Comparisons between a savanna on rocky soil tree-shrub community at Chapada dos Veadeiros, Goiás, and cerrado sensu stricto areas of the Cerrado biome

Foram determinadas a composição florística e a estrutura da vegetação arbustivo-arbórea, incluindo monocotiledôneas, em uma comunidade de cerrado rupestre, no município Alto Paraíso de Goiás, Goiás. Os objetivos desse estudo foram: 1. Comparar os aspectos florísticos e estruturais da área estudada com aqueles de outros 14 estudos com comunidades arbustivo-arbóreas, com e sem a presença de monocotiledôneas, 2. Avaliar os padrões fitogeográficos das 15 áreas comparadas. Foram amostradas 71 espécies, sendo cinco espécies de monocotiledôneas (três Velloziaceae e duas Arecaceae). Considerando as monocotiledôneas, a comunidade inventariada foi a mais densa (1.977 indivíduos ha-1) e apresentou a segunda maior área basal (11,25 m2 ha-1), entre as áreas comparadas. No entanto, sem as monocotiledôneas a densidade e área basal reduziram para 892 indivíduos ha-1 e 7,55 m2 ha-1, respectivamente. Os índices de diversidade (H’ = 2,81) e equabilidade (J’ = 0,66) foram baixos com a presença das monocotiledôneas, mas se elevaram, com a exclusão das espécies desse grupo (H = 3,63, J’ = 0,86). Os aumentos nos valores de riqueza, densidade e área basal, com a inclusão das monocotiledôneas indicaram elevada importância das famílias Velloziaceae e Arecaceae na comunidade de cerrado rupestre estudada. A flora foi representada predominantemente por espécies de cerrado sentido restrito sobre solos profundos. No entanto, cinco das dez espécies com maiores VI são consideradas habitat especialistas de cerrado rupestre (Vellozia variabilis Mart. ex Schult. f., Wunderlichia cruelsiana Taub., Schwartzia adamantium (Cambess.) Bedell ex Giraldo-Cañas, Hyptis pachyphylla Epling e Vellozia tubiflora (A. Rich.) Kunth). Além do mais, foi observada baixa similaridade florística entre a área de estudo e as áreas comparadas, sugerindo particularidade florística do cerrado rupestre de Alto Paraíso de Goiás. Os padrões fitogeográficos, revelados por análises de agrupamento (UPGMA) e ordenação (DCA), indicaram influência da altitude, da proximidade geográfica entre áreas e de suas localizações em relação aos biomas adjacentes ao Cerrado (Floresta Amazônica, Mata Atlântica e Caatinga).The floristic composition and the structure of a savanna on rocky soil (cerrado rupestre) tree-shrub community, including monocots, in the municipality of Alto Paraíso de Goiás, state of Goiás, were determined. Our objectives were: 1. To compare floristic and structural aspects between the tree-shrub community studied and 14 other cerrado sensu stricto areas, with and without monocots. 2. To evaluate phytogeography patterns of the 15 compared areas. We sampled 71 species, including five monocots (Velloziaceae = 3; Arecaceae = 2). Including monocots, the studied community was the most dense (1,977 individuals ha-1) and showed the second basal area (11.25 m2 ha-1) among the 15 compared areas. On the other hand, excluding monocots, density and basal area decreased to 892 individuals ha-1 e 7.55 m2 ha-1, respectively. The diversity and equability indices were low (H’ = 2.81; J’ = 0.66, respectively) when monocots were included; however, excluding species of this group, H’ and J’ increased to 3.63 and 0.86, respectively. Increases in richness, density and basal area, with the inclusion of monocots, suggested high importance of Velloziaceae and Arecaceae families in the studied community. The flora was mostly represented by deep-soil cerrado species. Nevertheless, five of the ten highest IV species are considered cerrado rupestre habitat specialists (Vellozia variabilis Mart. ex Schult. f., Wunderlichia cruelsiana Taub., Schwartzia adamantium (Cambess.) Bedell ex Giraldo-Cañas, Hyptis pachyphylla Epling and Vellozia tubiflora (A. Rich.) Kunth). Moreover, the low floristic similarities between the studied community and the others suggest floristic particularity of the Alto Paraíso de Goiás rocky cerrado. The phytogeographical patterns revealed through cluster (UPGMA) and ordination (DCA) analyses indicated the influence of altitude, of geographical closeness between the areas and of their location in relation to the Cerrado neighboring biomes (Amazonian Forest, Atlantic Forest and Caatinga)

