Navegando por Assunto "Ecologia das florestas tropicais"

Agora exibindo 1 - 3 de 3

Acesso aberto (Open Access)
Efeito da paisagem sobre a diversidade de vertebrados terrestres em fragmentos florestais na Amazônia Oriental
(Universidade Federal do Pará, 2019-01-17) SILVA, Jacqueline Almeida da; MASCHIO, Gleomar Fabiano; http://lattes.cnpq.br/7967540224850999
Context: The advance of anthropic activities on the Amazonian frontier has provoked an intense process of forest fragmentation that reduces biodiversity and subjects the species to a situation of high vulnerability. Objectives: To test the relation of fragment size, isolation and characterization of the forest fragments matrix, on the wealth of amphibians of the order Anura, reptiles of the order Squamata and mammals of small, medium and large size. Methods: The study was carried out in 12 fragments in the northeast of the Amazon. The size of the fragment was calculated in hectares, the isolation in ENN_MN (mean of the euclidean distance of the nearest neighbors) and the matrix was organized into categories. These landscape metrics were considered as explanatory variables and calculated on three spatial scales: 1, 2 and 3 km. The relationship of the metrics with the richness of terrestrial vertebrates was evaluated through multiple regressions with model selection. Results: 130 species of terrestrial vertebrates were recorded. There was no significant effect of fragment size on spatial scales for any group of species. The isolation was significant only in the 3 km scale for the group of amphibian and snake species. The category of open areas in the matrix was significant in the three spatial scales for the group of species of lizards and mammals of medium and large size. Conclusions: The landscape configuration is extremely important in the context of fragmentation, there were different responses from taxonomic groups, possibly due to differences in habitat use.
Acesso aberto (Open Access)
Integrando conhecimentos locais e armadilhas fotográficas para avaliar a detecção e as características ecológicas que afetam a presença e a abundância de vertebrados médios e grandes no Vale do Xingu, Amazônia Oriental
(Universidade Federal do Pará, 2024-10) VULCÃO, Otávio Augusto Pereira Leão; CARVALHO JUNIOR, Elildo Alves Ribeiro de; http://lattes.cnpq.br/7456274393700395; HTTPS://ORCID.ORG/0000-0003-4356-2954; PEZZUTI, Juarez Carlos Brito; http://lattes.cnpq.br/3852277891994862; https://orcid.org/0000-0002-5409-8336
The choice of appropriate methods to observe population changes of species of interest in environmental monitoring is crucial to ensure the sustainability of long-term programs. This is a challenge in assessing medium and large vertebrates due to their ecological importance and relatively high costs for evaluation. In tropical regions, the methods commonly used are transect censuses or camera traps. However, both methods have limitations and can incur high costs and difficult maintenance, especially in megadiverse tropical countries. Including methods based on local ecological knowledge (LEK) can contribute to the sustainability of monitoring programs. We assessed the congruence between detection rates obtained from camera traps and sightings and traces detected through LEK in two protected areas of Eastern Amazonia, comparing detection probabilities and testing the influence of three ecological traits. We observed that, despite an overall positive relationship, the rates obtained by both methods show high variability. For 11 out of 20 species, the probability of detection was greater using the method that identified traces through LEK from local monitors. Among the selected traits, body mass, sociability, and trophic niche, only the last characteristic was significant within our models, indicating a detection capability primarily based on the behavioral patterns of the species. Our results demonstrate the significant ability of local monitors to detect the presence of species of interest, as well as the applicability of LEK in faunal monitoring. We recommend collaborative research strategies and the inclusion of the knowledge and experience of local populations in monitoring and conservation programs in the Amazon and other tropical systems, which are the regions richest in both biological diversity and sociocultural richness.
Acesso aberto (Open Access)
Variação intraespecífica de características funcionais de espécies arbóreas ao longo de um gradiente de degradação florestal no leste da Amazônia
(Universidade Federal do Pará, 2017-03-28) CORDEIRO, Amanda Cardoso Nunes; FERREIRA, Joice Nunes; http://lattes.cnpq.br/1679725851734904; BARLOW, Bernard Josiah; http://lattes.cnpq.br/8559847571278134
Degradation of tropical forests has been intensified by anthropogenic activities such as fires and predatory logging, which are associated with a number of land use changes. As a result, in the tropical region, some 156 million hectares of forest degradation were detected during the period. There are only 10.3 million hectares of degraded forests in the Amazon alone. Given the magnitude and expansion of forest degradation in the region, it is very important to understand the resilience of vegetation to changes caused by environmental changes. Studies of functional diversity allow us to investigate the mechanisms used for plant survival and persistence that determine the resilience of ecosystems. In this work, we hypothesized that the species of arboreal plants of the Amazon are responding to the pressures of forest degradation through the variability of their functional traits. Therefore, it is expected that in more disturbed environments, the plants present greater variability of their functional traits, as a strategy of adaptation and survival, in face of the changes generated by the forest degradation. In this way, the objective of this study is to investigate if species of arboreal plants present intraspecific variability of their functional traits along a gradient of degradation in response to the alterations caused by the disturbances in the forest. The study was carried out in Santarém, Eastern Amazonia, in a landscape that varies between the classes of undisturbed forest (n = 5), logging forest (n = 5), logging and burned forest (n = 5) and secondary forest (n = 5). The tree species that contributed 80% of the basal area of each of the twenty plots of study, n = 268, were selected. Among the most abundant species, those that presented at least 4 individuals in two or more forest classes were evaluated. In total, three hundred and four individuals and twenty-one tree species were evaluated. Six functional traits were measured: leaf and petiole thickness, specific leaf area, leaf area, leaf dry-matter content and bark thickness were performed based on protocols established in the literature. The secondary density of the wood collected from the global wood density database (DRYAD) was used as secondary data. In this work, sixteen of the twenty - one species studied showed no significant variation of their functional traits between forest class pairs and 5 presented significant differences for leaf thickness, petiole thickness, leaf area and specific leaf area. The functional traits dry leaf matter and bark thickness did not show variations between forest classes. In forest classes with greater species abundance, the coefficient of variation of the functional traits did not differ along the forest degradation gradient. Here we also tested the relationship between the mean density of wood and the coefficient of variation of the functional traits of tree plants, it was observed that with the increase of the average density of the wood the variability of the functional traits reduced. These results demonstrate that plants have low plasticity and may not survive if forest degradation intensifies, leading to a change in floristic composition and loss of species with unique functions for the functioning of ecosystems.