Caatinga Forest Research Articles

Viabilidade econômica de um sistema silvipastoril com e sem a inclusão de crédito de carbono

ABSTRACT This study analyzes the economic viability of exotic and native caatinga forest species grown in silvopastoral systems, combined with the Guinea grass forage crop, compared to monoculture forestry systems, using carbon credits as an alternative source of extra income, aiming for an economic return on the sale of standing timber for firewood production. The experiment was conducted at the Experimental Station of the Pernambuco Agricultural Research Institute (IPA) in Belém do São Francisco, located in the semi-arid region of the state of Pernambuco, in the Itaparica micro region. Four tree crops were chosen, two of which are native to the Caatinga biome: Angico (Anadenanthera colubrina var. Cebil) and Aroeira (Myracrodruon urundeuva Allemão), and two exotic eucalyptus clones, E. urophylla x E. tereticornis. Guinea grass (Panicum maximum Jacq) was chosen as the forage. The intercropping of Guinea grass with the two eucalyptus clones proved to be economically viable in all the economic parameters analyzed, and this is the most suitable for marketing standing wood for firewood production. It is not economically advisable to sell the standing wood for firewood production in the monoculture and silvopastoral systems with the native species (Angico and Aroeira) at 96 months of age due to the system's economic unfeasibility. By adding the possibility of financial credit through the atmospheric carbon sequestered by the trees, it is possible to make all the costs of forestry crops in silvopastoral and monoculture systems economically viable.

Water storage of a typical tree species in the Caatinga biome (Caesalpinia pyramidalis Tul.)

AbstractOur understanding of the movement and storage of water in typical Caatinga plants is still limited and often disregarded in water balance calculations. This is why the objective of this work was to evaluate the water storage dynamic in typical trees of the Caatinga biome during the dry, rainy and transition period by gauging the water content levels that cause the onset of leaf emergence. In a preserved Caatinga forest, soil and stem water content of six trees of the representative species catingueira (Caesalpinia pyramidalis Tul.) were monitored with low‐cost capacitive sensors. Leaf moisture, leaf area index, leaf and stem water volume, and sap flow density were measured. The emergence of leaves occurred with a stem moisture of 0.32 m3 m−3, and the leaf area index was maximum with a stem moisture of 0.34 m3 m−3. Catingueira plants are able to absorb water below the soil water potential commonly determined as the permanent wilting point (−1.5 MPa). The volume of water stored in the plants represents 108% of the average volume stored in the Boqueirão reservoir during the study period.

The role of chronic anthropogenic disturbances in plant community assembly along a water availability gradient in Brazil’s semiarid Caatinga region

The effects of anthropogenic disturbances on the structure and function of seasonally dry tropical forests (SDTFs) are mediated both by disturbance type and intensity, and the environmental conditions, including climate. In a climate change scenario, the interaction between low water availability and chronic anthropogenic disturbances may potentially have drastic consequences on SDTF dynamics and the ecosystem services it provides. We hypothesized that in these naturally stressed systems, the effects of human disturbance are strongest in the most water-stressed sites, implying a worrisome synergism between harsh abiotic conditions (lower precipitation, higher temperature) and human effects, ultimately resulting in a less developed community structure and reduced diversity. By integrating information for the adult and regenerating vegetation strata in 21 sites distributed across climatic, plant cover and disturbance gradients in the Caatinga (seasonally dry tropical) forest of Brazil, we analyzed the individual and combined effects of chronic anthropogenic disturbances, as measured through the Cattle Pressure Index and the Human Activity Index, along climate gradients, on community structure, diversity, and composition. As expected, the Cattle Pressure Index was negatively related to diameter at ground level, basal area, and diversity in the adult stratum, whereas for the regenerating stratum, litter stock had the strongest effect on vegetation structure. Climatic factors were poor predictors of the variation in the three true diversity measures (0D, 1D, and 2D) of the regenerating community. Our results revealed important cross-site differences in both vegetation strata over a small range of climatic variation. We conclude that the most stressful conditions associated with a very low precipitation regime enhance the effects on chronic disturbances, gradually driving SDTF communities into new alternative states and rendering these environments more prone to desertification.