Fire in the Xingu region: its determinants and effects on vegetation and socio-environmental relevant resources

Slash-and-burning agricultural systems represent an important source of food for indigenous communities in Amazonia and have been conducted for centuries or millennia. However, the traditional use of fire has ignited an increasing number of wildfires. In 2010, for instance, 298,000 hectares of forests burned in the Xingu Indigenous Park (XIP). Yet, it is still unclear what are the main factors driving this apparent change in fire regimes inside the PIX, as well as the consequences of such changes to vegetation dynamics, ecosystem services, and food security for the indigenous communities. Here we describe the activities we are conducting on the scope of a project that aims to quantify the causes and consequences of changes in fire regimes inside the XIP and are funded by the Brazilian National Research Council (CNPq) and the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA). Objectives of the project include: 1) mapping burned areas inside the PIX over the past few decades using high-resolution imagery, differentiating those fire scars in slash-and-burn areas from wildfires in primary forests; 2) quantification of the combined roles of forest fires, droughts events, and forest management by indigenous peoples on recent changes of forest cover inside the XIP. Preliminary results indicate large areas on forest the XIP are now degraded mainly as a result of the increases in the burned area in the past two decades. The number of fire events in combination with number of drought years were the main predictors forest degradation. Overall, results of this project will contribute to a better understanding of the drivers of regional changes in fire regimes. We are also generating valuable information about management techniques that can reduce fire-related degradation of native forests and the ecosystem services that these forests provide for indigenous peoples, what can be used to improve food security for local communities of the PIX

Diversity, floristic composition, and structure of the woody vegetation of the Cerrado in the Cerrado–Amazon transition zone in Mato Grosso, Brazil

The final publication is available at Springer via http://dx.doi.org/10.1007/s40415-015-0186-2We compared the diversity and species composition and the structure of the vegetation of three distinct Cerrado phytophysiognomies (Cerradão, Dense Cerrado, and Typical Cerrado) in the Cerrado–Amazon transition, Mato Grosso (Brazil). Species richness (observed and estimated) in the Cerradão and Dense Cerrado was higher than that recorded in the Typical Cerrado. Species diversity, based on a Rényi profile, was highest in the Dense Cerrado, in comparison with the other phytophysiognomies. We recorded a higher number of exclusive species in the Cerradão and a greater similarity (Morisita and Sørensen indices) between this vegetation type and the Dense Cerrado. While individuals were tallest in the Cerradão and Dense Cerrado and lowest in the Typical Cerrado, there was no difference among phytophysiognomies in mean diameter. A gradient in decreasing species richness and diversity (hypothesis 1) and vegetation vertical structure (hypothesis 3) was expected for the Cerradão–Dense Cerrado–Typical Cerrado; however, neither hypothesis was supported by the results. The Cerradão and Dense Cerrado were most similar in species composition not confirming hypothesis 2, which predicted that the two savanna vegetation types (Dense Cerrado and Typical Cerrado) were more similar to one another than either is to the woodland (Cerradão). Overall, the similarities among the three study communities depended on the type of parameter analyzed. While the species richness and the vertical and structure of the vegetation of the Cerradão and Dense Cerrado are closely similar, the Cerradão and Typical Cerrado are more similar in their species diversity. With regard to the floristic composition, Dense Cerrado occupies an intermediate position between Cerradão and Typical Cerrado.UNEMAT Graduate Program in Ecology and ConservationBrazilian Higher Education Training Program (CAPES)“Tropical Biomes in Transition – TROBIT”CAPES/Science without Borders ProgramPELD/CNPq (Long-Term Ecological Studies)PROCAD UnB/UNEMA

