Simulating Araucaria angustifolia (Bertol.) Kuntze Timber Stocks With Liocourt’s Law in a Natural Forest in Southern Brazil

Abstract

This paper presents a simulation of the regulation of Araucaria angustifolia (Bertol.) Kuntze timber stocks using Liocourt’s law. Although this species is currently protected by law, recent government initiatives are being considered to propose sustainable forest management practices by selecting small rural properties in Southern Brazil. Here, we simulate the applicability of Liocourt’s law in a typical rural property, the size of which is approximately 85 ha. Forest inventory measurements were conducted by estimating the diameter at the breast height (d), total height (h), and annual diameter increments of 308 trees that fit the criteria of d ≥ 10 cm, distributed on 35 permanent plots of 400 m2 each. As a result, a reverse J-shaped d distribution was found. On average, 303 trees can be found per hectare (ha). Local allometric equations showed their basal area (G) to be 21.9 m2∙ha−1, and their commercial volume (V) to be 172 m3∙ha−1, whereas Liocourt’s quotient (q) was 1.31. Based on these attributes, nine different forest management scenarios were proposed by simulating a remaining basal area (Grem) of 10.0, 14.0, and 18.0 m2∙ha−1, and Liocourt’s quotient was changed to 1.1, 1.3, and 1.5. All scenarios consider a d of 62.5 cm. In the less intensive scenario (i.e., q value = 1.5 and larger basal area of 18.0 m2·ha−1) there is greater optimization of space, and higher economic return is ensured to rural producers due to the definition of shorter cutting cycles. This also allows a faster growth rate in both d and h for smaller trees, due to the higher incidence of light onto the lower canopy layer, increasing the natural regeneration implementation of other native species. Forest management should thus be considered a goal in addition to consumer market characteristics for defining the ideal timber stock scenario.

Age trends in genetic parameters for growth performance across country-wide provenances of the iconic conifer tree Araucaria angustifolia show strong prospects for systematic breeding and early selection

“…angustifolia is currently considered an endangered species at the international level and protected by a 20-year-old law in Brazil (BRASIL, 2001). Although the management of naturally forested areas of this species is mostly forbidden, recent initiatives have proposed that Mixed Ombrophilous Araucaria forests in Southern Brazil can be managed as sustainable sources of environmental, social and economic benefits (Longhi et al, 2018;Arnoni Costa et al, 2020). Clearly, however, much research is still needed to develop solid scientific data to support truly sustainable management strategies for such complex mixed stands subtropical forests, as models for low species diversity, temperate conifer stands, do not necessarily apply (Hess et al, 2018).…”

Simulating Sustainable Forest Management Practices Using Crown Attributes: Insights for Araucaria angustifolia Trees in Southern Brazil

“…In any case, forest management yields better results if it favors the growth of young trees with growth potential that does not require large gaps in the canopy, assuring a higher incidence of light onto the lower canopy layer, keeping more trees growing in the forest. Likewise, regular management actions at reduced intervals allow the formation of healthy trees that are well-distributed on the dimension classes [47].…”

“…The panorama vitality loss of Araucaria crowns and the reduction of growth capacity, coupled with the lack of management protocols currently imposed by the legislation, induces illegal logging. Previous studies reported illegal logging as one of the significant environmental threats besides deforestation and land conversion [47].…”

Fitting Volume Models for Parana Pine With a Nonlinear Regression, Genetic Algorithm and Simulated Annealing

“…Parana pine (Araucaria angustifolia), a characteristic species of the Mixed Ombrophilous Forest (MOF) of the Atlantic Forest biome, is an important coniferous species in southern Brazil of considerable economic importance due to its exceptional wood quality and its high-value edible seeds (Hess et al, 2019, Costa et al, 2020. The species' trunk is highly cylindrical, straight and, rarely, branched into two or more shafts, its bark is thick and resinous, and it also has a unique crown structure (Narvaes et al, 2005;Rodrigues, 2016).…”

“…Due to unsustainable logging and agricultural expansion in past decades, MOF typology have experienced a significant reduction in its original area, culminating in the development of legal barriers for the cutting of Parana pine (Eisfeld et al, 2020). However, several researches have pointed out that these restrictions has not been effective to improve the state of conservation of the species (IUCN, 2021), since the the lack of management in this typology has led to a great increase in competition between trees, impeding natural regeneration and stagnating growth (Beckert et al, 2014;Costa et al, 2020;Hess et al, 2020Hess et al, , 2018aHess et al, , 2018b. Therefore, studies that contribute to the planning of sustainable forest management and conservation of this species are crucial.…”