Temporal evaluation of natural regeneration in a semideciduous secondary forest in Pirenópolis, Goiás, Brazil

A regeneração natural em ambientes florestais é dinâmica, variável no espaço e no tempo, e integra o ciclo de desenvolvimento das florestas. Em florestas estacionais tropicais, devido à sazonalidade climática, a regeneração natural depende principalmente da disponibilidade de umidade no solo, que afeta tanto os padrões de produção de sementes quanto a germinação, a sobrevivência e o desenvolvimento das plântulas. O objetivo deste estudo foi analisar a dinâmica da regeneração natural em uma floresta estacional semidecídua secundária, em Pirenópolis, Goiás, verificando as mudanças na composição florística de plântulas e arvoretas ao longo do tempo, e relacionando-as a fatores ambientais das parcelas por Análises de Correspondência Canônica (CCA). Os resultados indicaram plântulas mais dinâmicas do que arvoretas, em função principalmente do clima. Isso ocorreu devido à maior susceptibilidade das plântulas com relação ao estresse hídrico do solo e ao aumento da incidência de radiação solar e da temperatura na estação seca. Foi encontrada alta similaridade florística (±50%) entre as populações da regeneração natural e a comunidade adulta, indicando estágio avançado de regeneração da floresta, com Índices de Diversidade superiores a 3,0 nats.indv-1. A CCA agrupou as espécies em função do gradiente ambiental de umidade e sombreamento versus cobertura do solo, posicionando próximas as espécies preferenciais de ambientes úmidos versus as preferenciais de ambientes mais secos de cerrado típico.The natural regeneration in forest environments is dynamic, variable in space and time and it is in the development cycle of forests. In seasonal tropical forests, due to seasonal climatic changes, natural regeneration depends mainly on availability of soil moisture, which affects patterns of seed production and germination, survival and development of seedling as well. The objective of this study was to analyze the dynamics of natural regeneration in a seasonal semideciduous secondary forest in Pirenópolis, Goiás, Brazil, by analyzing the changes in floristic composition of seedlings and small trees over time and relating them to environmental factors of plots in the study area by using Canonical Correspondence Analysis (CCA). The results indicated that seedlings were more dynamic than small trees mainly because of climate. This occurred because of the greater susceptibility of the seedling to soil water stress and the increase of solar radiation and temperature in the dry season. It was found a high floristic similarity (± 50%) among population of natural regeneration and the tree community, indicating an advanced stage of natural regeneration of the forest, with Diversity Index higher than 3.0 nats.indv-1. Canonical Correspondence Analysis grouped the species according to the environmental gradient of moisture and shade versus soil cover, placing near to each other, species of humid environments versus species of typical cerrado dry environments

Initial development of dipteryx alata vogel and myracrodruon urundeuva allemão in enrichment planting in a semi-deciduous secondary forest

Nesse estudo avaliou-se o desenvolvimento inicial de Dipteryx alata e Myracrodruon urundeuva plantadas em sistema de enriquecimento de floresta estacional semidecídua secundária, seguindo um gradiente ambiental de umidade, em direção a áreas de cerrado. As avaliações da sobrevivência e do crescimento em altura total e diâmetro do coleto foram feitas 12 meses após o plantio e foram constatados 10% de mortalidade para M. urundeuva e 45% para D. alata. Vinte e cinco meses após o replantio, a mortalidade foi de 15% para ambas as espécies. Não houve associação entre mortalidade das espécies e gradiente ambiental (χ²) e também não foram encontradas diferenças estatísticas nos incrementos diamétricos entre as espécies (ANOVA). O crescimento médio em diâmetro de Myracrodruon urundeuva e D. alata foi de 0,96 e 0,52 mm.ano-1, respectivamente. O crescimento médio em altura foi de 9,6 e 4,0 cm.ano-¹ em M. urundeuva e D. alata, respectivamente, diferentes estatisticamente. O menor crescimento em altura de D. alata em relação a M. urundeuva não deve ser utilizado para julgar a adaptação dessa espécie ao ambiente, podendo estar relacionado a diferentes padrões de crescimento, estratégias de adaptação ou diferentes necessidades ecológicas, demonstrando diferenças quanto à eficiência no uso dos recursos disponíveis. Este estudo destacou o potencial dessas espécies para compor sistemas de enriquecimento de capoeiras. _________________________________________________________________________________ ABSTRACTInitial development of Dipteryx alata Vogel and Myracrodruon urundeuva Allemão planting in enrichment in a semideciduous secondary forest. This study evaluated the initial development of Dipteryx alata and Myracrodruon urundeuva planted in enrichment system in a secondary semi-deciduous seasonal forest along an environmental gradient. The survival and growth in height and diameter were made 12 months after planting. There was 10% mortality for M. urundeuva and 45% for D. alata. Twenty-five months after replanting, the mortality was 15% for both species. There was no association between mortality of the species and environmental gradient (χ²) and also there were no statistical differences in diameter increment between species (ANOVA). Myracrodruon urundeuva and D. grew on average 0.96 and 0.52 mm.yr-1, respectively. The average growth in height was 9.6 and 4.0 cm.yr-¹ for M. urundeuva and D. alata, respectively, statistically different. The smaller growth in height of D. alata versus M. urundeuva should not be used determine the adaptation to the environment and may be linked to different patterns of growth, adaptation strategies, or different ecological needs, showing differences in efficiency in the use of available resources. This study highlighted the potential use of these species in enrichment systems

