern Brazil

Phenological patterns in tropical plants usually are associated with the clear seasonality of rainfall associated with very different wet and dry seasons. In southern Brazil, in a subtropical forest with no pronounced dry season (average annual precipitation = 1389 mm, minimum monthly average c. 75 mm), plant phenology was studied to test for patterns (periodicity), to examine how phenological patterns vary among life-forms, and to test whether phenological cycles are associated with climatic variables. Thirty-seven plant species in four life-forms (trees, shrubs, lianas and epiphytes) were studied for 2 yr (1996-98) in an Araucaria forest remnant in southern Brazil, in the state of Paraná. Correlation and multiple regression methods established relationships between phenology and climate in terms of daylength, temperature and rainfall. In this Araucaria forest, plants showed seasonality in most life-forms and phenological phases. Leaf-fall, with its peak during the drier months (April to July), was the most seasonal. Flushing and flowering occurred during the wetter months (September to December), while fruiting occurred all year long. Phenologies varied among life-forms, and were strongly associated with daylength or temperature of preceding months, suggesting that plants receive their phenological cues well in advance of their phenological response. Phenologies in this Araucaria forest appear to be associated with the most predictable and highly correlated of the climatic variables, daylength and temperature and least so with rainfall, which is unpredictable.

Fenologia de espécies do dossel e do sub-bosque de duas Florestas de Restinga na Ilha do Mel, sul do Brasil

Devido a ampla distribuicao geografica, a Floresta Atlântica e os ecossistemas associados estao sujeitos a condicionantes ambientais que variam de acordo com a latitude e que devem influenciar nos processos dinâmicos das comunidades. Para avaliar se a fenologia de florestas da regiao atlântica pode ser determinada por tais variacoes, plantas do dossel e do subbosque (total 55 especies) de duas Florestas de Restinga (Floresta nao inundavel e Floresta inundavel) foram acompanhadas por dois anos na Ilha do Mel, localizada em regiao meridional da distribuicao da Floresta Atlântica e com pouca diferenca climatica entre o periodo superumido (setembro a maio) e umido (junho a agosto). Apesar das diferencas floristicas e estruturais, as duas florestas apresentaram padroes semelhantes, com pico de queda de folhas (outubro a dezembro), brotacao (dezembro a janeiro), floracao (dezembro a janeiro) e frutificacao (marco a abril) ocorrendo sucessivamente ao longo da estacao superumida, o que esteve correlacionado principalmente com as variacoes do comprimento do dia e da temperatura. Dossel e sub-bosque apresentaram padroes fenologicos distintos, sendo que no primeiro houve maior sincronia interespecifica. Os resultados mostraram que mesmo localizadas na situacao marginal de distribuicao do clima tropical, as Florestas de Restinga da Ilha do Mel apresentam semelhancas fenologicas com outros ecossistemas da regiao atlântica, o que deve refletir a similaridade floristica entre estas areas.

Florística e estrutura de comunidades vegetais em uma cronoseqüência de Floresta Atlântica no Estado do Paraná, Brasil

We describe the tree structure of three Atlantic Forest fragments on the coast of Parana, in order to detect differences in community structure throughout the succession process and to support future vegetation restoration projects. The study area was the Reserva Natural Rio Cachoeira, where three sites were chosen based on length of time since the last manmade disturbance (mostly agriculture and lodging); these were, respectively, 20-, 80- and 120-year-old forests. The 20-year-old forest had the lowest richness, diversity, basal area and volume. The 80-year-old forest had the highest density and richness. The 120-year-old forest had the highest diversity, equitability and volume. Diversity, basal area and volume were significantly different among the three sites. There were no important differences among structures of populations of species shared by the three areas. On the other hand, structural characteristics of exclusive species were important to determine differences among sites.

