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Structural changes in succession of phosphorus-fertilized secondary forests with pasture history in central Amazonia
No full textSecondary forests with pasture history are regenerating in soils degraded by the intensive use of fire as a pasture management technique and by compaction caused by cattle trampling. The nutritional limitation, mainly for P, reported in great part of the soils of the Amazon Basin, can be aggravated by this type of soil use and, consequently, affect the natural regeneration after the abandonment of the area. Therefore, the main objective of this study was to analyze whether phosphate fertilization and soil acidity correction affect the structural characteristics of secondary forests in a chronosequence (different initial ages) with pasture history in central Amazonia. Ten secondary forests were fertilized in 2000, with four treatments each: phosphorus, phosphorus + liming, phosphorus + liming + gypsum and an unfertilized control. Five censuses were carried out between 2001 and 2005, the last one being in 2018, for calculation of aboveground biomass, stem density and individual mass average. Aboveground biomass stock and average individual mass of older forests increased during the successional trajectory in the control treatment, with no significant difference between P fertilization and control. In forests fertilized by P + Ca, the aboveground biomass stock decreased over time while the average individual mass increased. In forests fertilized by P + Ca + G, both aboveground biomass stock and average individual mass decreased over time. Fertilization did not affect stem density, which decreases during the successional trajectory. These results suggest a possible allocation of growth to belowground biomass and effect of phosphate fertilization and correction of soil acidity on the dynamics and floristic composition of secondary forests with pasture history.Florestas secundárias com histórico de pastagem estão se regenerando em solos degradados pelo uso intensivo do fogo como técnica de manejo do pasto e pela compactação causada pelo pisoteio do gado. A limitação nutricional, principalmente por fósforo, relatada em grande parte dos solos da Bacia Amazônica, pode ser agravada por esse tipo de uso solo e, consequentemente, afetar a regeneração natural após o abandono da área. Portanto, o principal objetivo deste estudo foi analisar se a fertilização fosfatada e correção da acidez do solo afetam as características estruturais de florestas secundárias em uma cronossequência (diferentes idades iniciais) com histórico de pastagem na Amazônia central. Dez florestas secundárias foram fertilizadas em 2000, com quatro tratamentos cada: fósforo, fósforo + calagem, fósforo + calagem + gessagem e um controle não fertilizado. Foram realizados 5 censos entre 2001 e 2005, sendo o último em 2018, para cálculo de biomassa acima do solo, densidade de caules e massa média individual. O estoque de biomassa acima do solo e massa média individual das florestas mais velhas aumentaram ao longo da trajetória sucessional no tratamento controle, sem diferença significativa entre fertilização por P e controle. Nas florestas fertilizadas por P+Ca, o estoque de biomassa acima do solo diminuiu ao longo do tempo enquanto a massa média individual aumentou. Nas florestas fertilizadas por P+Ca+G, tanto o estoque de biomassa acima do solo quanto a massa média individual reduziram ao longo do tempo. A fertilização não afetou a densidade de caules, que diminui ao longo da trajetória sucessional. Estes resultados sugerem uma possível alocação do crescimento para a biomassa abaixo do solo e efeito da fertilização fosfatada e correção da acidez do solo na dinâmica e composição florística de florestas secundárias com histórico de pastagem
Novo registro de ocorrência da perereca-franjada, Cruziohyla craspedopus (Anura: phyllomedusidae) estende o limite oriental de sua distribuição
Get PDFThe fringed leaf frog, Cruziohyla craspedopus is rarely sampled in the Brazilian Amazon, probably due to low detection probability associated with its arboreal habit. The knowledge about the species’ distribution stems from successive additions of occasional occurrence records, which indicate that the species is widely distributed throughout Amazonia. We present new occurrence records to update the geographic range of the species, which is hereby extended 224 km to the northeast. We also present morphological data from collected specimens and discuss the updated range from the geographic and ecological points of view. We show that the range of the leaf frog crosses several main tributaries along the southern bank of the Amazonas River, although the species occurrence is apparently limited by a minimum tree cover of 70%. © 2019, Instituto Nacional de Pesquisas da Amazonia. All rights reserved
Avaliação do índice de estado trófico do parque aquícola sucupira, reservatório do Lajeado, Palmas (to)