Light availability in a semideciduous forest management in Pirenópolis, Goiás, Brazil

Esta pesquisa foi realizada em um fragmento de floresta estacional semidecídua, localizada em Pirenópolis, Goiás, e investigou as alterações no regime de luz, medida pela densidade de fluxo de fótons, associadas a intervenções silviculturais que visaram, sobretudo, aumentar o crescimento de espécies arbóreas, sem permitir a invasão por espécies oportunistas que poderiam influenciar negativamente a dinâmica da regeneração natural. O delineamento foi em blocos casualizados, em esquema fatorial, testando as diferenças entre tratamentos silviculturais, estações climáticas e alturas de medida no sub-bosque (1,30 m e ao nível do solo). Foram testadas duas intensidades de corte seletivo de indivíduos arbóreos e de cipós na floresta. Os tratamentos foram suficientes para alterar o regime de luz, tanto na estação seca como na estação chuvosa, em acordo com a hipótese testada. O sombreamento na área controle foi de 97% na estação chuvosa e de 86% na estação seca, apresentando diferenças significativas com o sombreamento associado aos tratamentos silviculturais, que variaram de 93% a 94% na chuva e de 77% a 80% na seca. Esse estudo pode auxiliar na validação deste sistema de manejo florestal proposto para as florestas estacionais semidecíduas no Brasil Central, devendo ser associado aos estudos populacionais e de comunidade, preservando os fragmentos florestais encontrados na região e gerando benefícios ambientais e renda extra para a população rural.This study was carried out on a fragment of semi-deciduous forest in Pirenópolis, Goias, Brazil and investigated the changes in the photon flux density in relation to silvicultural interventions that aimed at increasing growth of tree species but without allowing invasion by exotic species that could influence the dynamics of natural regeneration. The design was a randomized block in factorial, testing the differences between silvicultural treatments, seasons and heights in the understory (1.30 m versus at the ground level). We tested two intensities of selective cutting of individual trees and vines in the forest. The treatments were sufficient to alter the understory light, both in the dry season and rainy season, in agreement with the hypothesis tested. The shading in the control area was 97% in the rainy season and 86% in the dry season, showing significant differences with the shading associated with silvicultural treatments, which ranged from 93% to 94% in the rainy season and from 77% to 80% in the dry season. This study may assist this forest management system for semi-deciduous forests in Central Brazil, and should be linked to population studies and community, preserving the forest fragments found in the region and generating numerous environmental benefits and extra income for the rural population

Crescimento diamétrico em função de tratamentos silviculturais em uma floresta estacional semidecídua no Brasil central