Effect of climate and phenological stage on fungal endophytes community in Sorghum bicolor leaves

Endophytic fungi comprise a group of microorganisms of great diversity, which can be modulated by biotic and abiotic factors. The present study aims to understand how environmental factors, blooming and cultivars change the diversity of the endophytic fungal communities in sorghum leaves in two forest areas in Brazil. Our results showed that Sorghum bicolor has a rich and diverse community of endophytic fungi distributed in Ascomycota, Basidiomycota and Mucoromycota, with members of Dothideomycetes and Sordariomycetes as dominant groups. We found 581 endophytic fungi (filamentous and yeasts) identified in 55 species of 37 genera. A greater diversity and richness of endophytic fungi were found in sorghum leaves from the Atlantic Forest (diversity = H′ = 2.68 and richness = 46), differing significantly from the Caatinga forest (diversity = H′ = 2.51 and richness = 25). No difference in richness or diversity was observed between the two crops or between the phenological stages. We detected different species indicator for the two areas, nine taxa were associated with sorghum in the Atlantic Forest (Colletotrichum sp. 2, Epicoccum sorghinum, Curvularia sp., Colletotrichum sp. 1, Fusarium thapsinum, Nigrospora oryzae, Phyllosticta capitalensis, Fusarium oxysporum and Amesia nigricolor) and five taxa were indicators of sorghum in the Caatinga Forest (Meyerozyma sp., Talaromyces pinophilus, Metschnikowia sp., Rhodosporidiobolus sp. and Acremonium pinkertoniae). One species was an indicator of the cultivar IPA 2502 and no species were related to the cultivar IPA SF15. In relation to pre-blooming and post-blooming stages, two species were considered indicators for the former while six were considered for the latter. We observed that the number of filamentous fungi increases with the post-blooming stage and higher rainfall, while the diversity of endophytic yeasts was influenced by smaller rainfall and pre-blooming stage. Our data improves the understanding of factors that may influence the endophytic fungal community in ecologically and economically important grass species. The endophytic fungal diversity associated with sorghum is important to the mycodiversity estimation and may be useful in studies of biocontrol of pathogens and promotion of crops growth.

Hohenbergia erecta (Bromeliaceae: Bromelioideae), a New Once-branched Species from Chapada Diamantina, Bahia State, Brazil

Hohenbergia is one the most diverse genera in Bahia state, and inhabits almost all regions of the state. As a result of ongoing studies on Hohenbergia in Bahia, Brazil, here we describe and illustrate Hohenbergia erecta, endemic to the municipality of Mucugê, at Chapada Diamantina. Hohenbergia erecta differs from its morphologically related, H. catingae, by an elongated tubular rosette (vs short stem with a crateriform rosette), and a once-branched cylindrical inflorescence (vs 2–3-branched pyramidal inflorescence), with branches congested at the apex (vs branches laxly arranged). Due to a small distribution area in the Caatinga forest and based on a spatial analysis we categorized it as Endangered (EN), following the IUCN criteria. Hohenbergia erecta is endemic to the central region of Chapada Diamantina, dominant in the area, where no other known Hohenbergia species have been found sympatrically. It is important, however, that new field expeditions are conducted in the region to observe the richness of the genus at Chapada Diamantina.

A Expansion of the geographic distribution and conservation status of Paullinia cearensis Somner & Ferrucci (Sapindaceae)

Paullinia cearensis Somner & Ferrucci (Sapindaceae) is an endemic species of Northeastern Brazil, hitherto known from the states of Ceará and Piauí, in areas of Caatinga and Atlantic Forest. The species is being recorded for the first time in the state of Maranhão and in the Brazilian Cerrado. It was collected in Morro do Alecrim, a remnant of Cerrado, in Caxias-Maranhão, during a botanical expedition in January 2021, where the species was found with fruits. A morphological description, taxonomic comments, data on geographic distribution, detailed images of the species, and an assessment of its conservation status, categorized as endangered, are presented. This data will contribute to the knowledge and conservation of this species for the northeastern flora.

