Microbial and soil properties in restoration areas in the jequitinhonha valley, Minas Gerais

Danielle Cristina Fonseca Santos,Enilson De Barros Silva,Lidiomar Soares Da Costa,Hesmael Antônio Orlandi Costa,Alexandre Christófaro Silva,Paulo Henrique Grazziotti,Aldo Vilar Trindade

doi:10.1590/s0100-06832011000600035

Danielle Cristina Fonseca Santos, Enilson De Barros Silva + Show 5 more

Open Access

https://doi.org/10.1590/s0100-06832011000600035

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Abstract

To mitigate the impacts of eucalypt monoculture, forestry companies in the Upper Jequitinhonha Valley (MG) have adopted the insertion of strips of native vegetation in-between the commercial plantations. The method used for the creation of these corridors is to allow spontaneous regrowth of native vegetation in areas previously under eucalypt. The objective of this study was to evaluate the effect of cover crops on microbial and soil properties for a detailed description of the restoration process of native vegetation in forest soils of the Jequitinhonha Valley. The treatments were represented by an initial restoration stage (< 4 years) with or without remaining eucalypt and the advanced restoration stage (> 4 years) with or without remaining eucalypt, plus the three controls: commercial eucalypt plantation, Cerrado vegetation and native forest. Soil samples were collected for three consecutive years in the dry and rainy season (August and February, respectively). The microbial activity, regardless of the presence of remaining eucalypt , did not differ among the restoration areas, except for the metabolic quotient (qCO2) in the rainy season of February 2007. At this time, this microbial activity was higher in the advanced restoration stage without eucalypt than initial restoration without eucalypt and advanced restoration with eucalypt. The restoration areas, in general, did not differ from the control: eucalypt plantation and Cerrado either. Compared to the forest, the levels of organic C, microbial C, basal respiration (Rbasal) and hydrolysis of fluorescein diacetate (FDA) in the restoration areas were, in general, lower and did not differ in qCO2 and microbial quotient (qMIC). In general, the soil quality was similar in the initial and advanced restoration stages. Most of the soil and microbial properties in the three years indicated that the restoration areas were most similar to the Cerrado. In the advanced restoration areas without eucalypt compared to Cerrado, the lower Rbasal in the 3rd year and the lower FDA and qMIC and higher qCO2 in the 2nd year indicated that the removal of the remaining eucalypt trees was unfavorable for restoration.

Highlights

Companies of the forest sector have been implementing new methods to reduce the negative impacts of monoculture, resulting in the insertion of areas with native vegetation in-between commercial plantations
The method used to create these areas in the Upper Jequitinhonha valley (MG) is the spontaneous regrowth of native vegetation in areas of previous eucalypt cultivation, where the presence of remaining eucalypt trees is common
As there is no information about spontaneous vegetation restoration on forest soil in the Upper Jequitinhonha valley, appropriate ecological indicators are required that reflect the disturbance degree in ecosystems and the stage of the restoration process

Summary

Introduction

Companies of the forest sector have been implementing new methods to reduce the negative impacts of monoculture, resulting in the insertion of areas with native vegetation in-between commercial plantations. Studies have demonstrated that spontaneous restoration is appropriate to regain the sustainability of previously cultivated areas (Behera & Sahani, 2003; Nappo et al, 2004). In this way, vegetation can recover from disturbances if secondary forest is allowed to grow in open areas where plant species naturally replace each other while ecological conditions are improved. Vegetation can recover from disturbances if secondary forest is allowed to grow in open areas where plant species naturally replace each other while ecological conditions are improved These changes go on, until a well-structured and stable community is established (Martins, 2001). The analysis of microbial and biochemical indicators of soil quality is needed to obtain relevant information about soil functions and their performance in nutrient recycling and storage

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