Get PDFAquaculture is a growing activity within the food producing segments, however, it may affect the environment. Current analysis studied the trophic state of the Sucupira Aquaculture Park, an area for fish cultivation in net cages locateds in Lajeado Reservoir - Palmas (TO) - Brazil, applying the Trophic State Index (TSI)). Monitoring was undertaken between January and April of 2017 and comprised sampling for the analysis of total phosphorus and chlorophyll-a. Water quality data as temperature, turbidity, dissolved oxygen, conductivity, pH and dissolved total solids were obtained in loco. Considering the TSI resultsbetween January and April, the area was predominantly supereutrophic. It can be observed that the lake's trophic statewithin t aquaculture area is highly influenced by the rainy period. Since studies were not undertaken during the dry period, the differences between rain effects and fish farming activities were not possible to be detected. Further studies are required to understand the effects of aquaculture activities in the environment in a short and medium term by limnological monitoring. © 2019 University Center of Maringa. All rights reserved
Avaliação da produção de metabólitos secundários em calos de Deguelia duckeana (Fabaceae)
No full textEfeito de fatores históricos e ambientais sobre a composição e diversidade de assembleias de lagartos no sudoeste da Amazônia brasileira
Get PDFEcological studies with standardized sampling conducted on a large scale can provide an
understanding of patterns and processes hitherto unknown in the structuring of megadiverse
assemblages such as those from the Neotropics. In this thesis we present an analysis based on
multiple sampling sites installed along a transect of approximately 1,000 km, in the Purus-
Madeira interfluve and on the banks of the Upper Madeira River, in order to understand the
distribution of the lizard assemblages of this region. In the first chapter we characterized the
composition and abundance of the lizard assemblage in 10 sampling modules along the BR-
319 highway. We counted 25 taxa belonging to eight families, distributed heterogeneously
along the interfluve. We also we emphasize the importance of faunal surveys for future
conservation measures of the species of lizards of interfluvial regions in face of the increasing
anthropic impact in Amazonia. In the second chapter we evaluated how the environmental
heterogeneity, mainly associated with the Open and Dense Ombrophilous Forests of the region
of the Purus-Madeira interfluve forms the lizard assemblages. For this, we quantified the
assemblies through taxonomic and functional measures in fourteen sampling modules. We
observed that environmental factors such as soil, vegetation and rainfall vary in biogeographic
scale along the interfluve and influence the pattern of occurrence of species and functional
richness of the assemblages. Thus, we detected a large-scale species substitution pattern shaped
by the influence of environmental filters. In the third chapter we investigated, at different
scales, the influence of historical and ecological factors in the structure of lizard assemblages
in the region of the upper Madeira River. For this, 83 plots were sampled along the east and
west banks of the river. At the regional level, the upper Madeira River acts as a biogeographic
barrier to 29.6% of the species. In contrast, the performance of environmental filters explains
the structure of the assemblages at a local scale. This study, which pioneered such a wide
geographic scale in the ecology of Amazonian lizards, suggests that historical and ecological
factors have hierarchical effects in determining the spatial structuring of assemblages. Such as
the present investigation, future research addressing different scales according to standardized
sampling methods promises to elucidate processes and patterns related to the heterogeneous
spatial distribution of Amazonian biodiversity.Estudos ecológicos com amostragem padronizada conduzida em ampla escala espacial podem propiciar a compreensão de padrões e processos até então desconhecidos na estruturação de assembleias megadiversas, como as Neotropicais. Nesta tese apresentamos uma análise baseada em múltiplos sítios de amostragem instalados ao longo de um transecto de aproximadamente 1000 km, no interflúvio Purus-Madeira e nas margens do Alto Rio Madeira, a fim de compreender a distribuição das assembleias de lagartos desta região. No primeiro capítulo caracterizamos a composição e abundância da assembleia de lagartos em 10 módulos de amostragem ao longo da rodovia BR-319. Contabilizamos 25 táxons pertencentes a oito famílias, distribuídas de forma heterogênea ao longo do interflúvio. Também destacamos a importância de levantamentos de fauna para futuras medidas de conservação das espécies de lagartos de regiões interfluviais frente ao crescente impacto antrópico que a Amazônia enfrenta. No segundo capítulo avaliamos como a heterogeneidade ambiental, principalmente associada às Florestas Ombrófilas Abertas e Densas da região do interflúvio Purus-Madeira, molda as assembleias de lagartos. Para isso, quantificamos as assembleias através de medidas taxonômicas e funcionais em quatorze módulos de amostragem. Observamos que fatores ambientais como o solo, vegetação e pluviosidade variam em escala biogeográfica ao longo do interflúvio e influenciam o padrão de ocorrência das espécies e riqueza funcional das
