Robust volumetric models for supporting the management of secondary forest stands in the Southern Brazilian Atlantic Forest.

Laio Z Oliveira,Heitor F Uller,Alexander C Vibrans,Alfredo C Fantini,Aline R Klitzke,Jean Correia

doi:10.1590/0001-3765201820180111

Abstract

The majority of Atlantic Forest fragments in Southern Brazil are second-growth forests dominated by fast-growing species with considerable market-value timber. Nevertheless, volume prediction models are scarce, especially to estimate tree total volume (i.e., stem plus branches). This study approached the issue through the following aims: to fit and select stem and total volume models (generic and species-specific) using data from 288 harvested trees in a management operation, and to fit generic and species-specific bark factors. The power model embedding diameter at breast height (D) and tree stem or total height (H) presented the greatest prediction strength for both stem and total tree volume. Models including only D to predict total tree volume were similar to double-entry models regarding goodness-of-fit. Therefore, they may be useful in the context of subtropical closed-canopy forests, where the difficulty and uncertainty in H measurements are not trivial. Species-specific models fitted for Miconia cinnamomifolia (DC) Naudin. and Hyeronima alchorneoides Allemão surpassed generic models only for the former species. Nevertheless, the prediction improvement should offset the eventual extra efforts implied in the collection of reliable samples of these species. Finally, bark factors stood as a satisfactory tool for inside bark mean volume estimation.

Highlights

Among all Brazilian vegetation domains, the Atlantic Forest suffers the greatest impact from human activities driving forest fragmentation and degradation (Ribeiro et al 2009)
Santa Catarina, in Southern Brazil, is privileged― approximately 29% of its territory is covered by native forests (Vibrans et al 2013), which in turn is divided into three main forest types/subdomains: evergreen rainforest (ERF), Araucaria forest, and seasonal deciduous forest (Klein 1978)
The generic models for total tree volume presented inferior performance compared to the stem volume models

Summary

Introduction

Among all Brazilian vegetation domains, the Atlantic Forest suffers the greatest impact from human activities driving forest fragmentation and degradation (Ribeiro et al 2009). The fragments’ extent varies widely within the states where the Atlantic Forest is found In this regard, Santa Catarina, in Southern Brazil, is privileged― approximately 29% of its territory is covered by native forests (Vibrans et al 2013), which in turn is divided into three main forest types/subdomains: evergreen rainforest (ERF), Araucaria forest, and seasonal deciduous forest (Klein 1978). Santa Catarina, in Southern Brazil, is privileged― approximately 29% of its territory is covered by native forests (Vibrans et al 2013), which in turn is divided into three main forest types/subdomains: evergreen rainforest (ERF), Araucaria forest, and seasonal deciduous forest (Klein 1978) In this state, forests are usually very fragmented, with 80% smaller than 50 ha. Notwithstanding, most of these remnants (~95%) are composed by second-growth forests, where pioneer and early secondary species dominate the successional process (Siminski and Fantini 2004, Schorn and Galvão 2006)

Objectives

Methods

Results