Beta Fulltext view is in preview — article structure may vary. Browse all articles
Contents
Open Access Journal of Agricultural Research Research Article 6 min read

Form Factor for Amazonian Forest Trees

Aguiar DR*, Garcia ML and Cavalcante EA
* Corresponding author
ISSN: 2474-8846  10.23880/oajar-16000248  Received: September 08, 2020  Published: September 21, 2020
 — views
 17 references
PDF
Keywords
Influence Heterogeneity Inventory
Abstract

The Amazon rainforest has a great diversity of species that provide a high variation of wood stock due to the characteristics of the trees. Among this, the taper of the shaft is essential to determine the form factor for the forest, which can be applied in previous estimates during the forest inventory. Thus, this mini-review aimed to show the variation of the form factor for different forest areas in the Brazilian Amazon. The form factor ranged from 0.874 to 0.4488 for several vegetations, if the average form factor (0.7) were applied in these sites it would have caused both over and underestimations. This demonstrates the high variation in taper that can be determinant in the estimation of forest stock. For this reason, a specific assessment of the form factor is essential for each forest to be managed, as it demonstrates the variation along the log and assists in forest planning.

Aguiar DR¹*, Garcia ML² and Cavalcante EA³

Keywords: Influence; Heterogeneity; Inventory

Introduction

Tropical forests with high heterogeneity can have different form factors for the tree stems. Each area has characteristics that influence the shape, the diameter with bark measured at 1.30 meters in height on the tree (DBH) and commercial height (Hc) of those that can be found, mainly in the Amazon region. This factor can be defined by means of a specific study for the area to be managed, where the volume of the cubed tree is divided by the volume of the cylinder. To calculate the volume of the cylinder and obtain its sectional area, use Hc and DBH. Thus, the volume is wide as: Vcylinder = [(π * DBH ²) / 40000] x Hc, with the DBH in centimeters [1, 2, 3]. In the Brazilian Amazon, research on the volumetry of species in the region determined a general factor (equal to 0.7) for trees in the Amazon forest [4]. Although it was provisional in nature, it continues to be used for previewing wood stocks in forest inventories. Thus, this mini-review aims to list the variations of the form factor for different forest areas in the Amazon region in Brazil.

Mini-Review

Form Factor in Tropical Forests

The form factor is an option used in situations where there is no information about the shape of the tree or, even when it is necessary to speed up the incentive work. It designates recognized, as long as the forest typology, species and diameter class are controlled. It may happen that trees with identical geometric shapes, but with different heights, produce different absolute form factors. This is transmitted by the influence of the bases of the bases, which in old and large trees exceeds the DAP region, which occurs mainly with tropical species [5]. It can also happen that two trunks with the same absolute form factor do not necessarily occur in the same form [6].

Hohenadl was able to express in the natural form the series of relative measures along the trunk by a single value or factor, in a way that allows us to say the algorithm on the development of the data series [7, 8]. However, to define the form factor in the Amazon region, it is used to calculate the volume according to Smaliam, according to normative instruction nº 5 of Conama [9], for forest management plans or a combination of methods (Smaliam and Hohenadl) in scientific research. Thus, there are several components that can affect the calculation of the form factor and its variation.

For 20 forest species in the state of Acre the form factor was 0.874, with a maximum value of 0.927 and a minimum of 0.804, this shows the great variation even for an area of forest with a form factor considered high, when compared with that of other species. regions [10, 11]. In a comparative study of methods to estimate the volume of species in the Tapajós Forest, it determined an average form factor of 0.75, with oscillations between 0.62 and 0.79 for 710 trees distributed in 68 species, however when it was effective for each species, the variation was minimal. When comparing the 0.7 form factor used in forest inventories in the Amazon, the associated error was -10.96 to + 12.85%, when volumetric estimates are highlighted [12].

In the dense ombrophilous forest to the south of the state of Roraima, a variation in the form factor was found for species from 0.70 to 0.78 [13]. For other areas in the Amazon rainforest, values of 0.73 were found in the state of Roraima and 0.74 in Mato Grosso [14]. In the state of Rondônia, the form factor was 0.4488, lower than the value generally used in the Amazon [15].

For cubing 167 trees in the state of Pará, with combined methods by Smaliam and Hohenadl, the form factor was 0.82, which may be associated with the insertion of trees with DBH from 5 cm [16]. In a dense ombrophilous forest in the central Amazon, the form factor increased according to the diameter class where it was 0.745 and 0.781 for trees with DBH ≥ 10 and ≥ 50 cm, respectively. The overall form factor was 0.709, similar to that found by the RadamBrasil project (0.70) [17].

