Navegando por Assunto "Cerrados"

Agora exibindo 1 - 20 de 23

Acesso aberto (Open Access)
Análise biogeográfica da avifauna de uma área de transição cerrado-caatinga no Centro-Sul do Piauí, Brasil
(Universidade Federal do Pará, 2001-01-16) SANTOS, Marcos Pérsio Dantas; SILVA, José Maria Cardoso da; http://lattes.cnpq.br/6929517840401044
Acesso aberto (Open Access)
Anatomia foliar de cinco espécies de Polygala de restinga e cerrado
(2012-06) DIAS, Ana Cristina Andrade de Aguiar; YAMAMOTO, Kikyo; CASTRO, Marília de Moraes
The ecological plasticity observed in plants that inhabit different vegetation formations is often accompanied by morphological variations, the leaf being the vegetative organ with the greatest structural variation. In view of this concept, the leaf anatomy of five species of Polygala L. occurring in restinga (sandy coastal plain) and cerrado (savanna) areas in the state of São Paulo were analyzed in order to inventory their principal characters and describe their leaf structure, to thus compare them and assess the possibility of verifying structural patterns common to the ecological conditions of both vegetation formations. The species studied were: P. cyparissias A.St.-Hil. & Moq., P. laureola A.St.-Hil. & Moq., P. paniculata L. found in restinga, and P. angulata DC. and P. violacea Aubl. emend. Marques occurring in campo cerrado and cerradão margin areas, respectively. The middle region of the leaf blade and petiole proximal region of each leaf were processed following the usual techniques for scanning electron and light microscopy. The results show two structural patterns common to the species from the restinga and cerrado area formations: mesomorphic characteristics are observed in P. laureola, P. paniculata, and P. violacea, and xeromorphic in P. cyparissias and P. angulata.
Acesso aberto (Open Access)
Baetidae (Insecta, Ephemeroptera) em córregos do cerrado matogrossense sob diferentes níveis de preservação ambiental
(2011-09) SOUZA, Hilton Marcelo de Lima; CABETTE, Helena Soares Ramos; JUEN, Leandro
The effect of different stream environmental preservation levels, in 1st to 4th orders, over the richness, abundance, similarity in the composition and the potential of Baetidae (Ephemeroptera) species as bioindicators were investigated in a Cerrado region located in the state of Mato Grosso, Brazil. A total of twenty species/morphospecies were catalogued from the 1752 samples of nymphs, resulting in a new record for two species in Brazil. Values of Habitat Integrity Index (HII) were categorized among damaged, modified, and preserved environments. Species richness was different between sites, being greater in disturbed habitats. Total abundance was higher among preserved and altered environments, and differed significantly from the degraded areas. The NMDS analysis indicates that, in preserved and modified sites, the similarity in the composition of species differs from degraded areas. Four species showed a positive relationship with increasing values of HII. Baetidae showed environmental indicator species with different levels of preservation, with Zelusia principalis Lugo-Ortiz & McCafferty, 1998 and Baetodes sp. being indicators of preserved environments and Aturbina nigra Salles, Boldrini & Shimano, 2011, Callibaetis sp. 2, Camelobaetidius aff. janae, Paracloeodes binodulus Lugo-Ortiz & McCafferty, 1996 and Waltzoyphius roberti Thomas & Peru, 2002 as indicators of modified environments. The knowledge on the ecology of species advances in terms of providing subsidies for the biomonitoring of basins and the use of indicator species.
