Atlantic Forest meeting Cerrado: floristic, structure, and species distribution of an ecotonal tree community

We evaluated the floristic and structural composition of a tree community in an ecotone between Cerrado (cerradão) and Atlantic Forest (seasonal semideciduous forest) domains located in Porto Ferreira State Park (PFSP), southeastern Brazil. We compared the floristic relationships of this ecotone with those of previous surveys carried out on the same vegetation types and checked the species distribution among the Brazilian biomes. We sampled all living trees with PBH>10 cm in 64 10x10 m plots (0.64 ha), totaling 1,755 individuals belonging to 101 species and 37 families. The richest families were Myrtaceae (13 spp.) and Fabaceae (11 spp.), and Siparuna guianensis was the most abundant species (188 individuals). We reported two threatened species. A great number of species are widely distributed, occurring in different Brazilian biomes. Floristic similarity values were low among the selected studies, but our sampled community clustered with communities of cerradão and ecotone areas of previous surveys. Our results corroborate that ecotonal areas have great tree diversity and the predominance of widely distributed species. This fact, combined with the vegetation thickening verified through historical photographs, reinforces that the study area belongs to an under-changing ecotone.

Passifloraceae s.s. na Chapada do Araripe, nordeste do Brasil

A Chapada do Araripe, localizada entre os estados do Ceará, Pernambuco e Piauí, abrange diferentes fitofisionomias e é reconhecida pela alta diversidade biológica e endemismos. O objetivo com este levantamento florístico foi identificar as espécies de Passifloraceae s.s. ocorrentes na Chapada do Araripe, bem como conhecer a distribuição geográfica associada aos habitats preferenciais e a fenologia, visando conhecer a flora local. Foram realizadas coletas em campo no período de fevereiro a junho/2020 em vários municípios e a coleção resultante foi depositada no Herbário Caririense Dárdano de Andrade-Lima- HCDAL. As identificações das espécies foram baseadas na análise de características morfológicas das amostras em campo, de exsicatas dos herbários CEN, EAC, HCDAL, HST, IPA, MBM, PEUFR e UFP, complementadas com o auxílio de bibliografias especializadas. Na Chapada do Araripe foram registrados nove táxons de Passiflora, ocorrendo preferencialmente em Floresta Estacional Semidecidual (Mata Seca), mas também há registros na Floresta Ombrófila Densa (Mata Úmida), Savana (Cerrado), Savana Florestada (Cerradão), Savana Estépica (Caatinga/Carrasco), Savana Estépica Arborizada (Caatinga Arbórea). Passifloraceae s.s. está bem representada na Chapada do Araripe e são indicadas coletas inéditas para alguns munícipios. Passifloraceae s.s. in the Chapada do Araripe, Northeast Brazil A B S T R A C TThe Chapada do Araripe is located between the states Ceará, Pernambuco and Piauí, covers different phytophysiognomies and recognized by high biological diversity and endemisms. The aimed with this floristic survey was to identify species of the Passifloraceae s.s. to the Chapada do Araripe, as well as know geographic distribution associated with preferred habitats and phenology, aiming to know better local flora. Field collections were performed from February to June/2020 in several municipalities and the resulting collection is deposited at the Herbário Caririense Dárdano de Andrade Lima-HCDAL. The identifications of the species was based on the analysis of morphological characteristics of samples collected in the field and exsiccates from herbariums CEN, EAC, HCDAL, HST, IPA, MBM, PEUFR and UFP, complementered with assistance of specialized bibliographies. In the Chapada do Araripe nine taxa of Passifora were recorded, preferably occurring in the Dense Ombrophylous Forest (Mata Úmida), but also there are records in the Seasonal Semideciduous Forest (Mata Seca), Savanna (Cerrado), Florested Savanna (Cerradão), Stepic Savanna (Caatinga/Carrasco), Arboreus Stepic Savanna (Caatinga Arbórea) and transition zone of Savanna/ Seasonal Semideciduous Forest. Passifloraceae s.s. is well represented in the Chapada do Araripe, are indicated unpublished collections for some municipalities, in addiction is necessary greater effort to collect in Piaui State.Keywords: Diversity, flora, Neotropical region, vegetation.

SOIL FAUNA AND LEAF LITTER DECOMPOSITION IN DIFFERENT SUCCESSIONAL STAGES OF A SUBMOUNTAINOUS SEASONAL SEMIDECIDUOUS FOREST

In tropical forests, the stage of ecological succession influences the nutrient cycling. This study aimed to analyze soil fauna community structure, composition, and leaf litter decomposition in fragments of intermediate-successional and late-successional Submountainous Seasonal Semideciduous Forest (ISF and LSF, respectively). We used a square metal frame to collect 10 samples of the leaf litter layer and surface soil (0.00-0.05 m depth) from each area in the wet and dry seasons. Soil fauna individuals were then extracted using a modified Berlese-Tüllgren funnel. For analysis of leaf litter decomposition, 15 litter bags containing 30 g of senescent leaves were randomly placed on the forest floor of each area in the dry season, and three bags were collected after 60, 90, 120, 150, and 180 days. LSF presented higher value of richness and was more associated with Diptera and Formicidae. There was no clear pattern in evenness and diversity with successional stage. The dissimilarity between ISF and LSF in terms of soil fauna community was greater in the dry season. Litter decomposition was almost identical in both areas.