Prediction of diametric and dynamic structures in a semiarid forest (Caatinga) area submitted to Forest Management, Brazil

Dynamics studies associated with prognosis can support planning actions for the conservation and sustainable use of forest resources. Therefore, the objective of this study was to evaluate the dynamics and predict the diameter structure using the Markov chain model for an area of caatinga forest submitted to different management practices. The study was carried out in the Contendas do Sincorá National Forest in the state of Bahia. Four treatments were installed, corresponding to three management systems and one control. Data was obtained measuring all individuals with a diameter greater than or equal to 5 cm. The measurements were performed at two moments in 2015 and 2018. The results indicated that the selective cut-by-diameter treatment had the lowest mortality rate and the highest recruitment rate. Predictions of the diameter structure using the Markov chain do not generally present statistical differences (α0.01) between the observed and expected frequencies for the year 2018. It was concluded that the basal area showed a tendency for recovery and growth in the treatments which involved suppression compared to the control, with no statistically significant differences among treatments until the moment after intervention.

Bioindicators of Behavior and Regeneration of a Caatinga Area in the Brazilian Semi-Arid - A Review

Studies that allow the understanding of the nutrient cycling processes and maintenance of soil fertility in the caatinga biome are necessary to assist in the proposal of possible management forms, in view of the sustainability of this ecosystem, to provide data in an area of knowledge the quantification of glomalin can be a good indicator of changes caused by the use of the soil and, in turn, therefore, it can become a good indicator of its recovery because it is correlated with important attributes of the soil. In addition to providing data of this process for a better understanding of the soils of the country, a study on this subject will also contribute with a new database for global monitoring. Research that can follow the regeneration rate of Caatinga forests in the Semi-arid will allow the development of models relating to several variables, not currently available for the semi-arid tropical region.

Biomass and vegetation index by remote sensing in different caatinga forest areas

ABSTRACT: Continued unsustainable exploitation of natural resources promotes environmental degradation and threatens the preservation of dry forests around the world. This situation exposes the fragility and the necessity to study landscape transformations. In addition, it is necessary to consider the biomass quantity and to establish strategies to monitor natural and anthropic disturbances. Thus, this research analyzed the relationship between vegetation index and the estimated biomass using allometric equations in different Brazilian caatinga forest areas from satellite images. This procedure is performed by estimating the biomass from 9 dry tropical forest fragments using allometric equations. Area delimitations were obtained from the Embrapa collection of dendrometric data collected in the period between 2011 and 2012. Spectral variables were obtained from the orthorectified images of the RapidEye satellite. The aboveground biomass ranged from 6.88 to 123.82 Mg.ha-1. SAVI values were L = 1 and L = 0.5, while NDVI and EVI ranged from 0.1835 to 0.4294, 0.2197 to 0.5019, 0.3622 to 0.7584, and 0.0987 to 0.3169, respectively. Relationships among the estimated biomass and the vegetation indexes were moderate, with correlation coefficients (Rs) varying between 0.64 and 0.58. The best adjusted equation was the SAVI equation, for which the coefficient of determination was R² = 0.50, R2aj = 0.49, RMSE = 17.18 Mg.ha-1 and mean absolute error of prediction (MAE) = 14.07 Mg.ha-1, confirming the importance of the Savi index in estimating the caatinga aboveground biomass.

