DSpace Community:
http://hdl.handle.net/1843/197
2024-03-28T09:14:45ZRoedores do Quaternário de Minas Gerais e Bahia, Brasil
http://hdl.handle.net/1843/65758
Title: Roedores do Quaternário de Minas Gerais e Bahia, Brasil
Abstract: Paleoecological studies have been increasingly used to determine the weather
in the past. Among all work views, the mammal fauna studies have widely
contributed to paleoenvironments knowledge and the climate dynamics. The
most common environmental reconstruction works are based on diversity
analysis and the species richness, dental morphology and community ecology.
Many papers on mammals fauna of the Brazilian Quaternary were made during
several years of study, even though few of them talk about paleoecology and
ambient reconstruction. The rodents are a great part of the mammal fauna of
the South American continent, representing over 20% of the mastofauna known
species. By representing specific ecological requirements, rodents are widely
used to paleoecological studies and paleoenvironments reconstructions.
Studies on fossils rodents are rare in Brazil and the only known fauna is Lagoa
Santa and sites in Rio Grande do Sul. This study has the objective of increasing
knowledge on Minas Gerais and Bahia Quarternary rodents, infer the
paleoambient of the studied region and the paleobiogeography aspects of the
identified species. Skeletal fragments from the micromammal fauna of two sites
(Toca da Boa Vista-BA and Lapa do Dragão-MG) were studied. By the end of
the work, nine thousand fragments were analyzed, in wich 400 were taxonomic
relevants for rodents. Nine taxons were identified, and the analysis showed
great taxonomic diversity and paleoclimates between both sites comparing to
now a days.
Type: Dissertação2012-02-16T00:00:00ZExiste facilitação vegetal em campo rupestre sobre canga no Parque Estadual da Serra do Rola Moça, MG?
http://hdl.handle.net/1843/65756
Title: Existe facilitação vegetal em campo rupestre sobre canga no Parque Estadual da Serra do Rola Moça, MG?
Abstract: The aim of this study was to evaluate the facilitation potential of Acianthera teres Lychnophora pinaster, Microlicia martiana, Mimosa calodendron, Stachytarpheta glabra, Vellozia compacta, and Vellozia graminea in an area of ironstone outcrop in Rola Moça State Park. Data on temperature, moisture and light were collected during the rainy and dry seasons from each species (15 individuals for temperature and moisture and 30 for light) and in an open area, without influence of species, as control. Organic matter was collected in both seasons to compare the amount accumulated under the individuals. To determine the richness and abundance of plants, 20 individuals of each species above were selected. Every plant found below or near each individual was recorded and identified. These data collected in the rainy and dry seasons were compared with those in open areas, adjacent to the species and with similar area. Data on temperature and moisture were collected at 8, 12 and 16 hours. In the rainy season the species showed temperature and moisture milder than the values of open area than in dry season. M. calodendron, S. glabra and V. Compacta remained milder temperatures and moisture in the rainy season and in the dry season only the first stood easing these variables. V. graminea and A. teres were the species with higher temperatures and lower moisture, similar to the values of open area. The light intensity bellow the canopy of species (except A. teres and V. graminea that were not evaluated for this variable) showed values lower than in open areas at both seasons, S. glabra and V. compacta showed the highest values. A. teres showed the highest amount of litter and S. glabra the least. Regarding richness and abundance, these were highest in the rainy season. No differences were found in species richness or abundance between individuals and their corresponding open area in the rainy season. However, in the dry season, the abundance was significantly higher in the open area next to the individuals of L. pinaster, M. martiana and V. compacta, being the same for richness for the latter specie. The results show an improvement of the microclimate next to some species relative to the open area, which could lead to facilitation. However, data on richness and abundance do not confirm that any of the focal species is a good nurse plant despite the improvements guaranteed by some. The topography heterogeneity ensuring the presence of nurse objects or the canga abiotic stress may be possible causes for not having found nurse effects in this work.
