ResumoAs formigas cortadeiras pertencentes ao gênero Acromyrmex (Hymenoptera: Formicidae), representam um dos principais problemas do empreendimento florestal no Brasil. Estudos objetivando determinar a ocorrência e os danos causados por essas formigas em áreas de plantio de Pinus na região Sul do Brasil são escassos. Os principais objetivos desta pesquisa foram a determinação da densidade de ninhos em áreas de plantio de Pinus taeda L. com e sem controle químico e a quantificação de plantas atacadas. Os estudos foram conduzidos no período de janeiro a junho de 2010. O experimento foi instalado em uma fazenda situada no município de Anita Garibaldi (SC). Foram demarcadas quatro parcelas de 0,5 ha, sendo que duas receberam um combate pré-plantio com isca formicida e duas não. Após o plantio, foram realizados censos quinzenais em cada parcela. Constatou-se a ocorrência de formigas das espécies Acromyrmex crassispinus Forel 1909 e Acromyrmex heyeri Forel 1899. Os danos totais médios por hectare causados às mudas foram no máximo de 3,0% no 35º dia e de 5,38% no 63o dia de avaliação. Os controles às formigas podem ser diminuídos se forem levados em consideração época do plantio, densidade dos formigueiros e porcentagem de danos causados às mudas.AbstractAssessment of damages caused by leaf-cutting ants of genus Acromyrmex (Hymenoptera: Formicidae) in plantations of Pinus taeda in Santa Catarina southern highlands. Leaf-cutting ants of genus Acromyrmex (Hymenoptera: Formicidae) represent one of the main problems of forest enterprise in Brazil. Researches aiming to determine occurrence and damage caused by such ants in areas of pine plantation in southern Brazil are scarce. The main aims of this research were determining density of nests in Pinus taeda L. planted areas with and without chemical control, and quantification of attacked plants. The research was developed from January to June 2010. The experiment was set up on a farm in the municipality of Anita Garibaldi, SC. Four plots of 0.5 ha were marked out, two received a pre-planting to combat ant bait, and two others not. After planting, censuses had been managed biweekly to each plot. It revealed the occurrence of the following ant species: Acromyrmex crassispinus Forel 1909 and Acromyrmex heyeri Forel 1899. The average total damage caused to seedlings per hectare reached the maximum of 3.0% at the 35th day, and 5.38% at the 63rd day of evaluation. Ants control can be decreased if it is considered planting time, density of nests and seedlings damage percentage.Keywords: Ant; ant bait; chemical control.
The objective of this study was to analyze the application of an artificial neural networks model and an ARIMA model to predict the consumption of sawnwood of pine. For this, we use real and secondary data collected and obtained from a historical data source, corresponding to the period from 1997 to 2016, which were later tested to generate the forecast models. Based on economic and statistical criteria, six explanatory variables were used to fit the best model. The choice of the model was made based on Mean Squared Error, Mean Absolute Error, Theil U metric, Percentage Error of Forecast and Akaike value information criterion. The results indicated that the models generated through the ARIMA model presented better performance when compared to the artificial neural network. The best adjusted model estimated a reduction of 1.33% in consumption of sawnwood of pine in Brazil for the period between 2017 and 2020.
RESUMOOs programas de controle para formigas-cortadeiras do gênero Acromyrmex na região sul do Brasil são pouco estudados, tendo suas informações embasadas no controle do gênero Atta e aos danos causados por formigas-cortadeiras em plantios de Eucalyptus spp. Esta falta de informações sobre controle de formigas-cortadeiras leva algumas empresas florestais de Santa Catarina à repetição de padrões que não são adequados às infestações e às espécies de formigas-cortadeiras que ocorrem neste Estado. Com isso, ocorre uma distribuição inadequada de iscas granuladas a granel, nas quatro estações do ano, que acabam degradadas pelo excesso de umidade provocado pela neblina e pelas precipitações constantes que ocorrem na região. Diante deste quadro, os experimentos deste trabalho tiveram como objetivos: identificar as espécies de formigas-cortadeiras; determinar a densidade de formigueiros por unidade área; analisar e avaliar a influência das estações do ano e da precipitação em cada estação sobre a conservação e degradação das iscas granuladas à base de sulfluramida (0,3%) distribuídas a granel e na forma de microporta-iscas. Para tanto, foram instalados experimentos na Fazenda Dois Irmãos, de propriedade da empresa Florestal Rio Marombas Ltda., em áreas de plantios de Pinus taeda L., localizados no município de São Cristóvão do Sul, no planalto sul do estado de Santa Catarina. Concluiu-se que: A única espécie de formiga-cortadeira encontrada na área avaliada é Acromyrmex crassispinus (FOREL, 1909). Na área experimental encontramse 17 formigueiros, a média é de 0,94 formigueiros por hectare, com área aparente menor que 1 m² cada um; a umidade da região do planalto sul-catarinense degrada as iscas granuladas distribuídas a granel; as iscas granuladas distribuídas a granel permanecem conservadas sete dias na primavera e três dias nas demais estações do ano; as iscas granuladas distribuídas em microporta-iscas permanecem conservadas 15 dias no verão e 30 dias nas demais estações do ano; os microporta-iscas apresentam maior resistência à umidade no campo em relação às iscas granuladas distribuídas a granel; a abertura dos microporta-iscas, provocada pelo consumo parcial das iscas, que é uma característica das formigas Acromyrmex spp., acelera a deterioração das iscas restantes em seu interior. Palavras-chave: Acromyrmex; sulfluramida; formiga-cortadeira. ABSTRACTControl programs for leaf-cutting ants of the genus Acromyrmex in southern Brazil are poorly studied and the information comes from the control of the genus Atta and the damage caused by leaf-cutting ants in Eucalyptus spp. This lack of information about this ant makes some forest companies of Santa Catarina
The charcoal is a renewable natural resource, produced from wood by the process of carbonization and with great energetic importance. However, there is still little research and use of new technologies to optimize the use of wood in the production of charcoal. Therefore, the present work was aimed at analyzing the yield from forest harvesting operations for the production of charcoal. The research was developed at Vallourec e Mannesmann Florestal, a company located at Itapoã farm, municipality of Paraopeba, Minas Gerais. To this end, the harvest and timber transport operations in the short log system, the carbonization, and the properties of the charcoal produced were assessed. To this end, data was collected from eighteen 9-hour shifts for the Harvester, fifty-four 9-hour shifts for the forwarder, and 36 carbonization cycles. The equipment was analyzed working with three different log lengths—2.1 m, 3.7 m, and 5.0 m. The results demonstrate, during the cutting and processing, that the yield by cutting longer logs is higher. Likewise, at forwarding, the operation’s yield increases according to log length for thick and thin logs. Finally, concerning carbonization, the yield at the furnace loading stage was higher as the length of the log used increased, however, upon unloading the furnace, it was when it decreased.
This study aimed to analyze the evolution of the production and price of biomass from native and planted forests of the state of Paraná (Brazil), between 1998 and 2015, based on the behavior of the prices of the products, according to variations of their supply or demand. The annual rates for growth of the price and quantity produced were calculated and related to the displacements of the supply and demand curves of the products. The results indicated a decrease in the quantity and an increase in the biomass price for native forests, which caused a shift in the supply curve to the left. For the biomass of planted forests, the demand curve shifted to the right due to the demand increase of this product for energy production. The behavior of both curves indicated a substitution of the biomass from native forests to biomass from planted forests due to factors related to the increase of environmental protection regarding the native forests located in the state of Paraná
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