Management of tropical dry forests in Brazil expanded 450% in the two latest decades; but little is known about the dynamics of these areas. Thus, the objective of this work was to evaluate if the recovery of mean original biomass stocks (MOBS) is a consistent criterion to define cut cycles in a managed forest for charcoal production, and determine the remaining biomass and its contribution to soil carbon stocks. The study was conducted at the Ramalhete Settlement, in General Sampaio, CE, Brazil, in 2018. The explorable shrubby-arboreous biomass (ESAB) and the ESAB mean annual increases (ESAB -MAI) were determined in five areas subjected to clearcutting after 3, 5, 8, 11, and 15 years, and in a preservation area with 40 years of regeneration. Each area was divided into seven plots (20 × 20 m), totaling 42 plots. The ESAB of the plots were compared and the remaining biomass (branches, stumps, and litterfall) in a recently explored area was calculated and converted into organic carbon. The remaining biomass of branches had higher contribution to soil carbon stocks, followed by the litterfall, and stumps. The carbon stocks of the branch component were 3.4-fold higher than those of the litterfall. The recovery of the MOBS of an area after clearcutting should not be used as a criterion to define the cut cycle, since these original carbon stocks do not represent the maximum ESAB production possible in the area; the biodiversity and amount of ESAB in the classes of larger diameter are more adequate criteria.

Litter is the most important way of transferring essential elements from vegetation to the soil. This is due to nutrient cycling, a process by which decomposition of the litter adds nutrients to the soil. An understanding of this process goes beyond the need for knowledge of nutrient dynamics, since it is a question of understanding the way in which ecosystems function in the search for a correct use of natural resources. The aim of this study was to quantify the average concentrations of the following nutrients: Nitrogen (N), phosphorus (P), Potassium (K), and Organic Carbon (C) in litter remaining in an area of tropical dry forest - Caatinga. The work was carried out on the Elias Andrade Private Natural Heritage Reserve (PNHR) of the Irmãos Andrade Farm, located in the semi-arid region of the State of Ceará. In February 2009, 48 nylon litter bags were randomly distributed, each containing 30 g of litter collected in the area of the Reserve. Every two months, from February 2009 to January 2011, four bags were randomly collected. Over time, variations were seen in the average levels of N, P and K for the litter in the nylon bags. The nutrient with the greatest contribution to the system from the litter was Nitrogen, followed by K and P. The highest N content occurred at the beginning of the experiment. The C content decreased over the study period. The mean C to N ratio of the litter was 21, which was in the borderline range between the processes of mineralisation and immobilisation.

In Brazil, logging in the Seasonally Dry Tropical Forest (SDTF) under management plans that include clear-cutting has increased in recent decades, and the structure, composition, diversity and functioning of the forest likely must have been affected. The aim of this study was to understand the growth dynamics of shrub–tree biomass (STB), species richness and vegetation structure as a function of regeneration time after clear-cutting (treatments), taking the Legal Reserve (40 years of regeneration) as reference. The study was carried out in 2018 at the Ramalhete Settlement, General Sampaio, in the state of Ceará. All plants with a circumference at breast height (CBH) ≥ 6 cm were identified and the CBH was measured across 42 sample plots (20.0 m × 20.0 m), using seven plots per treatment (3, 5, 8, 11 and 15 years after clear-cutting, and the Legal Reserve, 40 years of regeneration). The following were determined: STB (total and by species), density and basal area (by ecological group and diameter class), basal area (species of higher added value), diversity (Hill numbers), and the importance value index (IVI). It was found that during the early years (up to at least 11 years), many important forest characteristics related to the composition of the ecological groups and vegetation structure were strongly affected, and major impacts can be seen, the effects of which, however, decreased over time of regeneration, having almost no effect after 15 years. After 15 years following clear-cutting, the SDTF presented accumulated STB, species richness and structure similar to the area undergoing regeneration for 40 years. However, the small number of indicator species of more-preserved areas (even at T15 and T40) points out that management needs to be improved. However, promoting species of greater added value and determining whether the forest recovers its structure and diversity after successive cutting cycles also still need to be addressed.

A Revista Ciência Agronômica é voltada para estudos relacionados com as Ciências Rurais e Recursos Naturais