Long-term effects of grazing on the biological, chemical, and physical soil properties of the Caatinga biome

Soil degradation is a global issue that affects both plant productivity and human life. Intensive grazing practices can accelerate this process, mainly due to rapid removal of biomass from the soil surface. However, the long-term effects of grazing on biological, chemical, and physical properties remain poorly understood, particularly in tropical drylands, such as the Caatinga biome. Our aim was to evaluate the soil properties and combine both culture-dependent and -independent analyses to assess metabolic activity and bacterial community structure. We collected samples (0–20 cm) of three different types of soil in the Caatinga biome: secondary Caatinga forest (NC), grazing exclusion (GE), and degraded areas by overgrazing (OG). We sought to investigate how grazing affects soil properties to determine the effectiveness of grazing exclusion in the restoration of soil fertility/functions. Redundancy analysis demonstrated NC were positively correlated with organic carbon (λ = 0.18, p = 0.0012) and total nitrogen (λ = 0.16, p = 0.0011), while OG was correlated with harmful soil parameters such as Na+ (λ = 0.08, p = 0.0400), electric conductivity (λ = 0.13, p = 0.0060) and exchangeable acidity (λ = 0.11, p = 0.0030). In addition, GE showed lower aluminum content and saturation, reducing these harmful parameters by 48 % and 34 %, respectively. Also, GE showed the highest values for the β-glucosidase (63.62 mg ρ-nitrophenol kg−1 h−1) and arylsulfatase (5.8 mg ρ-nitrophenol kg−1 h−1) activities. Changes in bacterial community structure were significant (p = 0.0096), with a higher difference comparing GE and OG (p = 0.0135). The GE area showed 20 % more phosphate solubilizers than OG, but there were no differences for siderophores production. All isolates were halotolerant and had at least 60 % nitrogen fixers. Our findings indicate that while soil recovery is slow, with grazing-exclusion areas presenting 18 years of implantation, it seems to improve in subsequent years. Finally, our results provide evidence that microbe-based technologies can mitigate soil degradation in the Caatinga biome.

Anthropogenic Dispersal of Leishmania (Viannia) braziliensis in the Americas: A Plausible Hypothesis

There are several gaps in our knowledge on the origin and spread ofLeishmania (Viannia) braziliensis, an etiological agent of cutaneous and mucocutaneous or American tegumentary leishmaniasis, to different biomes, hosts, and vectors, with important epidemiological implications, including the possible existence of an anthroponotic component. Historical, biological, and epidemiological evidence suggests thatLeishmania (V.) braziliensisand its variants were preexistent in Amazonia with great genetic variability, where they dispersed with less variability to other regions (clonal expansion). During pre-Columbian times the parasite may have been transported by migrating humans and probably also their dogs, from western Amazonia to the high inter-Andean valleys and from there to other regions of South America. The same thing could have happened later, in the same way, when it spread to non-Amazonian regions of Brazil and other countries of South and Central America, between the late 19th and early 20th centuries, during the so-called Rubber Boom and construction of the Madeira-Mamoré Railway in the Brazilian Amazon, by migrant workers who later returned to their places of origin, transporting the agent. The parasite’s dispersal in genetic correlated clusters, involving unexpectedly distinct ecosystems in Brazil (Amazonian, Cerrado, Caatinga and Atlantic Forest biomes), has continued until the present through human displacement. The infection of certain species of domestic, synanthropic and even wild animals, could be secondary to anthropogenic introduction ofL. (V.) braziliensisin new environments. We admit the same phenomena happening in the probable transference ofLeishmania infantum(visceral leishmaniasis), and of Yersinia pestis (plague) from the Old world to the New world, generating domestic and wild enzotic cycles from these agents. These assumptions associated with human infections, chronicity and parasite persistence with possibility of recovery ofLeishmaniain peripheral blood, skin and scars of cured or asymptomatic patients, (that may provide an alternative blood meal), along with the sand flies’ adaptation to the peri-domicile and the high susceptibility of domestic dogs, horses, mules and cats to the parasite, can reinforce the evidence of anthropogenic spread ofL. (V.) braziliensis.

