Ectomycorrhizae are classified as biotechnology to increase the sustainability of planted forests, and fieldwork is needed to confirm its effectiveness. The growth of rooted cuttings of Eucalyptus clones GG100 and GG680, which had been previously inoculated in the nursery with ectomycorrhizal fungi, was evaluated after planting them in the field. The ectomycorrhizal fungi (EMF) inoculated were: Pisolithus microcarpus, Hysterangium gardneri, or Scleroderma areolatum. Uninoculated rooted cuttings were used as controls. The inoculated treatments and the uninoculated controls (low P control) were grown in a nursery with reduced phosphate fertilization. Additionally, uninoculated controls were grown on a substrate with complete phosphate nursery fertilization (high P control). After two months, the plant height of clone GG100 inoculated with P. microcarpus was 16% taller and of clone GG680 13% higher than the low P control treatment. At the same time, the collar diameter of the plants inoculated with H. gardneri and P. microcarpus was the same as in the high P control. At 12 months, the growth of the inoculated and low P control plants was the same as in the high P control. For ectomycorrhizal colonization, after six months, the mean percentage of colonized root tips was highest in plants inoculated with S. areolatum, followed by those inoculated with P. microcarpus and of the low P control. After one year, ECM colonization was equal in all treatments and 4.3 times greater than it was at 6 months. Inoculation with ECM fungi in the nursery boosts early plant growth after transfer to the field, although the effect depends on the specific ectomycorrhizal fungus and the clone. Further ectomycorrhizal colonization of Eucalyptus occurs naturally and increases with tree development in the field.

Monitoramento da estrutura e caracterização ecológica em floresta tropical manejada na Amazônia Brasileira - DOI:10.5039/agraria.v14i4a6867

This study aimed to analyze economically the production of wood and charcoal from a Eucalyptus plantation stratified in three classes of productivity in northwestern Minas Gerais. Were used data from not thinned Eucalyptus stands whose area was stratified in high, medium and low productivity, being described by the logistic model. The data were obtained and the economic evaluation of wood production and charcoal production was carried out. The economic evaluation was made by means of the indicators: Net present value (NPV) and internal rate of return (IRR) as a function of the prices of wood and charcoal, the yield of wood in charcoal and the transport distance of wood to the charcoal production unit. The economic viability of production of Eucalyptus wood and charcoal depends on the productive capacity of the forest stand. The viability of timber and charcoal production is sensitive to the variations in the prices of both, the yield of wood in charcoal and the transport distance from the production area to the processing unit.

A Mata Atlântica é um hotspot global para a conservação da biodiversidade devido à sua riqueza de espécies e endemismo, porém, as ações antrópicas ameaçam e desequilibram a dinâmica dos processos naturais do bioma. Assim, com o objetivo de contribuir com estudos sobre conservação em florestas tropicais, o presente estudo investigou o comportamento da projeção em diâmetro e altura, por meio de ferramentas de regressão e inteligência artificial, com a influência de índices de competição em um fragmento de floresta estacional semidecidual na área do Bioma Mata Atlântica no sudeste do Brasil. As análises foram realizadas de acordo a classificação em grupos ecológicos e quanto a exigência por luz. Foram ajustados quatro modelos de regressão, dois para estimar o diâmetro (DAP) e dois para estimar a altura (H). No processo de aprendizado das redes, selecionou-se as quatro melhores Redes Neurais Artificiais (RNA), em que cada RNA estimou, simultaneamente as variáveis DAP e H. Dentre as redes selecionada, foi definida a melhor RNA visando contrastar com os resultados dos modelos validados. A partir das estatísticas de precisão e análises gráficas, concluiu-se que projetar o crescimento dendrométrico por RNA foi mais eficiente que por modelos tradicionais.

Pesquisas que quantificam o estoque de carbono em matas ciliares destacam-se pela apresentação de serviços ambientais que essas florestas oferecem e assim minimizam os efeitos das mudanças climáticas. Objetivou-se com a realização deste trabalho: i) quantificar o estoque de carbono presente na biomassa acima do solo das espécies presentes em áreas de mata ciliar; ii) ranquear as espécies pelo índice de valor de importância ampliado (IVIA) em relação à análise fitossociológica padrão, pelo índice de valor de importância (IVI). Os dados utilizados no estudo foram obtidos a partir de um inventário realizado em áreas de vegetação ripária, região sudoeste do estado de Goiás. Estimou-se a biomassa da madeira de cada árvore para todas as espécies e posteriormente a estimativa de estoque de carbono (Mg.ha^-1) por hectare na fitofisionomia. A mata ciliar possui alta capacidade de estocar carbono e a incorporação dessa variável e o ranqueamento das espécies pelo índice de importância ampliado pode ser utilizado como razão para conservação e preservação das matas ciliares, bem como um critério na escolha de espécies com maior potencial de estoque de carbono para recuperação de áreas degradadas.

Competition for resources influences growth and mortality in eucalyptus stands, but its effects are still poorlyunderstood, especially under different thinning intensities which alter stand density and growth dynamics compared to unthinned areas. Understanding these effects is essential to optimize forest production and ensure the sustainability of management systems. The objective of this study was to propose, estimate and evaluate distance-independent indices and distance-semi-independent indices in individual trees from a stand of eucalyptus trees subjected to different thinning intensities. The thinning treatments studied were: T0: control (without thinning); T25: 25% reduction in the number of individuals; T33: 33% reduction; and T50: 50% reduction. The stand was measured at 60 (before intervention), 67, 74, 81, 88 and 95 months. Competition indices were estimated considering 8 and 24 competing trees. The inclusion of sum of basal areas of 24 trees closest to the object-tree (BA24) variable in the calculation of the competition indices was also evaluated. Our results indicate that only the Basal Area of Larger Trees (BAL) index was efficient to represent the competition after thinning stands between the traditional distance-independent indices. The semi-distance-independent indices with 8 and 24 trees were not efficient to capture the effect of thinning. The inclusion of the BA24 variable resulted in accurate indices to describe the competition between trees in thinned eucalyptus stands.