STRUCTURAL VARIATION OF SEASONAL DECIDUOUS FOREST IN SANTA CATARINA STATE AND ITS RELATIONSHIP WITH ALTITUDE AND CLIMATE

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 \u2013 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, Chapec\uf3, Antas and Peperi-gua\ue7u 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 e 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.O objetivo deste trabalho foi identificar as poss\uedveis similaridades estruturais entre remanescentes da Floresta Estacional Decidual (FED) em Santa Catarina e associar os grupos \ue0 influ\ueancia de condicionantes ambientais. Associado a este objetivo prim\ue1rio, tamb\ue9m se buscou a identifica\ue7\ue3o das zonas de contato entre esta tipologia florestal e a Floresta Ombr\uf3fila Mista (FOM). Foram analisados os dados de 78 unidades amostrais (UA) instaladas em remanescentes da FED entre 2008 e 2009 pelo Invent\ue1rio Flor\uedstico Florestal de Santa Catarina (IFFSC). Os dados foram tratados atrav\ue9s da An\ue1lise de Correspond\ueancia Corrigida (DCA) e da An\ue1lise de Correspond\ueancia Can\uf4nica (ACC), valendo-se de uma matriz de densidade de esp\ue9cies e uma matriz de vari\ue1veis ambientais, esta constitu\uedda por altitude e par\ue2metros clim\ue1ticos. A propor\ue7\ue3o da vari\ue2ncia explicada pelos tr\ueas primeiros eixos da DCA foi baixa, somando aproximadamente 21% do total de informa\ue7\ue3o contida no conjunto original de dados. Este resultado ofereceu baixo poder de interpreta\ue7\ue3o para os resultados. No entanto, quando a DCA foi aplicada sobre os dados de densidade m\ue9dia das esp\ue9cies em cada bacia hidrogr\ue1fica, os resultados apontaram para autovetores muito explicativos do conjunto (58,1% da varia\ue7\ue3o). Observada somente a ordena\ue7\ue3o provocada pelo primeiro eixo da DCA, v\uease a disposi\ue7\ue3o das bacias de leste, em um extremo, e das bacias de oeste, no outro extremo deste eixo. Na extremidade direita do primeiro eixo est\ue3o dispostas as bacias do rio Canoas, Pelotas e do Peixe, as quais s\ue3o caracterizadas pela presen\ue7a de esp\ue9cies como Ocotea pulchella , Zanthoxylum fagara , Lithrea brasiliensis , Matayba elaeagnoides , Cinnamodendron dinisii , comumente associadas com a Floresta Ombr\uf3fila Mista. Na extremidade esquerda est\ue3o distribu\ueddas as bacias de oeste, grupo que inclui as bacias dos rios Jacutinga, Irani, Chapec\uf3, Antas e Peperi-Gua\ue7u. Dentre as esp\ue9cies que mais fortemente influenciaram os resultados na an\ue1lise, cabe destacar Apuleia leiocarpa , Rauvolfia sellowii , Bastardiopsis densiflora , Chrysophyllum gonocarpum , Cordia trichotoma , Holocalyx balansae , Myrocarpus frondosus e Pisonia zapallo, as quais s\ue3o frequentes em florestas estacionais do interior meridional do Brasil. A an\ue1lise atrav\ue9s da ACC apontou para resultados similares e a interpreta\ue7\ue3o conjunta dos dados ambientais indicou que as UA situadas nas bacias de leste est\ue3o associadas a climas mais frios, em que as geadas s\ue3o mais frequentes, como consequ\ueancia de altitudes mais elevadas. Considerando que as altitudes tendem a declinar das por\ue7\uf5es lestes para oeste e, diante do resultados apresentados, os autores prop\uf5em a exist\ueancia de uma zona de transi\ue7\ue3o entre as duas regi\uf5es fitoecol\uf3gicas (FOM e FED) na faixa dos 600 m s.n.m., onde ocorre a interdigita\ue7\ue3o de elementos da flora estacional e aqueles da Floresta Ombr\uf3fila Mista, resultando na delimita\ue7\ue3o de uma \ue1rea core da FED abaixo deste patamar altim\ue9trico