Estudos ecogeográficos de Eplingiella fruticosa (Salzm. Ex Benth. Harley& J.F.B. Pastore): Uma espécie medicinal do semiárido do Brasil

A Lamiaceae é uma família de plantas com importantes aptidão medicinal, entre elas, a Eplingiella fruticosa (Salzm. Ex Benth. Harley& J.F.B. Pastore). Como a exploração desse vegetal dá-se de forma extrativista, existe um potencial risco de erosão genética, o que torna essencial estudos que incrementem estratégias de conservação, domesticação e melhoramento. O objetivo foi realizar estudos ecogeográficos com vistas a identificar interações do ambiente que possam ser preditivas do crescimento e desenvolvimento da espécie. Foram levantados dados edáficos, climáticos, relevo, geomorfológicos, fitogeográficos e biomas, nos sítios de ocorrência natural, nas mesorregiões do centro-norte, nordeste, metropolitana de Salvador na Bahia e mesorregiões leste e agreste no estado de Sergipe. As informações foram coletadas em visitas in situ e coletados em sites especializados como IBGE, INPE, INMET e EMBRAPA. Os dados foram submetidos a análise estatística (PCA). Concluiu-se que o ambiente de crescimento da espécie, tipifica-se como de solos arenosos, baixa fertilidade, elevado concentração e teor de alumínio (Al+3), nos domínios do bioma caatinga, mata atlântica e agreste dos estados Ba e SE, em uma larga faixa de adaptação às variantes de temperatura, chuva e altitude.

Evaluating single and multi-date Landsat classifications of land-cover in a seasonally dry tropical forest

Accurate information on the land cover is crucial for efficient monitoring and development of environmental studies in the Brazilian Caatinga forest. It is one of the largest and most biodiverse dry forests on the planet. Distinguishing different patterns of land cover through medium spatial-resolution remote sensing, such as the Landsat image series, is challenging to Caatinga due to heterogeneous land cover, complex climate-soil - vegetation interactions, and anthropogenic disturbance. Two remote sensing approaches have a high potential for accurate and efficient land-cover mapping in Caatinga: single and multi-date imagery. The heterogeneity of the land cover of this environment can contribute to a better performance of multispectral approaches, although it is usually applied for single-date images. In a land-cover mapping effort in Caatinga, the temporal factor gains relevance, and the use of time series can bring advantages, but, in general, this approach uses vegetation index, losing multispectral information. This manuscript assesses the accuracies and advantages of single-date multispectral and multi-date Normalized Difference Vegetation Index (NDVI) approaches in land-cover classification. Both approaches use the Random Forest method, and the results are evaluated based on samples collected during field surveys. Results indicate that land-cover classification obtained from multi-date NDVI performs better (overall accuracy of 88.8% and kappa of 0.86) than single-date multispectral data (overall accuracy of 81.4% and kappa coefficient of 0.78). The Z-test indicated that the difference in performance between the two approaches was statistically significant. The lower performance observed for single-date multispectral classification is due to similarities in spectral responses for targets of deciduous vegetation that lose their foliage and can be misread as non-vegetated areas. Meanwhile, an accurate classification by time series of plant clusters in seasonal forests allows incorporating seasonal variability of land-cover classes during the rainy and dry seasons, as well as transitions between seasons. The most important variables that contributed to the accuracy were the red, Near Infrared (NIR) and Short-Wave Infrared (SWIR) bands in single-date multispectral classification and the months in the dry season were the most relevant in multi-date NDVI classification.

Temporal dynamics of evapotranspiration in semiarid native forests in Brazil and Spain using remote sensing

