Tamanho e secagem de sementes de palmeira Jussara sobre a germinação e o vigor

With the objective to determine the influence of the dehydration and of the size and/or weight on germination percentage and the vigor of jussara palm seeds (Euterpe edulis Mart.), 10 individuals' ripe fruits, picked in the Experimental Station of Ubatuba (IAC) they were classified by size in 5 sieves of circular sieve: 26/64" (10,31mm), 28/64" (11,11mm), 30/64" (11,90mm), 32/64" (12,69mm) and 34/64" (13,49mm). It was determined, the medium weight of the classified seeds. The quality of the seeds was evaluated through the following parameters: water content of the seeds; germination and vigor (first germination counting). It was evaluated the drying speed of different seed sizes for 48 hours, in dry chamber. The sizes of 28/64", 30/64" and 32/64" represented 98,7% of the total weight of the harvested seeds and showed similar drying speed, percentage of germination and vigor. With the increase of the drying period, the smaller seeds (28/64") had their germination less affected them the intermediate (30/64") and bigger sized seeds (32/64").

Avaliação da qualidade fisiológica de sementes de açaí

Quarenta lotes de sementes de açaizeiro (Euterpe oleracea Mart.) colhidos na coleção de germoplasma de palmeiras do Instituto Agronômico de Campinas (Ubatuba, Estado de São Paulo) foram submetidos aos seguintes testes para a avaliação de qualidade fisiológica das sementes: grau de umidade, germinação, primeira contagem de germinação (emissão do botão germinativo aos quatro dias da semeadura), índice de velocidade de germinação (IVG) e condutividade elétrica. O grau de umidade das sementes apresentou valores de 32,2 a 45,5%. A avaliação da qualidade das sementes de açaizeiro pode fundamentar-se nos testes de germinação, de primeira contagem de germinação, de IVG e de condutividade elétrica quando interpretados em conjunto.

Effects of bamboo stands on seed rain and seed limitation in a rainforest

Bamboos often negatively affect tree recruitment, survival, and growth, leading to arrested tree regeneration in forested habitats. Studies so far have focused on the effects of bamboos on the performance of seedlings and saplings, but the influence of bamboos on forest dynamics may start very early in the forest regeneration process by altering seed rain patterns. We tested the prediction that the density and composition of the seed rain are altered and seed limitation is higher in stands of Guadua tagoara (B or bamboo stands), a large-sized woody bamboo native from the Brazilian Atlantic Forest, compared to forest patches without bamboos (NB or non-bamboo stands). Forty 1 m(2) seed traps were set in B and NB stands, and the seed rain was monitored monthly for 1 year. The seed rain was not greatly altered by the presence of bamboos: rarefied seed species richness was higher for B stands, patterns of dominance and density of seeds were similar between stands, and differences in overall composition were slight. Seed limitation, however, was greater at B stands, likely as a resulted of reduced tree density. Despite Such reduced density, the presence of trees growing amidst and over the bamboos seems to play a key role in keeping the seeds falling in B stands because they serve as food sources for frugivores or simply as perches for them. The loss of such trees may lead to enhanced seed limitation, contributing ultimately to the self-perpetuating bamboo disturbance cycle. (C) 2008 Elsevier B,V. All rights reserved.

Composição florística e estrutura fitossociológica de dois fragmentos de floresta de restinga no Município de Bertioga, SP, Brasil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Composição florística e estrutura da comunidade arbórea na transição da Floresta Ombrófila Densa das Terras Baixas - Floresta Ombrófila Densa Submontana do Núcleo Picinguaba/PESM, Ubatuba, sudeste do Brasil

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

Horizontal and vertical tree community structure in a lowland atlantic rain forest, southeastern Brazil

A estrutura horizontal e vertical do componente arbóreo foi investigada em um trecho de Floresta Atlântica baixo-montana através de um levantamento fitossociológico em dois blocos amostrais de 0,99 ha cada no Parque Estadual Intervales. Todos os indivíduos com DAP > 5 cm foram registrados. Foram amostrados 3.078 indivíduos distribuídos em 172 espécies. O índice de diversidade de Shannon foi de H' = 3,85 nat.ind.-1. A família Myrtaceae se destacou tanto em número de espécies (38) quanto em número de indivíduos (745) no levantamento. Euterpe edulis Mart. teve o maior valor de importância (33,98%), abrangendo 21,8% do total de indivíduos registrados. O índice de similaridade quantitativo foi maior do que o qualitativo, mostrando pouca variação estrutural entre os blocos amostrais, mas a grande quantidade de espécies pouco abundantes, resultou em pronunciadas diferenças florísticas entre eles. Uma análise de correspondência retificada (DCA) gerou três estratos verticais arbitrários. O estrato A (> 26 m) teve a menor densidade e foi bem representado pelas espécies Sloanea guianensis (Aubl.) Benth. e Virola bicuhyba (Schott. ex A.DC.) Warb. O estrato B (8 m < h < 26 m) mostrou a maior riqueza e diversidade florística, e o estrato C (< 8 m) a maior densidade. Euterpe edulis, Guapira opposita (Vell.) Reitz, Garcinia gardneriana (Planch. & Triana) Zappi e Eugenia mosenii (Kausel) Sobral foram bem representadas nos estratos B e C da floresta. A existência de estratos verticais em florestas tropicais é discutida, recomendando-se o uso da DCA para estudos da estratificação vertical em outras florestas tropicais.

