Navegando por Assunto "Tropical forest"

Agora exibindo 1 - 3 de 3

Acesso aberto (Open Access)
Conidial fungi associated with leaf litter of red cedar (Cedrela odorata) in Belém, Pará (eastern Brazilian Amazon)
(Instituto Nacional de Pesquisas da Amazônia, 2018-09) SANTOS, Renato Ferreira dos; SOTÃO, Helen Maria Pontes; MONTEIRO, Josiane Santana; GUSMÃO, Luís Fernando Pascholati; GUTIÉRREZ, Antonio Hernández
The aim of this study was to investigate the species of conidial fungi associated with leaf litter of Cedrela odorata (Meliaceae), an endangered red cedar species typical of Amazonian terra-firme forests. Conidial fungi were sampled around C. odorata individuals in three forest areas in the municipality of Belém (Pará State, Brazil). A total of 104 species were identified, with 53 new records for the state of Pará, 46 first records for the Brazilian Amazon, including new records for Brazil (Cordana abramovii), for South America (Acarocybiopsis cubitaensis, Xylocladium claviforme) and for the Americas (Dactylaria biguttulata). A review of species of conidial fungi reported on C. odorata is provided, indicating its distribution in Brazil. For each new record in Brazil, South America and the Americas we present a description, illustrations, geographical distribution and taxonomic comments.
Acesso aberto (Open Access)
Relação entre diâmetro do caule e espessura da casca das árvores amazônicas e sua implicação na resistência ao fogo
(Universidade Federal do Pará, 2024-03-28) GAMA, Valter Thiago Pantoja da; FERREIRA, Joice Nunes; http://lattes.cnpq.br/1679725851734904; https://orcid.org/0000-0002-4008-2341; BARLOW, Bernard Josiah; http://lattes.cnpq.br/8559847571278134
The characteristics of plants are important for understanding their functions and relationships with the environment and the functioning of ecosystems. Tropical forests, such as the Amazon, are important for promoting ecosystem services that are important for maintaining biodiversity and human well-being. However, these forests are facing major threats due to human interference, especially climate change and forest fires. Therefore, given this scenario, research focused on forest resistance to disturbance regimes can help in the monitoring and conservation processes of this type of biome. Therefore, the aim of this study was to evaluate the relationship between stem diameter at breast height (DBH) and bark thickness in tropical Amazonian forests, in order to identify the significance of the relationship between these variables and the possible effects on the degree of forest resistance to fire. The study was carried out using forest inventory data from 21 plots in the Lower Tapajós, in the Eastern Amazon - PA. In order to assess the relationship between DBH and bark thickness, data from 11 botanical families was used in a GLMM (Generalized Linear Mixed Effect Models). The relationship between the variables was significant, with an overall explanatory power of 34% for DBH over thickness, and considering the variation between botanical families, this power increased to 50%. Our results show that of the 11 botanical families studied, only half have trees with bark thick enough to be considered resistant (17-23 mm). In addition, in order to consider trees with or without resistance potential, we analyzed bark thickness at a minimum DBH of 10 cm and the increase in bark thickness as DBH increased. Fabaceae, Lecythidaceae and Burseraceae stood out as being more prone to fire mortality. Therefore, considering the high distribution of individuals belonging to these families in the Amazon and the current scenario of forest degradation, ecological impacts and climate change, this work raises insights into the Amazon's forest vulnerability to burning regimes, and the importance of its conservation for climatic conditions on a local and global scale.
Acesso aberto (Open Access)
Uso de caixas-ninho pela fauna de vertebrados em relação às variáveis ambientais em um fragmento de Floresta Amazônica em Altamira-Pa
(Universidade Federal do Pará, 2018-07-27) BENTO, Silnara Carmo; GOMES, Felipe Bittioli Rodrigues; http://lattes.cnpq.br/0924023357753741
The Amazon rainforest is considered one of the largest remnants of tropical rainforest in the world, but the sharp exploitation of natural resources in the Amazon has caused a growing loss of biodiversity. These impacts have worryingly reached the fauna that depends on natural cavities present in alive or dead trees as spots for nesting, sheltering or foraging. To compensate the loss of environmental complexity, the use of nest boxes has been successfully used, especially forests of temperate regions, for diverse groups of vertebrates, from birds to mammals. For the Neotropical region, it is necessary to evaluate the efficiency of this environmental intervention through the experimentation and observation regarding the use of these nest boxes in relation to the environmental variables, being our goal to develop these observations in a fragment of Amazon forest in Pará. The study used 30 wooden nest boxes distributed along a RAPELD research module located in a forest fragment in the Xingu region of Altamira. Eight boxes were installed in transect One and 16 transect the Two, added six boxes along the stream. Four boxes per parcel were installed, two at the beginning and two at the end, one 1.5 m hight and the other with 5 m. in relation to the ground; the boxes installed along the stream were fixed with intercalated height (1,5 and 5 m) distanced 50 m each other. Environmental and spatial variables were measured: opening the canopy edge distance, and an average density of the surrounding DAP trees, distance and altitude stream. The Principal Components Analysis (PCA), were used to correlate the occurrence of bird, amphibians and reptiles species, and used to verify the relationship between the nesting site variables and locations in relation to the sampling sites. Seven boxes were occupied by vertebrates, all then as sheltering. Four were occupied by mammals (Didelphidae and Rodentia), two reptiles (Thecadatilus rapicauda) and one amphibian (Osteocephalus taurinus). Sampling covered the entire study area through the heterogeneous distribution of the artificial cavities, there was slight variation between the variables and the nest boxes (PCA - 39.50% explanation of the axes). There was no significant correlation, but a tendency of use for T. rapicauda to occupy boxes associated with the variables distance of the stream and altitude, and mammals with the variable vegetation cover. Different from other Brazilian studies there was low occupation of nest boxes, and our results were not substantial to determine the use of nest boxes for environmental enrichment in fragmented environmental fragments in the Amazon.