No Bioma Cerrado, as florestas estacionais e o Cerrado stricto sensu estão intimamente ligados, fomando mosaicos. Essas florestas são compostas por espécies de alto valor comercial, bem aceitas no mercado madeireiro, o que provoca o desmatamento intensivo dessas matas. Assim, o manejo dessas florestas é uma alternativa importante para reduzir o desmatamento nos remanescentes, na medida em que proporciona o seu uso sustentável. Este estudo analisou o crescimento de espécies arbóreas em relação a tratamentos silviculturais de liberação de competição e corte de cipós, em uma floresta estacional semidecídua, no Brasil Central. Os resultados mostraram que a área basal da comunidade aumentou 24%, durante 4,8 anos e que a média do incremento periódico anual em diâmetro foi cerca de 20% maior nas parcelas onde ocorreram os tratamentos silviculturais: 2,9 mm.ano-1, na testemunha, comparado a 3,2 mm.ano-1 to 3,6 mm.ano-1 entre os tratamentos. O estudo demostrou que é possível aumentar o ritmo de crescimento das espécies com a aplicação dos tratamentos silviculturais testados.In the Cerrado biome of Brazil, savannas and dry forests are intimately linked and form mosaics. These forests are composed of species of high commercial value, well accepted in the timber market, which causes intensive deforestation on the remaining vegetation. Thus, the management of these forests is an important alternative to reduce deforestation in the remaining vegetation. The objective of this study was to analyze the response of tree species in relation to silvicultural treatments of competition and liana cutting in a semi-deciduous forest in Central Brazil. The results showed that community basal area increased 24% over 4.8 years and the median periodic annual increment in diameter was about 20% higher in plots with silvicultural treatments: 2.9 mm.yr-1 in the control compared to 3.2 mm.yr-1 to 3.6 mm.yr-1 between treatments. This study demonstrated that it is possible to increase the rates of radial growth through silvicultural techniques

Effect of fire onthe structure and floristic composition of a cerrado sensu stricto area in fazenda Água Limpa - DF

O objetivo desta pesquisa foi avaliar o efeito do fogo na estrutura e composição florística de uma área de 10 ha de cerrado sensu stricto, localizada na fazenda Água Limpa da Universidade de Brasília. Foram realizados dois inventários, sendo o primeiro em 1999, logo após a área ter sido totalmente queimada, devido a um incêndio criminoso, e o segundo em novembro de 2002. Quatro parcelas de 0,1 ha (20 x 50 m) foram tomadas, aleatoriamente, na área queimada. Todos os indivíduos lenhosos arbóreos vivos, com Db (diâmetro tomado a 0,30 m do solo) igualou superior a 3 cm, foram identificados botanicamente, e seus diâmetros e alturas foram registrados. Valores de densidade, dominância, freqüência e índice de valor de cobertura foram obtidos para os dois levantamentos. A avaliação da similaridade florística entre os dois inventários foi realizada para dados qualitativos (presença e ausênciade espécies), a partir do índice de Sφrensen. Os resultados mostraram que houve pouca mudança na composição florística da comunidade durante o período estudado. Entre os dois inventários houve um aumento de aproximadamente 125% na densidade por hectare. A similaridade entre os dois levantamentos foi alta (índice de Sφrensen igual a0,68). A densidade florística, obtida a partir do índice de Shannon, foi baixa (cerca de 2,5) nas duas épocas monitoradas, quando comparada com pesquisas a longo prazo no cerrado sensu stricto da FAL (cerca de 3,5). Contudo, este valor é comum em áreas de cerrado que sofreram distúrbios. No segundo inventário, realizado três anos após o fogo, surgiram 13 espécies novas na área, o que comprova a sua recuperação e recolonização.This research aimed to evaluate the effect of fire on the structure and floristic composition of a 10 hacerrado sensu stricto area located at the Ecological and Experimental Reserve of the University of Brasilia, Fazenda Água Limpa FAL. Two assessments were conducted in the area: the first, after the area had suffered a criminal firein 1999, and the second in 2002. A sample of four 20 x 50 m permanent plots was assessed. All individuals withstems 5 cm diameter at 0,30 m (Db) from the ground level were registered, and had their Db and total height measured. Density, basal area, frequency and value of covering index were calculated for the two assessments. The floristic similarity between the two surveys was evaluated for qualitative data (presence and absence of species)based on the Sφrensen Index. Few changes were observed in the floristic composition of the community during the studied period. There was an increase of 125% in density by hectare from 1999 to 2002. A high similarity (SφrensenIndex equal to 0.68)was found between the two assessments while diversity (Shannon Index) was small (about 2.5).This value is smaller than those found in natural areas of the Cerrado sensu stricto at Fazenda Água Limpa,although it is common in areas with disturbances. Three years after fire 13 new species were verified in the area