AbstractEvapotranspiration (ET) plays an important role in integrated water resource planning, development and management. This process is particularly relevant in semiarid regions. The aim of this study is, hence, to compare spatial and temporal patterns of actual ET, as well as the temporal trends in two different semiarid forests, Caatinga (Brazil) and Tierra de Pinares (Spain). We used the surface energy balance algorithm for land (SEBAL) to assess actual evapotranspiration (ETa) in both areas. In the Brazilian semiarid forest, Caatinga is the main vegetation, while it is Pinares in Spain. For this purpose, 69 Landsat‐5 and 42 Landsat‐8 images (1995–2019) were used. The Mann–Kendall test was applied to assess the occurrence of trends in precipitation, temperature and potential ET data; and the Temporal Stability Index (TSI) to know which areas have greater seasonal ETa. The annual amplitude of the potential evapotranspiration (ET0) is the same in both areas, however, the Caatinga values are higher. In the Caatinga forest, when ET0 presents its highest values throughout the year, ETa presents the lowest, and vice versa. In the Pinares forest, ETa follows the ET0 dynamics during the year, and the difference between ET0 and ETa is maximum during the summer. The Caatinga forest showed a greater spatial variation of ETa than the Pinares forest as well as a greater extension with lower temporal stability of ETa than the Pinares forest. Both the Caatinga forest and the Pinares forest showed significant positive trends in annual ET0 and ETa. We estimate that the value of ETa increases more rapidly in Pinares than in the Brazilian Caatinga. Taking Caatinga as a hydrological mirror, some consequences are expected to Pinares, such as significant changes in the water balance, increase of biodiversity vulnerability, and reduction of water availability in soil and reservoirs.

Variability and spatial distribution of hydrodynamic properties in soil with preserved Caatinga

ABSTRACT The functions of soil water retention and hydraulic conductivity are indispensable for the characterization and modeling of the infiltration and water transfer processes in the vadose zone. In the case of the Brazilian semi-arid region, characterized by the scarcity of water resources, there is a lack of information on the hydrodynamic properties of the soil. Also, these properties have numerous factors of variability, requiring the characterization of their magnitude and distribution in space. This research presents an analysis of the infiltration process and the hydrodynamic properties of the soil under native Caatinga forest, observing its spatial distribution. This vegetation is typical of the Brazilian semi-arid region. One developed a 48-point grid in an area of approximately 875 m2, and applied on it the Beerkan methodology. The analyzes were performed based on the application of the BEST-Slope algorithm and statistical measures of the position, dispersion, and adherence tests. The results showed medium to high variability indices for the hydrodynamic properties, with random spatial distribution, despite the verification of a homogeneous texture in the area. Thus, it was found that the soil structure was predominant in the processes of water infiltration.

Soil properties and microclimate of two predominant landscapes in the Brazilian semiarid region: Comparison between a seasonally dry tropical forest and a deforested area

The Brazilian semiarid region has been subjected to strong man-made actions since the 1970s, which have resulted in landscape transformation. The scientific literature presents several studies on the soil properties or microclimate of different types of landscapes; however, less attention was having been paid to the surface contrast between native vegetation and bare soil. The objective of this research was to evaluate the soil properties and microclimate of two common landscapes in the Brazilian semiarid region, a seasonally dry tropical forest (Caatinga) and a deforested area. Soil and microclimate data were obtained from two sites, both located in the State of Pernambuco, Brazil. Soil samples were collected on six dates and from layers, and microclimate variables were measured for three years. Soil properties and microclimatic data were evaluated using the Mann-Whitney test, as well as regression and principal component analysis. Successive years of agricultural practices affected the bulk density, promoting an increase in the total porosity of the soil in the deforested area site. In addition, changes were verified in the magnitude of many chemical properties (pH, P, K+, Mg2+, Cu2+, Fe, Mn, Zn2+ and Ca2+), indicating soil degradation. Compared with the Caatinga forest site, the minimum air temperature was 2.3 °C, and the maximum vapor pressure deficit was 7% higher in the deforested area site, and it is very likely that Caatinga removal there will lead to a reduction in precipitation. The results suggest that Caatinga vegetation removal followed by agricultural practices and subsequent land abandonment promotes significant changes in soil properties and the microclimate, which can contribute to advances in desertification and affects agricultural activities in the Brazilian semiarid region.

