-(The influence of Amazonian and Atlantic flora in the vegetation of cerrado sensu stricto). The contribution of Amazonian and Atlantic floras was analyzed in twelve localities in the cerrado biome. A total of 290 tree and shrub species were recorded in those localities. Of these, 41.1% occurred only in cerrado and are probably endemic, and 58.9% also occurred in Atlantic and/or Amazonian forest. For non-endemic species the contribution of Atlantic forest was greater (44.8%) than Amazonian ones (1.4%), with the remaining 12.7% species found in both forest biomes. The proportions of species with centers of distribution in Atlantic and Amazonian forest showed a slight decrease toward the center of cerrado biome. For the former, the distance explained only 30% of variation in proportions by a polynomial model fit to the data, and for the latter a significant linear model explained 78% of variations. The flora of Amazon forest and Atlantic forest showed a segregation with altitude. The proportions of species with centers of distribution in the Atlantic forest showed a slight increase with altitude, but a polynomial model explained only 18% of this variation. Inversely, there was a linear relationship between the proportions of species with centers of distribution in Amazonian forest and altitude that explained 31% of variation. The differences in contribution patterns of the Atlantic and Amazonian forest flora to the cerrado physiognomy is discussed with respect to climatic changes during the Quaternary and to differences in plant species tolerance to fire and low temperature in the cerrado biome.Key words -Amazon forest, Atlantic forest, cerrado, distribution patterns, phytogeography RESUMO -(Influência da flora das florestas Amazônica e Atlântica na vegetação de cerrado sensu stricto). A contribuição das floras Atlântica e Amazônica foi analisada em doze localidades no bioma do cerrado. Um total de 290 espécies de arbustos e árvores foram registradas nas localidades de cerrado. Deste total 41,1% ocorreram apenas no cerrado, sendo provavelmente endêmicas e 58,9% ocorreram nas florestas Atlântica e Amazônica. Para as espécies não endêmicas, a contribuição da floresta Atlântica foi maior (44,8%) do que a da floresta Amazônica (1,4%), com as 12,7% de espécies restantes ocorrendo nos dois biomas florestais. A proporção de espécies com centro de distribuição na floresta Atlântica e Amazônica mostraram um pequeno decréscimo em direção ao centro do bioma do cerrado. Para o primeiro, a distância explicou apenas 30% da variação na proporção de espécies, por um modelo polinomial ajustado aos dados e, para o último, um modelo linear explicou 78% da variação. A proporção de espécies com centro de distribuição na floresta Atlântica mostrou um pequeno aumento com a altitude, mas um modelo polinomial explicou apenas 18% dessa variação. Inversamente, ocorreu um decréscimo linear na proporção de espécies com a altitude para aquelas com centro de distribuição na floresta Amazônica; o modelo explicou 31% da variação. As dife...
-(Dispersal syndromes of shrub-woody species in the cerrado sensu stricto vegetation of Central Brazil and amazonian savannas). The objective was to identify the proportion of seed dispersion syndromes in areas of cerrado sensu stricto of Central Brazil and amazonian savannas. Lists of species of nine cerrado and five amazonian savanna areas were used. Dispersion syndromes were determined through literature data. Chi-square test (χ 2 ) was used to evaluate possible differences in proportion of zoocory and anemocory among cerrado sensu stricto of Central Brazil and among amazonian savanna areas. Floristic similarity was determined among the 14 areas. The averages of these proportions were compared through t test and no significant differences were found (p > 0.05). The proportion of zoocory species in cerrado sensu stricto and amazonian savannas were 56.7% ± 5.4 DP and 55.6% ± 11.7 DP; the proportion of anemocory were 39.7% ± 6.2 DP and 44.4% ± 11.7 DP, respectively. In the cerrado sensu stricto of Central Brazil the proportion of autocory ranged from 1.4 to 5%, while the amazonian savannas presented no autocoric species. Autocory is a rarely found strategy in cerrado sensu stricto and its absence in amazonian savanna areas could be related to the low efficiency in colonization of isolated areas.RESUMO -(Síndromes de dispersão de espécies arbustivo-arbóreas em cerrados sensu stricto do Brasil Central e savanas amazônicas). O objetivo deste trabalho foi identificar as proporções das síndromes de dispersão de sementes em áreas de cerrado sensu stricto do Brasil Central, comparando-as com as de áreas isoladas de savanas amazônicas. Foram utilizadas listas de espécies de nove áreas de cerrado e cinco áreas de savanas amazônicas. Determinou-se a similaridade florística entre as áreas. As síndromes de dispersão de espécies ocorrentes nestas áreas foram determinadas a partir de dados da literatura. Utilizou-se o teste Qui-quadrado (χ 2 ) a fim de detectar possíveis diferenças nas proporções de zoocoria e anemocoria entre as áreas de cerrado e entre as áreas de savanas amazônicas. As médias entre as duas regiões foram comparadas pelo teste t. Não foram encontradas diferenças significativas para as duas análises (p > 0,05). A média das proporções de zoocoria para o cerrado sensu stricto foi de 56,7% ± 5,4 DP e para as savanas amazônicas 55,6% ± 11,7 DP, e a média das proporções de anemocoria no cerrado sensu stricto foi de 39,7% ± 6,2 DP e para as savanas amazônicas 44,4% ± 11,7 DP. No cerrado sensu stricto, a autocoria variou de 1,4 a 5%, porém não se verificou a presença de espécies autocóricas nas savanas amazônicas. A autocoria é uma estratégia de dispersão raramente encontrada no cerrado e sua ausência nas áreas de savanas amazônicas pode estar relacionada à sua baixa eficiência em colonizar áreas isoladas.
