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| Registros recuperados: 42 | |
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| Grogan,James; Galvão,Jurandir. |
| Seasonally dry evergreen forests in southeast Pará, Brazil are transitional between taller closed forests of the interior Amazon Basin and woodland savannas (cerrados) of Brazil's south-central plains. We describe abiotic and biotic gradients in this region near the frontier town of Redenção where forest structure and composition grade subtly across barely undulating topography. Annual precipitation averaged 1859 mm between 1995-2001, with nearly zero rainfall during the dry season months of June August. Annual vertical migrations of deep-soil water caused by seasonal rainfall underlie edaphic and floristic differences between high- and low-ground terrain. Low-ground soils are hydromorphic, shaped by perching water tables during the wet season, pale gray,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Babaçu; Big-leaf mahogany; Disturbance; Soil nutrients; Water table. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672006000400009 |
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| Soares,Caio J. R. S.; Sampaio,Mauricio B.; Santos-Filho,Francisco S.; Martins,Fernando R.; Santos,Flavio A. M. dos. |
| ABSTRACT Patterns of species diversity are essential to understand community structure. We aimed to determine species diversity and patterns of beta diversity in different spatial scales. We sampled three thousand individuals between the coordinates 22°10'S to 22°16'S and 47°47'W to 48°00'W to assess species diversity in three spatial scales (maximum distances of 80 m, 1,400 m, and 12,000 m), using the point-centered-quarter method. We partitioned gamma diversity into alpha and beta components. Beta diversity was partitioned into dissimilarities produced by spatial species turnover and nestedness. The contribution of beta diversity to gamma diversity was greater than that of alpha diversity in all scales, although the patterns of species diversity were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Beta diversity; Biogeography; Disturbance; Diversity partition; Local spatial scale; Nestedness; Phytogeography; Spatial species turnover. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062020000100009 |
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| Massi,Klécia Gili; Franco,Augusto César. |
| ABSTRACT Cerrado tree species can survive fire by resprouting. Generally, large and less damaged plants produce new branches and leaves from stem buds (aerial), whereas small and highly injured individuals would resprout from the stem base or from underground organs (basal). We compared the three most common Cerrado woody plant species in a savanna area of the IBGE Ecological Reserve, Brasília, Brazil, aiming to verify if the resprouting strategy (aerial or basal) differed between species and if that was related to plant size. Guapira noxia had small-sized plants, a higher percentage of trunk charred and more individuals with basal resprouting, while Eriotheca pubescens had large-sized plants with a greater intensity of aerial resprouting, Basal... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cerrado; Disturbance; Fire; Resprout; Size; Tree. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062016000400693 |
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| Souchie,Fabiane Furlaneto; Pinto,Jose Roberto Rodrigues; Lenza,Eddie; Gomes,Letícia; Maracahipes-Santos,Leonardo; Silvério,Divino Vicente. |
| ABSTRACT Post-fire response by vegetation may reflect the severity of the damage suffered, but we still know little about the species-specific nature of responses to fire or their predictors. Here, we evaluated 26 woody species before and after a fire event in an Cerrado sensu stricto area (typical Brazilian savanna-type) in order to evaluate mortality rates and the type of resprouting (epigeal, hypogeal or epigeal + hypogeal). We evaluated the relative importance of stem diameter, height, and bark thickness as predictors of the type of post-fire resprouting, using a sequential logistic regression model (SLRM). Mortality was 4 %, while epigeal resprouting was recorded in 57 % of the individuals, hypogeal resprouting was recorded in 24 %, and epigeal +... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bark thickness; Cerrado sensu stricto; Disturbance; Fire; Resilience. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062017000200260 |
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| Silveira, Thiago Cesar Lima; UFRGS; Rodrigues, Gilberto Gonçalves; UFBA; Souza, Gabriela Peixoto Coelho de; UFRGS; Würdig, Norma Luiza; UFRGS. |
| Lagoons are considered protected areas because these systems play a key ecological role. However, the extraction of macrophyte Schoenoplectus californicus is held for manufacture of handcrafts, being an alternative income for riverbank communities. This study evaluated the impact of S. californicus experimental cutting on benthic macroinvertebrates trough a field experiment. Macroinvertebrates were sampled at 1, 12, 26 and 60 days after the macrophyte cutting in demarked plots (1 m²), as well at control plots. The families number was not statistically different (ANOVA, p > 0.05), but the total density of invertebrates, and the density of Ceratopogonidae were significant (ANOVA, p < 0.05) for interaction between sampling date and treatment. A... |
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Palavras-chave: 2.00.00.00-6; 2.05.00.00-9; Disturbance; Bioindication; Vegetal management; Schoenoplectus californicus; Aquatic macrophyte; Non-wood products Ecologia Disturbance; Bioindication; Vegetal management; Schoenoplectus californicus; Aquatic macrophyte; Non-wood products. |
| Ano: 2011 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/6383 |
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| FARIA,DENISE M. DE; COSTIN,JÚLIO C.; TREMARIN,PRISCILA I.; LUDWIG,THELMA A.V.. |
