As florestas têm dominado o trópico, e estas alterações, seja pela extração madeireira, pastagem e/ou agricultura, acarreta alterações nas composições químicas e físicas do solo e consequentemente na composição florística da área. O objetivo deste trabalho foi avaliar a influência dos fatores edáficos e altitudinais na composição florística de florestas alterados antropicamente na mesorregião do Sudeste Paraense. O levantamento da composição florística e estrutural e a coleta das variáveis ambientais foram conduzidos em 63 parcelas de 10m x 250 m, para quantificar os indivíduos com (DAP) ≥10 cm do estrato superior e, no interior destas parcelas de 10m x 10m para os indivíduos do estrato médio com 10cm < DAP > 2 cm. Foram coletadas, em cada parcela, variáveis ambientais relacionadas às características químicas e físicas dos solos e atitudinais em florestas degradadas e secundárias em estágio inicial e intermediário de sucessão classificadas conforme a Instrução Normativa 08 de 28/10/2015. O solo em floresta primária degradada apresentou baixa fertilidade de nutrientes, acidez muito elevada, presença de alto teor de alumínio trocável e baixos teores de matéria orgânica em relação às florestas secundárias. Para os três tipos de florestas, em geral, houve mudança nos atributos físicos e químicos do solo, especialmente na camada superficial (0-10 cm) em relação às camadas mais profundas. A composição florística foi influenciada pelo teor de potássio no solo no estrato médio da floresta secundária e sódio, areia grossa e topografia no estrato superior.

Amazon is made up of a mosaic of ecosystems that have important structure, flora, and ecological functions for Brazil and the world. Knowing aspects of this biome related to the production and biomass of fine roots is of major importance given the role that the plant root system plays in nutrient cycling and carbon storage. Therefore, this study aimed to quantify the fine root mass in two regeneration areas and in primary forest, with a forest edge, in order to verify whether in different environments there are significant differences in root mass, as well as to compare the seed bank of the three areas to try to identify similarities among banks. The native forest presented a higher root mass, which differs from the two regeneration areas. The seed bank of succession forests is more similar to each other. The native forest has a greater number of seeds per volume of soil and litter collected. Concerning morphospecies, a higher number was observed in succession forests. The three areas differ in terms of fine root mass; however, regarding the seed banks, a possible edge effect may be affecting the native forest.

Uso do biossólido como fertilizante em plantio de Paricá (Schizolobium parahyba var. Amazonicum (huber x ducke) barneby) na Amazônia Oriental Use of biosolid as a fertilizer in Paricá planting (Schizolobium parahyba var. Amazonicum (huber x ducke) barneby) in the Eastern Amazon

The objective of this study was to identify the harvesting system applied for Tectona grandis and its adaptations to describe the harvesting activities, characterization of the machines used and costing. The costs raised in this work were divided by activity and cost component. The work resulted in the description of the forest felling, this being carried out using three chainsaws of the Stihl brand, model MS 660 with the chainsaw teams adjusted to the scheme (1+1), an operator and a helper. As an adaptation of the system, the extraction was performed from inside the field to the storage yard, and executed with a Massey Ferguson tractor, model MF 275, of medium size with high axle, 4x2 rear-wheel drive, 75 horsepower and torque of approximately 28 kgfm adapted with a winch and use of drag chain, a tractor driver and two assistants. Labor was the most expensive cost, representing 80.82% of the total harvest cost. Gross profit per hectare was R$ 15,525.00, of which 30.76% was consumed by operating costs, being labor the most significant. Selling raw logs, as it was performed in this work, significantly decreases the price of the cubic meter.

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