Revista Ecologia e Nutrição Florestal - ENFLO

Leaf litterfall, decomposition and nutrients release in a Seasonal Semideciduous Forest in Southern Brazil

Monique Pimentel Lagemann — 2022-04-07

Biogeochemical cycling study of ecosystems and their functioning are fundamental for planning conservation practices and management of forest remnants in Brazil. The objective of the study was to characterize the leaf litterfall production rate and the nutrients release via decomposition in a fragment of Seasonal Semideciduous Forest, in Southern Brazil, in advanced stage of regeneration. For two years, evaluations of litterfall and leaf litter decomposition (using the mass loss method with litterbags) were performed monthly, as well as their nutrient content analysis. Annual input of leaf litterfall was 4,532.7 kg ha^-1 of dry matter, which promoted, for the two-year period, a supply of 195.5, 9.2 and 55.3 kg ha^-1 of N, P and K, respectively. The litter nutrients use efficiency followed the decreasing order P > K > N. The annual decomposition constant for leaf litter was 1.16, reaching a half-life at 215 days, making 84.4% N, 72.7% P and 92.9% K available at the decomposition end of two years. In the two years of collection, the largest deposition rate of litter occurred in the spring, with the highest peak in October, indicating a seasonal deposition behavior. The forest fragment presents high production of leaf litter (66% leaves) and input of N. The rapid decomposition of leaf litter contributes to the release of nutrients over time, N and K initially, and P in the long run. P is limited due to the high efficiency of its use.

Bovine and equine manure doses in the initial growth of white ipe seedlings

Cristiane Ramos Vieira — 2022-08-05

The application of organic residues can be a good alternative for the seedlings production, provided that, in an adequate amount for the species to be propagated. Therefore, experiments were developed to evaluate the initial growth of white ipe seedlings (Tabebuia rose-alba (Ridl.) Sandwith in different doses of bovine and equine manure. The experiments were carried out in a completely randomized design with five doses (treatments) and five repetitions for each type of manure, being: T0 - without addition of manure; T1 - 10 Mg ha^-1; T2 - 20 Mg ha^-1; T3 - 30 Mg ha^-1; T4 - 40 Mg ha^-1. At the end of 90 days, the morphological characteristics of the white ipe seedlings were evaluated. The addition of bovine and equine manure to the soil improved the conditions for the growth of white ipe seedlings, and the dose of 40 Mg ha^-1 was the most favorable for the species, for both manure types.

Nutrients in litter of four eucalyptus clones under an Integrated Crop-Livestock-Forest System (CLFS)

Amanda Prudente Velozo — 2022-02-07

The objective of this study was to evaluate the biomass production and nutrient stock in the accumulated litter of a plantation with four eucalyptus clones (AEC-2034 ((Eucalyptus camaldulensis x E. grandis) x E. urophylla)), AEC-2111 (E. urophylla x (E. camaldulensis x E. grandis)), AEC-007 (E. toreliana x E. citriodora) and AEC-0043 (E. citriodora x E. toreliana)) at four and a half years under an integrated crop-livestock-forest system (CLFS) in Inaciolândia, Goiás, Brazil. A template of an area of 0.0625 m² was used for the litter collection (leaves, branches, bark and miscellaneous). Thus, 20 litter samples were collected at random from each clone, totaling 80 samples. All of the material was processed in the laboratory through drying, weighing and grinding to determine biomass and analyze the nutritional content. The results obtained were an accumulation in the average total above ground biomass production estimated at 6.07 Mg ha^-1 for the AEC-2034 clone, 5.20 Mg ha^-1 for the AEC-2111 clone, 3.41 Mg ha^-1 1 for the AEC-007 clone and 3.23 Mg ha^-1 for the AEC-0043 clone. The leaf component showed the highest total accumulation in all clones. Nitrogen (N) was the element which presented the highest accumulation in the litter for all clones. The greatest accumulation of litter biomass occurred for the AEC-2034 clone, and the most representative component was leaves. The AEC-2034 clone showed the highest nutrient stock in the litter and the AEC-0043 clone presented the lowest stock. Nitrogen (N) was the macronutrient with the highest accumulation in the evaluated components, and iron (Fe) was the micronutrient. Based on litter and nutrient return, the most suitable clone in the CLFS system in this region is the AEC-2034 clone.