Acesso aberto (Open Access)
Califorídeos (Diptera, Oestroidea) associados a cadáveres suínos em uma área de cerrado na Reserva Ecológica do Inhamum, Caxias, Maranhão, Brasil: subsídios para aplicação em processos forenses
(Universidade Federal do Pará, 2012-05-22) SILVA, José Orlando de Almeida; ESPOSITO, Maria Cristina; http://lattes.cnpq.br/2112497575917273
The objective of this study was to determine the fauna and the pattern in the temporal distribution of blow flies collected visting or reared from pig carcasses in a cerrado area at the Reserva Ecológica do Inhamum (REI), Caxias, MA. Two experiments were performed, one in the dry season (July and August of 2010) and the another in the rainy season (March and April of 2011). In each experiment three pig carcasses weighing 12 kg each were utilized. The carcasses were placed inside wire metal cages to prevent the access of large scavengers. A suspended trap was placed above each cage to capture adult blow flies that visited the pig carcass. Trays containing sawdust were placed under the cages in order to collect larvae leaving the carcass for pupation. A total of 51,234 specimens was collected. Of these, 25,093 adults were collected in the suspended traps and 26,141 adults were reared from the carcasses. The following species were identified: Chloroprocta idioidea (Robineau-Desvoidy, 1830) Chrysomya albiceps (Wiedemann, 1819), Chrysomya megacephala (Fabricius, 1794), Chrysomya rufifacies (Macquart, 1843), Cochliomyia macellaria (Fabricius, 1775), Hemilucilia benoisti Séguy, 1925, Hemilucilia segmentaria (Fabricius, 1805), Hemilucilia townsendi Shannon, 1926, Lucilia eximia (Wiedemann, 1818) and Lucilia sp1. Chrysomya rufifacies and H. townsendi are new records for Brazil. Cochliomyia macellaria and C. idioidea were the most abundant among the adults collected in traps, and C. albiceps and C. rufifacies were most abundant among reared specimens. The species of Hemilucilia were the only ones not reared from the carcasses. The mean time of decomposition of the pig carcasses was 10 days, and there was no difference between carcasses exposed in dry and rainy seasons. In adition, the duration of each decomposition stage did not vary between the two seasons. The duration of the stages was different, and the fermentation stage was the longest. Lucilia eximia, C. idioidea and C. macellaria, collected in the traps, were the pioneers in colonizing the pig carcasses, and they were found in all stages of decomposition. However, only L. eximia showed an association with the Initial stage, according to the IndVal index. The larvae of L. eximia were the first to leave the carcasses for pupation, followed by C. macellaria, C. albiceps and C. rufifacies. According to the IndVal index, the adults of H. townsendi and H. benoisti collected in the traps, were the only species that showed an association with only one stage, the Bloated stage. Chrysomya rufifacies and C. megacephala showed an association with the Black Putrefaction and Fermentation stages. The other species showed an association with four stages. With respect to species reared from carcasses, L. eximia and C. macellaria were the only ones that showed an association with the Bloat stage, and C. rufifacies and C. albiceps were the only species that had an association with the Dry Decay stage. The abundance values of L. eximia, C. idioidea, C. macellaria, C. albiceps, and C. rufifacies, collected in the traps, were different between the stages of decomposition, and the Black Putrefaction was the more attractive to these species. The abundance values of C. albiceps, C. rufifacies, and L. eximia, reared from the carcasses, were different between the stages, and the Dry Decay and Black Putrefaction stages showed the higher abundance of Chrysomya species and L. eximia, respectively. The species of L. eximia and C. idioidea, collected in the traps, and reared specimens of C. rufifacies were more abundant in the rainy season. With respect to the specimens collected in the traps, the ordination analyses showed that the community of blow flies has higher similarity between the Black Putrefaction, Fermentation and Dry Decay stages, due to higher richness and abundance values. However, with respect to the reared species, the community of the Fermentation and Dry Decay stages were the most similar. These results contribute to understanding the successional process of visitors adults and reared larvae of blow flies during the decomposition of pig carcasses in a cerrado area of the state of Maranhão.
