Quantification of biomass and nutrients content of different origens of black wattle (Acacia mearnsii of wild)

RESUMOS DE DISSERTAÇÃO DE MESTRADO

Summares of dissertations submitted to the graduate program at the Centro de Ciências Rurais da Universidade Federal de Santa Maria and researches at this Center

Quantification of biomass and nutrients content of different origens of black wattle (Acacia mearnsii of wild)¹

Autor: Marcos Vinicius Winckler Caldeira²

Comissão Examinadora: Mauroi Valdir Schumacher³ Fábio Poggiani⁴ Flávio Luiz Foleto Eltz⁵

The biomass and the nutrient content of three origins of 2.4-year old black wattle (Acacia mearnsii De Wild.) were quantified. The three Australian origins of black wattle were estabilished on low fertility soils, with high acidity, located in Fazenda Menezes, in the District of Capão Comprido, Country of Butiá/RS, Brazil, belonging to the Empresa Florestal Agroseta S.A.A total of nine trees from each origin were selected as samples. The destructive sampling, consisted of the separation of the compartments of the aboveground biomass (leaves, live branches, dead branches, bark and wood) for sampling, to determine the dry matter and the nutrients content. The production of above-ground biomass for Batemans Bay origin was of 36.1Mg ha^-1 with the following percent distributions: 20% for leaves, 19.5% for live branches, 2.8% for dead branches, 11.8% for bark, and 45.9% for wood. For the Bodalla origin the total above-ground biomass was 19.4Mg ha^-1 with 22.4, 19.8, 0.4, 12.4 and 45.0% acumulated respectivily in the leaves, live branches, dead branches, bark and wood. For the Lake George Bunge Dore origin the production of above-ground biomass was of 41.1Mg ha^-1, with the following percent distributions: 18.2% for leaves, 19.5% for live branches, 1.2% for dead branches, 11.6% for bark, and 49.5% for wood. The amounts of nutrients contained in the total biomass for Batemans Bay were of 297.87kg ha^-1 of P, 191.74kg ha^-1 of K, 101.06kg ha^-1 of Ca, 28.92kg ha^-1 of Mg and 18.28kg ha^-1 of S. In Bodalla there were 182.14kg ha^-1 of N, 8.17kg ha^-1 of P, 104.38kg ha^-1 of K, 66.67kg ha^-1 of Ca, 16.06kg ha^-1 of Mg and 10.03kg ha^-1 of S. The hightest amounts of nutrients were found in Lake George Bunge Dore with the following distributions: 334.37kg ha^-1 of N, 23.65kg ha^-1 of P, 259.67kg ha^-1 of K, 107.73kg ha^-1 of Ca, 35.09kg ha^-1 of Mg and 21.43kg ha^-1 S. From the ecological and silvicultural points of view, the three origins exported similar amounts of all nutrients. When the wood is harvested with all the bark, K, Ca and Mg are the elements exported int he highest amounts.

Key words: biomass, nutrients cycling, Acacia mearnsii of Wild, sustainability.

²Engenheiro Florestal, MSc. em Engenharia Florestal, CCR, UFSM.

³Engenheiro Florestal, Doutor, Professor Adjunto, Departamento de Ciências Florestais, CCR, UFSM.

⁴Engenheiro Florestal, Doutor, Professor , Departamento de Ciências Florestais, ESALQ/USP.

⁵Engenheiro Agrônomo, Doutor, Professor, Departamento de Solos, CCR, UFSM.

Recebido para publicação em 01.02.99. Aprovado em 17.03.99

¹

Resumo da dissertação apresentada ao curso de Pós-graduação em Engenharia Florestal, Centro de Ciências Rurais(CCR), Universidade Federal de Santa Maria (UFSM) em 31/08/1998.

Publication Dates

• Publication in this collection
  11 Dec 2006
• Date of issue
  Mar 2000