Programa de Pós-Graduação em Ecologia - PPGECO/ICB

URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/8937

O Programa de Pós-Graduação em Ecologia (PPGECO) foi criado em 2015, por meio de um convênio firmado entre a Universidade Federal do Pará (UFPA) e Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) e visa avançar no conhecimento teórico e empírico da Ecologia, incluindo suas abordagens básicas que são a autoecologia, a biologia de populações e os estudos de comunidades e ecossistemas.

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Agora exibindo 1 - 14 de 14

Acesso aberto (Open Access)
Aspectos ecoepidemiológico associados à fauna flebotomínica de um fragmento florestal urbano
(Universidade Federal do Pará, 2017-03-31) ROSÁRIO, Ingrid Nazaré Garcia; MÁLAGA, Sérgio Marcelo Rodríguez; http://lattes.cnpq.br/4348571126707708; SILVA, Ivoneide Maria da; http://lattes.cnpq.br/5206284058104362
Sand flies are insects vectors of several disease-causing pathogens, responsible for the transmission to animals and humans of numerous diseases, the main being leishmaniasis. The present study evaluated the ecoepidemiological aspects of the phlebotominal fauna in a forest fragment in the urban area of Belém (PA). From December 2015 to November 2016, monthly collections of sand flies were carried out in the forest fragment and in the peridomicile of nearby residences, with the aid of a CDC type light trap. A total of 4070 phlebotomines were collected, with identification of two genera and 24 species. The predominant species was Lutzomyia (Trichopygomyia) longispina (32.16%), followed by Lutzomyia (Evandromyia) infraspinosa (21.72%). The wealth estimators indicated that the sampling effort was satifastory for the studied area. There was no significant relationship between accumulated precipitation, temperature and relative humidity when analyzed with sandfly abundance. When related to climatic variables with species richness, only the accumulated monthly rainfall presented a negative relation on the richness of captured species. In the analysis of the vertical distribution the number of sandfly specimens captured at ground level was significantly higher than in the canopy, where 21 species were found in the soil, four of them exclusive to this stratum and 20 species in the canopy, with three occurring exclusively in the canopy. Four species with epidemiological importance were found: Lutzomyia (Nyssomyia) flaviscutellata, Lutzomyia (Psychodopygus) ayrozai, Lutzomyia (Psychodopygus) paraensis and Lutzomyia (Nyssomyia) antunesi. The females evaluated by PCR were negative for Leishmania spp. And most of the engorged females analyzed were fed on mammals. The knowledge of the fauna in an area of preservation under intense anthropic influence, can help in the understanding of the relation between the species and the degree of preservation of an area, and also in the knowledge of species that may play an effective role in the transmission of pathogens to man and animals.
Acesso aberto (Open Access)
Avaliação da população de Botos-do-Araguaia (cetacea: iniidae: inia araguaiaensis hrbek et al., 2014) no Baixo Rio Tocantins, Amazônia oriental
(Universidade Federal do Pará, 2017-05-17) MOREIRA JUNIOR, Reginaldo Haroldo Medeiros; LIMA, Neusa Renata Emin de; http://lattes.cnpq.br/9249838863447997; LOPES, Maria Aparecida; http://lattes.cnpq.br/3377799793942627
The aims of this study were to estimate the abundance and home range size of Araguaian river dolphin’s (Inia araguaiaensis), to characterize their habitat, and to describe their habitat use in lower Tocantins River, Eastern Amazonia. Data were collected in November 2015 and March 2016. When encountered, the dolphins were counted and photographed, their location was recorded and environmental parameters (depth and turbidity) and landscape parameters (distance from sightings to the Cametá market) were measured. Abundance was estimated by marking and recapture method allied to photo identification, and home range was measured by minimum convex polygon method and by Kernel density estimator. Generalized Linear Models were used to evaluate dolphins’ habitat use patterns. Solitary animals and assemblies of up to eight individuals were observed (X ̅ = 6,43 ± 1,13 individuals). Thirteen individuals were identified and a total of 18 dolphins were estimated in the area. Estimated home range and core area were up to 14.55 km² and 5.25 km², respectively. A high frequency of records occurred in front of Cametá market. The distance from sightings to this market was the only metric with a significant effect on habitat use (GLM, z = 2.79, p <0.01). This high frequency is associated with food provision to dolphins in the market.