Acesso aberto (Open Access)
A composição de Scarabaeidae (Coleoptera) coprófagos na região de Alter do Chão, Pará: a influência dos biomas Amazônia e cerrado e da sazonalidade e os efeitos de tamanho de área, isolamento e proximidade de estradas
(Universidade Federal do Pará, 2006-05-22) TEIXEIRA, Frederico Machado; VALENTE, Roberta de Melo; http://lattes.cnpq.br/9638288458835324; ALBERNAZ, Ana Luisa Kerti Mangabeira; http://lattes.cnpq.br/1220240487835422
This work had as objective to investigate the effect of the size of the forest islands, of its distances for the continuous forest (isolation) and for the adjacent roads on the coprófagos community of Scarabaeidae. Samples had been collected in 24 islands of semideciduous forest, between 0,5 and 360 ha, in an Amazonian savanna matrix and eight places in predominantly secondary, semideciduous continuous forest, in the region of Alter do Chão, Santarém, Pará. The Scarabaeidae had been collected with pitfall traps with bait (human dung) in two seasonal periods (dries and rain). For each point of collection 10 traps had been installed in two 250 m transects, distant 100 m between itself. 5 traps in each transect that had been placed 50 m apart. For each place of collect was registered the DAP (Height Brest Tree Diameter), of all trees with equal or superior diameter of the 5 cm, in four 250 transectos of 2 x m, being these used data to derive the indices from the structure of the vegetation (average diameter and number of individuals). The area, perimeter and the distances of the islands for the continue forest had been calculated using respectively the extensions "X-Tools" and "Nearest Features v3.6d" for ArcView, on the map of the area digitalized from an image of Landsat TM of 1996. The collected units had been identified with the aid of specialized bibliography and specialists. For the characterization of the fauna, the joined species had been compared with a list of species generated from publications for the Cerado, Amazonia and Brazilian ecotone (cerrado-floresta). To evaluate the robustness of the sampling, curves of rarefação had been used and gotten estimates of wealth using itself diverse estimators. For the analysis of the standards of the communities, an analysis HNMDS (Semi-strong Hibrid Multidimensional Scaling) using itself in the distance of Bray-Curtis was used. 18 pertaining sorts and 36 species to biomas of the Cerrado and Amazonia had been found, but was not possible to have a complete notion of the parcel of each biome represented in this ecotone of transition savanna-forest, once that the samples had not been enough for the exhausting survey of the wealth of Scarabaeidae. The ordinance showed a trend of grouping of the continuous forests and separation of these of the forest islands. Although the survey to have registered a bigger number of species in the forest islands that in the areas of continuous forest, the communities had presented a strong hierarchic standard [ P (T< 14,87°)<0,001 ], indicating that in the islands they are persisting only one parcel of the total of species of the region. A relation was not found enters the composition of Scarabaeidae and the size and the form of the forest islands. But a significant relation between the composition (axle 1) and the isolation (F=5,363, P=0,031) and the composition (axle 1) and the number of trees was found (DAP > 5 cm) (F=6,103, P=0,012, corrected for Bonferroni). The number of trees of each place of sampling was related with the proximity of roads (0,658), what it strengthens the idea of that the roads are contributing for changes in the structure of the vegetation, that in turn has a effect on the fauna of Scarabaeidae.
Acesso aberto (Open Access)
Composição e riqueza de espécies de anfíbios anuros em três diferentes habitat em um agrossistema no Cerrado do Brasil central
(2013-03) CAMPOS, Vitor Azarias; ODA, Fabrício Hiroiuki; JUEN, Leandro; BARTH, Adriane; DARTORA, Aline
Adaptive plasticity has been postulated as one of the integrating factors that explain the distribution and abundance of species on different habitat with different environmental variations. The environmental heterogeneity is the most important factor for the maintenance, increment or decrement of biodiversity. On this study we determined the effect of periodicity and habitat structure on the richness and composition of species of three different habitat: stream (P1), temporary ponds (P2) and permanent dam (P3) in an agrosystem in the Central Brazilian Cerrado. We performed nine excursions to the field during November 2005 to April 2007. We found and registered the species by direct search and vocalization orientation. We identified 19 anuran species belonging to four families: Bufonidae (one species), Hylidae (nine species), Leptodactylidae (five species), and Leiuperidae (four species). The greatest richness and abundance were recorded in temporary ponds (P2), which differed significantly from the stream (P1) and from the permanent dam (P3). Dendropsophus nanus, Hypsiboas raniceps and Leptodactylus chaquensis showed strong association with P2. P2 and P3 showed greater differentiation between themselves in species composition than when compared to P1. Despite the fact that the studied areas are surrounded by intense farming and present a high degree of anthropic disturbance, these areas showed a high species richness being an important refugee for the amphibians, although the species found on this work are usually associated to impacted areas or open phytophysiognomies and are favored with the creation of artificial environments such as those in this study.
