scholarly journals DETERMINAÇÃO DO PONTO DE AMOSTRAGEM PARA A QUANTIFICAÇÃO DE MACRONUTRIENTES EM Acacia mearnsii DE WILD.

FLORESTA ◽  
2010 ◽  
Vol 40 (1) ◽  
Author(s):  
Fábio Luiz Fleig Saidelles ◽  
Marcos Vinicius Winckler Caldeira ◽  
Mauro Valdir Schumacher ◽  
Rafaelo Balbinot ◽  
Waldir Nagel Schirmer
Keyword(s):  
Forest Inventory ◽  
Sampling Point ◽  
Optimal Sampling ◽  
Acacia Mearnsii ◽  
Total Height ◽  
Point Determination ◽  
Black Wattle

O objetivo deste estudo foi determinar o ponto ótimo de amostragem para a quantificação de nutrientes em árvores de Acacia mearnsii com quatro anos de idade. O trabalho foi realizado em um povoamento de acácia-negra localizado na cidade de Arroio dos Ratos/RS, em uma fazenda pertencente à empresa SETA S/A, nas coordenadas 30°07’12” de latitude sul e 51°57’45” de longitude, com altitude média de 90 m. O primeiro passo foi a realização do inventário florestal no povoamento, onde foram derrubadas 21 árvores, distribuídas em 7 classes diamétricas, sendo determinados a biomassa e o teor de nutrientes dos componentes folha, galho vivo, galho morto, raiz, madeira e casca. Para os componentes madeira e casca, foram retiradas amostras ao longo de fuste nas posições de 1, 3, 10, 20, 30, 40, 50, 60, 70, 80 e 90% da altura total das árvores. O ponto ótimo de amostragem para quantificação dos nutrientes (N, P, K, Ca, Mg e S) no fuste deve situar-se a 50% da altura total das árvores de Acacia mearnsii. É possível a estimativa do estoque de macronutrientes por amostras coletadas no DAP aos 4 anos de idade. Recomenda-se para isso a utilização de trado para não ser necessário derrubar as árvores amostradas. Palavras-chave: Acácia-negra; ponto de amostragem; nutriente.   Abstract Sampling point determination for macronutrients quantification on Acacia mearnsii De Wild. The objective of this study was to quantify the biomass and to determine the optimal sampling point for nutrients quantification in four year old Acacia mearnsii trees. It was conducted in black wattle stand, located in Arroio dos Ratos city in a farm belonging to SETA S/A, having as coordinates 30° 07’ 12” of south latitude and 51° 57” 45” of longitude, with 90 m of average altitude. The first step was the forest inventory, where 30 trees were felled, distributed in 7 diametric classes, to cover the stand heterogeneity, then the biomass and the nutrients amount in the leaves, live branches, dead branches, roots, wood and bark were determined. Samples of wood and bark were taken along the stem in the positions of: 1, 3, 10, 20, 30, 40, 50, 60, 70, 80 and 90% of the total height. The optimal sampling point for nutrients (N, P, K, Ca, Mg, and S) quantification along the stem should be 50% from the total height in Acacia mearnsii trees. It’s possible to estimate the stock of macronutrients by samples collected at DBH at 4 years of age. For this it’s recommended to use the borer, for not to be necessary to fell the sampled trees.Keywords: Black wattle; sampling point; nutrient.

scholarly journals MIXED AND MONOSPECIFIC STANDS OF EUCALYPTUS AND BLACK-WATTLE. II - FINE ROOT BIOMASS DENSITY

CERNE ◽  
2015 ◽  
Vol 21 (2) ◽  
pp. 209-217 ◽  
Author(s):  
Márcio Viera ◽  
Mauro Valdir Schumacher ◽  
Edenilson Vieira Liberalesso ◽  
Roque Rodríguez-Soalleiro
Keyword(s):  
Root Biomass ◽  
Fine Root ◽  
Block Design ◽  
Eucalyptus Grandis ◽  
Fine Root Biomass ◽  
Sampling Point ◽  
Acacia Mearnsii ◽  
Biomass Density ◽  
Randomized Block Design ◽  
Black Wattle

The aim of this study was to evaluate fine root biomass density (FRBD) in mixed and monospecific stands of Eucalyptus grandis x E. urophylla and Acacia mearnsii(black wattle) in Bagé-RS (Southern Brazil). An experimental trial was installed with three treatments: 100% Eucalyptus (100E); 100% Acacia mearnsii (100A); 50% Eucalyptus + 50% Acacia mearnsii (50E:50A). The trial was carried using a randomized block design with three replicates. The fine root (≤ 2.0mm) biomass density was determined 8 and 18 months after planting the trees. Soil samples were collected, with a cylindrical extractor auger (d = 7.0 cm), from four depths (0 - 5, 5 - 10, 10 - 20 and 20 - 30 cm) at each sampling point. After 8 months, the FRBD distribution was the same in both species and in all soil layers, reaching the maximum projection at 125 cm from the tree trunk. After 18 months, the root biomass density was higher in the monospecific black wattle stand than in the monospecific eucalyptus stand and the mixed stand. The fine root biomass density was highest in the 5 - 10 cm layer close to the trunk, for the planting row spacing, the planting line and the diagonals between two planting lines. Knowledge about fine root growth and distribution in soil at initial stages of stand development may help in decision-making for intensive forestry, thus ensuring more efficient use of soil resources.

