Alexandre Uhlmann

Inventário florístico florestal de Santa Catarina: espécies da Floresta Ombrófila Mista

Resumo estudo e resultado da amostragem sistematica da flora da floresta ombrofila mista em Santa Catarina, realizada em 155 pontos amostrais em toda a sua extensao e permite atualizar o conhecimento sobre a ocorrencia de especies. Foram registradas 925 especies de espermatofitas, distribuidas em 439 generos e 116 familias botânicas. A familia com a maior riqueza especifica foi Asteraceae (119 especies), seguida por Myrtaceae (88), Fabaceae (58) e Solanaceae (52). Dentre as familias restantes, 34 apresentaram somente uma e outras 27 tiveram duas especies registradas. Os generos com maior numero de especies foram Solanum (31 especies), Baccharis (27), Eugenia (23), Ocotea (21) e Myrcia (19). Araucaria angustifolia (Bertol.) Kuntze, Butia eriospatha (Mart. ex Drude) Becc., Ocotea odorifera (Vell.) Rohwer e O. porosa (Nees & Mart.) Barroso sao as especies ameacadas de extincao registradas. Entre todas as especies do componente arboreo ou arbustivo/subarboreo, 56,5% sao comuns a ambos os componentes e dentre as 194 especies arboreas citadas para o planalto catarinense, 157 foram amostradas pelo IFFSC. O levantamento floristico extra registrou 474 especies de angiospermas a mais do que o levantamento nas unidades amostrais do IFFSC. O IFFSC amostrou um conjunto significativo das especies do Dominio Floresta Atlântica. Estas coletas georreferenciadas e realizadas com uma amostragem sistematica e consistente, representam um importante avanco e atualizacao do conhecimento da flora de Santa Catarina. Inventarios sistematicos desta natureza sao necessarios as demais regioes no Sul do Brasil, para que se possa compor um banco de dados consistente e atualizado e possibilitar a implantacao de politicas de conservacao e manejo. Palavras-chave: coleta botânica, diversidade, Floresta de Araucaria, lista de especies, Mata Atlântica.

Ordenação dos dados de estrutura da Floresta Ombrófila Mista partindo de informações do inventário florístico-florestal de Santa Catarina: resultados de estudo-piloto.

The forest floristic inventory of Santa Catarina State in Southern Brazil aims at quantifying the forest resources and increasing the knowledge on vascular plant diversity. The study includes sampling of trees, shrubs, herbs and vascular epiphytes. Santa Catarina State’s surface is about 95,443 km², covered by four major vegetation types: Dense Tropical Humid Forests, Mixed Rainy Forests with Araucaria angustifolia , highland grasslands and Seasonal Deciduous Forests. Forest land cover is about 30%, although extremely fragmentized, especially in the western region. This pilot study has been conducted in Mixed Rainy Forest domain during 2005, measuring 74 sample plots (2000 m² each) randomly distributed in this forest type’s area (41,380 km²). Besides the usual analysis of vertical and horizontal vegetation structure, species density data were utilized to construct species/samples matrix that was the basis for Detrended Correspondence Analysis (DCA). The survey results indicate that Myrtaceae, Fabaceae, Lauraceae are the most numerous families, followed by Asteraceae and Solanaceae. The survey registered 133 species with DBH ≥ 10cm, 101 species with DBH <10cm ≥1cm and 105 species with DBH smaller than 1 cm. There is a restricted number of very frequent tree species and a large number (120) of species occurring in less than 10 of the total of 74 sample plots; 46 species are present in only one plot, showing vulnerability of species diversity. According to results of Correspondence Analysis, there are two well distinguished clusters of plots, one of them dominated by typical mixed forest species; the other cluster clearly dominated by supposed to be typical seasonal deciduous forest representants , although located in geographical region until now attributed to mixed forests. The two groups are very dissimilar with respect to their structure and floristics. These results indicate the necessity of new surveys in order to verify the existence of a floristic differentiation along this preliminary established border line. The next steps of Floristic-Forest Inventory could give way to support this hypothesis.

