Chemical and biochemical properties of Araucaria angustifolia (Bert.) Ktze. forest soils in the state of São Paulo

Fernanda De Carvalho,Fatima Maria De Souza Moreira,Elke Jurandy Bran Nogueira Cardoso

doi:10.1590/s0100-06832012000400013

Fernanda De Carvalho, Fatima Maria De Souza Moreira + Show 1 more

Open Access

https://doi.org/10.1590/s0100-06832012000400013

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Abstract

Araucaria angustifolia, commonly named Araucaria, is a Brazilian native species that is intensively exploited due to its timber quality. Therefore, Araucaria is on the list of species threatened by extinction. Despite the importance of soil for forest production, little is known about the soil properties of the highly fragmented Araucaria forests. This study was designed to investigate the use of chemical and biological properties as indicators of conservation and anthropogenic disturbance of Araucaria forests in different sampling periods. The research was carried out in two State parks of São Paulo: Parque Estadual Turístico do Alto do Ribeira and Parque Estadual de Campos de Jordão. The biochemical properties carbon and nitrogen in microbial biomass (MB-C and MB-N), basal respiration (BR), the metabolic quotient (qCO2) and the following enzyme activities: β-glucosidase, urease, and fluorescein diacetate hydrolysis (FDA) were evaluated. The sampling period (dry or rainy season) influenced the results of mainly MB-C, MB-N, BR, and qCO2. The chemical and biochemical properties, except K content, were sensitive indicators of differences in the conservation and anthropogenic disturbance stages of Araucaria forests. Although these forests differ in biochemical and chemical properties, they are efficient in energy use and conservation, which is shown by their low qCO2, suggesting an advanced stage of succession.

Highlights

Mixed ombrophilous forests, known as Araucaria forests, represent a vegetation type of the Atlantic Forest biome
The following Araucaria forests were selected in PETAR (P): 1) Natural forest (NF) on a red-yellow latosol, with a great flora diversity, where Araucaria grows beside centennial trees, such as Ocotea spp., Nectandra spp., Cedrella fissilis Vell., Ficus spp., Hymenaea courbaril L., Virola oleifera (Schott) A
The soil of this forest was classified as Haplic Cambisol; 3) Anthropogenically influenced natural forest (ANF)

Summary

Introduction

Mixed ombrophilous forests, known as Araucaria forests, represent a vegetation type of the Atlantic Forest biome. The main constituent of these forests is Araucaria angustifolia (Bert.) O. Due to its timber quality, this species has been heavily exploited for many years, resulting in the fragmentation of the existing forests, which caused the Brazilian Institute of Environment and Renewable Natural Resources (Instituto Brasileiro do Meio Ambiente e Recursos Naturais Renováveis) (IBAMA, 1992) to classify Araucaria as a Brazilian tree species at risk of extinction. It is estimated that the remaining Araucaria forests, either in early or advanced succession stages, cover no more than 0.7 % of the original area (Brasil, 2002), making this vegetation type one of the most threatened phytophysiognomies of the Atlantic Forest Biome (Medeiros et al, 2005)

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