Acesso aberto (Open Access)
Clima, solo e água: importância de variáveis ambientais na determinação da distribuição potencial de peixes de rios e riachos amazônicos
(Universidade Federal do Pará, 2017-10-19) ALVAREZ, Facundo; MONTAG, Luciano Fogaça de Assis; http://lattes.cnpq.br/4936237097107099; GERHARD, Pedro; http://lattes.cnpq.br/5621269098705408
Estimating the spatial distributions of species is one of the main objectives of macroecology, especially when sampling efforts fail to reach the demographic knowledge of the target species. In this sense, the species distribution models (SDM) allow us to approach the fundamental niche of the species from the extrapolation of predictor variables. The Amazonas-Tocantins basin is characterized by a strong environmental and physical dynamics that act differently in the regional ichthyofauna at different spatial scales. Due to the differential perception of hábitats by the species, four species of rivers were included, Ageneiosus inermis, Acestrorhynchus falcatus, Pygocentrus nattereri and Plagioscion squamosissimus, and four species of streams, Crenuchus spilurus, Helogenes marmoratus, Helogenes marmoratus and Trichomycterus hasemani. The objectives of the study were: (i) To determine which set of predictor variables allows better spatial representations for the species of rivers and streams using SDM; and (ii) To evaluate the predictive power of MaxEnt to generate SDM of rivers and streams using different sets of Predictor variables. The spatial records that presented spatial autocorrelation were processed from the spThin package. To characterize the environmental dynamics, 78 predictors were divided into three treatments: PCA1 (climatic variables), PCA2 (climatic variables, slope and accumulated flow) and PCA3 (climatic variables, slope, accumulated flow, topographic and edaphic variables). MaxEnt software was used and configured from the ENMeval package. Two aspects can be observed in the results: the use of hydrological, topographic and edaphic variables allows to obtain more precise and spatially restricted representations than only climatic variables. In the second place, it is evident that, regardless of the dimensional complexity of the system, MaxEnt allows to obtain MDEs with high predictive power for both river species and species of streams. In the case of river species, the macroscopic predictors (climatic variables - PCA1) allowed to represent their environmental requirements and their wide spatial distributions. Meanwhile, climatic, hydrological, topographic and edaphic variables (PCA3) acted as environmental filters restricting the spatial distributions of both species of rivers and streams. The dimensional complexity of the system does not affect the spatial representation capacity of Maxent, observing that, in the case of species of streams MaxEnt showed greater capacity of spatial representation.