Post-fire resprouting strategies of woody vegetation in the Brazilian savanna

Post-fi re response by vegetation may refl ect the severity of the damage suff ered, but we still know little about the species-specifi c nature of responses to fi re or their predictors. Here, we evaluated 26 woody species before and after a fi re event in an Cerrado sensu stricto area (typical Brazilian savanna-type) in order to evaluate mortality rates and the type of resprouting (epigeal, hypogeal or epigeal + hypogeal). We evaluated the relative importance of stem diameter, height, and bark thickness as predictors of the type of post-fi re resprouting, using a sequential logistic regression model (SLRM). Mortality was 4 %, while epigeal resprouting was recorded in 57 % of the individuals, hypogeal resprouting was recorded in 24 %, and epigeal + hypogeal resprouting in 15 %. Our SLRM analysis indicated that bark thickness, followed by stem diameter, were the best predictors of the type of resprouting. Th ere was a greater than 60 % probability that individuals with bark thicker than 1.6 cm resprouted only epigeally. Our results confi rm the resistance (low mortality) and resilience (high resprouting capacity) of the woody vegetation of the Cerrado sensu stricto to fi re, and that thick bark is an eff ective protection against fi re damage

Post-fire dynamics of woody vegetation in seasonally flooded forests (impucas) in the Cerrado-Amazonian Forest transition zone

Journal ArticleAuthor versions of article. The version of record is available from the publisher via doi: 10.1016/j.flora.2014.02.008© 2014 Elsevier GmbH. All rights reserved.Fire disturbance alters the structural complexity of forests, above-ground biomass stocks and patterns of growth, recruitment and mortality that determine temporal dynamics of communities. These changes may also alter forest species composition, richness, and diversity. We compared changes in plant recruitment, mortality, and turnover time over three years between burned and unburned sites of two seasonally flooded natural forest patches in a predominantly savanna landscape (regionally called 'impucas') in order to determine how fire alters forest dynamics and species composition. Within each impuca, 50 permanent plots (20m×10m) were established and all individuals ≥5cm diameter at breast height (DBH) identified and measured in two censuses, the first in 2007 and the second in 2010. Unplanned fires burned 30 plots in impuca 1 and 35 in impuca 2 after the first census, which enabled thereafter the comparison between burned and unburned sites. The highest mortality (8.0 and 24.3% year-1 for impuca 1 and 2) and turnover time (69 and 121.5 years) were observed in the burned sites, compared to 3.7 and 5.2%year-1 (mortality), and 28.4 and 40.9 years (turnover), respectively, for the unburned sites. Although these seasonally flooded impuca forests are embedded in a fire-adapted savanna landscape, the impucas vegetation appears to be sensitive to fire, with burned areas having higher mortality and turnover than unburned areas. This indicates that these forest islands are potentially at risk if regional fire frequency increases. © 2014 Elsevier GmbH.Natural Environment Research Council (NERC)Gordon and Betty Moore FoundationMato Grosso State Research Support FoundationProgram of Academic Cooperatio

Structure and floristic composition of woody vegetation in cerrado rupestre in the Cerrado-Amazonian Forest transition zone, Mato Grosso, Brazil

