-(Floristic and phytosociological study of an urban forest fragment -Bosque dos Alemães, Campinas, SP). The Alemães Wood is an urban-area of 2 ha of tropical semideciduous forest situated in Campinas, state of São Paulo, Brazil (22º53' S and 47º04' W, 685 m elevation). A census of the arboreal vegetation (PBH ≥ 15 cm) was carried out, in which 1937 individuals were recorded, being 1851 alive and 86 standing dead. One hundred and five species were identified, distributed in 43 families and 67 genera; 80 are native species and 25 introduced ones. The Shannon index was estimated as 3.45 nats.ind. -1 . The families with the highest richness were Leguminosae, Myrtaceae, Moraceae, Rutaceae, Euphorbiaceae, and Bignoniaceae. The species with the highest IVC were Cryptocarya aschersoniana Mez, Piptadenia gonoacantha (Mart.) Macbr., and Eucalyptus tereticornis Smith. The total IVC of the introduced species was 31.17. Of the native species, 17 presented only one individual and 44 less than six. This paper discusses the risk of structural and floristic changes with both the high IVC of introduced species and low density of the native ones. Based on these findings, some handling measures for the conservation of this remnant are proposed. RESUMO -(Estudo

The species abundance distribution of ecological communities has been represented through several mathematical models, of which the most common are: geometric series, logseries, lognormal, and a type of broken stick, this latter found only in animal communities. There is no consensus on the underlying biological processes, but initial observations on plant communities related these models to equilibrium and high richness (lognormal), stress or disturbance and low richness (logseries and geometric series). Recently the value of these relationships was challenged, and other descriptors were considered better predictors of richness, disturbance and stress. We aimed at investigating how these models and their parameters, as well as dominance and evenness are related with species richness, stress and disturbance in six tropical forest communities, SE Brazil: two well-conserved fragments, two disturbed by fire, and two swampy forests (anoxic stress). The models did not show consistent relationships with richness, disturbance or stress. The parameters and indices of diversity α (logseries) and λ (lognormal) varied closely with richness, and the dominance was larger in the communities submitted to stress or disturbance. Our results indicate the need of further studies in order to validate (or refute) the use of abundance distribution models for detection of patterns related to richness, stress or disturbance in tropical arboreal communities. On the other hand, richness and dominance did respond to disturbance and stress.

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-(Water defi cit affects wood vessels of Croton fl oribundus Spreng. in different vegetation types, São Paulo State, Brazil). In this paper we showed that water defi cit affects the wood vessels of Croton fl oribundus in fi ve areas with different vegetation types: Rain Forest, Semi-deciduous Forest and Woody Savanna. We concluded that variations in the vessels are due especially to water defi cit and the number of months with water defi cit. Larger diameter vessels occurred in areas with higher water defi cit, which may represent a strategy to optimize the water transport in favorable periods. Vessels with smaller diameters occur in areas with lower defi cit, which may be related to lower minimum temperatures and frost occurrence, which like drought can cause vessel embolism. In Caetetus Ecological Station, a Semi-deciduous Forest (area of highest water defi cit), we observed investments in effi ciency and safety, with the occurrence of larger diameter vessels associated with one of the lowest vulnerability indexes and highest proportions of multiple vessels of four or more elements. Key words: Ecological anatomy, mesomorphy, vulnerability, water availability RESUMO -(Défi cit hídrico interfere nos vasos do lenho de Croton fl oribundus Spreng. em diferentes tipos de vegetação, SP, Brasil). O défi cit hídrico infl uenciou na formação dos vasos da madeira de Croton fl oribundus ocorrentes em cinco áreas com as seguintes vegetações: Floresta Ombrófi la, Floresta Estacional Semidecidual e Cerradão. As variações dos vasos devem-se especialmente ao défi cit hídrico e número de meses com défi cit hídrico. Vasos de maior diâmetro ocorreram em áreas com maior défi cit hídrico, o que pode indicar uma estratégia para otimizar o transporte de água em épocas favoráveis. Vasos com menores diâmetros ocorreram em áreas com menor défi cit hídrico, possivelmente infl uenciados pelas menores temperaturas mínimas e a ocorrência de geadas, que semelhante a seca, causa a embolia dos vasos. Na Estação Ecológica de Caetetus, Floresta Estacional Semidecidual (área com maior défi cit de água) observaram-se investimentos em efi ciência e segurança, com a ocorrência de vasos de maior diâmetro associados a um dos menores índices de vulnerabilidade e maior proporção de vasos múltiplos de quatro ou mais elementos. Palavras-chave: Anatomia ecológica, disponibilidade hídrica, mesomorfi a, vulnerabilidade

; Léo ZIMBACK 2 RESUMO -A Estação Ecológica de Avaré é uma unidade de conservação com 720,4 ha localizada no município de Avaré, sudoeste do Estado de São Paulo. O presente trabalho apresenta os resultados dos estudos sobre o tema vegetação elaborados para o seu Plano de Manejo. Com base na análise de dados primários e secundários e de fotografias aéreas, a cobertura vegetal foi caracterizada e uma proposta de zoneamento foi elaborada. Dados primários e secundários totalizaram 265 espécies de plantas vasculares, cinco delas apresentado algum grau de ameaça de extinção: Anemopaegma arvense, Cedrela fissilis, Clitoria densiflora, Machaerium villosum e Rourea pseudospadicea. Foram identificadas cinco formações vegetais, sendo três pertencentes ao bioma Cerrado e duas pertencentes ao bioma Mata Atlântica compreendendo, respectivamente, 72,17% e 24,63% da área da Estação. Entre as fisionomias de Cerrado, destaque pode ser dado às savânicas e campestres, que juntas ocupam 49,91% da Estação, acentuando a sua significância devido à representatividade relativamente elevada do componente não arbóreo do Cerrado nessas fisionomias, o qual é tido como o mais rico em espécies vegetais no bioma. Três espécies invasoras foram amostradas, o pinus (Pinus sp.), o capim-gordura (Melinis minutiflora) e a braquiária (Urochloa brizantha), sendo esta última a que representa maior ameaça para a diversidade florística da Unidade. Na proposta de zoneamento preliminar, a Zona de Recuperação foi a mais expressiva, totalizando 84,81% da área total da Unidade, onde o manejo enfatiza o controle de gramíneas invasoras.Palavras-chave: Cerrado; Mata Atlântica; unidade de conservação; zoneamento.ABSTRACT -Avaré Ecological Station is a protected area with 720.4 ha located in the municipality of Avaré, southwestern São Paulo state. This study presents the results of the vegetation survey made for its Management Plan. Based on primary and secondary data and on aereal photographs analysis, the vegetation cover was characterized and a zoning proposal was elaborated. Primary and secondary data totaled 265 vascular plant species, of which five presented some degree of extinction risk: Anemopaegma arvense, Cedrela fissilis, Clitoria densiflora, Machaerium villosum and Rourea pseudospadicea. Five plant formations were identified, three belonging to the Brazilian Savanna biome and two belonging to the Atlantic Forest biome occupying, respectively, 72.17% e 24.63% of the Station area. Among the Savanna physiognomies, highlight can be given to the grassland type ones, which occupied 49.91% of the Station, reinforcing its significance due to relatively height representativeness of the non-arboreal component in these physiognomies, which is considered as the richest component in plant species in the biome. Three invading species were sampled, the pine (Pinus sp.) and the grasses Melinis minutiflora and Urochloa brizantha, being the last the uppermost threat for the floristic diversity of the area. In the preliminary zoning the Recuperation Zone was the most exp...