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--- trabalhos:abstracts [2021/12/07 22:32]
jennifervasconcelosjdsv2
+++ trabalhos:abstracts [2021/12/08 00:32]
jennifervasconcelosjdsv2
@@ Linha 286: / Linha 286: @@
 **Abstract:** Niche and dispersal limitation are important coexistence mechanisms that can spatially structure tree communities. We aimed to verify the influence of environmental heterogeneity in the relative importance of those processes. We used data from ForestGEO plots with different environmental heterogeneity (Colombia-CO < Brazil-BR < Ecuador-EQ). We selected the most plausible of four concurrent spatial models: Randomness (CSR), Niche (NH), Dispersal Limitation (DL), and both (NH+DL). BR e EQ didn't diverge in the probability of model selection, having 85,6% and 83% of niche models selected (NH and NH+DL), while in CO only 57,5% were observed. The proportion of no model selected was four times higher in CO than in BR and EQ. We attribute these differences to CO's lesser environmental heterogeneity and conclude that it influences the relative importance of processes. Plots with a higher proportion of coexistence mechanisms are also significantly more diverse (BR and EQ > CO).
+=== PEREIRA, Thiago ===
+**Effects of light quality on seed germination of Myrtaceae species from restinga of Cardoso Island**
+**Abstract:** The Myrtaceae family is one of the most ecologically important families, mainly in the Atlantic forest, being the dominant family in diverse tropical forests. Specifically in 3restinga" (coastal sandy plains) areas, Myrtaceae is noted for high species richness, being among the trees, often the most diverse. However there are few studies about the ecology and physiology of this family. Knowledge about the conditions for seed germination, in the case of Myrtaceae species, may increase the success in producing of seedlings in nurseries for use in forest restoration The analysis of light requirements for germination of the Myrtaceae species provides data that can be useful both in evolutionary studies about the family Myrtaceae, as to indicate the correct phase of succession to use of these species of Myrtaceae occurring in the Ilha do Cardoso in restoration projects in tropical areas. The germination of seeds of three species, //Eugenia umbelliflora//, //Myrcia multiflora// and //Blepharocalyx salicifolius//, were analyzed in a white light treatment and in the control (dark). An analysis of seed germination under distinct Red/Far red ratios was also performed for the species //Eugenia umbelliflora//. The seeds of the three species germinated in the presence of light and in the dark, indicating that the seeds have great environmental plasticity about light and can occupy different habitats. //E. umbelliflora// and //B. salicifolius// probably have their germination controlled by phytochrome A (phyA), using a Very Low Fluence Response (VLFR). The species //M. multiflora// show a higher germination rate under white light, which could indicates positive photoblastic seeds, but this classification requires complementary studies. Tests at different levels of R / FR for //E. umbelliflora// reinforce that this species has wide environmental plasticity, with the ability to germinate both in treefall gaps and under the canopy.
+=== PEREIRA, Nathália Helena Azevedo ===
+**Spatial distribution of terrestrial tank bromeliads in restinga: causes and consequences**
+**Abstract:** The plants’ spatial distribution pattern is the result of biotic and abiotic factors, from space
+competition to nutrients, light and water availability. To analyze the factors that vary spatially, light incidence and edaphic characteristics for example, is key to comprehend the influence they could have over the space distribution of the vegetation species in natural environments. This study aimed to analyze the possible factors that determine the distribution of terrestrial bromeliads, a group of plants that is very abundant in restinga, dominating the herbaceous layer on large tracts. On the other hand, the presence of bromeliads in the herbaceous layer can hinder the establishment of arboreal species and affect the vegetation structure. Thus, the consequences of the presence of bromeliads over the vegetation structure were also analyzed in this study. The study was conducted in a patch of restinga forest, at the “Parque Estadual da Ilha do Cardoso”, south coast of São Paulo state. Were sampled 5,76 ha, in 144 contiguous shares of 20 x 20m, in wich was registered the total number of rosettes of terrestrial bromeliads, as well as the percentage of coverage of the ground of each species. Were found seven terrestrial bromeliads species: //Bromelia antiacantha//, //Canistrum cyanthiforme//, //Nidularium innocentii//, //Nidularium procerum//, //Quesnelia arvensis//, //Vriesea carinata// e //Vriesea ensiformis//, and about 50% dos 5,76ha of the forest of restinga sampled were covered by bromeliads. The species that presented the greatest number of rosetas and the biggest coverage area were //N. procerum//, //N. innocentii// e //C. cyanthiforme//. The results indicate that the terrestrial bromeliads distribution is positively related with the canopy opening and that the growing of the porcentage of thick sand between 5 and 20m underground is related to the decrease of the number of bromeliads per share. The variety of individual arboreal adults decreased with the rising of the number of rosetas on a share. It wasn't noticed any relationship between the presence of bromeliads and the abundance of adult arboreal species on the shares, what suggests that the bromeliad don't interfere the structure of the forests dossel and seems to be using other space than the ocuppied by the arboreal species.

Laboratório de Ecologia de Florestas Tropicais

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