assembleias. Desse modo, detectamos um padrão de substituição de espécies em larga escala moldado pela influência de filtros ambientais. No terceiro capítulo investigamos, em diferentes escalas, a influência de fatores históricos e ecológicos na estruturação das assembleias de lagartos da região do alto Rio Madeira. Para isso foram amostradas 83 parcelas ao longo das margens leste e oeste do rio. Em escala regional, o alto rio Madeira atua como uma barreira biogeográfica para 29,6% das espécies. Diferentemente, a atuação de filtros ambientais explica a estruturação das assembleias em escala local. Este estudo, pioneiro em abranger uma escala geográfica tão ampla na ecologia de lagartos amazônicos, sugere que fatores históricos e
ecológicos apresentam efeitos hierárquicos na determinação da estruturação espacial das assembleias. Assim como a presente investigação, futuras pesquisas abordando diferentes escalas de acordo com métodos padronizados de amostragem prometem elucidar processos e padrões relacionados à heterogênea distribuição espacial da biodiversidade amazônica
Waterbird community composition in relation to lake physical traits and wetland limnological conditions in the Amazon basin
No full textThe mechanisms governing assemblages and the maintenance of biodiversity in tropical environments remain disputed. Two hypotheses were tested for waterbird communities in the Amazonian wetlands: (1) waterbird richness and gradients in species composition differ in Amazonian white- and black-water lakes, and are influenced by variation in lake-to-lake differences in characteristics including area, perimeter, shape, and isolation; (2) waterbird assemblages are also influenced by neighboring water-body richness (rivers, channels, ponds, and other lakes) and location of lakes in the wetlands in relation to the tributary rivers. Bird surveys were conducted using a boat in 264 lakes stretching over 1,000 km of Amazon River floodplains. The hypotheses were tested using multivariate ordination analysis, followed by multiple linear models, to evaluate how bird richness (number of species) and species composition (which species) are affected by abiotic lake characteristics. At a local scale, lake perimeter, area, and shape affected local heterogeneity in species composition of the bird community, whereas at larger scales differences among sites in water-body richness and black- and white-water types were associated with variation in waterbird richness. The patterns found indicate that lake limnological attributes influence local heterogeneity in waterbird communities within Amazonian floodplains. © 2018, Springer International Publishing AG, part of Springer Nature
Impacts of soil compaction persist 30 years after logging operations in the Amazon Basin
No full textThis study was conducted in a humid tropical forest located in Brazil within the Amazon Basin on a heavy clay Ferralsol 24 and 30 years after logging to evaluate the recovery process of skid trails. All timber was extracted with a D6 track-type tractor. In total, four skid trails were evaluated, all logged in 1987 and two of them again in 1993. Systematic sampling was applied to the four trails and two controls. The data collected were rut depth, soil bulk density (BD), soil penetration resistance (PR) and seedling and sapling density. Soil physical properties were determined in three layers from 0 to 15 cm in depth, and seedling density was determined from 36 plots of 4m² in size at the soil sample locations. Rut depths were significantly different (p < 0.05) between years, with the greatest depth of 32 cm recorded for the soil in 1993. The results for BD and PR differed from each other only slightly. In the 0–5 cm depth between the ruts both BD and PR were still significantly higher (p < 0.05) than the control for both years, but within the ruts there were no significant differences between the controls of either year. However, in the 5–15 cm depth within the ruts, BD was always significantly higher (p < 0.001) than the control for both years, as well as was PR for the depths 5–10 cm (p < 0.05) and 10–15 (p < 0.001) within the ruts for both years. The soil layers between the ruts in the depth of 10–15 cm for 1993 were significantly different (p < 0.05) for BD and PR, but the means for this same depth were not root limiting for plants for either BD or PR. The evaluation of seedling and sapling density revealed significant differences for the class of saplings greater than 150 cm. Both the 1987 and the 1993 plots had significantly lower numbers per m², 1987 (p < 0.01) and 1993 (p < 0.001), than the control. There were more saplings located between the ruts than in the ruts for both years, but this was not statistically significant. The conclusion of this study is that partial recovery of the disturbed soil had occurred after 24 and 30 years, with the soil surface horizon within the ruts no different than the undisturbed soil of the control. However, the results show that even 30 years is not sufficient for a full recovery of the soil. © 2019 Elsevier B.V