José Henrique Tertulino Rocha

Quantification of biomass and nutrients in the accumulated litter in a section of Submontane Seasonal Semideciduous Forest, ES.

Objetivou-se, com o trabalho, quantificar o acumulo de serapilheira, bem como os macronutrientes e o carbono orgânico na Floresta Estacional Semidecidual Submontana, localizada em Cachoeiro de Itapemirim, ES. A amostragem da serapilheira foi realizada em 12 parcelas (20 m x 50 m), sendo as mesmas distribuidas de forma sistematica no campo. Em cada uma das 12 parcelas, foram coletadas mensalmente 12 amostras de serapilheira acumulada, de forma aleatoria, com o auxilio de um gabarito de metal de 0,25 m x 0,25 m. O estudo de acumulo de serapilheira na floresta foi analisado segundo o delineamento inteiramente casualizado, com 12 tratamentos (meses do ano) e 12 repeticoes. O acumulo de serapilheira mostrou-se sazonal, com maiores acumulos, ocorrendo no final da estacao seca e de menores temperaturas do ar (Dez/09, Jan/10, Set/10 e Out/10), contendo em media 5,5 Mg ha-1 de serapilheira acumulada. O Calcio foi encontrado em maior teor e conteudo, sendo o conteudo medio de macronutrientes contidos na serapilheira de 293,59 kg ha-1.

Eucalypt plantation management in regions with water stress

Most eucalypt plantations are managed in short rotations (6–8 years) and are established in regions with water and nutritional stresses of varying degrees. The mean annual increment in these regions ranges from 20 to 45 m3 ha−1 y−1 depending on the level of environmental stress. Improving natural resource use efficiency by breeding and matching genotypes to sites and using appropriate site management practices is a key challenge to sustain or increase productivity. Climate change is emerging as a driving force behind many of the current issues facing natural resources, and is likely to intensify the water constraint. The Intergovernmental Panel on Climate Change has predicted significant increases in surface air temperatures and decreases in rainfall (with more erratic rainfall patterns) over the tropics and subtropics, affecting drier regions in particular. To be truly sustainable, forest management practices must be environmentally friendly, prevent or reduce land degradation, improve biodiversity and increase resilience to climate variation and change. The main efforts should address the problems of water scarcity, low soil fertility and reduced biodiversity. Forest growers should take into account the inherent risks of different forest management systems on the regional water availability and consider reducing forest productivity in order to maintain both ecological and social equilibrium. The design and implementation of management techniques should be adapted to the specific production and protection objectives, which depend on the regional and local edaphoclimatic circumstances, water resources management, protection against soil erosion, diseases, pests, bushfires, strong winds and alien species. This paper addresses the basic requirements for integrating genetic and silvicultural strategies to minimise the water constraints in eucalypt plantations and surrounding water and native vegetation resources. We show several examples of effective forest management actions on the scale of forest stand and watershed in use in Brazil.

Reflorestamento e Recuperação de Atributos Químicos e Físicos do Solo

The objective with this study was to evaluate the influence of reforestation with native species from seasonal semideciduous forest, eucalyptus plantation, and pasture in the soil chemical and physical properties of degraded areas. Five sites were selected in the watershed of the Aguapei River in the Garca city, Sao Paulo state: two reforestation areas with native species, with four and nine years old; a reforestation area with eucalyptus plantation, a pasture area, and a forest fragment used as control. The forest fragment presented the lowest exangeable bases and the highest levels of P, SOC and CEC; it also showed the lowest penetration resistance, and the largest diameter and aggregate stability. The chemical and physical soil attributes of the reforestation areas differed from those of the forest fragment (control), showing that the recovery period was not sufficient to restore these attributes. However, the 9-year-old reforestation area presented significant improvement of these soil attributes, tending to approach those of the control area.

PRODUTIVIDADE DO MINIJARDIM E QUALIDADE DE MINIESTACAS DE UM CLONE HÍBRIDO DE Eucalyptus grandis x Eucalyptus urophylla (I-224) EM FUNÇÃO DE DOSES DE NITROGÊNIO

For being part of innumerable compounds and being directly related with the photosynthetic capacity of plants, Nitrogen (N) can significantly influence the production and rooting of cuttings. On the basis of this context, the work aimed to evaluate the effect of increasing doses of N in the productivity, capacity and speed of rooting mini-cuttings produced from mini-stumps of hybrid clones of Eucalyptus grandis x E. urophylla (I-224), beyond the quality of the formed changes. The present work was carried through in nursery seedlings of Eucalyptus, in a mini-garden of sand stream bed of FAEF, in Garca, Sao Paulo state. The used experimental delineation was complete randomized design with 4 replications, being the treatments consisted of 5 different doses of Nitrogen in nutritional solution (0; 80; 160; 240 and 320 mg L-1). The variables analyzed were: number of cuttings produced, the productivity index, rooting of cuttings produced and determination of the dry mass of seedlings. The dose of nitrogen applied in the mini-garden influenced the production of stakes, with a quadratic, reaching maximum production (13,1 stakes strain-1 month-1) with the estimated dose of 129 mg L-1.The percentage of rooting presented increasing linear behavior. The dose that provided the biggest index of productivity of the mini-garden was of 194 mg L-1. The dose of nitrogen applied in the mini-garden influenced the rooting significantly and the dry mass of formed seedlings.