scholarly journals An approximate point-based alternative for the estimation of variance under big BAF sampling

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Thomas B. Lynch ◽  
Jeffrey H. Gove ◽  
Timothy G. Gregoire ◽  
Mark J. Ducey
Keyword(s):  
Forest Inventory ◽  
Variance Estimation ◽  
Basal Area ◽  
Volume Estimation ◽  
Delta Method ◽  
Sampling Point ◽  
Variance Estimator ◽  
Computer Simulation Studies ◽  
New Formula ◽  
Estimation Of Variance

Abstract Background A new variance estimator is derived and tested for big BAF (Basal Area Factor) sampling which is a forest inventory system that utilizes Bitterlich sampling (point sampling) with two BAF sizes, a small BAF for tree counts and a larger BAF on which tree measurements are made usually including DBHs and heights needed for volume estimation. Methods The new estimator is derived using the Delta method from an existing formulation of the big BAF estimator as consisting of three sample means. The new formula is compared to existing big BAF estimators including a popular estimator based on Bruce’s formula. Results Several computer simulation studies were conducted comparing the new variance estimator to all known variance estimators for big BAF currently in the forest inventory literature. In simulations the new estimator performed well and comparably to existing variance formulas. Conclusions A possible advantage of the new estimator is that it does not require the assumption of negligible correlation between basal area counts on the small BAF factor and volume-basal area ratios based on the large BAF factor selection trees, an assumption required by all previous big BAF variance estimation formulas. Although this correlation was negligible on the simulation stands used in this study, it is conceivable that the correlation could be significant in some forest types, such as those in which the DBH-height relationship can be affected substantially by density perhaps through competition. We derived a formula that can be used to estimate the covariance between estimates of mean basal area and the ratio of estimates of mean volume and mean basal area. We also mathematically derived expressions for bias in the big BAF estimator that can be used to show the bias approaches zero in large samples on the order of $\frac {1}{n}$ 1 n where n is the number of sample points.

scholarly journals Analytical approaches for modeling tree crown volume in black wattle (Acacia mearnsii De Wild.) stands

2016 ◽  
Vol 11 (49) ◽  
pp. 4979-4989
Author(s):  
C. Cadori Guilherme ◽  
R. Sanquetta Carlos ◽  
Pellico Netto Sylvio ◽  
Behling Alexandre ◽  
Costa Junior Sergio ◽  
...  
Keyword(s):  
Tree Crown ◽  
Acacia Mearnsii ◽  
Crown Volume ◽  
Black Wattle ◽  
Analytical Approaches

Analysis of Black Wattle (Acacia mearnsii De Wild) Bark by Near Infrared Spectroscopy

Holzforschung ◽  
2003 ◽  
Vol 57 (5) ◽  
pp. 527-532 ◽  
Author(s):  
L. R. Schimleck ◽  
Y. Yazaki
Keyword(s):  
Near Infrared ◽  
Rapid Assessment ◽  
Nir Spectroscopy ◽  
Hot Water ◽  
Soluble Solids ◽  
Tannin Content ◽  
Acacia Mearnsii ◽  
Considerable Potential ◽  
Black Wattle

Summary The analysis of two sets of Acacia mearnsii De Wild (Black Wattle) samples by near infrared (NIR) spectroscopy is reported. Set 1 samples were characterised in terms of hot water extractives, Stiasny value and polyflavanoid content. Set 2 samples were characterised by nine different parameters, including tannin content. NIR spectra were obtained from the milled bark of all samples and calibrations developed for each parameter. Calibrations developed for hot water extractives and polyflavanoid content (set 1) gave very good coefficients of determination (R2) and performed well in prediction. Set 2 calibrations were generally good with total and soluble solids, tannin content, Stiasny value-2 and UV-2, all having R2 greater than 0.8. Owing to the small number of set 2 samples, no predictions were made using the calibrations. The strong relationships obtained for many parameters in this study indicates that NIR spectroscopy has considerable potential for the rapid assessment of the quality of extractives in A. mearnsii bark.

Forest inventory: further results for optimal sampling schemes based on the anticipated variance

2001 ◽  
Vol 31 (10) ◽  
pp. 1845-1853 ◽  
Author(s):  
Daniel Mandallaz ◽  
Adrian Lanz
Keyword(s):  
Forest Inventory ◽  
Optimal Allocation ◽  
Optimality Criterion ◽  
Second Phase ◽  
Optimal Sampling ◽  
Two Stage ◽  
Two Phase ◽  
Sampling Density ◽  
Sampling Schemes ◽  
Inclusion Probabilities

This work presents optimal allocation rules for two-phase, two-stage sampling schemes in which the sampling density and the costs of the second phase can vary over domains. The optimality criterion is based on the anticipated variance. It also gives an improved version of discrete approximation for the resulting inclusion probabilities. An example illustrates the theory.

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