Mauro Valdir Schumacher

Litterfall in an Araucaria angustifolia (Bertol.) Kuntze forest in Pinhal Grande, RS

The objective of this work was to evaluate the annual deposition of litter and macronutrient devolution (N, P, K, Ca and Mg) in a 17 year - old stand of Araucaria angustifolia in Pinhal Grande, RS. The experiment was arranged in a randomized design (5 plots of 10 m x 20 m). In each plot 4 wooder collectors of 1 m2 of area were systematically distributed. The material was collected monthly during one year and separated in needle and branch fractions, stove-dried and weighed in a precision balance, milled and analyzed chemically. Litter deposition was 6.96 Mg/ha, composed by 74% needles and 26% branches. An outstanding deposition seasonality with deposition peacs between spring and summer was observed, decreasing towards the autumn and winter months, according to the average monthly precipitation. Needles and branches were responsible for the return to the forest floor of 84% and 16% of the total of the nutrients, which was 254,3 kg/ha. Calcium presented the highest devolution (177.1 kg/ha). The expressive amount of nutrients returned to the soil demonstrates the importance of litter in maintaining productive local capacity.

Avaliação da sazonalidade da produção de serapilheira numa Floresta Estacional Decidual no município de Santa Maria-RS

The amount of litter produced and its seasonal fall were estimated during the period of one year, in a Seasonal Deciduous Forest ecosystem next to Santa Maria, RS. Thirty round-shaped metal collectors (50 cm diameter) were used, systematically distributed in 6 rectangular plots (10 m x 20 m) presenting similar environmental characteristics. The material deposited was collected monthly, separated into different fractions, dried and weighed. Litter production was 9.2 Mg/ha/year, presenting the following composition: 67.8% of leaves, 19.3% of fine branches and 12.9% of miscellany (flowers, fruit, seeds and other plant materials). The greatest amounts of litter production occurred between the months of July and September, in the winter, and the smallest productions between October and April, in the spring and summer. The devolution of litter presented negative correlations with the temperature.

Avaliação da eficiência nutricional de três procedências australianas de acácia-negra (Acacia mearnsii De Wild.)

The present study aimed to determine the nutritional efficiency of the macronutrients N, P, K, Ca, Mg and S, in the different components of trees from three provenances of black wattle (Acacia mearnsii De Wild.), 2.4 years old, planted in Butia, RS, Brazil. The selected Australian provenances were Lake George, Bodalla and Batemans Bay. There was a wide variation in the nutritional efficiency among the provenances. In a decreasing ranking for efficiency of nutrient utilization for the production of wood and bark, products that are exploited in the even-aged forest, the following results were obtained: Bodalla > Batemans Bay > Lake George. Although Lake George is less efficient in using nutrients to produce wood, bark and crown, it has a great capacity of production.

Crescimento inicial de Pinus taeda L. relacionado a doses de N, P e K.

This study aimed to evaluate the effect N, P and K on the growth of young (19 month-old) Pinus taeda . The experiment took place near Cambara do Sul county, with UTM coordinates of 562125 E and 6777386 N. The statistical methodology was the confounding technique, for three factors, with four levels, totalizing 64 treatments, allocated in four blocks. The following variables were measured: total height, crown height, steam diameter and crown diameter. The results pointed out a significant linear quadratic effect for P, indicating that P fertilization is essential on the initial development of Pinus taeda plants, with a maximum cylindric volume achieved at 64 and 87 kg ha -1 doses of P 2 O 5 and K 2 O respectively.

CONCENTRAÇÃO E RETRANSLOCAÇÃO DE NUTRIENTES EM ACÍCULAS DE Pinus taeda L.

Aiming at evaluating nutrients concentration and retranslocation in the Pinus taeda L. needles, this study was developed in two stands, in native grass area and in second rotation area, with same species and same age (7.5 years old) in Cambara do Sul, RS. The needles were collected in plants in four orthogonal points (South, North, East and West), sampled new needles, mature needles and old needles. The material was dried in a stove, milled and chemically analyzed (macro and micronutrients). The concentrations of N, P, K, B, Cu and Zn had decreased, of Ca, Fe and Mn increased, and the Mg and S have remained constant with the age of the needles. The retranslocation rate (old-new needles) was more than 50% for most nutrients, except for Mn and Fe, showed that cumulative effect and the Ca reference element.