Acesso aberto (Open Access)
Composição, ecologia e história natural das serpentes de uma região de transição Amazônia - Cerrado, Mato grosso, Brasil
(Universidade Federal do Pará, 2010) ABE, Pedro Santos; COSTA, Maria Cristina dos Santos; http://lattes.cnpq.br/1580962389416378
This study aimed to document the composition and natural history of a community of snakes recorded at Tanguro Farm, Querência municipality, State of Mato Grosso, Brazil, an area which represents a transition between two major neotropical biomes, Amazonia and Cerrado. Six expeditions to the study site were carried out, resulting in the record of 203 specimens (194 captures), distributed in 34 species, 26 genera and 8 families. An estimate based in the incidence of rare species (Jackknife 1) indicated a total richness of 38 species in the study site, which demonstrate that the inventory was relatively exhaustive. The most abundant species were Caudisona durissa (N=50), Philodryas olfersii (N=15), Philodryas nattereri (N=13), Xenodon rabdocephalus (N=12), Lachesis muta (N=10) e Liophis almadensis (N=10). A Principal Coordinates Analysis (PCO) demonstrated that the taxocenosis are superimposed, revealing a trend to formation of three distinct groups: Amazonia’s, Cerrado´s and Mata Atlantica´s taxocenosis. The species composition at Tanguro Farm was intermediary between the groups formed by Amazonian and Cerrado species, occurring species with wide distribution ranges as well as species restrict to either Amazonia or Cerrado. The pattern of habitat use of the studied taxocenosis is terrestrial, followed by semi-arboreous and fossorial. With regards to the feeding strategies, there are a predominance of generalist snake species. An analysis of ecological groupings showed four functional groups, suggesting that the taxocenosis complexity could be explained by ecological and historical factors.
Acesso aberto (Open Access)
Efeito da escarificação e luminosidade na germinação in vitro de sementes de cagaiteira (Eugenia dysenterica DC.)
(2007-12) MARTINOTTO, Cristiano; PAIVA, Renato; SANTOS, Breno Régis; SOARES, Fernanda Pereira; HERRERA, Raírys Cravo; SILVA, Álvaro Augusto Naves
Cagaiteira is a native specie of brazilian cerrado with high yield. Because it seeds show high variability, it is yet considered recalcitrant and dormant, the germination in vitro appears as an alternative for specie propagation, in addition to obtain juvenile explant for micropropagation. The present research aimed to evaluate the effect of scarification and ligth on germination in vitro of cagaiteira seeds. Seeds without teguments and intact seeds were inoculated in MS medium and kept in abscence and presence of radiation. Seeds without tegument germinated in the presence or abscence of ligth showed 86.25% and 88.25% germination at 31 and 71 days of inoculation, respectively. After 150 days of inoculation, plantlets from seeds without tegument germinated in the presence and abscence of ligth, showed 10% and 12% of abnormalities, respectively.
Acesso aberto (Open Access)
Efeito da perda de cobertura florestal sobre a diversidade de peixes de riachos em uma zona de transição Cerrado-Amazônia
(Universidade Federal do Pará, 2019-02-28) FREITAS, Pâmela Virgolino; JIQUIRIÇÁ, Paulo Ricardo Ilha; http://lattes.cnpq.br/3392388693636935; SILVA, Karina Dias da; http://lattes.cnpq.br/2271768102150398
Currently, the expansion of the agricultural frontier in the Amazon represents a profound change in the world’s vegetation cover. This expansion causes decrease of forest cover, affecting the environmental integrity of streams, as well as the richness of associated communities. We aimed to evaluate the effects of loss of forest cover on the physical integrity of streams, and on the taxonomic and functional diversity of fish assemblages in a Cerrado-Amazon transitional zone. We sampled nine streams in the Alto Xingu river basin. The streams possess microbasins covered by different percentages of transitional Cerrado-Amazon forest and croplands. We did not detect the effect of loss of forest cover on the physical integrity of streams, and neither on fish taxonomic diversity. However, we found a negative effect on the functional diversity. The physical integrity of streams was not associated with taxonomic and functional diversity of fish assemblages. The conversion of forest areas to croplands, on the riparian zone, affects negatively the functional richness of fish assemblages, acting as an environmental filter, leading to the disappearance of species that could have performed important ecosystem functions. Furthermore, the establishment of restoring and conservation strategies of areas affected by deforestation must be a priority on all streams drainage systems, especially on the riparian zone scale, to minimize impacts on species. To understand which factors can better structure fish assemblages in streams, it is necessary to do research, that can give basis to formulate strategies for the preservation of those organisms.