DENSE OMBROPHILOUS FOREST IN SANTA CATARINA - BRAZIL: CLUSTER ANALYSIS AND ORDENATION BASED ON SYSTEMATIC SAMPLING

This study aimed to characterize the remnants of Ombrophilous Dense Forest in Santa Catarina state. The dataset used in this study was provided by Project of Floristic and Forest Inventory of Santa Catarina, coming from 197 sample units that consist of basic clusters. The basic cluster was composed of four subunits of 20 x 50 m, in which all individuals with DBH 65 10 cm were measured. The forest structure was characterized through phytosociological parameters and indices. Based on structural data of the species, cluster analysis and ordination were performed in an attempt to identify groups of watersheds and altitude ranges. It was identified 577 species belonging to 226 genera and 83 families. The most representative families in number of species and individuals were Myrtaceae, Lauraceae and Fabaceae. Species of disturbed areas as Alchornea triplinervia , Caseria sylvestris and Miconia cinnamomifolia were dominant in the forest. Cluster analysis resulted in the identification of three vegetation types along the altitudinal gradient: Lowland Ombrophilous Dense Forest (< 30 m a.s.l.), Submontane (30 - 500 m) and Montane (> 500 m). Floristic and structural variations could be detected between the three vegetation types. In lowland communities, the presence of Anacardiaceae and Clusiaceae was more expressive and the average height of trees was higher. In montane environments, there was an increase in the number of individuals, basal area and diversity, as well as a greater representation of Cyatheaceae, Lauraceae and Rubiaceae. The occurrence of Arecaceae was remarkable in submontane forest. Spatial groups could not be defined based on structural data of watersheds.O presente trabalho teve por objetivo caracterizar os remanescentes da Floresta Ombr\uf3fila Densa, no estado de Santa Catarina. O conjunto de dados utilizado neste estudo foi disponibilizado pelo projeto Invent\ue1rio Flor\uedstico Florestal de Santa Catarina, sendo oriundo de 197 unidades amostrais do tipo conglomerado. Os conglomerados foram constitu\ueddos por quatro subunidades de 20 x 50 m, nas quais foram mensurados todos os indiv\uedduos arb\uf3reo-arbustivos com DAP 65 10 cm. A estrutura da floresta foi caracterizada com o emprego de par\ue2metros e \uedndices fitossociol\uf3gicos. Com base na densidade das esp\ue9cies, foram realizadas an\ue1lises de agrupamento e ordena\ue7\ue3o na tentativa de identificar grupos de bacias hidrogr\ue1ficas e faixas de altitude. Foram encontradas 577 esp\ue9cies, pertencentes a 226 g\ueaneros e 83 fam\uedlias. As fam\uedlias mais representativas em n\ufamero de esp\ue9cies e indiv\uedduos foram Myrtaceae, Lauraceae e Fabaceae. Esp\ue9cies de \ue1reas perturbadas como Alchornea triplinervia , Caseria sylvestris e Miconia cinnamomifolia est\ue3o dentre as que dominam a floresta. Por meio da an\ue1lise de agrupamento, foi poss\uedvel identificar tr\ueas forma\ue7\uf5es ao longo do gradiente altitudinal, aqui denominadas: Floresta Ombr\uf3fila Densa de Terras Baixas (< 30 m), Submontana (30 \u2013 500 m) e Montana (> 500 m). Varia\ue7\uf5es flor\uedsticas e estruturais puderam ser detectadas entre as tr\ueas forma\ue7\uf5es. Em comunidades das terras baixas, a presen\ue7a das fam\uedlias Anacardiaceae e Clusiaceae foi mais expressiva e a altura m\ue9dia das \ue1rvores foi superior. Nos ambientes montanos, observou-se um aumento no n\ufamero de indiv\uedduos, \ue1rea basal e diversidade, al\ue9m da maior representatividade das fam\uedlias Cyatheaceae, Lauraceae e Rubiaceae. A ocorr\ueancia de Arecaceae foi marcante nos patamares submontanos. Grupos espaciais n\ue3o puderam ser seguramente definidos a partir de dados estruturais de bacias hidrogr\ue1ficas

Improving collection efforts to avoid loss of biodiversity: lessons from comprehensive sampling of lycophytes and ferns in the subtropical Atlantic Forest

ABSTRACT Estimating species richness with herbarium data and new collections allows us to understand the distribution of diversity. We investigated the accuracy of lycophyte and fern sampling along a vegetation gradient in the subtropical Atlantic Forest in southern Brazil. We compiled lycophyte and fern collection metadata and estimated species richness and assessed sampling accuracy for sixty 50 x 50 km units using ACE, Chao 1, Chao 2, Jackknife 1 and Jackknife 2 estimators. We compiled data for 12,779 fern specimens of 441 species, 67 of which were sampled in only one unit (singletons) and 35 in two units (duplicates). Of the 60 units examined, only 11 had observed values that were above 70% of their estimated values, and 14 had observed levels between 65-70% of the estimated values, meaning that 35 units had a sampling accuracy of less than 65%. In spite of the long history of lycophyte and fern collecting in the study area, there remain units with a lower than expected sampling accuracy for a subtropical forest. This finding indicates that a sizeable collection effort is needed in order to discover the actual distribution of species before the effects of fragmentation and deforestation become permanent

Toward a better understanding of the subtropical Atlantic Forest in the state of Santa Catarina, Brazil: tree sampling accuracy, species richness and frequency of rare species

Accurate knowledge of floristic composition is crucial when planning and designing research projects and public policies. In this study, our goal was to assess tree sampling accuracy and to identify sites with higher concentrations of rare tree species, as well as those with the highest tree species richness, in the state of Santa Catarina, Brazil. We determined sampling accuracy using the first-order jackknife and Chao 2 estimators, calculated the number of rare species (singletons and doubletons) and applied sampled-based rarefaction. We found that sample accuracy (estimated vs. observed values) was over 90% for the state as a whole, the best estimates having been obtained for the areas of rain forest (first-order jackknife: 91%; Chao 2: 95%). Of the tree species identified, 16.6% were considered rare in the state and only 4% were found in all forest types. Among the various forest types, semideciduous forests showed the highest proportions of rare tree species. Tree species richness was highest in the rain forests and lowest in the dwarf cloud forests. Our results make an important contribution to the conservation of tree species within one of the "hottest" biodiversity hotspots in the world