Ciclagem de nutrientes em Acacia mearnsii de wild. V. Quantificação do conteúdo de nutrientes na biomassa aérea de Acacia mearnsii de wild. Procedência australiana

Nutrient contents of 2.4 years old black wattle (.), from Bodalla Australian provenance, were quantified. This provenance was established on soils of low fertility and high acidity, at Menezes Farm of Agroseta S.A. Forest CompAcacia mearnsii De Wildany in the Capao Comprido District, municipality of Butia-RS. A total of nine trees were selected to form the sample. The destructive sampling was constituted in the individualization of compartments of above-ground biomass (leaves, live branches, dead branches, bark and wood) to determine dry matter and nutrient contents. The quantity of total nutrients in the above-ground biomass from Bodalla provenance was 182.1kg ha-1 of N; 8.2kg ha-1 of P; 104.4kg ha-1 of K; 66.7kg ha-1 of Ca; 16.1kg ha-1 of Mg and 10.0Kg. ha-1 of S. For the Bodalla provenance, 57.4% of dry matter was allocated to the leaves, live branches, dead branches, bark and wood, containing 74% of N; 72.1% of P; 63% of K; 68.5% of Ca, 69.3% of Mg and 74.1% of S in the total found in the aerial part. The trunk component (bark and wood) accumulated 26% N; 27.9% P; 37% K; 31,5% Ca; 30.7% Mg and 25.8% S.

Quantificação da biomassa de um povoamento de Acacia mearnsii De Wild. na região sul do Brasil.

The present study was carried out in stand of Black wattle 8 years old, in the southeastern mountain range, in Minas do Leao - RS County. The objective of this work was to quantify the total biomass of the stand and its distribution in each component of the tree biomass. After evaluation of dendrometric characteristics, 21 trees were selected and cut for estimation of biomass in the components: leaves, live and dead branches, bark wood, stem wood and roots. To estimate the different components of the biomass, the coefficients of the equation ln y = b0 + b1 * ln d were determinated. At eight years old, a Black wattle can concentrate more than 60% of its biomass in the wood. The biomass below ground under these conditions can reach approximately 12% of total biomass.

Eficiência do uso de micronutrientes e sódio em três procedências de acácia-negra (Acacia mearnsii De Wild.)

Objetivou-se avaliar a eficiencia nutricional de micronutrientes (Mn, B, Cu, Zn e Fe) e Na nos diferentes componentes das arvores de tres procedencias de acacia-negra (Acacia mearnsii), com 2,4 anos de idade, plantadas em Butia-RS (Brasil). As procedencias selecionadas foram Lake George, Bodalla e Batemans Bay. Constatou-se grande variacao na eficiencia nutricional entre as procedencias. A Lake George, alem de acumular maior biomassa total, foi tambem a mais eficiente na utilizacao dos nutrientes na producao de biomassa total das arvores. No entanto, a Bodalla mostrou ser a procedencia mais eficiente no uso dos nutrientes para producao de biomassa da casca e da madeira.

Quantificação da biomassa acima do solo de Acacia mearnsii De Wild., procedência Batemans Bay - Austrália.

The above-ground biomass of the Australian provenance Batemans Bay of black wattle ( Acacia mearnsii De Wild.), at 2.4 years after planting was quantified. The provenance was established in soils of low fertility, with high acidity, at Fazenda Menezes, District of Capao Comprido, County of Butia/RS. Nine trees were selected to form a sample. The destructive sampling comprised the individualization of the compartments of the above-ground biomass (leaves, live branches, dead branches, bark, and wood), and the determination of the dry matter allocated in each of these compartments. The production of above-ground biomass of the Australian provenance Batemans Bay was 36,1 Mg ha -1 with the following distribution: 20% in the leaves; 19,5% in the live branches; 2,8% in the dead branches; 11,8% in the bark and 45,9% in the wood.

Teores e aporte de nutrientes na serapilheira de Pinus taeda L., e sua relação com a temperatura do ar e pluviosidade

The objective of this study was to evaluate the contents and input of nutrients to forest floor in a Pinus taeda L. stand and the relation with rainfall and air temperature, in an area previously occupied with native grass, in Cambara do Sul, RS, through litterfall, evaluated during a three-year period, from the 5th to the 7th year of the stand. Litter was monthly collected in 1.0 m2 (1.0 x 1.0 m) collectors, from April/ 2004 to March/2007. After each collection, litter samples were chemically analyzed for macro and micronutrients. The contents of K, Mg and Cu showed a positive correlation (p < 0,05) with air temperature, while Fe (p< 0.01), Mn and Zn (p < 0,05) showed a negative correlation with this climatic variable. The contents of N and K showed a negative correlation (p < 0.01 e p < 0,05, respectively). The contents of K, Mg and Cu showed a positive correlation (p < 0,05) with rainfall and the contents of S showed a positive correlation (p < 0,05) with air temperature, while the contents of Fe (p < 0.01), Mn and Zn (p < 0,05) showed a negative correlation with this variable.The contents of N and K showed a negative correlation (p < 0.01 and p < 0,05, respectively) with litter amount monthly deposited. Macronutrient mean annual input to soil, through litter deposition, in kg ha-1 was: 18.8 of Ca; 13.0 of N; 3.0 of Mg; 1.6 of K; 1.3 of S and 1.1 of P and for micronutrients the transference, in g ha-1 was: 4,708.3 of Mn; 592.3 of Fe; 74.1 of Zn; 34.0 of B and 7.6 of Cu. The results demonstrate the importantance of keeping the litter over the soil to maintain nutrient cycling.