Acesso aberto (Open Access)
Efeito do uso do hábitat sobre a comunidade de Gerromorpha (Heteroptera) em uma área de transição Amazônia-cerrado, Mato Grosso, Brasil
(Universidade Federal do Pará, 2008) WANZELER, Elaine Cristina de Miranda; FERNANDES, José Antônio Marin; http://lattes.cnpq.br/6743352818723245
The aquatic and semiaquatic bugs (Heteroptera) belong to three different monophyletic infra-orders: Gerromorpha, Nepomorpha and Leptopodomorpha. In Brazil only a few studies on these groups have been carried out, mostly in the state of Minas Gerais. This study aimed to determine land use intensity effect over the aquatic Heteroptera-Gerromorpha community. The study was carried out at Tanguro farm, state of Mato Grosso, in a area of transition between cerrado and tropical rain forest. Samples were collected on May and July in 2006 and 2007 in six streams within three different environments: soybean plantation, pasture and forest. Five families, 19 genera, 36 species and 13 morphospecies of Gerromorpha were collected. Species accumulation curves for each environment did not reach an asymptote, though they showed a clear tendency to stabilization. Therefore, increasing the number of samples probably will set the real species number close to the observed for the whole study area. Although vegetation coverage was significantly different among the three environments (ANOVA, F2,45= 23,72; P < 0,001), the habitat type did not influence the number of Gerromorpha species (ANOVA F3,44= 0,77; P = 0,52). In addition, the two axis of a MDS analysis based on species composition did not discriminate the habitats. On the other hand, the abundance of seven species was significantly different among habitats. Analysis of the abundance matrix shown (axis 1- MANOVA; F2,45 = 16,27; P < 0,001 and axis 2- MANOVA; F2,45 = 6,31; P = 0,004) segregated forest species. The three habitats shared 57,14% of the species collected. The considerable decrease in number of specimens from the forest to the pasture may be related to the lost of vegetation coverage in disturbed areas. The species Brachymetra lata, Brachymetra sp. 1, Cylindrostethus palmaris, Tachygerris celocis, Rhagovelia paulana, Rhagovelia whitei and Neogerris lubricus could be considered indicator species based on significant differences in abundance between disturbed and undisturbed areas.
Acesso aberto (Open Access)
Efeitos do tipo de floresta e da estrutura de habitat em assembléias de primatas no sudoeste da Amazônia
(Universidade Federal do Pará, 2013) ALVES, Sandro Leonardo; LOPES, Maria Aparecida; http://lattes.cnpq.br/3377799793942627
Environmental heterogeneity of natural vegetation types is a key determinant of local primate species richness and abundance. In this study we investigate primate assemblages composition and structure in four types of forest: unflooded (terra firme) forest, open and dense igapó forests (those seasonally inundated by clear water rivers) and cerradão (dense savanna woodland) in the Guaporé Biological Reserve in southwestern Brazilian Amazonia. In addition, we evaluate associations between primate occurrence and abundance with structural differences between forests types. We carried out 617.8 km of line-transect census (~154 km per forest type) and evaluated vegetation structure in 108 200 m2 plots (0.54 ha per forest type). Ten primate species were recorded during the 11-month study. Terra firme forest presented the highest primate species richness and density, predominantly as it is the only habitat playing host to Callicebus moloch and has the highest abundance of Sapajus apella. The high density of Ateles chamek in open igapó forest led to this habitat recording the highest primate biomass of any forest type. In the open and dense igapós and terra firme forests, Ateles chamek and Sapajus apella together made up over 70% of primate biomass, whilst in cerradão Sapajus apella accounted for 68% of primate biomass. Differences across forest types in primate species composition and relative abundances were associated with flood regimes and with several habitat structure variables (such as understory and canopy tree densities, canopy openness, total canopy height, and palm and liana densities). Our results reinforce the importance of heterogeneous landscapes in Amazonia, since these areas tend to contribute to elevating species diversity on this spatial scale.
Acesso aberto (Open Access)
Effects of environmental factors on community structure of Leptophlebiidae (Insecta, Ephemeroptera) in Cerrado streams, Brazil
(2013-09) BRASIL, Leandro Schlemmer; SHIMANO, Yulie; BATISTA, Joana Darc; CABETTE, Helena Soares Ramos
We analyzed the effects of environmental factors on abundance, species richness, and functional group richness of Leptophlebiidae in 16 sampling points along four Cerrado streams. Across three periods of 2005, we collected 5,492 larvae from 14 species in stream bed substrate. These species belong to three functional feeding groups: scrapers, filtering collectors and shredders. The abundance and species richness were not affected by water quality, but habitat quality related to presence of riparian vegetation had positive effects on the abundance of shredders. Our results add important information on the natural history of the species and functional groups of aquatic insects and also provide relevant data for the monitoring and conservation of streams in the Brazilian Cerrado.