O objetivo desse estudo foi determinar a composição florística e a estrutura da vegetação lenhosa (incluindo monocotiledôneas e lianas) em cerrado rupestre na zona de transição Cerrado-Floresta Amazônica, no Parque do Bacaba, em Nova Xavantina, MT (14º 41’ S e 52º 20’ W) e compará-las com outros estudos de cerrado sentido restrito. Foram demarcadas aleatoriamente 10 parcelas de 20 × 50 m, nas quais foram medidos os indivíduos vivos e mortos em pé com diâmetro mínimo a 30 cm do solo (DAS) ≥ 3 cm. O cerrado rupestre apresentou alta densidade (3.766 indivíduos vivos), riqueza florística (85 espécies, 67 gêneros e 34 famílias) e área basal (15,72 m2ha-1), e ainda elevado valor do índice de diversidade de espécies de Shannon-Wiener (H’ = 3,47) e equabilidade de Pielou (J = 0,78) em relação às áreas comparadas. As espécies com maior valor de importância foram Erythroxylum suberosum, Qualea parviflora, Anacardium occidentale, Kielmeyera rubriflora e Vatairea macrocarpa. A maior similaridade florística entre comunidades de cerrado típico e rupestre localizadas em áreas com menores altitudes do leste mato-grossense sugere que nessa região a proximidade geográfica e a altitude exercem influência sobre a composição de espécies, independentemente do substrato. A comunidade apresentou distribuição de alturas unimodal, predominando indivíduos de porte arbustivo com altura < 3 m e DAS < 5 cm. É sugerido aqui que estudos florísticos e fitossociológicos realizados em cerrado rupestre empreguem DAS mínimo de 3 cm e incluam espécies de monocotiledôneas e de lianas para representar de maneira mais realística a riqueza e composição de espécies e a estrutura da vegetação. A elevada riqueza e diversidade de espécies registrada no presente estudo podem estar relacionadas à posição pré-Amazônica deste cerrado rupestre, enfatizando a importância da manutenção do Parque do Bacaba no sentido de garantir a proteção de sua diversidade biológica.This study aimed to analyze the floristic composition and the structure of a savanna on rocky soil (“cerrado rupestre”) woody vegetation (including monocots and lianas) in the Cerrado-Amazon Forest transition zone located at Parque Municipal do Bacaba, Nova Xavantina, State of Mato Grosso (14º 41’ S and 52º 20’ W), and compare it with other cerrado stricto sensu studies. Ten 20 × 50 m plots were randomly established, within which all live and dead woody plants with at least 3 cm of trunk diameter at 30 cm above ground level (DSH30 ≥ 3 cm) were measured. The cerrado rupestre showed high density (3,766 live individuals), richness (85 species, 67 genera and 34 families) and basal area (15.72 m2ha-1), as well as high levels of Shannon-Wiener species diversity (H’ = 3.47) and evenness (J = 0.78) indices. The most important species were Erythroxylum suberosum, Qualea parviflora, Anacardium occidentale, Kielmeyera rubriflora and Vatairea macrocarpa. The greatest floristic similarity found between typical cerrado and “cerrado rupestre” communities from lower altitude areas of Northeastern Mato Grosso suggest that, in this region, altitude and geographical distance influence the species composition, regardless of the substrate. The community presented unimodality in the heights distribution and is mostly compounded by shrubby individuals with height < 3 m and DSH < 5 cm. We suggest that floristic and phytosociological studies conducted in “cerrado rupestre” should adopt DSH ≥ 3 cm and include monocot and liana species, so as to more realistically represent the vegetation richness, species composition and structure. The high species richness and diversity registered in this study might be related to this “cerrado rupestre” pre-Amazonian location, which emphasizes the importance of “Parque do Bacaba” maintenance as a guarantee of its biological diversity protection

A passagem do fogo resulta em mudanças de curto prazo para a fenologia vegetativa de espécies lenhosas em um cerrado stricto sensu

Avaliamos os efeitos do fogo sobre o comportamento fenológico vegetativo (cobertura de copa, brotação, folhas jovens e folhas adultas) de espécies lenhosas em dois sítios de cerrado sensu stricto: um queimado acidentalmente e outro não queimado. Usamos modelos aditivos mistos generalizados para testar a hipótese de que 1) o fogo danifica a cobertura de folhas das copas, o que resulta em alterações nos padrões fenológicos vegetativos das espécies; sendo isso verdadeiro, testamos se 2) os danos causados pelo fogo na cobertura de copa e nas folhas adultas são maiores em espécies sempre verdes do que em espécies decíduas e se 3) os efeitos negativos do fogo sobre a fenologia vegetativa persistem após um ano sem fogo. As duas primeiras hipóteses foram corroboradas, mas a terceira não. Os efeitos do fogo na cobertura de folhagem da copa e nas folhas adultas foram maiores após três meses da ocorrência do fogo e significativamente maiores para espécies sempre verdes. Para brotação e folhas jovens, as maiores diferenças foram entre três e sete meses após a queimada. Por outro lado, não foram percebidas diferenças entre os eventos fenológicos vegetativos dos sítios no segundo ano após a ocorrência do fogo, o que indica que os efeitos do fogo foram expressivos apenas por curto período. Os nossos resultados mostraram que o efeito do fogo sobre os eventos fenológicos vegetativos é negativo e mais intenso logo após a ocorrência da queimada, mas também que estes efeitos são temporários, e não são mais percebidos após o primeiro ano da ocorrência do fogo.We evaluated the effects of fire on the vegetative phenological behavior (crown foliage cover, sprouting, mature and young leaves) of woody species at two sites in the Brazilian savanna, one of which had been accidentally burned. We used generalized additive mixed models to test the hypothesis that: 1) fire damages total foliage cover, thus leading to changes in vegetative phenological patterns. As this hypothesis was corroborated, we also tested whether 2) the damage caused by fire to the total crown foliage cover and mature leaves is greater in evergreen than in deciduous species, and 3) the negative effects of fire on vegetative phenology persist after the first fire-free year. The first two hypotheses were corroborated, but the third was not. Fire effects on total crown foliage cover and mature leaves were greatest during the first three months following the fire, and were significantly greater in evergreen species. For shoots and young leaves, the greatest differences found between three and seven months post-fire. On the other hand, no differences were observed in phenological events between burned and unburned sites in the second year post-fire, indicating that marked effects of the fire were only observed over a short period. Our results showed immediate negative effects on the vegetative phenophases, but also that these effects are transient, and cannot be discerned after the first fire-free year