Conclusion

Deviation from the area where the forest is located and from the form factor analysis, there are different conicities that influence the wood volume indicators. The variability in the shape of the shaft can impact the determination of the volume explored in tropical areas of the Amazon biome. Therefore, it is essential to calculate the form factor for each site to be managed, as it helps in forest planning and demonstrates a variation along the log for vegetation of interest.

References

  1. Campos JCC, Leite HG (2002) Mensuração florestal: perguntas e respostas. Viçosa, MG: UFV, pp: 407.
  2. Scolforo JRS, Figueiredo Filho A (1993) Mensuração florestal 2: volumetria. Lavras: ESAL: FAEPE, pp: 126.
  3. Figueiredo EO, Schroeder R, Papa DA (2009) Fatores de forma para 20 espécies florestais comerciais da Amazônia. Rio Branco, AC: Embrapa Acre, pp: 4.
  4. Heinsdijk D, Bastos AM (1963) Inventários Florestais na Amazônia. Rio de Janeiro, Ministério da Agricultura. Setor de Inventários Florestais (Boletim 6), pp: 100.
  5. Loetsch F, Zohrer F, Haller KE (1973) Forest Inventorv. München: BLV. 2: 469.
  6. Caillez F (1965) Forest volume estimation and yield prediction. Rome: FAO, 1980 1: pp: 98. (FAO Forestry Paper 22/1 ).
  7. Hohenadl W (1924) Der Aufbau der Baumschfte.
  8. Prodan M (1965) Holzmesslehre. Frankfurt: Sauerlanders, pp:644.
  9. Conama (2009) Dispõe sobre procedimentos para inspeção de indústrias consumidoras ou transformadoras de produtos e subprodutos florestais madeireiros de origem nativa, bem como os respectivos padrões de nomenclatura e coeficientes de rendimento volumétricos, inclusive carvão vegetal e resíduos de serraria 86: 93-96.
  10. Araújo HJB (2018) Crescimento de espécies madeireiras comerciais em florestas no Acre. Embrapa Acre. 61.
  11. Moura JB (1994) Estudo da forma do fuste e comparação de novos estudos de estimativa volumétrica de espécies florestais da Amazônia brasileira. Curitiba: UFPR. Dissertação de Mestrado, pp: 132.
  12. Tonini H, Borges RA (2015) Equação de volume para espécies comerciais em Floresta Ombrófila Densa no sul de Roraima. Pesquisa Florestal Brasileira (Impresso) 35: 111-117.
  13. Gimenez BO, Danielli FE, Oliveira CKA, Santos J, Higuchi N (2015) Equações volumétricas para espécies comerciais madeireiras do sul do estado de Roraima. Sci. For., Piracicaba 43(106): 291-301.
  14. Colpini C, Travagin DP, Soares TS, Silva VSM (2009) Determinação do volume, do fator de formae da porcentagem de casca de árvores individuais em uma Floresta Ombrófila Aberta na região noroeste de Mato Grosso. Acta Amazonica 39(1): 97-104.
  15. Sanquetta CR, Sanquetta MNI, Bastos A, Queiroz A, Corte APD (2017) Estimativa da altura e do volume em povoamentos jovens de restauração florestal em Rondônia. BIOFIX Scientific Journal 2(2): 23-31.
  16. Aguiar DR, Lima AJN, Gama JRV, Andrade DFC, Santos J, et al. (2017) Adjustment of volumetric equations from fallen trees for analysis of the logging effect in the Tapajós National Forest, Pará, Brazil. Australian Journal of Basic and Applied Sciences 11(10): 48-59.
  17. Nogueira EM, Fearnside PM, Nelson BW, Barbosa RI, Keizer EWH (2008) Estimates of forest biomass in the Brazilian Amazon: new allometric equations and adjustments to biomass from wood-volume inventories. Forest Ecology and Management 256(11): 1853-1867.
More from this journal

Cite this article

BibTeX
APA
RIS
@article{aguiar2020,
  title   = {Form Factor for Amazonian Forest Trees},
  author  = {Aguiar DR, Garcia ML and Cavalcante EA},
  journal = {Open Access Journal of Agricultural Research},
  year    = {2020},
  volume  = {5},
  number  = {2},
  doi     = {10.23880/oajar-16000248}
}
Aguiar DR, Garcia ML and Cavalcante EA (2020). Form Factor for Amazonian Forest Trees. Open Access Journal of Agricultural Research, 5(2). https://doi.org/10.23880/oajar-16000248
TY  - JOUR
TI  - Form Factor for Amazonian Forest Trees
AU  - Aguiar DR, Garcia ML and Cavalcante EA
JO  - Open Access Journal of Agricultural Research
PY  - 2020
VL  - 5
IS  - 2
DO  - 10.23880/oajar-16000248
ER  -