Acesso aberto (Open Access)
Desenvolvimento colonial em abelhas nativas sem ferrão Amazônicas (Apidae: Meliponini): tamanho populacional, nutrição e alocação fenotípica
(Universidade Federal do Pará, 2019-11) LEÃO, Kamila Leão; MENEZES, Cristiano; http://lattes.cnpq.br/9845970576214577; CONTRERA, Felipe Andrés Léon; http://lattes.cnpq.br/0888006271965925; https://orcid.org/0000-0002-7078-5048
Meliponines or stingless bees comprise a diverse and abundant group of eusocial bees, which live in perennial colonies and have a wide range of behavioral characteristics. The general objective of this thesis is to understand population dynamics and developmental patterns of Amazonian stingless bee species. In Section I, we evaluated the population size and several biological characteristics of colonies (e.g. worker external activity, queen egg-laying rate) of five stingless bee species in order to understand how colony characteristics relate to population size. We found an average adult population of 1,046.00 in Melipona flavolineata, Friese, 1900, 592.75 in Melipona fasciculata, Smith, 1854, 7,404.00 in Scaptotrigona aff. postica (Latreille, 1807), 2,425.33 in Frieseomelitta longipes (Smith, 1854) and 404.75 in Plebeia minima (Gribodo, 1893). External activity was the variable that best explained population size. In Section II we investigate the longevity of stingless bee workers fed soy-based diets. Our objective was to compare the effect of a semi-artificial soybean diet versus a natural diet on the longevity of adult workers of two stingless bee species (Melipona flavolineata Friese, 1900 e Scaptotrigona aff. postica (Latreille, 1807)). We found a higher longevity in workers that consumed only pollen compared to those that consumed the soybean diet for both species studied. Finally, In Section III we evaluated the phenotypic allocation in stingless bees. In this work we investigate phenotypic allocation as a response to climatic and environmental variation, using the stingless bee Melipona fasciculata Smith, 1854 as a model species. Our results reveal that phenotypic allocation in M. fasciculata was strongly associated with seasonal variation and not the quality of the environment (local). The production of virgin queens was influenced by season and year (being higher in the dry season), but not by location. Male production was explained by season and local environmental variables and season and study year influenced the percentage of workers produced, showing differences between years. We believe that this thesis contributes to our understanding of the natural history of Amazonian stingless bees and the development of regional meliponicultural practices.
Acesso aberto (Open Access)
Ecologia populacional de Clibanarius symmetricus (Anomura: Diogenidae) em uma praia exposta da Costa Amazônica Brasileira
(Universidade Federal do Pará, 2017-06) DANIN, Ana Paula Ferreira; SANTOS, Cleverson Ranieri; PETRACCO, Marcelo; http://lattes.cnpq.br/6834814201680920; https://orcid.org/0000-0001-6501-0099
The hermit crab Clibanarius symmetricus has a wide geographical distribution along the Western Atlantic where is a conspicuous species in intertidal and shallow waters of several ecosystems as sandy beaches, tidal flats, mangroves and rocky shores. However, information on the life history traits of this species is in general limited to the subtropical regions. Here, we access the population structure and dynamics, and the shell occupation pattern of a C. symmetricus population inhabiting a rocky outcroup of an exposed sandy beach on the Amazon coast. For this purpose, monthly samplings were carried out from October 2015 to September 2016. Higher density of C. symmetricus occurred in the drier season and the frequent presence of ovigerous females suggests continuous reproduction. The overall sex-ratio was skewed toward females (0.6:1, M:F) and sexual dimorphism was recorded. Males and females had similar curvature, but smaller growth performance index than others subtropical populations. The turnover rate (P/B) was also similar between sexes as a consequence of similar growth constant. Thaisella coronata was the most occupied (97.1%) gastropod shell and the overlap in shell utilization by hermit crabs of same size may reflect competitive interactions. Also, some difference in occupation between sexes was documented, suggesting that males can occupy larger and more suitable shells.
Acesso aberto (Open Access)
Ecologia populacional de Ocypode quadrata (Brachyura: Ocypodidae) em uma praia arenosa exposta de macromaré da costa amazônica do Brasil
(Universidade Federal do Pará, 2017-03) SOUZA, Diego Garcia Cordeiro; POMBO, Maíra; http://lattes.cnpq.br/0599201977466564; PETRACCO, Marcelo; http://lattes.cnpq.br/6834814201680920; https://orcid.org/0000-0001-6501-0099
The present study analyzes the population ecology of Ocypode quadrata (Brachyura: Ocypodidae) on an exposed, macrotidal, dissipative sandy beach located on the Amazon coast, during one year. Indirect (burrow counting and measurement) and direct (burrow excavation and assessment of individuals) methods were used on population assessments. Burrow abundance variation was analyzed over time and as a function of environmental variables (sediment properties, precipitation, air and seawater temperature, salinity). Zonation was described through burrow distribution by distance from the high tide mark. Burrow diameter was used to estimate individual growth parameters of the population. Burrow occupation rate, sex ratio and relation between burrow diameter and crab measures (carapace length, width and depth) were also estimated. Abundance was higher on the rainy season (0.78 ± 0.24 burrow.m-1, against 0.37 ± 0.13 burrow.m- 1 on the dry season) and related positively to precipitation and negatively to sediment grain size. The population was practically restricted to the supralittoral zone. The estimated individual growth parameters (L∞=53.36 mm, K=0.76 yr-1, t0=0.014 yr, Φ=3.34) describe a well-adjusted curve to cohort progression over time. Burrow occupation rate varied between 12.5% and 28.7%. There was sex equilibrium during the rainy season, however, changing to male predominance on the dry season. Burrow diameter was related mainly to carapace width. These are the first data of ghost crab population behavior on Amazon macrotidal environments. These, compared to available data on other regions, also gives insight on latitudinal tendencies of population parameters.