Estrutura e dinâmica de uma população de Calophyllum brasiliense Camb. em floresta higrófila do sudeste do Brasil

Age and spatial structures of a population of Calophyllum brasiliense (Clusiaceae) were studied in a 3600 m2 area of a swamp forest in Brotas, Sao Paulo State. During the first census, 1658 plants were tagged and after one year this number increased to 1706. Age structure did not change over the period of study, with a greater number of seedlings (individuals £ 0.2 m) and juveniles (> 0.2 - 2 m) and a smaller number of subadults ( > 2 - 10 m) and adults ( > 10 m). Seedling (29.7%) and juvenile (5.3%) mortality was caused, mainly, by soil erosion and deposition during the rainy season, because the plants were buried. Subadult (0.7%) and adult (0%) mortality was very low. A large number of new seedlings was concentrated in the lower parts of the study site and in soil depressions where the water carried seeds which were deposited and germinated. Recruitment rate for seedlings was high (48.1%), while for juvenile (7.3%), subadult (1.9%) and adult (0%) were much lower. Plants of all classes, from seedlings to adults, presented a clustered distribution, due to the topography of the study site, which facilitates seed accumulation, and to a higher number of seeds under the canopy of reproductive individuals. Fruit dispersion by bats or water, seed survival under hypoxic conditions, seedling tolerance to waterlogging, age structure with a significant predominance of seedlings and population growth explain why C. brasiliense is the most abundant species in the forest studied and also in other similar forests in Southeastern Brazil.

Seed germination and growth of Calophyllum brasiliense (Clusiaceae), a typical species of flooded forests

Soil waterlogging and the subsequent reduction in the amount of oxygen available for the respiration of the root system selected, along the evolutive process, plants able to thrive in seasonally or permanently flooded areas. In neotropical plants there are many types of adaptations to flooding. In this paper we present the results of the work carried out with seeds and seedlings of C brasiliense subjected to hypoxia during germination and early development. C brasiliense seeds are not photoblastic and survive up to three months burried in a water saturated substrate, but germination only takes place in well-drained soils. Soil waterlogging does not inhibit seedling growth and there are no apparent morphological changes of the aerial part of flooded plants. New and aerated roots that make plant survival possible replace old and spoiled roots. In contrast to many typical species of flood-prone areas where growth is inhibited by oxygen stress. C. brasiliense seedlings seem to be well adapted to their waterlogged environment. Seed dispersion, the absence of photoblastic response as well as seed and seedling capacity of surviving and growing in waterlogged soils contribute to the wide geographic distribution of C. brasiliense always associated with areas subjected to soil waterlogging.

Phylobetadiversity among Forest Types in the Brazilian Atlantic Forest Complex

Phylobetadiversity is defined as the phylogenetic resemblance between communities or biomes. Analyzing phylobetadiversity patterns among different vegetation physiognomies within a single biome is crucial to understand the historical affinities between them. Based on the widely accepted idea that different forest physiognomies within the Southern Brazilian Atlantic Forest constitute different facies of a single biome, we hypothesize that more recent phylogenetic nodes should drive phylobetadiversity gradients between the different forest types within the Atlantic Forest, as the phylogenetic divergence among those forest types is biogeographically recent. We compiled information from 206 checklists describing the occurrence of shrub/tree species across three different forest physiognomies within the Southern Brazilian Atlantic Forest (Dense, Mixed and Seasonal forests). We analyzed intra-site phylogenetic structure (phylogenetic diversity, net relatedness index and nearest taxon index) and phylobetadiversity between plots located at different forest types, using five different methods differing in sensitivity to either basal or terminal nodes (phylogenetic fuzzy weighting, COMDIST, COMDISTNT, UniFrac and Rao’s H). Mixed forests showed higher phylogenetic diversity and overdispersion than the other forest types. Furthermore, all forest types differed from each other in relation phylobetadiversity patterns, particularly when phylobetadiversity methods more sensitive to terminal nodes were employed. Mixed forests tended to show higher phylogenetic differentiation to Dense and Seasonal forests than these latter from each other. The higher phylogenetic diversity and phylobetadiversity levels found in Mixed forests when compared to the others likely result from the biogeographical origin of several taxa occurring in these forests. On one hand, Mixed forests shelter several temperate taxa, like the conifers Araucaria and Podocarpus. On the other hand, tropical groups, like Myrtaceae, are also very representative of this forest type. We point out to the need of more attention to Mixed forests as a conservation target within the Brazilian Atlantic Forest given their high phylogenetic uniqueness.