Acesso aberto (Open Access)
Estudo da comunidade de pequenos mamíferos não-voadores, sob efeito do fogo e da borda, em área de floresta de transição Amazônia-Cerrado, Querência, MT
(Universidade Federal do Pará, 2008-10-10) SANTOS, Paulo Guilherme Pinheiro dos; OLIVEIRA, Ana Cristina Mendes de; http://lattes.cnpq.br/1199691414821581
The deforestation of the Amazon, caused by farming and agribusiness activities in the northern state of Mato Grosso, has committed Transition Forests Amazon-Savanna, before the biodiversity of these areas is known by researchers. The fauna of small non-flying mammals is part of the little-known groups in the region, and may be suffering impacts of human activities, primarily effect of fire, used for cleaning of pastures and deforestation for the soybean plantations. This study characterized the diversity of small mammals not flying in an area of Amazon forest-savannah transition in the northern state of Mato Grosso and investigated the effect of fire and the effect of edge on this group of fauna. Two areas of 150 hectares were sampled, a preserved and another under impact of fire, with 183 traps of the type live-trap for three years in two season (dry and rainy seasons). The method used was the capture-mark-recapture. The sampling effort was 23,424-traps night. 390 individuals were captured with a successfully capture of 1.66%. A total of 11 species were caught, 6 rodents and 5 marsupials. Hylaeamys megacephalus was the most abundant species. The diversity of small mammals in the study area was more related to the Savanna than Amazon. In relation to fire, the species richness was not statistically different, but the abundance was significantly higher in transects located in an area without fire. Two distinct groups of transects were characteristic depending on the presence or absence of fire based on the composition of small mammals. The abundance of Hylaeamys megacephalus was significantly higher in transects that suffered no impact from fire. Regarding the effect of edge in Area 2, despite the richness of species was not significantly different, the abundance was significantly higher regarding distance from the border. Already in Area 1, nor richness nor abundance was statistically different regarding distance from the edge. This fact could be masked by both the direct and indirect effect of experimental fire on small mammals. When considered together fire and distance from the border, the relationship between them became clearer, since all transects sampled under effect of the fire had minor abundances. The population size of Hylaemys megacephalus was calculated over five seasons (dry and wet) in the area without influence of fire, and the rainy season of 2006 was statistically different peak and the other that growth can be explained by the “Alle effect”. There was no statistically significant differences in the structure of the community of small non-flying mammals between the dry and rainy seasons. This work contributed to the search of mammal knowledge at this region threatened by human pressures.
Acesso aberto (Open Access)
Feeding ecology of Liophis reginae semilineatus (Serpentes: Colubridae: Xenodontinae) in eastern Amazon, Brazil
(2010-02) ALBARELLI, Luiz Paulo Printes; COSTA, Maria Cristina dos Santos
We studied the diet of Liophis reginae semilineatus (Wagler, 1824) from eastern Amazon, Brazil, based on the analysis of 182 preserved specimens. Thirty-six individuals had prey in their stomachs; 34 (95%) contained exclusively anurans and 2 (5%) contained both anurans and lizards. The most common prey items were small Leptodactylus sp. (33.3%), followed by Physalaemus ephippifer (Steindachner, 1864) (10.3%). Prey ingested head-first (78%; n = 25) were significantly larger than prey ingested tail-first (22%; n = 7). Females of L. reginae semilineatus have longer and wider heads than conspecific males with the same body length, which correspond to sexual divergences in the diet (size of the prey). No correlation was found between snake head length vs. prey size (SVL, width and mass). Liophis reginae semilineatus is an anurophagous snake that probably forages actively on the ground.