How mycorrhizal associations and plant density influence intra- and inter-specific competition in two tropical tree species: Cabralea canjerana (Vell.) Mart. and Lafoensia pacari A.St.-Hil.

Arbuscular mycorrhizal fungi (AMF) associations benefit host plants due to increased ability to obtain resources and hence may influence competitive interactions. Here we experimentally examine growth in Cabralea canjerana and Lafoensia pacari at different densities and with and without AMF. In the density treatment pots had either six or 12 individuals. Half of each treatment was innoculated with AMF and the other half was not. The proportion of each species in each pot was also varied. The AMF did not apparently influence interspecific competitive interactions because growth was similar in both treatments. However, intra-specific competition was very strong in C. canjerana while more moderate in L. pacari and both were influenced by the presence of the AMF. The AMF—Cabralea canjerana interaction was parasitic, while AMF—L. pacari interactions were mutualistic. Thus, dependence upon AMF and intraspecific interactions that result as a consequence of that dependence varies among species and may be an important influence in community structure.

Inventário de Dicksonia sellowiana Hook. em Santa Catarina

The intense exploitation of Dicksonia sellowiana has led this species to become endangered and to be included on the red list of threatened species. Therefore, this paper presents a study of D. sellowiana populations in Santa Catarina State, and points out the places where it occurs the most, the status of these populations and also evaluates the relationship between density, climatic variables and elevation. Two hundred and twenty-five sample plots, which were 4.000 m2 each, were located within the study area and based on a 10 x 10 km grid according to procedures of the Forest and Floristic Inventory of Santa Catarina. Dicksonia sellowiana was found in 94 of these plots, where it ranged from 1 to 391 individuals. The density of the species at higher elevations (above 1.000 m) seemed to be related to climatic data that directly influences the populations, as pointed out by the corrected Akaike Information Criterion (AICc). This study also found that the species populations exhibit high densities in the lower height and diameter ranges, reaching values up to 977 individuals/ha in some stands. The information obtained during this study makes it possible to suggest conservation measures for this species, such as areas to be conserved in a way that supports small farms.

Floristic and Forest Inventory of Santa Catarina: species of evergreen rainforest

O presente trabalho objetivou apresentar a lista de especies da floresta pluvial subtropical (Floresta Ombrofila Densa) em Santa Catarina, com base em 202 unidades amostrais implantadas pelo Inventario Floristico Florestal de Santa Catarina para estudo do componente arboreo-arbustivo e da regeneracao, alem de coletas floristicas externas as unidades amostrais. Foram registradas 1.473especies, 19,0% das especies citadas para esta tipologia florestal no Brasil, dentre estas tres gimnospermas e 1.470 angiospermas. As familias mais ricas em especies foram: Orchidaceae (143 especies), Myrtaceae (142), Asteraceae (98), Melastomataceae (86), Fabaceae (78), Rubiaceae (65), Solanaceae (61), Bromeliaceae (57), Piperaceae (56) e Lauraceae (52). Entre as especies registradas, oito constam na Lista Oficial das Especies da Flora Brasileira Ameacadas de Extincao: Aechmea blumenavii, Araucaria angustifolia, Billbergia alfonsijoannis, Euterpe edulis, Heliconia farinosa, Ocotea catharinensis, O. odorifera e O. porosa.

Fungos micorrízicos arbusculares na recuperação de florestas ciliares e fixação de carbono no solo