Caracterização florística e fitossociológica do componente arbustivo-arbóreo de uma floresta paludosa no Município de Rio Claro (SP), Brasil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Temporal variation in the abundance of two species of thrushes in relation to fruiting phenology in the Atlantic rainforest

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

Florística e fitossociologia em parcelas permanentes da Mata Atlântica do sudeste do Brasil ao longo de um gradiente altitudinal

This paper summarizes floristic and phytossociology data of 11, out of 14 plots of 1 ha, allocated along an altitudinal gradient in the Serra do Mar, Silo Paulo, Brazil. The study was conducted at Serra do Mar State Park and the plots start at the sea level (10 m - plot of Restinga Forest that occurs at Praia da Fazenda, Picinguaba, municipality of Ubatuba) up to 1100 m above sea level (the Montane Ombrophilous Dense occurs alongside the Itamambuca Trail, municipality of Silo Luis do Paraitinga). The Restinga Forest occurs in Pleistocenic Coastal Plain where the soil is classified as a sandy Quartzipsamment (Quartzenic Neosol), while along the slopes of the Serra do Mar, the Ombrophylus Dense Forest grows on the top of a pre-Cambrian crystalline basement with granitic rocks, where the soil is a sandy-loam Dystrophic Inceptisol (Cambisol/Latosol). In all 14 plots soils are acidic (pH 3 - 4), chemically poor, with high dilution of nutrients and high saturation of aluminum. In the Restinga and at the foot of the slope the climate is Tropical/Subtropical Humid (Af/Cfa), with no dry season, an average annual rainfall over 2,200 mm and an average annual temperature of 22 degrees C. Towards the top of the Serra do Mar there is a gradual cooling along the slope, but there is no reduction in rainfall, so at 1,100 m above sea level the climate is classified as Humid Subtropical (Cfa/Cfb), with no dry season and an average annual temperature of 17 degrees C. It is important to remark that, almost daily, from 400 m above sea level up to the top of slopes the mountains are covered by a dense fog. In the 14 plots 21,733 individuals with DBH >= 4.8 cm, including trees, palms and ferns, were marked, measured and sampled. The average number of individuals sampled in each plot was 1264 ind.ha(-1)(+/- 218 SE 95%). Within the parameters considered trees prevailed (71% in the Montane ODF to 90% in the Restinga Forest), followed by palms (10% in the RF and 25% in the Montane Ombrophilous Dense Forest/ODF) and ferns (0% % in the RF and 4% in the Montane ODF). Regarding these proportions the Exploited Lowlands ODF differs from the others with only 1.8% of palm trees and striking 10% of ferns. The forest canopy is irregular with heights ranging from 7 to 9 m, rarely emergent trees reach 18 m, and due to this irregularity of the canopy the amount of light that gets through sets conditions for the development of hundreds of epiphytic species. Aside from Montana ODF, where the number of dead trees was more than 5% of individuals sampled, in the other phytophysiognomies this value was below 2.5%. In the 11 plots where the floristic study was conducted we found 562 species in 195 genera and 68 families. Only seven species - Euterpe edulis Mart. (Arecaceae), Calyptranthes lucida Mart. ex DC. and Marlierea tomentosa Cambess (both Myrtaceae), Guapira opposita (Veil.) Reitz (Nyctaginaceae), Cupania oblongifolia Mart. (Sapindaceae), Cecropia glaziovii Snethl. and Coussapoa microcarpa (Schott) Rizzini (both Urticaceae) - occurred from Restinga to Montane ODF, while 12 other species did not occur only in the Restinga Forest. Families with the greatest number of species are Myrtaceae (133 spp), Fabaceae (47 spp), Rubiaceae (49) and Lauraceae (49) throughout the gradient and Monimiaceae (21) specifically in portions Montane ODF. Only in the F plot, where logging has occurred between 1950 and 1985, the abundance of palm trees has been replaced by Cyatheaceae. The study shows a peak of diversity and richness, Shannon-Weiner index (H') ranging from 3.96 to 4.48 nats.ind(-1), in the intermediate altitudes (300 to 400 m) along the slope. Several explanations for this result are raised here, including the fact that these elevations are within the limits expansions and retractions of the different phytophysiognomies of the Atlantic ODF due to climate fluctuations during the Pleistocene. The results presented in this paper demonstrate the extraordinary richness of tree species of the Atlantic Rainforest from the northeastern coast of the State of São Paulo, reinforcing the importance of its conservation throughout the altitudinal gradient. The richness of this forest justifies a long term commitment to study its dynamics and functioning through permanent plots, and monitor the impacts of climate change in this vegetation.