Absorbing Roots Areas and Transpiring Leaf Areas at the Tropical Forest and Savanna Boundary in Brazil

© Copyright 2014 Nova Science PublishersThis is the prepublication draft of a chapter published by Nova Science Publishers in the book Savannas: Climate, Biodiversity and Ecological Significance, published in 2013. Available to purchase at https://www.novapublishers.com/catalog/product_info.php?products_id=39734TROBIT Project (Tropical Biomes in Transition

Composição florística, diversidade e efeitos edáficos em duas comunidades de savanas rochosas na Amazônia e Cerrado, Brasil

Despite the uniqueness and reach of the flora from natural savannas in the Brazilian Amazon, and the existence of studies on its origin and diversity, there are no local studies associating floristic patterns with soil properties in savanna enclaves in the Amazon region of the state of Mato Grosso. Floristic composition and diversity were compared between a woody community from a rocky savanna inselberg in a transition region (RTS) between the two largest South American biomes (Cerrado-Amazon), and an enclave of rocky savanna in the Amazon (RAS), and the effects of soil properties were investigated. Floristic comparisons were also made between the two studied communities and two other rocky savanna communities near the Cerrado-Amazon transition. The flora and physical and chemical soil properties in twenty-five 20 × 20 m subplots (1 ha) in each community were sampled and georeferenced. An evident floristic distinction was found between the two studied communities, with low similarity values and a high number of indicator species. The observed and estimated richness and Rényi diversity profiles indicated lower species diversity in RAS than in RTS. Soils were found to be litholic, poorly drained, dystrophic, alic, extremely acidic, sandy and nutrient poor. Species composition and abundance was associated with soil properties in both communities. The clear difference in species composition and diversity between RTS and RAS seem to be shaped by soil properties, geographic isolation and floristic influence from the Cerrado and the Amazon. These results broaden the knowledge regarding the composition and diversity of woody plants of savannas in Amazonian enclaves and Cerrado inselbergs, and provide an important set of floristic and edaphic descriptors for the phytogeography of rocky savannas.Apesar da singularidade e extensão da flora de savanas naturais na Amazônia brasileira, e da existência de trabalhos sobre sua origem e diversidade, não há estudos locais que associam padrões florísticos com propriedades do solo em enclaves de cerrado na região amazônica no estado de Mato Grosso. Comparamos a composição florística e a diversidade entre uma comunidade lenhosa de um inselberg de savana rochosa em uma região de transição (STR) entre os dois maiores biomas sul-americanos (Cerrado-Amazônia) e um enclave de savana rochosa na Amazônia (SAR) e investigamos os efeitos das propriedades do solo. Além disso, comparamos as duas comunidades estudadas com outras duas comunidades de savanas rochosas próximos da transição Cerrado-Amazônia. A flora e as propriedades físicas e químicas do solo de vinte e cinco subparcelas de 20 × 20 m (1 ha), em cada comunidade foram amostradas e georreferenciadas. Uma evidente distinção florística foi encontrada entre as duas comunidades estudadas, com baixos valores de similaridade e um número elevado de espécies indicadoras. A riqueza observada e estimada e os perfis de diversidade de Rényi indicaram menor diversidade de espécies na SAR do que na STR. Os solos são litólicos, pouco drenados, distróficos, álicos, extremamente ácidos, arenosos e pobres em nutrientes em ambas as comunidades. A composição e a abundância de espécies foram associadas às propriedades do solo. A clara diferença na composição e diversidade entre STR e SAR parecem ser moldadas pelas propriedades do solo, isolamento geográfico e influências florísticas do Cerrado e Amazônia. Esses resultados ampliam o conhecimento sobre a composição e diversidade de plantas lenhosas de savanas em enclaves da Amazônia e inselbergs do Cerrado e fornecem um importante conjunto de descritores florísticos e edáficos para a fitogeografia de savanas rochosas