TAXONOMY OF MELASTOMATACEAE JUSS. IN THE BRAZILIAN CERRADO: A SYSTEMATIC REVIEW OF THE LITERATURE (2012-2021)

We present a systematic review of the current taxonomic knowledge of Melastomataceae in the Brazilian Cerrado, covering the period from 2012 to 2021. The review includes a historical approach to the studies carried out in this period, as well as the circumscriptions of the family, tribes and genera. Additionally, studies on new species, studies on the flora that represent the group, and its geographic distribution in the different phytophysiognomies of the Cerrado and Brazilian regions, along with reviews of genera, are also addressed. The objective of this work is to highlight the importance of taxonomic studies in the Brazilian Cerrado, to value existing knowledge, and to offer contributions on the potential of these researches, as well as future studies in areas that are still lacking. To carry out the systematic review, the search strategy was used with the descriptors: Melastomataceae (and) Cerrado (and) Brazil, in the databases of Periódico CAPES and Google Scholar. Initially, 5,904 publications were identified. After reading the title and abstract, 320 works that met the inclusion criteria were evaluated. In the second stage, the publications were read, and 155 were selected that aligned with the objectives of this study. Most studies focus on the description of new species, with the largest number of publications in the years 2016, 2018 and 2019, mainly in areas of rocky fields). A total of 76 municipalities were cited, distributed in 10 Brazilian states and the Federal District, with the largest number of taxonomic studies of Melastomataceae found in the states of Minas Gerais, Goiás and Bahia. Five journals stood out: Phytotaxa, Systematic Botany, Rodriguésia, Kew Bulletin and Brittonia. The Federal University of Uberlandia presented the largest number of publications of Course Completion Work and dissertations. Specialist researchers from the Federal University of Uberlândia, State University of Campinas, State University of Maringá, University of Brasília, State University of Feira de Santana, Federal University of Goiás and The New York Botanical Garden (USA) also stood out. The use of the free-walking methodology was observed instead of the fixed area plot allocation method. Based on this information, the relevance of this study is emphasized, as it addresses lesser-explored regions of the Cerrado in relation to the flora of Melastomataceae, contributing to a more comprehensive understanding of the diversity of this group in the ecosystem. This systematic literature mapping can contribute to the improvement of the group's regional data for the Cerrado

Indolbutyric Acid (IBA) in the african mahogany (Khaya grandifoliola C. DC.) cuttings and mini-cuttings development

The current expansion of the forest sector in the Cerrado (Brazilian Savannah), especially of the species of genus Khaya sp. (African Mahogany), requires several silvicultural and technical studies of various natures. Seed and clonal propagation enable noble and vigorous seedlings, which will future compose commercial plantations aiming timber production. The species Khaya grandifoliola C. DC is considered of distinct wood characteristics and with great economic potential. The objective of this work was to evaluate the effect of different indolbultyric acid (IBA) concentrations – between 0 and 12 g.L-1– on the rooting of K. grandifoliola cuttings and mini-cuttings. The experiment was carried out at the "Mudas Nobres" private nursery, located in Goiânia (Goiás State, Brazil). The experiment was conducted in a completely randomized design in a 5 × 2 factorial scheme. Each treatment consisted of four replications with 20 cuttings (clonal origin) or mini-cuttings (seed origin) per repetition. Models were also applied to estimate the number of shoots in clonal cuttings, according to the data observed in seed mini-cuttings. The results indicate that IBA has the opposite effect on the two evaluated types of propagule origin, being more suitable for seed mini-cuttings (should apply 8 g.L-1of IBA) and less for clonal cuttings (should not apply IBA). If a standard application must be recommended (to cuttings either mini-cuttings), the most appropriate concentration is 6 g.L-1of IBA