Fitossociologia em fragmento de floresta estacional semidecidual em reserva legal no sudoeste do estado de Goiás

In Goiás, seasonal forests structure studies are scarce, especially in fragments located in legal reserves, subject to human disturbances. Therefore, the study aimed to perform the phytosociology of a fragment of a rural property, in a seasonal semideciduous forest. We evaluated structure, richness, diversity, dispersion mechanisms, ecological groups, and species distribution patterns found in the study and floristic links between Cerrado, Amazon and Atlantic Forest. In a one-hectare sample plot, all live trees with a diameter at breast height ≥ 10 cm were measured. The values of density and basal area were 561 ind.ha-1 and 26.2 m².ha-1, respectively. We recorded 37 species with diversity indices (H’) of 2.36 and evenness (J’) of 0.65. Toulicia reticulata, Chaetocarpus echinocarpus, Bocageopsis mattogrossensis and Nectandra cuspidata were species with the highest importance value, corresponding to 69% and 65% of all density and basal area, respectively. Fabaceae obtained the highest floristic richness, with six species, although it was little represented in terms of abundance. Our results suggest that the fragment is a mature forest in good conservation status. This is reinforced by the high size of trees, in addition to the predominance of zoochoric (83.8%) and secondary (92.1%) individuals in the survey.

Preservação de fitólitos em solo no Parque Nacional do Iguaçu, Paraná

O acompanhamento da evolução da vegetação é importante para compreensão das possíveis modificações naturais na composição das formações florestais. O presente trabalho tem por objetivo abarcar a conservação da assembleia fitolítica em solos do Parque Nacional do Iguaçu/Paraná (PNI). Os fitólitos são micropartículas silicosas produzidas por gramíneas e algumas famílias arbóreas, que no final do ciclo de vida da planta são incorporados aos solos. Os procedimentos metodológicos pautaram-se em atividades de campo e de laboratório. Foram coletados 12 perfis de solo (trincheira 1, tubo de alumínio 1 e 10 tradagens). Os resultados tornaram possível a identificação e compreensão da distribuição fitolítica no PNI. Na discussão é abordada a correspondência das morfologias e comparação dos resultados obtidos, bem como a relação com a literatura. Identificou-se que as amostras que apresentaram os maiores valores no quantitativo fitolítico foram P1, T1, P4, P9, Fazenda Salinet, RPS, P8, P2, P5, P6, P3 e P7 respectivamente. Determinou-se que até as profundidades estudadas a vegetação arbórea e rasteira sempre coabitaram com prevalência do estrato arbóreo. No entanto, ressalta-se que ocorreram variações da vegetação com momentos de floresta mais e menos densa, e, com maior e menor sinais de umidade; tendo cada ponto amostrados peculiaridades. Concluiu-se que ocorreram diferenças tanto na Floresta Ombrófila Mista quanto na Floresta Estacional Semidecidual, bem como nos diferentes solos amostrados. Preservation of phytoliths on soil in the Iguaçu National Park, Paraná A B S T R A C T The monitoring evolution of vegetation is important to understand possible natural changes in the composition of forest formations. This work aims to cover the conservation of the phytolytic assembly in soils of the Iguaçu/Paraná National Park (PNI). Phytoliths are siliceous microparticles produced by grasses and some tree families, which at the end of the plant's life cycle are incorporated into the soil. The methodological procedures were based on field and laboratory activities. Twelve soil profiles were collected (trench 1, aluminum tube 1 and 10 edgings). The results made it possible to identify and understand the phytolytic distribution in the PNI. In the discussion, the correspondence of the morphologies and comparison of the results obtained is addressed, as well as the relationship with the literature. It was identified that the samples that presented the highest values in the phytolytic quantity were P1, T1, P4, P9, Fazenda Salinet, RPS, P8, P2, P5, P6, P3 and P7 respectively. It was determined that even the depths studied, tree and undergrowth vegetation always cohabited with prevalence of tree strata. However, it is noteworthy that vegetation variations occurred with moments of more and less dense forest, and with greater and lesser signs of humidity; having each point sampled peculiarities. It was concluded that differences occurred both in the Mixed Ombrophilous Forest and in the Seasonal Semideciduous Forest, as well as in the different sampled soils.Keywords: Conservation Unit, Proxy, Vegetation.

