Equations to Estimate Tree Gaps in a Precision Forest Management Area the Amazon Based on Crown Morphometry

Abstract

The precision forest management technique still has much to be improved with the incorporation of forest biometric techniques and forest profiling with airborne LIDAR. When planning the cutting of a tree in forest management, the volume to be produced for industry is estimated but not the area impacted by removal of the tree. The objective of the present study was to develop equations for the Amazon rainforest that are able to estimate the impact area of gaps from harvesting individual dominant and co-dominant trees based on the canopy morphology obtained through forest profiling. On two separate occasions profiles were made in an annual forest-production unit in the Antimary State Forest (FEA) in the state of Acre, Brazil. The first was done a few days before the start of logging in 2010 and the second was done after completion of harvest activities in 2011. With field measurements and processing of the cloud of LIDAR points, dendrometric and morphometric variables were obtained for the canopy in order to develop equations for estimating gap areas. After evaluation of the explanatory variables with the highest correlation with gap area, the method used considered all possible models and included 2-4 parameters. The explanatory variables that best represent the impact of clearings are volume of the crown (VCop) and crown-projection area (APC). Ten equations were selected, of which two were chosen for use; these had R2 aj > 75% and Syx <23%. The good fit of the equations demonstrates the potential use of LIDAR to obtain information for estimating in advance the gaps in the forest cover that will be created from harvesting trees of different sizes.

Forest complexity drives dung beetle assemblages along an edge‐interior gradient in the southwest Amazon rainforest

“…available area, fragmentation patterns) where local conditions do not allow the use of the proposed sample design. Our study represents such a case because the large proportion of bamboo (Aquino et al ., ) and the occurrence of small clearings (Figueiredo et al ., ) within the forest prevented us from using the proposed distance of 100 m between pairs of traps. Moreover, da Silva and Hernández () did not evaluate movement patterns of dung beetles along forest edges.…”

“…Logging takes place from June to September. The clearings caused by planned logging ranged from 406.3 to 1238.4 m 2 with a mean ± SE value of 526.28 ± 45.89 m 2 (Figueiredo et al, 2017). The clearing consists of an abandoned timber processing area (09 ∘ 19 ′ 53 ′′ S, 68 ∘ 19 ′ 08 ′′ W, 220 m a.s.l., 3.600 m 2 ) with a road running through it.…”

Morfometria de copa en <i>Prosopis alba</i> Griseb.

“…Fuente: Autores (2018) Source: Authors 2018Por su parte, Figueiredo et al (2014) encontró que las variables morfométricas son una herramienta útil para desarrollar ecuaciones capaces de estimar con precisión el volumen del fuste de árboles dominantes y co-dominantes en bosques tropicales. Recientemente, Figueiredo et al (2017), desarrollaron ecuaciones para estimar el área de claros individuales de árboles dominantes y codominantes a partir de la morfometría de la copa, encontrando que las variables explicativas que mejor estiman los claros son el volumen de copa (VCop) y el área de proyección de la copa (APC). El ajuste con ecuaciones demuestra el potencial y la practicidad que tienen las variables morfométricas para obtener información de importancia en el manejo de la masa (estimar claros, volúmenes de árboles, estabilidad, vitalidad) a partir de variables sencillas de medir.…”

“…Estudios de morfología de copas efectuados por Assmann (1970) cuantificaron la eficiencia de las copas en cuanto al incremento volumétrico del árbol, quedando demostrada la mayor viabilidad de copas largas y estrechas para el crecimiento del árbol. Por su parte Figueiredo et al (2017) muestran el potencial predictivo que presentan variables morfométricas, sobre todo el volumen de copa, ya que esta información está directamente relacionada con el dominio espacial del árbol en el entorno forestal. En la figura 7-A, se observan las líneas de regresión para volumen de copa según la posición social.…”