Dynamics and diversity of flooded and unflooded forests in a Brazilian Atlantic rain forest: a 16-year study

Background: Disturbance and small-scale variation in environmental conditions are potential factors that influence structure and diversity in tropical forest communities. In the coastal lowland vegetation in Brazil, forests that differ in flooding regimes could differ in these metrics, although long-term data are usually lacking. Aims: Our aim was to determine if a stand in an unflooded forest and a stand in a flooded forest had distinct structural characteristics and patterns of change over a 16-year period. Methods: Individuals ≥4.44 cm in diameter at breast height were recorded on two 0.3-ha plots in 1991 and 2007. The differences in stem density, species richness, community-level mortality and recruitment, and stem growth rates were assessed. Results: The unflooded forest plot had a higher density of smaller individuals, but a substantially lower basal area than the flooded forest plot. Basal area increased by 4% and 20% over 16 years in the flooded and unflooded plots, respectively. Species richness per area was twice as high in the flooded forest plot than in the unflooded plot. Conclusions: These data provide tentative support for the hypothesis that enhanced tree turnover contributes to maintenance of small-scale differences in diversity at the landscape scale. We conclude that flooded and unflooded habitats provide distinct environments that support contrasting communities of woody plants.

Relações entre a distribuição das espécies de diferentes estratos e as características do solo de uma floresta aluvial no Estado do Paraná, Brasil

Soil characteristics are the most important factors influencing species distribution in alluvial forests. Here we evaluated species composition, diversity and structure of three forest strata and their relationship with soil characteristics in a fragment of alluvial forest in the Iguacu River basin, Parana state. We asked if forest structure and diversity can be explained by edaphic and hydrological factors. We evaluated structural variables and floristic composition of three forest strata: regeneration stratum (20 cm 1.30 m; 20 subplots, 5 m×5 m) and upper stratum (pbh > 15 cm, 20 subplots, 10 m×10 m). In addition, we correlated species abundance with soil parameters in each subplot. The forest was characterized by a low diversity (Shannons index: regeneration stratum = 2.36; intermediate stratum = 2.49; upper stratum = 1.59) and high floristic similarity among strata (Sorensen index > 0.65). The relationship of species spatial distribution and soil characteristics was distinct among strata: species distribution was correlated with soil water-table levels and organic matter content in the upper stratum and with soil water-table levels and aluminum concentration in the intermediate stratum. On the other hand no significant correlation was verified in the regeneration stratum. Our results suggest that community structure and floristic composition in alluvial forests reflect different interactions during individual life cycles.

Forest structure and species composition along a successional gradient of Lowland Atlantic Forest in Southern Brazil

The Lowland Forest is one of the most disturbed and fragile ecosystems in the Atlantic Forest biome, yet little is known regarding its successional trajectory and resilience. We evaluated changes in species assemblages and forest structure of the canopy and understory along a successional gradient (young 21-yrs old forest, immature 34-yrs old forest and late successional 59-yrs old forest) aiming to assess changes in species composition and successional trajectory of different strata of secondary forests. A 0.1 ha plot (ten 10x10 m sub-plots) from each forest stand was surveyed for trees and shrubs with a diameter at breast height (DBH) ≥ 4.8 cm (canopy) and for individuals with heights ≥ 1 m and DBH < 4.8 cm (understory). A total of 3,619 individuals from 82 plant species were sampled. The successional gradient was marked by a unidirectional increase in species richness and a bidirectional pattern of density changes (increasing from young to immature forest and decreasing from immature to late successional forest). Community assemblages were distinct in the three forests and two strata; indicator species were only weakly shared among stands. Thus, each successional forest and stratum was observed to be a unique plant community. Our results suggest slight predictability of community assemblages in secondary forests, but a relatively fast recovery of forest structure.

Lavagem pulmonar total – A propósito de quatro casos de proteinose alveolar

Resumo A lavagem pulmonar e uma tecnica desenvolvida na decada de 60 do seculo xx com o intuito de remocao fisica de material proteinaceo dos bronquios, em doentes com proteinose alveolar, levando a uma melhoria clinica e funcional. A tecnica foi evoluindo e o que era inicialmente realizado com anestesia local a um segmento do pulmao e actualmente realizado sob anestesia geral, sequencialmente, a ambos os pulmoes. A presente revisao descreve a tecnica de lavagem pulmonar total, a sua principal indicacao, a proteinose alveolar e, a proposito, relatamos alguns dados relativos a experiencia do nosso servico, onde a realizam com regularidade desde 2002.