FIRE EFECT ON THE SEASONAL FOREST STRUCTURE IN THE CERRADO BIOME

There are few studies on the effects of fire on the seasonal semideciduous forest of the Cerrado region. This study aimed to assess the effect of fire on Semideciduous forest fragments located in the Altamiro Moura Pacheco State Park (AMPSP). The study area is located in the central state of Goiás. A total of 10 plots (50 x 20 m; 1,000 m2) were drawn in the remaining forests seeking to portray two areas: area which underwent forest fire (burned area; B) and unburned area (unburned; UB). A total of 771 individuals with DBH (≥ 5 cm) were identified. A total of 303 individuals were recorded in the burned area (B), comprising 28 families, 41 genera and 47 species, while the unburned area (UB) had 468 individuals comprising 25 families, 43 genera and 50 species. The species Anadenanthera colubrina (Vell.) Brenan, Emmotum nitens (Benth.), Zanthoxylum rhoifolium Lam, Tapirira guianensis Aubl., Myracrodruon urundeuva Allemão and Luehea candicans Mart. had the highest Importance Value Index (IVI) values and occur in both areas. The percentage of dead trees differed between the areas, where the burned area had a mortality of 12.69% and the unburned area of 7.29% in regards to the number of individuals. Density per plot was the only parameter that differed between the areas, where the burned area (B) had the lowest values. The fire affected all diameter classes, demonstrating the fragility of this vegetation type in regards to fire. The fire had a greater effect on trees in the smaller diameter classes, reducing the frequency of individuals in the burned area and changing height distribution, which may have favored the establishment of lianas and invasive species.

Arborização urbana para mitigação das condições microclimáticas em Goiânia, Goiás

Urban trees can influence from landscape factors to microclimatic, affecting human well-being. This study had as objective to characterize two different sectors in Goiânia, Goiás, Brazil and to verify how urban trees influence the microclimate. Two different areas, 1 km long each one, in two avenues from the city (Goiás Av. and Planície Av.). In each area, a census from all trees was conducted and the following variables were measured: temperature (ºC), relative humidity (%), wind speed (km/h) and light intensity (lux). Descriptive analysis with absolute and relative frequency of tree species, Mann-Whitney (95%) test for comparing abundance among species, T Test (95%) for microclimate variables comparison among full sun and shaded areas in each one of the avenues and the last procedures were a principal components analysis (PCA) and a correspondence analysis (CCA) to verify the influence of environmental variables between full light and shaded areas. In areas shaded by trees crowns, temperatures, light intensity and wind speed showed lower values than shaded areas, while relative humidity showed higher values in these environments than in places without trees. Urban trees contribute to microclimatic conditions improvement in urban landscapes, positively influencing human well-being in urban centers.A arborização urbana pode influenciar desde fatores paisagísticos a microclimáticos, com efeitos ao bem estar humano. Sendo assim, o objetivo deste trabalho foi caracterizar a arborização urbana de dois diferentes setores de Goiânia, Goiás, Brasil e verificar como a arborização influencia o microclima da região. Analisaram-se dois trechos, de 1 km cada, em duas avenidas da cidade de Goiânia (av. Goiás e av. Planície). Em cada trecho realizou-se o censo das árvores e a medição das seguintes variáveis climáticas: temperatura do ar (ºC), umidade relativa do ar (%), velocidade do vento (km/h) e intensidade luminosa (lux). Utilizou-se análise descritiva com frequência absoluta e relativa das espécies de árvores, teste de Mann-Whitney (95%) para comparar a abundância entre as espécies, Teste T (95%) para comparação das variáveis microclimáticas entre áreas ensolaradas e sombreadas em cada uma das avenidas e por último uma análise dos componentes principais (PCA) e análise de correspondência (CCA) para verificação da influência das variáveis ambientais entre áreas ensolaradas e sombreadas. Nas áreas sombreadas pelas copas das árvores a temperatura do ar, intensidade luminosa e a velocidade do vento apresentaram valores mais baixos do que nas áreas ensolaradas, enquanto que a umidade relativa do ar se mostrou maior nesses ambientes do que nos que apresentavam ausência de árvores. A arborização contribui para melhoria das condições microclimáticas dos ambientes urbanos, influenciando positivamente o bem-estar humano nos centros urbanos