Germinação de sementes de Amburana cearensis (Allemao) A. C. Sm. submetidas a diferentes substratos

Espécies florestais da Caatinga são comumente utilizadas para a recuperação de áreas degradadas, normalmente para a produção das mudas as sementes são colocadas para germinar em substratos. Com isso, objetivou-se com essa pesquisa avaliar diferentes tipos de substratos para a germinação de sementes de A. cearensis, buscando a determinação do mais adequado para promover o desenvolvimento inicial da espécie. O experimento foi realizado em delineamento inteiramente casualizado, com cincos substratos, sendo, areia, vermiculita textura fina, vermiculita textura grossa, húmus e fibra de coco, com quatro repetições de 25 sementes. Após a semeadura realizou-se irrigações diariamente até ao 30o dia após o semeio. Foram avaliados, porcentagem de emergência, tempo médio de emergência, índice de velocidade de emergência, altura das plântulas, comprimento radicular, massa seca da parte aérea e do sistema radicular e a massa seca total das plântulas. O substrato vermiculita textura média proporcionou os melhores resultados quanto a porcentagem de emergência, o índice de velocidade de emergência, o comprimento da parte aérea e do sistema radicular. A vermiculita textura média é o substrato mais indicado para o desenvolvimento inicial de A. cearensis.

<p><strong><em>Tillandsia itatiensis</em></strong><strong>: a new species of <em>Tillandsia</em> L. (Bromeliaceae) from Bahia, Brazil</strong></p>

The authors describe, discuss, and illustrate Tillandsia itatiensis, a new species from the Caatinga biome in the municipality of Itatim, Bahia, Brazil. The new species is similar to T. streptocarpa and T. grao-mogolensis, regarding morphological characters such as caulescent habit, curved stem, simple inflorescence with no more than five flowers per inflorescence and simple-erect stigma. It inhabits inselbergs in Caatinga forest, where it is critically endangered (CR) due its small distribution and human extractivism.

Análise de séries temporais de focos de calor em biomas brasileiros utilizando o Grafo de Visibilidade Horizontal

As queimadas são processos complexos que podem ter causas naturais ou serem resultado da interferência humana. O efeito do fogo em um ecossistema varia de acordo com sua sensibilidade, mas a recorrência do fogo pode afetar o equilibrio ambiental e a saúde humana. Buscando reduzir os efeitos negativos das queimadas, faz-se necessário monitorar sua ocorrência e compreender sua dinâmica. No Brasil, o monitoramento é realizado via satélite, com que se detectam os focos de calor. Esse processo é realizado pelo Instituto Nacional de Pesquisas Espaciais (INPE), que disponibiliza os dados utilizados neste trabalho. Com o objetivo de estudar a variabilidade temporal das queimadas nos biomas Amazônia, Cerrado, Caatinga e Mata Atlântica, utiliza-se neste trabalho o método Grafo de Visibilidade Horizontal, com que se transformam as séries temporais de focos de calor desses biomas em redes complexas. Delas, extraem-se as medidas topológicas com as quais é possível avaliar se a dinâmica que governa cada rede gerada representa um processo estocástico ou caótico. Tais medidas são: o Coeficiente λ da distribuição de grau do nó, o Coeficiente de Agrupamento e o Comprimento Médio do Caminho. Os resultados obtidos mostraram que as propriedades topológicas das redes variam de acordo com o número de focos de calor e com a relação (n° de focos de calor)/(área do bioma). A dinâmica de queimadas apresentou características de um processo estocástico correlacionado para os biomas Amazônia, Cerrado e Mata Atlântica, e um processo caótico para o bioma Caatinga.

Tauritermes bandeirai: A new drywood termite (Isoptera, Kalotermitidae) from the Caatinga and Atlantic Forest of Brazil

The imago and soldier castes of a new Tauritermes Krishna, 1961 species, Tauritermes bandeiraisp. nov. are described. It is the fourth species of Tauritermes and occurs from the Caatinga and Atlantic Forest of Brazil. Unlike its congeners, the soldier of T. bandeirai has prominent frontal horns.