Navegando por Assunto "Florestas tropicais"

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Estoque de serrapilheira como indicador de qualidade em três ambientes ciliares de floresta tropical úmida na Mata Atlântica
(2019-12-13) Reis, Marina Isabel Lima de Oliveira; Silva, Ana Carolina Borges Lins e; Fonsêca, Nathan Castro; http://lattes.cnpq.br/4924065580196245; http://lattes.cnpq.br/7518216414237885; http://lattes.cnpq.br/0666969331135228
The suppression of the world's forests for commercial use has caused an unprecedented loss of biodiversity and ecosystem services that nature provides to mankind. However, the restoration of these ecosystems to recover lost services is increasing, and an evaluation of the effectiveness of these processes by environmental quality bioindicators are necessary, such as the litterstock quantification. This study aimed at quantifying litter stock in three rainforest riparian areas as a way of subsidizing the improvement of ecosystem recovery strategies. The work was carried out at the São José Agroindustrial mill, located in Igarassu, Pernambuco, Brazil, with a total area of 246 km2. Three riparian forest were selected: one restored, one in advanced secondary succession and one conserved mature forest, and in each one 5 plots of 10 x 10 m were allocated on both sides of the river. The stock of litter deposited on the forests floor was collected using a 0.5 m x 0.5 m template. After collecting the material, samples were submitted to oven drying at 60º C for 72 hours. Then, each sample was selected and weighed by fractions (leaves, branches, reproductive parts and miscellaneous). The three areas differed in litter stock, presenting 8.7 t/ha (+- 1.39) for the Mature Area, 7.0 t/ha (+- 1.03) for the Advanced Succession Area and 5.0 t/ha (+- 1.69) for the Restored Area, with values similar to those found in other tropical forests. A predominant leaf fraction represented 72% of the litter in the Mature Area, 60% in the Advanced Succession Area and 55% in the Restored Area, probably because it is the largest source of soil nutrients. We conclude that the Restored Forest is in good process of returning of the ecosystem services, becoming necessary the maintenance and monitoring of the area allowing it to move towards a mature forest stage.
Estudo de compactação de solos coesos em tabuleiro costeiro cultivados com cana-de-açúcar: experimentação e modelagem
(2019-06-28) Mendonça, Edwardo Antonio dos Santos; Lima, Renato Paiva de; http://lattes.cnpq.br/0597097892809102; http://lattes.cnpq.br/5751088127061977
Modelagem de distribuição e bioacústica de aves co-distribuídas em florestas úmidas da América do Sul
(2022-05-27) Ferreira, Maria Eduarda Alves; Fernandes, Alexandre Mendes; http://lattes.cnpq.br/0273567197386804
The tropical rainforests of South America have a somewhat intriguing evolutionary history. Moments of expansion and retraction of these forests at different periods of time are suggested to be crucial for species dispersal, extinction, and speciation events. Studies with numerous taxa co-distributed between the Amazon and Atlantic Forest, and the existence of forest refugia, such as the Brejos de Altitude, in the middle of the Caatinga demonstrate the existing similarity between these forests and evidence a past and recurrent forest connectivity between the biomes. Routes through which such connections between forests have occurred have been proposed for a better understanding of their historical dynamics. In the present research, we predicted, through distribution modeling and analysis of vocal characters of different bird species co-distributed in the Amazon, Atlantic Forest and in fragments of these forests along the Cerrado and Caatinga (Brejos de Altitude), biogeographic connections between the biomes during the Last Glacial Maximum (UMG - 21 thousand years - Ka). In addition to identifying past connections, this study sought to understand how climate changes that occurred from the UMG into the future may influence the distribution of species. To do so, potential distribution models were built in different scenarios, being past (UMG-21Ka, Holocene-6Ka), Present (1970-2000) and Future (2070); and vocal parameters of suboscine and oscine species were analyzed. Modeling results for the UMG identified connections between Amazon and Atlantic Forest through the southernmost regions of the country, supporting the SE-NW route, and through Caatinga, via the NE route. Both connection routes may have played an important role in the dispersal of taxa between the biomes. Vocal analysis found no difference between the vocalizations of the species and the different environments, thus suggesting recent connections between forests and contact between populations so that the time of separation between Amazon and Atlantic Forest was not enough to distinguish them vocally. For the future, the models indicate shrinking areas suitable for the occurrence of the species. This result serves as a warning for actions aimed at the conservation of biomes and birds that occur in forest environments.