Acesso aberto (Open Access)
Efeito da perda de cobertura florestal sobre a diversidade de peixes de riachos em uma zona de transição Cerrado-Amazônia
(Universidade Federal do Pará, 2019-02-28) FREITAS, Pâmela Virgolino; JIQUIRIÇÁ, Paulo Ricardo Ilha; http://lattes.cnpq.br/3392388693636935; SILVA, Karina Dias da; http://lattes.cnpq.br/2271768102150398
Currently, the expansion of the agricultural frontier in the Amazon represents a profound change in the world’s vegetation cover. This expansion causes decrease of forest cover, affecting the environmental integrity of streams, as well as the richness of associated communities. We aimed to evaluate the effects of loss of forest cover on the physical integrity of streams, and on the taxonomic and functional diversity of fish assemblages in a Cerrado-Amazon transitional zone. We sampled nine streams in the Alto Xingu river basin. The streams possess microbasins covered by different percentages of transitional Cerrado-Amazon forest and croplands. We did not detect the effect of loss of forest cover on the physical integrity of streams, and neither on fish taxonomic diversity. However, we found a negative effect on the functional diversity. The physical integrity of streams was not associated with taxonomic and functional diversity of fish assemblages. The conversion of forest areas to croplands, on the riparian zone, affects negatively the functional richness of fish assemblages, acting as an environmental filter, leading to the disappearance of species that could have performed important ecosystem functions. Furthermore, the establishment of restoring and conservation strategies of areas affected by deforestation must be a priority on all streams drainage systems, especially on the riparian zone scale, to minimize impacts on species. To understand which factors can better structure fish assemblages in streams, it is necessary to do research, that can give basis to formulate strategies for the preservation of those organisms.
Acesso aberto (Open Access)
Efeito dos ambientes estuário e reservatório na fecundidade de Macrobrachium amazonicum (Decapoda: Palaemonidae) (Heller, 1862)
(Universidade Federal do Pará, 2019-02-27) SILVA, Breno Richard Monteiro; FERREIRA, Maria Auxiliadora Pantoja; http://lattes.cnpq.br/1832728101486131
Studies reveal that the Amazon region is suffering a strong anthropogenic and climatic influence which interferes in the environmental conditions. In crustaceans, climate change can influence growth and reproduction, and as life history patterns is influenced by environmental factors, the fertility is an important factor to estimate the reproductive potential and natural population stock. The specie Macrobrachium amazonicum has a wide geographical distribution and ecological and morphological plasticity. Based on the hypothesis that the physical and chemical conditions different of the environment influence on populations of M. amazonicum, we have the following question: What are the main environmental factors that will influence M. Amazonicum fecundity between populations of different places? Thus, the aim of present study is to determine the influence of physical and chemical factors on the relative fecundity of populations of M. amazonicum in estuary and reservoir. In the period of study, temperature, pH, salinity, turbidity and dissolved oxygen concentration in the water were obtained in situ. Precipitation was obtained from INMET, 2018 with establishment of four seasonal periods: dry, transitional dry-rainy, rainy, transitional rainy-dry. A total of 255ovigerous females, 181 from the estuary environment and 75 from the reservoir were collected for analysis of biometrics, number and size of eggs throughout the year. Embryonated eggs were measured according to the developmental stages. In the relationship effect of the environmental variables on the ovigerous females, turbidity and precipitation were the main factor on estuary. The mass-length relationship of females was represented by the following equations, Mt = 0.017xCt2.630 (R² = 0.880) for the estuary and Mt = 0.021xCt2.441 (R² = 0.810) for the reservoir, where ovigerous females in the estuary were larger and larger mass in comparison