A associacao micorrizica arbuscular estabelecida entre os fungos micorrizicos arbusculares (FMAs - Filo Glomeromycota) e as raizes das plantas tem papel fundamental na sobrevivencia e nutricao das plantas. Nesta revisao, e salientado que a triade floresta ciliar-fixacao de carbono-fungos micorrizicos arbusculares deve ser considerada uma estrategia ambientalmente correta para recuperar areas outrora ocupadas por florestas ciliares. Sao apresentadas brevemente as classes de solos que ocorrem em ambientes riparios e a entrada de carbono (C) nos ecossistemas terrestres. Posteriormente, e enfatizado que os fungos micorrizicos arbusculares possuem papel importante no processo de fixacao de carbono no solo, visto seus efeitos na absorcao de nutrientes pelas plantas e aumento na producao de biomassa vegetal em especies arboreas, principalmente especies pioneiras e secundarias iniciais, utilizadas na recuperacao de florestas ciliares. Outrossim, as hifas externas desses fungos impactam a estrutura do solo tanto fisicamente, pela acao fisica das hifas, como bioquimicamente, pela producao de uma glicoproteina. As estruturas diferenciadas pelos fungos, como esporos e hifas, tambem servem como via de entrada de C no solo, por meio de componentes celulares ricos em C. A recuperacao de florestas ciliares pelo plantio de especies arboreas resulta na emergencia de um novo servico ambiental: a fixacao de C, a qual pode ser incrementada quando no processo de recuperacao seja considerada a inoculacao com fungos micorrizicos arbusculares.

FITOSSOCIOLOGIA DE FRAGMENTOS DE FLORESTA ESTACIONAL DECIDUAL NO ESTADO DE SANTA CATARINA – BRASIL

O estudo objetivou avaliar a fitossociologia da Floresta Estacional Decidual no Estado de Santa Catarina, em seus componentes arboreo/arbustivo e regeneracao natural, bem como comparar estes quanto a composicao floristica e inferir sobre o estadio de conservacao dos remanescentes. Foram usados dados de 78 unidades amostrais levantadas no Inventario Floristico Florestal do Estado de Santa Catarina. Em cada unidade amostral foram amostrados os componentes arboreo/arbustivo (DAP ≥ 10 cm) em 4000 m2 e a regeneracao natural (altura ≥ 1,50 m; DAP < 10 cm) em 100 m2. Foi efetuado o calculo dos parâmetros fitossociologicos e indices de diversidade de Shannon e equabilidade, bem como, classificaram-se as especies quanto ao grupo ecologico. Para verificar a associacao entre os dois componentes executou-se uma analise de ordenacao NMSD (Non-metric Multidimensional Scaling) seguida do Teste de Mantel. Foram amostradas 245 especies, sendo 215 no componente arboreo/arbustivo e 79 exclusivas deste, 165 na regeneracao natural e 30 exclusivas deste e, 136 comuns aos dois componentes. A NMDS apresentou uma tendencia de associacao entre as matrizes dos dois componentes, o que foi confirmado pelo Teste de Mantel (r = 0,34; p = 0,001). A composicao floristica, bem como as especies com maiores valores de importância se constituiram predominantemente de especies secundarias, fato que evidencia o historico de exploracao e degradacao da Floresta Estacional Decidual no Estado.

Influência da posição na encosta na manifestação do caráter coeso em solos da formação Macacu, no estado do Rio de Janeiro

The cohesive nature of horizons of certain soils interferes directly with plant growth, by reducing the effective soil depth, plant root volume and seedling emergence, due to the decreased availability of water and air in the soil. This paper aimed to use soil physical characteristics to describe the cohesive character and the influence of the soil landscape position on two slopesof soils developed from sediments of the Macacu Formation in Itaborai, RJ, Brazil. The soils of both slopes were classified as Argissolo Amarelo distrocoeso tipico (Ultisol) in the upper position and as Latossolo Amarelo distrocoeso tipico (Oxisol) at the foot slope. The soil bulk density of the cohesive subsurface horizons reached 1.78 Mg m-3. Another evidence of the trendto show cohesive character was the great difference between soil physical propertiesofthe A horizon and the subsurface layers (BA and BW). In the soils at the foot slope position the moisture content, hydraulic conductivity, and available water content were higher. The expression of the cohesive character was stronger at the upper position of the landscape. The physical properties that best distinguished the soil samples in terms of landscape positions were bulk density and macroporosity for soils at the summits, and available water and total porosity for the foot slope. The soils at the bottom of the slope had higher water contents, which must have minimized the expression of the cohesive character. This study indicates the importance of developing more studies on different aspects of the degree of cohesion existing along a landscape, controlled primarily by water flows down the slope.