Type: Dissertação2011-03-10T00:00:00ZHistória natural de dois furnarídeos (Aves: Furnariidae) endêmicos dos campos rupestres da porção sul da Cadeia do Espinhaço, Minas Gerais
http://hdl.handle.net/1843/65734
Title: História natural de dois furnarídeos (Aves: Furnariidae) endêmicos dos campos rupestres da porção sul da Cadeia do Espinhaço, Minas Gerais
Abstract: This work is the result of a study carried out with two furnarid taxa
(Aves:Furnariidae) that currently occur restrictedly at the tops of the southern portion of the
Espinhaço, in the state of Minas Gerais. These taxa are biogeographic relics, living fossils, which
tell about an ancient biota connection that today is isolated in the high altitudes of the
Southern thornback and related species distributed in the Andes, Patagonia and
Chaco. The first chapter consists of the description of one of these taxa, sister of Cinclodes pabsti
(endemic to Serra Geral, Rio Grande do Sul and Santa Catarina). The new species was discovered
in some mountains in the vicinity of Serra do Cipó, southern portion of the Espinhaço Range in
state of Minas Gerais, located approximately 1140 km from the most distant town of Cinclodes
pabsti. In this chapter we present morphological and genetic characters, as well as differences
vocals, which corroborate our proposal. The divergence between these two species of Cinclodes
Brazil was estimated to have occurred around 220,000 years ago (Pleistocene period). The chapter
two consists of a study with two populations of the joão cipó Asthenes luizae (Aves: Furnariidae),
a bird threatened with extinction, has a restricted distribution along rocky outcrops
on the mountain heights of the southern portion of the Espinhaço Range. The individuals were
monitored with radio transmitters between March 2009 and November 2011, in two areas
in Serra do Cipó. We count the number of adult individuals with established territories,
we provide data on sex ratio, mortality, nestling dispersal movements,
site fidelity, home range, territoriality, singing behavior and habitat use. O
Knowledge of the spatial ecology of the species is important because its population has a dynamic
of metapopulations in a threatened and naturally fragmented environment.
Type: Dissertação2011-02-22T00:00:00ZResearch bias and scientific shortfalls in seed ecology literature compromise conservation of a megadiverse flora
http://hdl.handle.net/1843/65657
Title: Research bias and scientific shortfalls in seed ecology literature compromise conservation of a megadiverse flora
Abstract: Vieses nas pesquisas em ecologia são assuntos persistentes, embora suas consequências
na conservação da biodiversidade sejam negligenciadas. A presença de vieses na
literatura contribui para lacunas de conhecimentos, pois alguns taxa, áreas geográficas e
atributos de espécies carecem informações. A ausência do conhecimento desses
atributos dificulta previsões da resposta das espécies frente às perturbações
antropogênicas, resultando em estratégias de conservação inadequadas. Avaliamos
vieses na pesquisa em ecologia de sementes no Brasil, um país megadiverso com
biodiversidade ameaçada. Nosso foco em ecologia de sementes deve-se a sua
importância para a conservação ex situ e in situ. Hipotetizamos que (1) a distribuição
desigual das instituições de pesquisa brasileiras promovem vieses geográficos; (2) a
importância econômica e ecológica das espécies resultam em vieses filogenéticos; e (3)
essas espécies, geralmente, possuem frutos carnosos e dispersão biótica, produzindo
vieses ecológicos. Usamos as plataformas Scielo e Web of Science para construir nossa
base de dados. Analizamos vieses geográficos, filogenéticos, ecológicos e geramos um
mapa Kernel de densidade. Encontramos que a pesquisa em ecologia de sementes foi
enviesada geograficamente. As maiores densidades de estudos foram registradas na
Mata Atlântica e Cerrado. Taxa com importância econômica e ecológica foram sobre
estudados, resultando em vieses filogenéticos. Igualmente, detectamos que espécies
ameaçadas são subestudadas. Encontramos também vieses ecológicos, pois árvores com
frutos carnosos e dispersão biótica foram sobre-estudadas. Vieses e lacunas de
conhecimento na pesquisa em ecologia de semente resultam em implicações negativas
na conservação, pois limitam prever as respostas da flora brasileira aos distúrbios e
manejo adequado da biodiversidade.
Type: Dissertação2015-02-12T00:00:00Z