Abstract. Windthrows change forest structure and species composition in central Amazon forests. However, the effects of widespread tree mortality associated with wind disturbances on soil properties have not yet been described in this vast region. We investigated short-term effects (7 years after disturbance) of widespread tree mortality caused by a squall line event from mid-January of 2005 on soil carbon stocks and concentrations in a central Amazon terra firme forest. The soil carbon stock (averaged over a 0-30 cm depth profile) in disturbed plots (61.4 ± 8.2 Mg ha −1 , mean ±95 % confidence interval) was marginally higher (p = 0.09) than that from undisturbed plots (47.7 ± 13.6 Mg ha −1 ). The soil organic carbon concentration in disturbed plots (2.0 ± 0.17 %) was significantly higher (p < 0.001) than that from undisturbed plots (1.36 ± 0.24 %). Moreover, soil carbon stocks were positively correlated with soil clay content (r 2 = 0.332, r = 0.575 and p = 0.019) and with tree mortality intensity (r 2 = 0.257, r = 0.506 and p = 0.045). Our results indicate that large inputs of plant litter associated with large windthrow events cause a short-term increase in soil carbon content, and the degree of increase is related to soil clay content and tree mortality intensity. The higher carbon content and potentially higher nutrient availability in soils from areas recovering from windthrows may favor forest regrowth and increase vegetation resilience.
Abstract:The Eschweilera genus has great ecological and economic importance due to its wide abundance in the Amazon basin. One potential use for the Eschweilera genus is in forest management, where just a few trees are removed per hectare. In order to improve the forest management in the Amazon, this study assessed two critical issues: volume equations fitted for a single genus and the development of a non-destructive method using climbing techniques. The equipment used to measure the sample trees included: climbing rope, ascenders, descenders, and carabiners. To carry out the objectives of this study, 64 trees with diameter at breast height (DBH) ≥ 10 cm were selected and measured in ZF-2 Tropical Forestry Station near the city of Manaus, Brazil. Four single input models with DBH and four dual input models with DBH and merchantable height (H) were tested. The Husch model (V = a × DBH b ) presented the best performance (R 2 = 0.97). This model does not require the merchantable height, which is an important advantage, because of the difficulty in measuring this variable in tropical forests. When the merchantable height data are collected using accurate methods, the Schumacher and Hall model (V = a × DBH b × H c ) is the most appropriated. Tree climbing techniques with the use of ropes, as a non-destructive method, is a good alternative to measure the merchantable height, the diameter along the stem, and also estimate the tree volume (m 3 ) of the Eschweilera genus in the Amazon basin.
Abstract. Windthrows change forest structure and species composition in Central Amazon forests. However, the effects of widespread tree mortality associated with wind-disturbances on soil properties have not yet been described. In this study, we investigated short-term effects (seven years after disturbance) of a windthrow event on soil carbon stocks and concentrations in a Central Amazon terra firme forest. The soil carbon stock (averaged over a 0–30 cm depth profile) in disturbed plots (61.4 ± 4.18 Mg ha−1, mean ± standard error) was marginally higher (p = 0.009) than that from undisturbed plots (47.7 ± 6.95 Mg ha−1). The soil organic carbon concentration in disturbed plots (2.0 ± 0.08 %) was significantly higher (p < 0.001) than that from undisturbed plots (1.36 ± 0.12 %). Moreover, soil carbon stocks were positively correlated with soil clay content (r = 0.575 and p = 0.019) and with tree mortality intensity (r = 0.493 and p = 0.045). Our results indicate that large inputs of plant litter associated with large windthrow events cause a short-term increase in soil carbon content, and the degree of increase is related to soil clay content and tree mortality intensity. Higher nutrient availability in soils from large canopy gaps created by wind disturbance may increase vegetation resilience and favor forest recovery.
RESUMOEste artigo objetiva apresentar o programa Microempreendedor Individual (MEI) como uma alternativa para redução da incidência do emprego informal no Brasil, apontando-a como um mecanismo viável para o aumento do número de trabalhadores legalizados juntos às autoridades governamentais. O trabalho foi desenvolvido utilizando-se dois métodos de pesquisa: documental e bibliográfi co, fazendo uso de publicações ofi ciais do governo e de especialistas no assunto em livros e periódicos, além de resultados de pesquisa do Serviço Brasileiro de Apoio às Micro e Pequenas Empresas (SEBRAE). Percebeu-se que o MEI oferece aos interessados vantagens consideráveis que motivam os trabalhadores a procurarem a formalização da sua situação profi ssional, vislumbrando a possibilidade de obter os mesmos benefícios dos demais e oportunidades que a informalidade não lhes proporciona, bem como o acesso à Previdência e a possibilidade de expandir seu empreendimento. Palavras-Chave:Informalidade. Desenvolvimento. Simples Nacional. Empreendedor. Microempreendedor Individual. ABSTRACTThis paper aims to present the Microempreendedor Individual (MEI) program as an alternative to reducing informal employment in Brazil, pointing it out as a feasible mechanism to increase the number of workers legalized with the government authorities. This work was developed by making use of two research methods: documenting and bibliography, whereas offi cial documents and specialists' researches in books and journals were linked to results found by the Serviço Brasileiro de Apoio às Micro e Pequenas Empresas (SEBRAE). It was noted that the MEI offers advantages that motivate workers to look for legalizing their professional activities, looking for the possibility of obtaining the equal
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