Composition and diversity of medium and large size mammals in the Cerrado of central Brazil. Studies about medium-and large sized mammals (≥ 1.0 kg) in disturbed areas in the Cerrado showed that many species are adapted to anthropogenic environments. We investigated the structure of mammals assemblages in an area of 92,000 ha located in southwest of Bahia and covered by plantations of Pinus spp., soybeans and conserved strips of cerrado sensu stricto. The mammals were recorded in nine sampling campaigns of 12 days between January/2008 and May/2009 in diurnal and nocturnal transects that varied 5-15 km in length per campaigns totaling 3,600 km traveled/period. In this area 29 species were recorded, 23 through the line transect and others outside transect by indirect observation, capture and previous records. The mammal community consists mostly of representatives of the Carnivora (41.4%) and omnivore species (36.7%). The only endemic species of Cerrado recorded in the area was hoary fox, Lycalopex vetulus. Only 13.6% of species were present in all sampling (Ozotoceros bezoarticus, Pecari tajacu and Tolypeutes tricinctus) and seven of which correspond to 91.73% of the records made. The species that had largest number of records (23.76%) is three-banded armadillo (T. tricinctus), probably this area holds the largest population of this endangered species in biome, highlighting the importance of avoiding areas of native vegetation are replaced by monocultures and reforestation. Many of the species recorded are generalists in habitat use and widely distributed throughout the biome, occurring even in disturbed habitats. The maintaining of observed diversity in this area is due to its large size and the mosaic of environments that provide a greater variety and diversity of resources such as shelter and food, allowing also the presence of species with low densities and specialists in the diet and habitat. Keywords: altered landscape, community structure, feeding guilds, linear transect, richness. Resumo: Composição e diversidade de mamíferos de médio e grande porte no Cerrado do Brasil central. Estudos com mamíferos de médio e grande porte (≥1,0 kg) em áreas alteradas no Cerrado revelam que muitas espécies se adaptam aos ambientes antropizados. Foi investigada a estrutura da comunidade de mamíferos em uma área de 92.000 ha localizada no sudoeste baiano e constituída por plantios de Pinus spp., soja e faixas de cerrado sentido restrito. Os mamíferos foram registrados ao longo de nove campanhas de 12 dias, entre janeiro/2008 e maio/2009, no período diurno e noturno através de transectos lineares variando entre 5-15 km de extensão e que totalizaram 3.600 km percorridos/ período. Foram registradas 29 espécies, sendo 23 através dos transectos lineares e as demais por observação indireta, captura e registros pretéritos. A comunidade é constituída em sua maioria por representantes da ordem Carnivora (41,4%) e espécies onívoras (36,7%), sendo Lycalopex vetulus a única espécie endêmica do Cerrado registrada na área. Ape...
We examined differences in microhabitat utilization by two sympatric rodents in the Brazilian cerrado (tropical savanna). We censused the populations by livetrapping techniques in March and May 1984, and simultaneously we measured a set of eight microhabitat variables. Patterns of habitat utilization and species relationships were examined with t tests, Mann Whitney-U tests and regression analysis. The two species differed markedly in three microhabitat variables : plant species richness (PSR), forb ground cover (FGC) and distance to nearest tree or shrub (DTS). Bolomys lasiurus was a generalist associated with high richness and high cover of forbs, shrubs and trees. Oxymycterus roberti was associated with a less diverse lower forb, shrub, tree cover and higher grass ground cover (GGC). Regression analysis showed that the most important estimator of Bolomys lasiurus abundance was GGC and tree and shrub cover TSC. For Oxymycterus roberti, FGC, PSR and TSC. The differences in microhabitat variables between these two species, could be related to foraging mode and/or predation avoidance.
Caryocar brasiliense is a native tree found throughout the Cerrado savanna biome in central Brazil, and is exploited by rural population as food and industry. Although the abundance and popularity of this species in Cerrado have been an important component of local extractive economy, several aspects of sustainability as fruit production per tree size and growth rate have received little attention. We monitored, during two growing seasons, the stem growth rates and fruit production of tree in a wild population in Distrito Federal, central Brazil. The results showed a low growth rate of trees. The proportion of adult population fruiting was higher in 2006 than in 2007. For the smallest size (7.3-cm stem diameter) to begin fruiting, the estimated age was between 30 and 51 years old, and for tree with the largest stem diameter in the plot (43-cm diameter) the age was estimated to be between 110 and 153 years old. The whole fruit production by hectare was highly variable between years and was associated with differences in annual precipitation. The total fruit production was 1,004 fruits per ha (72.9 kg ha -1 ) in 2006, and 299 fruits per ha (21.7 kg ha -1 ) in 2007. The fruit production per tree was significantly positively correlated between 2006 and 2007 fruit season. Although an estimated fruit yield for whole Cerrado region is more than enough to support the actual demand, the slow growth rates and intensive harvesting indicates that more attention to sustainable management is required to avert demographic collapse of this cornerstone of the Cerrado extractive economy.
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