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Most of the morphological and developmental characteristics of different parts of a plant may vary in function of the species architecture, microenvironment and degree of ecological restriction where its has begun it growth. This study aimed to analyze the allometric relation between height and the largest horizontal crown axis and, for a community of tree seedlings and saplings up to 1 m in height in the Reserva Estadual do Morro Grande (23o35'S -23o50'S; 46o45'W47o15'W), situated in São Paulo's Atlantic Plateau, SE Brazil. We sampled 600 individuals in 34 1m 2 plots distant 2.5 m from each other along six transects, 100 individuals per transect. For each individual we measured their height and largest crown axis. We adjusted different regression models (linear, exponential, power, polynomial and logarithmic) to the data. The best fit was for the power model (r 2 = 0.640, p<0.001). The fact that juveniles from different species adjust to the same allometric model suggests that ecological factors could have an important restrictive role in the allometry of seedlings and saplings of tree species. Key words: allometry, seedling, height, crown, Atlantic forest ResumoMuitos caracteres morfológicos e de desenvolvimento de diferentes partes de uma planta variam dependendo da arquitetura da espécie, do microambiente, e do grau de restrição ecológica onde esta iniciou seu crescimento. Dentro deste contexto, este estudo teve como objetivo analisar a relação alométrica entre o maior eixo de copa e a altura, para a comunidade de plântulas e indivíduos jovens de espécies arbóreas com até 1 m de altura na Reserva Estadual do Morro Grande (23o35'S -23o50'S; 46o45'W -47o15'W), situada no Planalto Atlântico de São Paulo. Foram feitas seis transecções onde a cada 2,5 metros foi estabelecida uma parcela de 1x1m, totalizando 34 parcelas. Todos os indivíduos encontrados dentro das parcelas tiveram a altura e o maior eixo horizontal da copa medidos, sendo amostrados em cada transecção 100 indivíduos, totalizando uma amostra de 600 indivíduos. Foram ajustados diferentes modelos de regressão aos dados (linear, exponencial, potencial, polinomial e logarítmica) sendo que a potencial apresentou o melhor ajuste (r 2 = 0,640, p<0,001). O fato de jovens de diferentes espécies se ajustarem a um único modelo alométrico sugere que os fatores ecológicos podem ter um papel restritivo na alometria das plântulas e jovens de espécies arbóreas. Palavras-chave: alometria, plântula, copa, altura, floresta AtlânticaBiota Neotropica v3 (n2) -http://www.biotaneotropica.org.br/v3n2/pt/abstract?article+BN00503022003

-(Unusual branching in the palm Euterpe edulis Mart.). The unusual development of branches along the stem of Euterpe edulis is described for the first time. Branches originated at 2 to 190 cm from the ground. Ramified individuals and branches were able to produce reproductive structures and some branches produced roots. A plausible cause for the observed anomaly could be genetic problems due to small population sizes. The better agreement of this process can have a positive effect in the harvest of the heart of palm through the artificial induction of sprouts, what would prevent the death of the individual. Key words: Arecaceae, Atlantic Forest, palm heart RESUMO -(Ramificação incomum na palmeira Euterpe edulis Mart.). O desenvolvimento anormal de ramos ao longo do estipe de Euterpe edulis é descrito pela primeira vez. Os ramos se originaram a uma altura que variou de 2 a 190 cm do solo. Indivíduos ramificados e ramos foram capazes de produzir estruturas reprodutivas e alguns ramos produziram raízes. Uma possível causa para a anomalia observada seriam problemas genéticos decorrentes dos pequenos tamanhos populacionais. Um melhor entendimento desse processo pode ter um efeito positivo na extração do palmito dessa espécie através da indução artificial de brotos, evitando assim a morte do indivíduo.

Abstract:The main threats to natural populations in terrestrial ecosystems have been widly recognized to be the habitat fragmentation and the exploitation of forest products. In this study, we compared the density of the populations and the structure of three tropical palm species, Astrocaryum aculeatissimum, Euterpe edulis and Geonoma schottiana. For this, we selected five forest fragments of different sizes (3 500ha, 2 400ha, 57ha, 21ha and 19ha) where palms were censused in nine 30x30m plots. We tracked the palms survival from 2005 to 2007, and recorded all new individuals encountered. Each individual was assigned in one of the five ontogenetic stages: seedling, infant, juvenile, immature and reproductive. The demographic structure of each palm species was analyzed and compared by a generalized linear model (GLM). The analysis was performed per palm species. The forest fragment area and the year of observation were explanatory variables, and the proportion of individuals in each ontogenetic class and palm density were response variables. The total number of individuals (from seedlings to reproductives, of all species) monitored was 6 450 in 2005, 7 268 in 2006, and 8 664 in 2007. The densities of two palm species were not influenced by the size of the fragment, but the population density of A. aculeatissimum was dependent on the size of the fragment: there were more individuals in the bigger than in the smaller forest fragments. The population structure of A. aculeatissimum, E. edulis, and G. schottiana was not altered in the smaller fragments, except the infants of G. schottiana. The main point to be drawn from the results found in this study is that the responses of density and population structure seem not to be dependent on fragment size, except for one species that resulted more abundant in bigger fragments. Rev. Biol. Trop. 62 (2): 433-442. Epub 2014 June 01.

Habitat loss in highly deforested landscapes such as the Brazilian Atlantic Forest has been severely affecting the diversity and survival of palm species. As some species are more sensitive than others, trait responses to the environment, as well as environmental effects on fecundity, growth, and mortality rates, may affect species demography. Considering this context, we studied functional and demographic responses of three palm species (Astrocaryum aculeatissimum, Euterpe edulis, and Geonoma schottiana) to habitat loss in the Atlantic Forest in southeastern Brazil by measuring morpho-physiological traits related to plant growth and light acquisition for photosynthesis. We also tested the response of population fitness to fragment size. Plant survival and growth was subsequently monitored in 2006 and 2007, and population dynamics were summarized in pool matrices for large and small forest fragments in the monitoring periods comprehending one full year between 2005–2006 and 2006–2007. The asymptotic growth rate of populations (defined here as population fitness, λ) in five forest fragments was then calculated. Diameter of individuals of the demography plots (from year 2005 to 2007) was used to calculate the relative diameter growth rate. Later, in 2015, we measured a set of morpho-physiological functional traits in palms in the same plots used in the demographic studies. While A. aculeatissimum populations were stable in both monitoring periods in small and large fragments, E. edulis populations were predicted to decline due to intense predation by monkeys in the large fragment, but were stable in the smaller fragments, and G. schottiana populations were stable in the large fragments in both monitoring periods, but populations in the smaller fragments were predicted to decline in the second period, i.e., with lower fitness in these fragments. In addition, the functional traits analyzed showed that G. schottiana is a forest interior species associated with the shade/understory environment response. E. edulis was also affected by the size of the fragment, but due to a disruptive interaction with a predator and showed intermediate functional traits values. On the other hand, A. aculeatissimum thrived in areas with higher and lower incidence of light and was not demographically affected by forest remnant size. This suggests that E. edulis and A. aculeatissimum are habitat generalists. We concluded that differences in the ecophysiological performance of palms due to distinct morpho-physiological functional traits related to leaf economic spectrum, such as LDMC or specific leaf area (SLA) and to photosynthetic responses to light environment as electron transport rate (ETR) and saturation irradiance (Ik) were linked to the demographic variation observed in forest remnants of different size.

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