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--- trabalhos:abstracts [2021/05/27 00:15]
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+++ trabalhos:abstracts [2021/05/27 01:18]
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@@ Linha 187: / Linha 187: @@
 **Abstract:**Many studies have been proving the importance of positive interactions to the distribution and diversity of species in plant communities. Positive and negative interactions occur simultaneously and the net effect of a species on another is the product of these combined interactions. The objetive of the present study was to evaluate if nitrogen fixing legumes facilitate other tree species in a nitrogen poor environment. We studied the effect of the presence of legumes on the density of species and individuals belonging to two different layers (DBH > 1 cm and 1≤ DBH ≥ 10 cm) around them and also patterns of spatial association between the legumes and other tree species, using a null models approach. The results obtained were dependent on the legume species considered. In chapter 1, the legume Balizia pedicellaris (DC.) Barneby & J.W.Grimes presented higher species density around it, for both layers, although there was no effect on the density of individuals. The species Ormosia arborea Harms did not present effect on the density of species and individuals around it. For the first layer Andira anthelmia (Vell.) J. F. Macbr. did not show effect on the densities, but this species presented a negative effect on the density of species and individuals of the upper layer (1 ≤ DBH ≥ 10 cm), in opposition to our hypothesis. In chapter 2, the spatial association patterns were also distinct between the legume species that showed different species identity associated and different kinds of association (positive or negative). The results indicate that, in spite of belonging to the same functional group, the legumes influence the species around them differently, depending on their morphological and physiological characteristics, as the ability to fix nitrogen in some systems or even the ability to produce alellopathic compounds.
+=== LACERDA, Victória Duarte ===
+**Structure and vegetation composition of a herbaceous-shrub mussununga in southern Bahia, Brazil**
+**Abstract:** Mussununga is a vegetation type present in the Atlantic Forest, occurring on tablelands
+in the north of Espirito Santo and southern Bahia. This vegetation occurs on patches of
+white sandy soil embedded within forest areas and retains physiognomies similar to
+restinga vegetation. This work was performed in a herbaceous/shrub Mussununga area
+in southern Bahia, Brazil. Part of this area was subjected to a disturbance in the past due
+to the cultivation of //Cocos nucifera L.//, however the cultivation was abandoned. The aim
+of this study was to analyze the structure and composition of this plant community and
+evaluate the floristic relationships with other areas. The first chapter covers only the
+area with no evidence of recent disturbance. The structure and species composition of
+this area was described and a floristic analysis was performed to verify similarity
+patterns among 20 physiognomic similar areas occurring on white sand soils on the
+Atlantic Coast of Brazil. We found 76 species in 37 botanical families and the richest
+families were Fabaceae, Orchidaceae and Myrtaceae. The diversity was low
+(h'=2.53nats), however the area presented a large environmental heterogeneity.
+Floristic analysis showed a strong spatial correlation and low correlation with
+environmental variables. In chapter 2, a portion of the area without evidence of recent
+disturbance was compared to a portion of disturbed area based onrichness, diversity,
+composition and the distribution of functional groups. Richness and diversity were
+similar in both areas, however there was a remarkable difference in species
+composition. The most abundant species in both areas was //Renvoizea trinii// (Poaceae).
+The aggressive species //Pteridium arachnoideum// (Dennstaedtiaceae) increased
+considerably in the disturbed area. Functional groups showed significant differences in
+their mean coveragein each area.
+=== MORAES, Adriana de Olinda ===
+**Effect of anthropized matrices on the epiphyte community of understory in forest fragments of Southern Bahia, Brazil**
+**Abstract:** The landscape mosaic of the southern state of Bahia consists of forest fragments, pasture
+areas and shaded cacao (//Theobroma cacao L.//) plantations (cabruca). The cacao
+agroforestry matrix is considered efficient to the conservation of several species compared
+to the other agricultural systems, because it preserves large trees of the original forest.
+Therefore, we investigated the influence of the both matrixes on the community of vascular
+epiphytes and hemiepiphytes richness and abundance in Wildlife Refuge – Una Biological
+Reserve (Revis-REBIO), Una, Bahia, Brazil. Eight plots (10 x10 m) were installed at the
+edge (5-10 m) and eight plots in the interior (100 m) of four fragments with cabruca matrix
+and four fragments with pasture matrix. A total area of 12.800 m2 was sampled. All trees
+with circumference at breast height (CBH) ≥ 5 cm the circumference were measured and
+the number of epiphytes and hemiepiphytes was counted up to three meters tall. We
+sampled 10.557 trees and 4.057 were phorophytes that housed 57 species of epiphytes and
+of hemiepiphytes, distributed in 20 families. A total of 7984 individuals were sampled.
+The family with the highest number of species was Araceae (20 spp.) and the most
+abundant species was //Philodendron surinamense// (2.150 individuals). About matrix
+influence, the interior of fragments surrounded by a pasture matrix had the highest values
+of abundance and richness of epiphytes and hemiepiphytes. The abundance of epiphytes
+was significantly higher (p<0,001) in the fragments with pasture matrix. Hemiepiphytes
+were also more abundant within fragments with pasture matrix. The fragments inserted
+into the pasture matrix had significantly (p< 0,02) more species than the fragments
+immersed in the cabruca matrix. For hemiepiphytes, the plots of the interior of the
+fragments had significantly (p= 0,0007) more species than the edge plots. The edge of
+fragments inserted in pasture matrix had a higher average number of trees than the interior
+and in plots inserted in the interior of fragments with cabruca matrix, there were a higher
+average number of trees than the edge. The largest circumferences and the largest number
+of phorophytes were in fragments with pasture matrix. Overall, in cabruca matrix
+fragments, the epiphytes and hemiepiphytes occurred on the phorophytes with the larger
+perimeter and on interior of pasture matrix fragments, the epiphytes occupied the trees
+with larger perimeter and hemiepiphytes occupied both the edge and interior, trees with the
+larger CBH The sampling units were not grouped within the same condition. Anetium
+citrifolium was an indicator species of the interior of fragments in the pastures matrix.
 === PANNUTI, Márcia Ione da Rocha ===

Laboratório de Ecologia de Florestas Tropicais

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