Os Sistemas Agroflorestais (SAF) são um modelo de produção que visa associar o cultivo ou o manejo de espécies arbóreas e agrícolas integradas na presença ou ausência de animais em uma mesma área, de forma simultânea ou escalonada ao longo do tempo. Os aspectos morfológicos da espécie florestal presente nesse sistema são fatores relevantes, dada a interação com os demais componentes do SAF. Por meio do presente estudo, objetiva-se realizar uma revisão bibliográfica sobre o ideótipo morfológico para espécies arbóreas na composição de Sistemas Agroflorestais. Os aspectos de copa do componente florestal definem o nível de sombreamento que será imposto aos demais integrantes do sistema, determinando em grande parte a finalidade do SAF e a produção de todo o sistema. As particularidades do tronco e do sistema radicular do componente florestal também devem ser avaliadas considerando-se o objetivo final do SAF, pois enquanto as características do tronco podem definir o momento de inserção do componente animal, o sistema radicular será determinante em outras variáveis, como a ciclagem de nutrientes e o grau de competição com o componente agrícola e/ou forrageiro. Sendo assim, a escolha da espécie florestal na composição do SAF deve ser ponderada, visando atender aos aspectos técnicos, econômicos, ambientais e sociais do sistema adotado.

A produção de mudas de qualidade superior é um dos pontos mais importantes para a recuperação de áreas degradadas, dado que a qualidade da muda é um fator que interfere no sucesso e nos custos da recuperação. Assim, o presente estudo objetivou avaliar o efeito da fertilização com fósforo (P) e a inoculação com fungos micorrízicos arbusculares (FMAs) no crescimento, produção de biomassa e qualidade de mudas de Peltophorum dubium. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 5 × 3, sendo avaliadas cinco doses de P (0, 50, 100, 200 e 400) mg kg-1 e três tratamentos microbiológicos (inoculado com Rhizophagus clarus, Gigaspora margarita e um controle sem inoculação), com quatro repetições, totalizando 60 vasos. Foram avaliados a colonização micorrízica, características morfológicas e a qualidade das mudas produzidas aos 120 dias após o transplantio. P. dubium não demonstrou colonização radicular em resposta à inoculação com R. clarus e G. margarita. Todas ases características morfológicas avaliadas no presente estudo apresentaram comportamento quadrático em função da aplicação de P, exceto a relação massa seca da parte aérea / massa seca de raízes (MSPA/MSR), a qual obteve ponto de máxima de 3,90 g g-1 na dose 400 mg kg-1. A inoculação com R. clarus e G. margarita não influenciou nenhum dos atributos avaliados nas mudas de P. dubium. A adubação fosfatada foi benéfica para o crescimento, produção de biomassa e qualidade das mudas de P. dubium, sendo recomendada a aplicação de P entre 218 mg kg-1 e 295 mg kg-1.

Compost and Arbuscular mycorrhizal fungi are environmentally sustainable and low-cost materials that can benefit tropical soils with high phosphorus fixation and low organic matter content. This study investigated the effects of Arbuscular mycorrhizal fungi (AMF) and compost on the growth and nutrient uptake efficiency of sugarcane (Saccharum officinarum) seedlings. The experimental design was a completely randomized factorial design, where factor A (n = 5) was the compost doses (0, 15, 30, 60 and 120 t ha-1) and B (n = 3) the AMF inoculum (Rhizophagus clarus, Gigaspora margarita, and non-inoculated). At 30 and 90 d, seedlings’ diameter and height were measured. Mycorrhizal colonization rate, biomass production, nutrient uptake (P and N), and mycorrhizal dependency were assessed at the end of the experiment. The AMF and compost doses affected the colonization rate, initial growth, biomass production, and nutrient uptake of sugarcane seedlings. Overall, the AMF benefited plant growth at lower doses of compost. R. clarus had a higher impact on the shoot diameter of sugarcane seedlings. Mycorrhizal colonization increased with compost addition only in seedlings inoculated with G. margarita. There was no clear trend among AMF treatments for nutrient uptake. In general, sugarcane seedlings dependency on mycorrhizal condition to produce growth was higher at lower compost doses.

