Navegando por Data de Publicação, começando com "2017-08-24"

Filtrar resultados por ano ou mês

Agora exibindo 1 - 4 de 4

Influência do solo e do tamanho de semente no crescimento e sobrevivência de nove espécies arbóreas tropicais em área ripária degradada
(Universidade Federal de São Carlos, 2017-08-24) Scaloppi, Julie Christine; Souza, Andréa Lúcia Teixeira de; https://lattes.cnpq.br/5216112068627151; https://lattes.cnpq.br/5189815801147165
Understanding the mechanisms that involves the relations between plants and the abiotic environment is vital for the knowledge of the successional dynamics of native vegetation in degraded areas. Several studies have shown that seed size positively influences survival and negatively influences the growth of plants in the early stages of their development. However, soil conditions can influence these relationships, since the availability of soil resources can generate variations in plant survival and growth. This study evaluated the influence of seed mass and soil properties on the performance of nine native tree species that formed a seed size gradient: Cedrela fissilis, Pterogyne nitens, Cariniana estrellensis, Enterolobium contortisiliquum, Copaifera langsdorffii, Enterolobium timbouva, Platypodium Elegans, Schizolobium parahyba and Hymenaea courbaril. These species were introduced as seedlings with the objective of restoring a degraded riparian area. From a conceptual model, we simultaneously evaluated the survival and growth of plants in function of seed mass, initial plant size and soil chemical properties at four time intervals over the first three years after planting. During this period, the seed mass and the chemical properties of the soil influenced directly and indirectly, through initial plant size, growth and survival. In the first time interval, the period between planting and the two subsequent months, seed mass was the main factor influencing survival and growth rate, but the initial diameter (plant diameter when they where planted) and soil fertility also influenced growth. In the second time interval (between the first two months and the end of the first year), seed mass and initial diameter positively influenced survival. In this period, the initial diameter, soil fertility and seed mass influenced the growth rate. In the following two years, the survival of young plants was influenced only by their initial diameter and plant growth was influenced by seed mass and influenced negatively by soil potential acidity. In general, the smaller seed species generated smaller individuals and had a faster growth until the end of the first year, whereas the larger seed species generated larger individuals, but with a slower and constant growth, surpassing the growth of the small seeded species during the second year. Larger seeds also achieved higher survival rates during the first year. Larger plants grew more by the end of the first year and had greater chances of survival after the first year. Soil fertility stimulated plant growth resulting in larger plants, while potential acidity variation negatively influenced performance in some study periods. Our results corroborate with the hypothesis of seedling size and the metabolic hypothesis. Prior analysis of soil properties, improvement of edaphic conditions in degraded areas and consideration of functional traits in the choice of tropical tree species can improve the effectiveness of restoration projects.
Estudo da quiropterofauna (Chiroptera; Mammalia) em área nativa e de Sistema Agroflorestal (SAF) em Pirassununga, São Paulo, Brasil
(Universidade Federal de São Carlos, 2017-08-24) Silva, Ana Elisa Teixeira da; Rocha, Vlamir José; https://lattes.cnpq.br/8044368595391973; Figueiredo, Rodolfo Antônio de; https://lattes.cnpq.br/0854609216769461; https://lattes.cnpq.br/3754419507530715
The intense fragmentation of natural areas, like Semideciduous Forest (Native Area), with consequent pressure under native fauna, emphasizes the search for alternatives to the monoculture system, like Agroforestry Systems (AFSs), which simultaneously cultivate agricultural and native species and can contribute to the subsistence and conservation of species. The present study aimed to investigate which species of bats occur in the Native and AFS areas of CEPTA-ICMBio, Pirassununga (SP). It was recorded 228 individuals belonging to 20 species and three families. About species, 14 (N = 95) were captured in Native Area and 13 (N = 133) in AFS. The results point to a certain degree of species similarity among the studied areas, absence of significant differences on diversity index and similar richness coefficients among Native and AFS areas. Although the AFS can function as corridor between matrices and can contribute to the maintenance of common frugivorous, nectarivorous and insectivorous bats species, probably due the presence of spontaneous pioneer plants in studied areas, it is suggested the greater plant and structural diversity of Semideciduous Forest fragment can ensure the persistence of bat species considered uncommon. About the diet and dispersal seeds, the great majority of fecal samples (N=83 out of N=87) was obtained from phyllostomid bats and contained 16 food items: fruits of Solanaceae, Piperaceae, Urticaceae, Moraceae, Siparunaceae and exotic Muntingia calabura, nectar of Mabea sp., arthropods remains (insects and spider) and clay. While the other four fecal samples were obtained from vespertilionid bats and contained insects remains.
Aplicações entre 3-variedades Sol e números de Nielsen para coincidências
(Universidade Federal de São Carlos, 2017-08-24) Panzarin, Karen Regina; Vendrúscolo, Daniel; https://lattes.cnpq.br/8602232587914830; https://lattes.cnpq.br/3082816481278839
Let MA be the torus bundle over S1 obtained using as gluing map an Anosov matrix A. In this work we discuss maps from MA to MD and compute the coincidence Nielsen numbers for some families of such maps, moreover we use that such manifolds are double covers of torus semi-bundles and compute the coincidence Nielsen number for selfmaps of Sol 3-manifolds which are torus semi-bundles.
Distribuição da variação genética nos canídeos Cerdocyon thous e Chrysocyon brachyurus de paisagens antropizadas da região centro-oeste e sudeste do Brasil
(Universidade Federal de São Carlos, 2017-08-24) Rodriguez Castro, Karen Giselle; Galetti Júnior, Pedro Manoel; https://lattes.cnpq.br/7398754661670478; https://lattes.cnpq.br/0505422022027092
The Crab-eating fox (Cerdocyon thous) and the Maned Wolf (Chrysocyon brachyurus) are a fundamental part from the habitats where they occur, due to the ecosystemic functions they play, as seed dispersers and controlling the population size of their preys. In order to protect these species is necessary to know about its genetic population structure in the current scenario of anthropized and highly transformed landscape. In this context, this work aimed to gather genetic, biological and ecological information for both species from molecular-genetic approach. Thus, we assessed and compared population sizes and densities, we evaluated genetic variation distribution and population structure, besides we evaluated possible sex-biased dispersion, and finally relatedness between and within sampled areas for both canids species. For that propose, we collected tissue, blood and scat samples of both species in three anthropic areas of three states in the central-west and southeastern regions of Brazil: Mato Grosso do Sul, Goiás and São Paulo. We extract the total DNA and amplify it for species identification (using mtDNA), for sexing (using nuclear genes) and for population genetic analyses (using microsatellites). A total of 122 Crab-eating foxes belonging to the three different sampled populations were studied. The relatedness values to Crab-eating foxes were high and migrant individuals are present among the studied areas. We found two populations for the Maned Wolfs (N=93): one including the São Paulo state individuals and the other one including Mato Grosso do Sul and Goiás individuals. The two identified populations showed no population isolation. We found a positive correlation between the geographic and genetic distances, resulting in isolation by distance in both species. Fragment size was not so important, while landscape conservation status and permeability level cause strong impacts on the genetic diversity of both species. Thus, more altered, anthropized and less permeable landscapes, such as the São Paulo state, showed genetic diversity reduction, mainly in the Maned Wolf, a solitary, more sensitive and a lower population density species. None of the species showed philopatry evidence or preferential dispersion for neither sex.