to the reservoir. In the relationship between fecundity and biometry of the animal, from both sites, there was a high positive correlation, between the length (r = 0.788) and the weight (r = 0.843) of the ovigerous females, as well as the relation with the morphometry of the eggs. The estuarine environment presented females with the highest amount of eggs in the dry-rainy and rainy periods in relation to the females from the reservoir that presented the highest fecundity in the rainy-dry and dry season. In our results observed four stages of development considering the presence and the appearance of the eye, and the eggs of the females reservoir, although in smaller numbers, presented larger sizes in relation to the estuary. The correlation observed if the physical and chemical factors influence the fecundity of M. amazonicum from the estuary was confirmed, with precipitation and turbidity being the factors that contributed the best reproductive performance of the species in the estuary. When it comes to the reservoir, we believe that there is a combination of all the environmental factors involved promoting the tolerance of the animal to maintain its life cycle.
Acesso aberto (Open Access)
Efeitos da inundação e da antropização sobre padrões de diversidade de árvores da floresta de várzea amazônica
(Universidade Federal do Pará, 2019-05-29) MAGALHÃES, Jose Leonardo Lima; LOPES, Maria Aparecida; http://lattes.cnpq.br/3377799793942627; https://orcid.org/0000-0002-6296-5487
The white-water floodplain forest in Amazon (locally várzea) is a highly heterogeneous floodplain ecosystem that encompasses a large number of adapted species. It is distributed along the entire length of the main channel of the Amazon River and of tributaries of Andean origin. In addition, due to periodic flooding by waters with high sediment load, it has high fertility when compared to other Amazonian systems. What on the one hand is important for high primary productivity also makes it the target of human colonization for its benefits to food production. In this sense, because it presents continental dimensions and crosses almost all the biome from East to West, it has been the main access route of present and previous human populations to the most distant points of the basin. All these factors contribute to these forests being an important model for testing diversity patterns along natural and anthropogenic gradients. This thesis is presented in two chapters that use distinct approaches, focusing on different aspects of forest diversity and structure. Chapter 1 examines the phylogenetic structure of the arboreal component of floodplain forests in the Central and Eastern macro-regions and investigates whether the current human presence has modified it, specifically reducing the number of tree lineages present and leading to the phylogenetic homogenization of these forests. Chapter 2 investigates whether the taxonomic diversity and the local and regional tree species found today in the macro-regions of the study are associated with historical patterns of human density since the arrival of Europeans in the region. To reach the objectives, seven areas were sampled along the 2,400 km stretch of the Brazilian portion of the Amazon River, which covers different flood regimes and human influences. Thus, tree individuals with DBH ≥ 10 cm were sampled and data were collected in situ and in databases available to be used as predictors variables in modeling tree diversity at different scales. With the results, it was detected that the flood regime is the main factor that influences the phylogenetic structure whereas the human density of almost three centuries ago is responsible for the patterns of taxonomic diversity that are currently found. The diversity patterns were detected in the evolutionary and ecological scale, where it was shown that human influences may have a long-delayed response after they have occurred. Because várzea is a system of relatively easy access in the region and has few protected areas, it is necessary to understand how these forests are important for the maintenance of essential ecosystem services, even though they have been affected by human influence for a long period.
