Alcides Gatto

Estoque de carbono na biomassa de plantações de eucalipto na região centro-leste do estado de Minas Gerais

Forest ecosystems are a viable possibility to mitigate the increase in concentration of CO2 in the atmosphere by carbon (C) sequestration by the trees and its storage in biomass and in the soil, but such information are scarce. The main objective of this study was to assess production of dry matter of aerial section, roots and litter layer on the soil and C stock of trees in eucalyptus crops in the Central-East region of Minas Gerais State, Brazil, in five regions: Cocais (CO), Rio Doce (RD), Sabinopolis (SB), Santa Barbara (SA), and Virginopolis (VI). Regarding dry matter production, the most productive region was SA, with 32.80 t ha-1 yr-1, in trees at 84 months of age and 21.09 and 25.21 t ha-1 yr-1 in trees at 120 months of age, respectively. Stabilization of productivity was after 96 months of age in SA and at 84 months of age for RD and SB. For region CO and VI, productivy and average year C stock maintained increasing rates until 120 months of age, showing that the greatest productivy occurs in advanced ages. Productivity and average C stock of those crops were 26.96 t ha-1 yr-1 of biomass and 13.64 t ha-1 yr-1 C.

Ciclagem e balanço de nutrientes no sistema solo-planta em um plantio de Eucalyptus sp., no Distrito Federal

The species of the Eucalyptus genus are the most cultivated in the world and have become a solution for reducing the pressure on native forests. The aim of this study was to evaluate the dry biomass and its distribution in the different compartments of the trees (leaves, branches, bark, wood and roots), and assess their macronutrient content and nutrient balance in the soil-plant system in a Eucalyptus urophylla x E. grandis plantation at 60 months of age on the Agua Limpa Farm in the Distrito Federal, Brazil. Data were obtained from three eucalyptus trees that had been rigorously scaled and the roots dug to a depth of 60 cm. Data were statistically analyzed by Pearson correlation. Most of the dry weight of the trees was observed in the wood compartment (69.19 %), followed by roots (10.15 %), branches (9.75 %), bark (6.06 %) and leaves (4.85 %). The highest levels of macronutrients were observed in leaves (N = 13.55 g kg-1, P = 1.33 g kg-1, K = 8.52 g kg-1, Ca = 7.12 g kg-1, Mg = 2.44 g kg-1, and S = 1.76 g kg-1), while the wood had the lowest concentrations (N = 1.73 g kg-1, P = 0.23 g kg-1, K = 0.34 g kg-1, Ca = 0.20 g kg-1, Mg = 0.03 g kg-1, and S = 0.43 g kg-1). The order of total contents of macronutrients observed for tree shoots was N > K > Ca > S > Mg > P while for the roots it was N > Ca > K > Mg > S > P. The roots accumulate approximately 11.90 % of the nutrients in the biomass of trees, and this amount decreases with increasing depth. The nutrient balance indicates that P and S are not enough for a new growth cycle in the forest.

Soil Stabilization with Lime for the Construction of Forest Roads

The mechanical performance of soil stabilization using lime to improve forest roads was assessed. This study was conducted with lateritic soil (LVAd30) using lime content of 2% in the municipality of Niquelândia, Goias state, Brazil. Geotechnical tests of soil characterization, compaction, and mechanical strength were performed applying different compaction efforts and curing periods. The results showed that lime content significantly changed the mechanical performance of natural soil, increasing its mechanical strength and load-carrying capacity. Compaction effort and curing time provided different responses in the unconfined compressive strength (UCS) and California Bearing Ratio (CBR) tests. The best UCS value (786.59 kPa) for the soil-lime mixture was achieved with modified compaction effort and curing time of 28 days. In the CBR test, soil-lime mixtures compacted at intermediate and modified efforts and cured for 28 days were considered for application as subbase material of flexible road pavements, being a promising alternative for use in layers of forest roads.

Aspectos Socioambientais da Comercialização de Pequi em Goiás

The pequizeiro provides fruits traditionally used in cooking Goias and regions of the Cerrado biome. Based on the pequi marketing analysis in CEASA-GO and local fairs (Ipameri and Pires do Rio, GO), this study assesses the importance of the species and threats related to extraction. The data revealed 12 micro-regions producing pequi in the state, being sold 5500 tons of pequi in 2011, with the box price ranging from 25 to 40 reais. The price paid in the fairs per liter in 2010 was five Brazilian Reais, with an increasing percentage of interested in the sale of non-timber product. The variation in the price paid to the pequi and changes producing regions in Goias is noteworthy, in addition to the purchase of this product from other states. To meet the growing demand of pequi, it is suggested, besides the responsible extraction, planting the species in the cerrado, in orchards or agroforestry systems.

Estoque de serapilheira em três fisionomias no cerrado do Distrito Federal

The aim of this study was to evaluate the monthly and annual litter stock, and the seasonality in two phytophysiognomies (Cerrado stricto sensu and Gallery Forest) and one eucalyptus plantation, located in Fazenda Agua Limpa, DF. The litter stock was monthly collected by using a metal jig of 0.25 m2, during one year. The material was manually sorted into leaves, bark, twigs, roots, flowers/fruits and particulate matter. There were no significant differences in the litter stock between the Gallery Forest (9.36 t ha-1) and the eucalyptus plantation (9.12 t ha-1), which were both higher than the Cerrado stricto sensu (6.08 t ha-1). The leaf fraction presented a larger amount in the three vegetation types when compared to the other fractions. There were two different patterns of litter stock seasonality: higher litter stock in the Cerrado stricto sensu and eucalyptus plantation in the dry season; and higher stock in Gallery Forest in the rainy season.

Eficiência de regenerantes como indicador de restauração ecológica no Cerrado, Brasil

The objective of this study was to evaluate the efficiency of regenerating as an ecological indicator of restoration in riparian forests in the Cerrado, DF, from January/2012 to January/2013. The restoration experiment contained six treatments with three repetitions each (T1 = Nucleation; T2 = Nucleation + perches; T3 = perches; T4 = planting in rows: lines with fast growing and good covering species and diversity lines; T5 = control with brachiaria; T6 = brachiaria suppression). The percentage of coverage of saplingwas made using the Braun-Blanquet method, and then applied the nonparametric Kruskal-Wallis test. There was a significant difference between the initial and final cover for the T1. The other treatments there was little increase in the coverage of sapling, but not significant, even as in the increase between treatments. There were no differences between treatments when analyzing only the density of sapling, which may be associated with high mortality rate of certain species. Although early, the percentage of coverage of sapling was a good indicator of the ecological restoration process, according with aspects: sensitivity, results, cost, understanding and interpretation, predictability or trend and scale. Thus, it can be concluded that the percentage of coverage of sapling demonstrated efficiency as an indicator.