Amazonian large trees act as central elements of forest ecosystems, storing a disproportionate fraction of aboveground biomass. However, these trees are not randomly distributed across the landscape, and it is expected that edaphic attributes influence floristic composition, forest structure, and vegetation biomass. In this study, we investigated how soil variation affects the diversity and biomass of large trees. Forest inventories were conducted at five sites within protected areas in the states of Pará and Amapá. Aboveground biomass was estimated using allometric equations, while soil samples were analyzed for their physical and chemical properties. Diversity indices, rarefaction, Redundancy Analysis, and Generalized Additive Models were applied. Edaphic variables such as soil pH, organic matter, phosphorus, and aluminum were associated with floristic composition and the biomass of these individuals. Trees with a diameter at breast height greater than or equal to 70 centimeters accounted for up to 80% of total biomass, revealing a pattern of biomass hyperdominance. The results indicate that the occurrence of large trees is related to edaphic and structural factors, suggesting that these individuals are not randomly distributed along soil gradients. Understanding these patterns is essential for improving ecological models, biomass extrapolations, and management strategies aimed at conserving the Amazon rainforest.

Knowing the nutritional needs of these plants, the interactions that favor their growth and survival in the field, such as inoculation with arbuscular mycorrhizal fungi (AMF), are essential to subsidize tropical forestry. The present study aimed to evaluate the effect of applying phosphorus (P) and inoculation with AMF on growth, biomass production, quality, and nutrition in seedlings of Senegalia polyphylla. The experiment was carried out in a completely randomized design, in a 5 x 3 factorial scheme, with five doses of P (0, 50, 100, 200, and 400 mg kg⁻¹), and three microbiological treatments (inoculated with Rhizophagus claru, Gigaspora margarita, and control without inoculation). At 120 days after transplanting (DAT), there were evaluated the rate of root mycorrhizal colonization (MC), plant shoot height (H), stem diameter (D), N and P content in the shoot of the plants (NC and PC, respectively), dry matter mass of shoot, roots, and total (DMS, DMR, and DMT, respectively). Those variables allowed the calculation of Dickson’s Quality Index (DQI) and mycorrhizal dependence (MD). Phosphate fertilization influenced all evaluated characteristics of S. polyphylla (p < 0.01), while inoculation with AMF alone influenced only DMS, DMT, DQI, and PC. Plants inoculated with R. clarum and G. margarita showed MC ranging from 12.5 to 55%. At the dose of 0 mg kg⁻¹ of P, seedlings of S. polyphylla showed high MD. The inoculation with AMF and the application of P are indicated to obtain seedlings of S. polyphylla.

Amazonian large trees act as central elements of forest ecosystems, storing a disproportionate fraction of aboveground biomass. However, these trees are not randomly distributed across the landscape, and it is expected that edaphic attributes influence floristic composition, forest structure, and vegetation biomass. In this study, we investigated how variation in soil chemical and physical properties affects the diversity and biomass of large trees. Forest inventories were conducted at five sites within protected areas in the states of Pará and Amapá. Aboveground biomass was estimated using allometric equations, while soil samples were analyzed for their physical and chemical properties. Diversity indices, rarefaction, Redundancy Analysis, and Generalized Additive Models were applied. Edaphic variables such as soil pH, organic matter, phosphorus, and aluminum were associated with floristic composition and the biomass of these individuals. Trees with a diameter at breast height greater than or equal to 70 cm accounted for up to 80% of total biomass, revealing a pattern of biomass hyperdominance. The results indicate that the occurrence of large trees is related to edaphic and structural attributes, such as tree density and size distribution, suggesting that these individuals are not randomly distributed along soil gradients. Understanding these patterns is essential for improving ecological models, biomass extrapolations, and management strategies aimed at conserving the Amazon rainforest.