Acesso aberto (Open Access)
Geographical variation in the reproduction and sexual dimorphism of the Boddaert's tropical racer, Mastigodryas boddaerti (Serpentes: Colubridae)
(2013-10) SIQUEIRA, Débora Mendes; NASCIMENTO, Loana Pastana; MONTINGELLI, Giovanna Gondim; COSTA, Maria Cristina dos Santos
We obtained data on time of sexual maturity, dimorphism, fecundity and on the reproductive cycle of Mastigodryas boddaerti (Sentzen, 1796) through the examination of 321 preserved specimens, of which 221 were collected in the Brazilian Amazon region and 100 in the Cerrado savannas of Central Brazil. The degree of sexual size dimorphism (snout-vent length, SVL) was significantly greater in the specimens from the Cerrado in comparison with those from the Amazon. Females had a significantly larger number of ventral scales, on average, whereas males had more sub-caudal scales. However, there was no intersexual difference in tail length or head width, although the heads of the males were significantly longer, which may reflect dietary differences. Breeding females from the Amazon region contained between one and six eggs (N = 12, mean = 3.0), whereas two females from the Cerrado had four to six eggs (N = 10, mean = 5.0). No relationship was found between the SVL of the Amazonian females and the number of eggs or vitellogenic follicles they contained (Cerrado females were not analyzed here due to small sample size). Males are smaller than their female counterpart when they reach sexual maturity. Even though females from the Amazon reproduce throughout the year, females from the Cerrado breed seasonality.
Acesso aberto (Open Access)
Influência dos fatores ambientais na diversidade e modos reprodutivos de anuros em área de floresta de transição, Mato Grosso
(Universidade Federal do Pará, 2010) BITAR, Youszef Oliveira da Cunha; COSTA, Maria Cristina dos Santos; http://lattes.cnpq.br/1580962389416378
Acesso aberto (Open Access)
Influências dos ninhos de saúva (Formicidae: Attini) na nutrição, crescimento e proteção da vegetação contra o fogo, em uma floresta de transição Amazônia-Cerrado
(Universidade Federal do Pará, 2008) CARVALHO, Karine Santana; STERNBERG, Leonel; http://lattes.cnpq.br/2673570808369028; MOUTINHO, Paulo Roberto de Souza; http://lattes.cnpq.br/7277077476036269
The leaf-cutting ant nests are important natural disturbances which may create mosaics of certain types of vegetation and affect the structure and composition of Neotropical ecosystems. So, this study evaluated the effects of leaf-cutting ant nests (Atta spp.) on dynamic of vegetation growth in a Amazon-Cerrado transitional forest submitted to subsequent fire events, in south Amazon basin, Mato Grosso State, Brazil. Specifically, it was evaluated the effects of the nests on: (1) vegetation growth and nutrition; (2) vegetation protection against fire and (3) the forest regeneration pos-fire. The nests and associated vegetation (within a 10-meter radius of the nests) established in 150-hectare areas of transitional forest were mapped and monitored in order to determine such effects. These areas subdivided in 50-ha parts with different treatments: triannual fires, annual fires and fire protection (control) take part in the project “Savannization” coordinated by Amazon Environmental Research Institute – IPAM. The experiments about the effects of the nests on vegetation growth and nutrition indicated that plants next the nests have a facilitated nutrient absorption and therefore they present a higher foliar concentration of Phosphorus. Consequently, it was registered a higher growth in diameter of stem to these plants when compared to those far from the nests. The nests worked as active firebreaks (due to accumulation of land on mound resulting from leaf-cutting ants diggings) reducing the total burned area around them, mainly in areas with high number of nests and protecting the surrounding vegetation from the mortality by fire. In opposition to these benefits, it was verified higher herbivory of seedlings and the removal of seeds by leaf-cutting ants in areas with high density of active colonies, a result which compromise the early stages of pos-fire forest succession. This study shows the importance of leaf-cut ants in the redistribution and nutrient recycling and demonstrates, for the first time, the vegetation protection against fire, by their nests. On the other hand, it also shows that anthropic disturbances, such as fire, increase the leaf-cut ant population. This can stop the pos-fire forest regeneration. Considering this study, it can predict that natural environments may have the vegetation growth accelerated due to the presence of leaf-cut ant nests, but in disturbed environments the action of leaf-cut ants may be the main threat to the original vegetation regeneration. So, it can conclude that the effects (beneficial or harmful) of the leaf-cut ants depend on the level of disturbance or maturity of biome in which their nests are established.