Acesso aberto (Open Access)
Efeitos de atividades de subsistência de ribeirinhos sobre a heterogeneidade ambiental e a diversidade de insetos aquáticos em diferentes níveis espaciais de riachos amazônicos
(Universidade Federal do Pará, 2021-09) COSENZA, Jorge Felipe Abreu; FARIA, Ana Paula Justino de; http://lattes.cnpq.br/6041546003155327; https://orcid.org/0000-0003-2729-5358; SANTOS, Raphael Ligeiro Barroso; http://lattes.cnpq.br/7227882802366966; https://orcid.org/0000-0001-9717-5461
The deleterious effects of large-scale impact activities such as agriculture, intensive ranching, dam construction and mining on Amazonian biodiversity have been constantly studied. On the other hand, the effects of smaller-scale impact activities are neglected. An example is the activities practiced by traditional populations, such as riverside populations, who have lived for generations on the banks of rivers and streams in the Amazon basin. There are still few studies that evaluate the effects of anthropic activities considered to have less impact on the diversity patterns of aquatic insects at different spatial scales using taxonomic and functional approaches concurrently. Thus, we evaluated how subsistence activities practiced by riverside populations affect the taxonomic and functional alpha and beta diversity of aquatic insects of the orders Ephemeroptera, Plecoptera and Trichoptera - (EPT), at different spatial levels (between sampling units within streams and between streams). We tested the hypotheses that (H1) the altered streams have less environmental heterogeneity among themselves and the composition of environmental characteristics different from the control streams; (H2) altered streams have lower alpha taxonomic and functional diversity than control streams; (H3) the taxonomic and functional beta diversity between sampling units and between altered streams is lower than between sampling units and control streams; (H4) the beta diversity observed between sampling units and between altered streams is generated primarily by richness difference, while between sampling units and control streams, the replacement of species/functional groups predominates. We conclude that the disturbance caused by the riverside populations subsistence activities, specially navigation, altered the characteristics of the habitats and, in certain aspects, the EPT assemblages of the streams of the Caxiuanã region. Beta diversity patterns did not change, but there was a loss and increase in abundance of some genera as a result of the changes. Thus, the maintenance of beta diversity is not necessarily a sign of high diversity and ecological integrity, as the increased variation in the composition of these assemblages may be a result of the loss of sensitive species and the increase of more generalist species. The functional approach responded similarly to the taxonomic one in all environments and spatial levels, which suggests that this effect is dependent on the biological group analyzed and on the type and intensity of change in the environment. The activities practiced by the riverside populations altered the local community of aquatic insects in a less impactful way compared to other activities commonly practiced in the Amazon, such as logging, agriculture, palm plantation, grazing and mining. To reduce a possible loss of species in the streams in the region, it is necessary to maintain the natural conditions of the habitats, such as a high density of vegetation cover on the banks, a large number of leaf banks in the riverbed and a high frequency of slow flows.
Acesso aberto (Open Access)
Efeitos do manejo do açaí (Euterpe oleracea Mart.) sobre a avifauna em florestas de várzea estuarina na Amazônia
(Universidade Federal do Pará, 2017-05-30) NUNES, Raphael de Vasconcelos; LEES, Alexander Charles; http://lattes.cnpq.br/8887958109144699; LOPES, Maria Aparecida; http://lattes.cnpq.br/3377799793942627
Human actions and use of natural resources, by removing plant species, food resources or altering the environment’s structure, may have indirect effects on animal communities. The expansion of açaí (Euterpe oleracea) production has been altering floodplain forests through its management actions, resulting in environmental degradation and even substitution of forest for plantation areas, thus causing floristic empoverishment. In this paper we investigate the effects of this species management on the structure of bird community in an insular system of the Amazon River delta. Our hypothesis was that we would find less bird species diversity on managed areas (low and high intensity management) compared to non-managed forest fragments due to the environmental degradation caused by this practice. To assess the diversity and abundance of bird species we conducted point counts with auditory recordings and observations in three sites per treatment. We found a decrease tendency in bird species richness in intensively managed areas; but didn’t detect any changes on bird abundance and diversity in areas managed for açaí fruit production. We found alterations on bird community composition, being this more homogenous in managed areas. The effects of açaí management upon the fauna are still hard to detect but may arise in the future and our results point to the homogenization and species loss in areas subjected to intense management, causing birdlife empoverishment.