Synopsis of Rubiaceae from the Iguaçu National Park, Paraná, Brazil

Iguaçu National Park represents the largest fragment of Inland Atlantic Rainforest of Paraná state. The vegetation is predominantly seasonal semideciduous forest, in the areas of Foz do Iguaçu and Capanema and a transition of this with Araucaria forest, in the Céu Azul area. This work aimed to recognize the genera and species of Rubiaceae occurring in the Park, through monthly collections from August 2013 to July 2014, supplemented with sporadic collections from May 2018 to April 2019. Thirty-five species were recorded, belonging to 19 genera. The most representative genera were Palicourea and Psychotria with five species, Galianthe, Manettia, Borreria with three, Geophila and Coccocypselum with two, and the other genera with only one species each. The areas with the major species richness were Foz do Iguaçu, with 24, of which four are exclusive to this area, followed by Céu Azul with 22 species, of which eight are exclusive. Of the 35 species recorded, seven occur in all areas and in both forest formations, seven occur only in the Araucaria forest area, and 20 occur only in the seasonal semideciduous forest. Borreria orientalis is highlighted due to its restricted distribution in Brazil, occurring only in Paraná, and Manettia tweedieana is considered endangered.

SEASONALITY IN LITTERFALL PRODUCTION IN A NATIVE FOREST IN THE CENTRAL REGION OF RS, BRAZIL

Studies on litter deposition are considered an important indicator of environmental quality of forest ecosystems. It is the main route of entry of organic matter and nutrients to forests. The objective of this study was to quantify the annual litterfall and seasonality in a fragment of native forest located in São Sepé in the Central Depression of Rio Grande do Sul. The experiment was conducted in a fragment of a Seasonal Semideciduous Forest. Inside this forest, in a place with homogeneous conditions, five plots of 20 m x 15 m length were systematically allocated 30 meters away from each other, where five litterfall traps were distributed in each plot (0,1963 m2 each trap), totaling 25 traps. The collection of all plant material deposited by the trees in the collectors was performed monthly in a four-year period. In the laboratory, the samples were separated into leaves, small twigs (diameter < 0.5 cm) and miscellaneous, and after they were oven dried and weighed on a precision balance. Higher litterfall was observed in the spring, with the highest return peaks mainly in October, indicating a seasonal deposition behavior. The mean litterfall was 6.56 Mg ha-1 year-1; of this total, the leaves were responsible for 67.61%, followed by the miscellaneous with 19.04% and the small twigs with 13.29%. Only a high significant correlation was obtained between the miscellaneous fraction and the temperature.

HYDRO-MICROBIOLOGICAL ATTRIBUTES OF THE SOIL IN EDGE OF SEASONAL SEMIDECIDUOUS FOREST FRAGMENT

Native forests have been suffering changes, such as fragmentation and edge effect, and these have implications for the dynamics of carbon within the same fragment, differentiating vegetation and soil. In this way, the work aimed to evaluate the hydro-microbiological attributes of the soil in rainy and dry periods, as well as to indicate if there is an edge effect in a seasonal semideciduous forest fragment. The study was carried out in a forest fragment in the area of the State University of Goiás, Ipameri Campus, consisting of three transects divided into three blocks from the edge. Sampling was performed in two periods of the year, rainy and dry, to determine the gravimetric soil water content (UG), microbial biomass carbon (MBC), basal respiration (BR), and the metabolic quotient (qCO2). The data were subjected to analysis of variance (F test), and when significant, the means were evaluated by the Tukey test at 5% probability. Response variations of microorganisms are closely related to the periods studied; the rainy season benefits the carbon incorporation activity, and the dry season stimulates the carbon release. Consequently, metabolic efficiency is more pronounced in the rainy season. The edge of the fragment only influenced the MBC, evidencing that disturbances caused at the extremity of fragment interfere with the C input in the microbial biomass.

THE IMPORTANCE OF HETEROGENEITY OF HABITATS FOR THE SPECIES RICHNESS OF VASCULAR EPIPHYTES IN REMNANTS OF BRAZILIAN MONTANE SEASONAL SEMIDECIDUOUS FOREST

Epiphytes are an important component of the diversity of tropical forests, and they also have several ecological functions. Vegetation heterogeneity is one of the features responsible for the high biodiversity of the Atlantic Forest, especially in the domain’s seasonal semideciduous forest (SSF). This biodiversity presents as high endemism and species richness. Owing to the seasonal nature of SSF, organisms that require high humidity (e.g. epiphytes) would be expected to show low species richness in these forests. The aims of this study were to conduct a survey of the vascular epiphytes in remnants of montane SSF in the Serra do Ibitipoca, Brazil, and to evaluate the importance of habitat heterogeneity for the richness and composition of species in these areas. We also evaluated whether the intrinsic characteristics of the SSF phytophysiognomy and fragmentation could result in low species richness and a high number of accidental epiphyte species. The study was conducted in the course of 18 expeditions undertaken between September 2013 and December 2016, covering five fragments of montane SSF (totalling 23.6 ha). We recorded 96 species (only one of which is an accidental epiphyte), distributed across 41 genera and 10 families. This is the highest epiphytic species richness recorded in Brazilian SSF to date. The results refuted the initial hypothesis and reinforce the importance to the epiphytic community of conservation of fragments with different structures.