Alocação de recursos (carboidratos) no desenvolvimento inicial de plântulas de Schizolobium parahyba (Vell.) S.F. Blake (Fabaceae - Caesalpinioideae)

Utilizou-se Schizolobium parahyba, objetivando analisar a alocacao dos teores de acucares soluveis totais e de reserva (amido) e biomassas no desenvolvimento das plântulas. Apos a quebra de dormencia, 200 sementes foram semeadas em substrato composto por casca de arroz carbonizada e areia. Em cada coleta foram utilizadas 10 amostras para dosagem de acucares soluveis totais e amido e 10 para mensuracao das massas frescas e secas (MS e MF) no 7o, 14o, 21o, 28o, 35o e 42o dia apos a germinacao (DAG). As sementes apresentaram 94,5% de germinacao. Os acucares soluveis totais estao em maiores quantidades nas raizes, hipocotilo e epicotilos. Os cotiledones apresentaram maiores teores de amido, ja que este e um orgao de reserva. O aumento da MF e diretamente proporcional ao incremento de acucares soluveis e amido nas estruturas analisadas. As relacoes de biomassa e teores de acucares soluveis totais e amido encontrados ressaltaram a mobilizacao dos compostos de reserva dos cotiledones nas outras partes da planta, a medida que a reducao da biomassa e de acucares dos cotiledones reflete o aumento na producao de biomassa de epicotilos, hipocotilos e raizes da plântula.

VARIAÇÃO DA ESTRUTURA DA FLORESTA ESTACIONAL DECIDUAL NO ESTADO DE SANTA CATARINA E SUA RELAÇÃO COM A ALTITUDE E CLIMA

This study aims to identify structural similarities between the remnants of seasonal deciduous forest (SDF) in Santa Catarina state and check the influence of environmental factors that leads the formation of these groups. Associated with this primary objective, it was also sought to identify the areas of contact between this forest type and Araucaria forest (mixed ombrophilous forest - MOF). We analyzed data from 78 sample units (AU) installed in the remnants of SDF between 2008 and 2009 by professional team of Floristic and Forest Inventory of Santa Catarina project (IFFSC). The data were processed through the Detrended Correspondence Analysis (DCA) and Canonical Correspondence Analysis (CCA), using a matrix of species density associated with a environmental variables matrix, that consisted of altitude and climate parameters. The proportion of variance explained by the first three axes of DCA was low, accounting for approximately 21% of the information contained in the original data set. This result provides low power of interpretation of the results. However, when DCA was applied to the data of mean density of species in each river basin, the results pointed to better explanatory eigenvectors (three first eigenvectors explain 58.1% of total variance). The first ordination axis of DCA grouped the eastern watersheds SUs at one end, and the western watersheds SUs at the other end of this axis. At the right end of the first axis are arranged the watersheds of the river Canoas, Pelotas and Peixe, which are characterized by the presence of species such as Ocotea pulchella, Zanthoxylum fagara, Lithrea brasiliensis, Matayba elaeagnoides, Cinnamodendron dinisii commonly associated with Mixed Ombrophilous Forest (Araucaria forest). At the left end, the grouped SUs are mainly those of western watersheds, a group that includes the basins of the Jacutinga, Irani, Chapeco, Antas and Peperi-guacu rivers. Among the species that most strongly influence the results in the analysis, we highlight Apuleia leiocarpa, Rauvolfia sellowii, Bastardiopsis densiflora, Chrysophyllum gonocarpum, Cordia trichotoma, Holocalyx balansae, Myrocarpus frondosus and Pisonia zapallo, which are common in seasonal forests of the hinterlands of southern Brazil. The analysis through the ACC pointed to similar results and joint interpretation of environmental data indicated that the basins located in the east are associated with colder climates where frosts are more frequent as a result of higher altitudes. As the altitudes tend to decline from east to west and portions, the authors propose the existence of a transition zone between the two phytoecological regions (MOF and SDF) in the range of 600 m asl, where occurs the interdigitation of elements from seasonal flora and those of Araucaria forest, resulting in the delineation of a core area of ​​the SDF below this altitudinal level.