Acesso aberto (Open Access)
Filtros ambientais determinando caracteres funcionais de assembleias de Odonata
(Universidade Federal do Pará, 2017-03-24) PEREIRA, Diego Fernandes Gomes; JUEN, Leandro; http://lattes.cnpq.br/1369357248133029
Species distribution is affected by availability of habitas that fit within the limits of variation of their niche and by interaction with other species. Environmental modifications, especially those of anthropic origin, are increasingly common, and are considered major causes of species extinction during the Anthropocene. Aquatic ecosystems are considered among the most vulnerable on the planet because of its dependence on the surroundings and the drainage system. However, species responses to these changes are not random, and can follow patterns that are caused by the specific functionality or morphology of each taxon. This work’s goal was to evaluate if environmental factors work as ecological filters for the establishment of Odonata species through selection of their functional and morphological characters, testing the hypotheses that a) the environment works as a filter over species, by facilitating or hindering characters and b) that due to their thermoregulatory and reproductive requirements, indispensable for colonization and population maintenance, thorax width and oviposition type will be the most affected biological variables. Considering that, we sampled 97 streams in the oriental side of the Brazilian Amazon Forest, distributed over an environmental gradient which covers areas ranging from untouched primary forest to areas extremely modified by agriculture and livestock. We used six functional traits (total body length, fore wing length, fore wing width, thorax width, abdominal length and oviposition type) and seven environmental variables (habitat integrity index, dissolved oxygen, water temperature, canopy cover, macrophytes cover, pH and condutivity). To evaluate if the environmental variables affected the odonate communities, we used the combination of the RLQ and Fourth Corner analysis, with which we assessed the relation between each of the selected traits with each of the habitat descriptors. Among the studied environmental variables, habitat integrity index presented the largest effect over the community of Odonata, having a negative relation with fore wing width, thorax width and exophytic oviposition, and a positive relation with endophytic oviposition. Macrophytes cover showed a negative relation with abdominal length and a positive relation with thorax width and exophytic oviposition. No other environmental descriptor presented significant relations. The results show that poorly preserved habitats facilitate the occurrence of organisms with larger thorax and the substitution of the endophytic by the exophytic type of oviposition. Since environmental impacts usually do not change Odonata species richness, only community composition, these results point that there is favouritism towards groups of species with those characters, like the Libellulidae family, with detriment to other families or groups (specially of the Zygoptera suborder), what might result in community homogeneity and loss of functional and phylogenetic diversity. Thus, the preservation of primary forest is indispensable for the maintenance of Odonata, being the best way to conserve the different ecophysiological and behavioural groups in the order. The dragonfly communities’ responses, directed by morphological and behavioural traits, enlightens ecological response patterns, and the addition of oviposition categories to conservation policies for the Odonata is critical in making them more effective, as they are absolutely necessary for population stability and colonizing new sites.