| Abstract: Diatom growth strategies, which are used as a proxy to analyze disturbances and environmental impacts, can also provide reliable information about environmental gradients. In this study, we used diatom communities and biological traits to assess the structure of epilithic diatoms after an oil spill in a large tributary of the Iguaçu River (Paraná, Brazil). Epilithon and water samples were taken on July 12th, 2004, and after an unexpected oil spill, on the following days: 09/19, 10/03, and 10/13/2004. We observed that the spill caused a distinct shift in both diatom composition and guild group. Diversity decreased and pollution-tolerant diatoms of the motile group became dominant in response to the elevated nutrient levels and reduced light.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Diatom guilds; Disturbance; Diversity; Epilithon; Growth forms. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000300609 |
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| Silveira,Thiago Cesar Lima; Rodrigues,Gilberto Gonçalves; Souza,Gabriela Peixoto Coelho de; Würdig,Norma Luiza. |
| Wetlands are important because they have high biodiversity and are considered, by environmental agencies, permanently protected areas due to their importance to conservation. In Southern Brazil the aquatic macrophyte Typha domingensis is harvested to be used in the manufacture of handicraft, being an important income source to small farmers. This work aims to test the cut effect of T. domingensis on benthic macroinvertebrates as well as on macrophyte regeneration. These phenomena were analyzed in small areas (1 m²) in a T. domingensis stand by comparing cut treatments and control treatments. Macroinvertebrate were sampled with a corer in the following time sequence after the cut event in both treatments: one day, 26 days, 60 days, 89 days, and 182 days.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Disturbance; Bioindication; Vegetal management; Aquatic macrophytes; Non-wood products. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032012000300014 |
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| Sánchez-Botero,Jorge Iván; Sequeira Garcez,Danielle; Pellegrini Caramaschi,Erica; Miguel Saad,Adriana. |
| The effects of a disturbance by sandbank opening on the fish fauna community were evaluated through a long-term study in the Imboassica coastal lagoon, Rio de Janeiro State, Brazil. The fish and salinity samples were conducted between 1993 and 2004, with the goal of characterizing the structure and effects of four sandbank openings on this community, such as resilience and resistance measurements. During three sandbank openings, between the years of 1993 and 1996, the resilience time of the fish community could not be identified due to the short time period between openings, their magnitude and the discontinuity of the fish sampling. Monitoring studies previously conducted between 1993 and 2004, indicated that factors structuring the fish fauna of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Disturbance; Fish community; Coastal lagoon; Brazil. |
| Ano: 2009 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0122-97612009000100010 |
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| Mesa,Leticia Mariana. |
| The aim of this study was to assess the interannual and seasonal changes in the community composition, abundance and presence-absence of macroinvertebrates in the streams of the northwestern of Argentina. The importance of environmental variability in determining these changes was also analyzed. Macroinvertebrates were collected in eleven streams during high (March) and low (September) water periods during two years. Physical variables and water parameters were also recorded at each site. Community composition and abundance differed significantly between seasons, but the presence-absence data did not exhibit a clear pattern of seasonal change. Rapid recolonization of disturbed substrate could ensure the recuperation of benthic community. Small body sizes,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Andean streams; Disturbance; Northwestern Argentina; Seasonal spates. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132012000300011 |
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| Boccanelli,Silvia; Pire,Eduardo; Lewis,Juan. |
| Agriculture has been practised in the Argentine Pampa region for more than a century. This long history of disturbance has strongly modified the native vegetation of the region. Some original species have disappeared or its area has been remarkably reduced. The objective was to evalúate vegetation changes over time after the abandonment of agriculture practice. Our hypothesis was that over time vegetation in this region will evolve towards a "flechillar" (Stipa spp. community) similar to the original vegetation. The experiment was conducted at Zavalla (Santa Fe) Argentina (33° 01' S, 60° 53' W and 50 m.a.s.1.). Vegetation evolution was studied during 15 years (1982-1997) after abandonment, considering four initial crop situations (i.e. wheat, soybean,... |
| Tipo: Journal article |
Palavras-chave: Abandoned field; Agriculture; Disturbance; Secondary succession; Weeds. |
| Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-16202010000200005 |
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| Chaneton,Enrique J; Mazía,Noemí; Garibaldi,Lucas A; Chaij,Jaquelina; Kitzberger,Thomas. |
| Volcanism has been a major force shaping the dynamics of Andean landscapes during the Holocene. Yet we still know little about the consequences of modern volcanic events on forest functioning. Ash fall may elicit multiple direct and indirect effects on key ecosystem attributes, with disturbance severity likely varying with distance to the crater. We examined the impact of ash deposition on foliage productivity and insect herbivory after the 2011 eruption of the Volcán Puyehue-Cordón Caulle system, in Nothofagus pumilio forests of northern Patagonia, Argentina. Tree leaf litterfall, a surrogate for annual foliar production, was measured before and after the event in wet and dry forest sites, which were located 22 km and 80 km east from the crater and were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Canopy insects; Disturbance; Herbivory; Long-term study; Nothofagus pumilio; Productivity; Volcanism. |
| Ano: 2014 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2014000100007 |
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| Registros recuperados: 42 | |
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