Florística e fitossociologia do componente arbóreo da transição Floresta Ombrófila Densa das Terras Baixas - Floresta Ombrófila Densa Submontana do Núcleo Picinguaba/PESM, Ubatuba, sudeste do Brasil

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

Effects of frugivore impoverishment and seed predators on the recruitment of a keystone palm

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

Secagem e armazenamento de sementes de juçara

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

Composição florística de um trecho de floresta ripária na Mata Atlântica em Picinguaba, Ubatuba, SP

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Temporary storage of jussara palm seeds: effects of time, temperature and pulp on germination and vigor

As sementes da palmeira juçara (Euterpe edulis Mart.) são recalcitrantes, apresentando baixa longevidade e sensibilidade à desidratação e ao armazenamento em temperaturas baixas. Neste trabalho foram estudadas condições de temperatura mais adequadas ao armazenamento temporário destas sementes com e sem a polpa. Frutos maduros foram colhidos em 24 plantas provenientes da coleção de palmeiras do Instituto Agronômico (IAC) localizada em Ubatuba, estado de São Paulo, e encaminhadas, em embalagem impermeável, à Faculdade de Ciências Agronômicas da UNESP, Campus de Botucatu (SP). Metade dos frutos foi despolpada e outra metade foi mantida com polpa, sendo ambas armazenadas em sacos fechados de polietileno (20 µm de espessura) mantidos em temperaturas de 5; 10; 15 e 20-30ºC. Amostras para os testes de qualidade foram retiradas aos 0; 3; 6; 9 e 12 dias após a colheita dos frutos. As sementes armazenadas com polpa foram despolpadas imediatamente antes da instalação dos testes. Foram avaliados o grau de umidade das sementes, porcentagem de germinação, comprimento e matéria seca das plântulas. Os resultados mostraram que há efeito positivo de pós-amadurecimento em sementes de Euterpe edulis. Um período de armazenamento de 9 a 12 dias, após a colheita e antes da semeadura, favoreceu a germinação e o vigor das sementes de juçara. Os efeitos foram maiores para sementes armazenadas sem polpa do que com polpa. Temperaturas na faixa de 5 a 20-30ºC são igualmente adequadas para o armazenamento temporário de sementes sem polpa. No entanto, para sementes com polpa, a temperatura de armazenamento não deve exceder a 20ºC, visto que um decréscimo na germinação e no vigor e um acréscimo no número de botões germinativos apodrecidos e sementes mortas foram observados na temperatura de 20-30ºC.

Effects of microhabitat on palm seed predation in two forest fragments in southeast Brazil

The establishment of plants depends crucially on where seeds are deposited in the environment. Some authors suggest that in forest understory seed predation is lower than in gaps, and higher than at the forest edge. However, most studies have been carried out in large forest patches and very little is known about the effects of microhabitat conditions on seed predation in forest fragments. We evaluated the effects of three microhabitats (gaps, forest edge, and understory) on seed predation of two palm species (Euterpe edulis and Syagrus romanzoffiana) in two semi-deciduous forest fragments (230 and 2100 hat in southeast Brazil. Our objective was to test two hypotheses: (1) Low rodent abundance in small fragments as a result of meso-predator action levels leads to lower seed predation in small fragments. (2) Most mammal species in small fragments are generalists with respect to diet and habitat, so that seed predation is similar in different microhabitats (gaps, forest edge and understory) in the small fragment, but not in the larger one. The study community of small fragments is usually composed of generalist species (in diet and habitat aspects), so we expected the same rate of seed predation among microhabitats (gaps, forest edge and understory) in the tested smaller fragment. The experiment was carried out in the dry season (for E. edulis) and in the wet season (for S. romanzoffiana) in 1999. We conclude that post-dispersal seed predation in forest fragments can be directly connected with mammal communities, reflecting their historical and ecological aspects. (C) 2004 Elsevier SAS. All rights reserved.