Acesso aberto (Open Access)
Inventário da araneofauna (Arachnida, Araneae) do Parque Nacional de Sete Cidades, Piauí, Brasil
(Universidade Federal do Pará, 2008-03-25) CARVALHO, Leonardo Sousa; BONALDO, Alexandre Bragio; http://lattes.cnpq.br/8721994758453503
An inventory of the spider fauna of Sete Cidades National Park (Brasileira and Piracurua municipalities, State of Piauí), is presented using standardized sampling procedures to allow comparisons between the spider assemblages of six phytophysiognomies present at the study site and to obtain richness estimates. Data from sampling with pit-fall traps (PTF), Winkler apparatus (WIN), beating tray (GCE), sweeping net (RV) and nocturnal manual colleting (MN), totalizing 1386 samples were analyzed, together with all other specimens previously collected at the study site (n=1166). The statistical analyses were performed using data obtained with GCE, RV and MN. Altogether, 14.890 individuals (4491 adults), belonging to 364 species, were collected. From these, 72 were determined at specific level, 62 are new records for the study site, 2 are new records for Brazil and 48 were recognized as new species by specialists. The application of the methods GCE, RV and MN resulted in 11.085 spiders, belonging to 303 species. The richness estimates varied between 355 (Boostrap) and 467 (Jack 2) species. The best fit estimator, which first showed a trend to reach an asymptote, was Chao 2 (403 spp.). The observed richness was greater in tropical semideciduous dry forest (mata seca semi-decídua, 131 spp.), followed by the tropical ombrophilous alluvial occasionally flooded forest (mata de galleria, 104 spp.), medium tall grassland consisting mainly of bunch grasses (campo limpo, 102 spp.), evergreen broad-leaved woodland (cerradão, 91 spp.), evergreen broad-leaved sclerophyllous shrubland (cerrado típico, 88 spp.) and smaller in deciduous subdesert shrubland (cerrado rupestre). The efficiency of the collecting methods exhibited variation according to the phytophysiognomy in which it was applied, especially in the case of the sweeping net, which was much more efficient in open areas. The variation in species composition between the sampled phytophysiognomies can be, in part, explained by differences in the structural complexity of these vegetation types. The results of the cluster analysis suggest that, in conditions of high dominance, these tests should be performed with qualitative coefficients, in order to neutralize the effect of coefficient choose and/or the need of data transformation. The Sete Cidades National Park´s spider fauna does not followed the clustering patterns suggested by botanical analysis, by which grasslands, savannas and forested phytophysiognomies are grouped.
Acesso aberto (Open Access)
Mamíferos de médio e grande porte do Parque Nacional das nascentes do Rio Parnaíba, Brasil
(Universidade Federal do Pará, 2009-04-08) LIMA, Marcela Guimarães Moreira; SILVA JÚNIOR, José de Sousa e; http://lattes.cnpq.br/4998536658557008
The Nascentes do Rio Parnaiba National Park is located at the convergence of the states of Piauí, Maranhão, Tocantins and Bahia. In order to evaluate the composition, richness, relative abundance, activity pattern of medium and largesized mammals of the Park, as well as the use of phytophysiognomies present at the study site by these species, an inventory was made using camera-trap, semi-structured interview and complementary sampling methods. It was registered a total of 37 species of mammals of medium and large size, distributed in 14 families and seven orders, 20 of which recorded by cameratraps, 16 by sightings and traces (footprints, feces and carcasses), and all through interviews with residents of the region. The estimator of the nonparametric richness Jackknife1 estimated 22 species for the Park (D.P. ± 1,41). Regarding phytophisiognomy, only gallery forest and cerrado sensu stricto showed a significant difference about the richness and relative abundance. Among the species recorded in the Park, the foxes Cerdocyon thous and Lycalopex vetulus were the most abundant, respectively. Concerning the use of habitat, only Cerdocyon thous and Mazama gouazoubira showed significant differences between the phytophisiognomy, the first being from general habit and recorded specially in areas of cerrado sensu stricto, and the second most frequent in areas of more dense vegetation (cerradão). With respect to the composition of species, the cluster analysis indicated the areas of cerrado sensu stricto and cerradão with close similarity, which is probably due to the closer floristic similarity between these environments. The analysis of regional composition showed that the Park presents greater similarity in species composition with the UCs located in the southern of Piauí state (E.E. of Uruçuí- Una and PARNA of Serra das Confusões) than with other areas of Cerrado.
Acesso aberto (Open Access)
Padrões de distribuição da avifauna em área de Ecótono Cerrado-Caatinga no Nordeste do Brasil
(Universidade Federal do Pará, 2015) GONÇALVES, Gabriela Silva Ribeiro; OLIVEIRA, Arthur Ângelo Bispo de; http://lattes.cnpq.br/1100433822757573; SANTOS, Marcos Pérsio Dantas; http://lattes.cnpq.br/7941154223198901