Acesso aberto (Open Access)
Padrões de diversidade, ocupação e coexistência de mamíferos terrestres na região neotropical
(Universidade Federal do Pará, 2019-05-10) SANTOS, Fernanda da Silva; JUEN, Leandro; http://lattes.cnpq.br/1369357248133029; PERES, Carlos Augusto da Silva; http://lattes.cnpq.br/9267735737569372
Community structure and diversity result from a complex and dynamic phenomenon, determined by a large number of processes in space and time, which are driven by environmental conditions, spatial factors, resource availability, and species interactions, including competition and predation. This study used the terrestrial mammal group as a model to investigate part of the processes shaping communities, and to understand patterns of diversity, occupancy, and coexistence in the Neotropical forests. Data from a long-term camera trapping monitoring of terrestrial vertebrates across eight protected area sites were combined. The study sites comprise eight areas distributed through six countries (Costa Rica [1], Panama [1], Ecuador [1], Peru [2], Suriname [1] e Brazil [2]), and include both intact forest and fragmented forest landscapes. Firstly, β diversity was estimated among the eight mammal communities to identify: which sites and species contributed to differences in the variation of community composition (LCBD and SCBD, respectively); which process (species replacement or richness difference) explain the observed β-diversity patterns; and which factors affect local contribution (LCBD) and species contribution (SCBD) to β diversity. Posteriorly, data from five sympatric cat species [jaguar (Panthera onca), puma (Puma concolor), ocelot (Leopardus pardalis), jaguarundi (Herpailurus yagouaroundi) and margay (Leopardus wiedii)], that potentially occur across the eight sites, were used to examine mechanisms that allow coexistence among ecologically similar species. Finally, data from one of the sites was used to test the hypothesis that terrestrial mammals, mainly frugivores and granivores, move seasonally as a response to resource availability fluctuation (e.g., water and fruits) between rainy and dry seasons in a terra-firme forest. The results indicated that fragmented forests contribute more to β diversity than intact forest sites, and that variation in species composition is determined by richness difference rather than replacement. The eleven species ranked as the most important in structuring the communities were also the ones with the highest abundance variation among sites. Regarding felids’ coexistence, the study reveals an apparent spatial and temporal partitioning for most species pairs, with prey abundance being more important than species interactions to the local occurrence and spatial distribution of Neotropical forest cats. Concerning seasonal dynamics, only three species presented differences on occupancy between dry and rainy seasons, while the other analyzed species did not seem to move as a response to variation in water and food availability. In summary, the results provide a broad characterization of terrestrial mammals occurring in the Neotropical region, assessing their conservation status, factors that influence their occurrence, as well as the spatial and temporal patterns of several felid species along eight Neotropical protected forests.
Acesso aberto (Open Access)
Variação temporal de Ephemeroptera, Plecoptera e Trichoptera (EPT) com base em sua especificidade ambiental em riachos impactados pela mineração na Amazônia Oriental
(Universidade Federal do Pará, 2022-03) PÉREZ, Juan Mateo Rivera; JUEN, Leandro; http://lattes.cnpq.br/1369357248133029; https://orcid.org/0000-0002-6188-4386; FEITOZA, Yulie Shimano; http://lattes.cnpq.br/7380463661182614; https://orcid.org/0000-0003-2931-4719
Knowing aquatic diversity and understanding how different species are distributed in time and space has become one of the main focuses of research in ecology in recent decades. This is mainly due to the rapid environmental changes caused by human activities. In this scenario, aquatic insects of the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT) are used to monitor environmental conditions because they are sensitive to these changes. The intensity of the response depends directly on the breadth of the niche of each taxon given the variability and changes in the habitat. With the general objective of investigating the effects of iron mining based on the environmental specificity of EPT in streams of the Carajás National Forest in Pará, over six years, this dissertation is divided into two chapters. In the first, we classified EPT taxa into generalists and specialists and evaluated whether the estimated abundance and richness of these groups vary according to the level of alteration of the streams impacted by mining activities. In the second, we evaluated the spatial and temporal variation of the beta diversity of generalist and specialist EPT. In both studies, EPT data sampled annually in 24 streams over six years were used in streams conserved and impacted by mining in the Carajás Flona. A total of 49,922 individuals distributed in 59 genera were collected, of which 31 were classified as specialists and 28 as habitat generalists. In the first chapter, we verified that there was a negative effect of mining on the estimated wealth and a positive effect on the abundance of specialist genera. On the other hand, the abundance and estimated wealth of generalists were negatively influenced by the mining effect. In the second chapter, no differences were found in gender composition or heterogeneity between treatments. However, over time, both generalists and specialists changed their composition. Mining affects the communities of EPT generalists and specialists, in particular, specialists from sites impacted by mining that showed an increase in their abundances, possibly due to the expansion of habitat made available by the process of habitat homogenization. For generalists, gender loss was the main component in temporal beta diversity, while specialists showed gender gains and losses. Therefore, mining has affected communities of both generalist and specialist groups over the years, despite their habitat specificity, presenting different patterns of environmental changes.

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