Does the Process of Passive Forest Restoration Affect the Hydrophysical Attributes of the Soil Superficial Horizon?

Nayana Alves Pereira,Miguel Cooper,Renata Cristina Bovi,Rafaela Pereira Naves,Gustavo De Godoy,Laura Fernanda Simões Da Silva,Simone Di Prima

doi:10.3390/w12061689

Abstract

There has been an increase in the area of secondary tropical forests in recent years due to forest restoration in degraded areas. Recent analyses suggest that the success of passive forest restoration is highly uncertain and needs to be better understood. This study aimed to investigate the behavior of saturated hydraulic conductivity (Ks) and some hydrophysical soil attributes between agricultural land uses, restored forests, and a degraded forest fragment. The areas evaluated are located in the municipality of Rio Claro, São Paulo, Brazil, under different types of land use: (i) two areas in the process of passive forest restoration: one of 18 and another of 42 years (NR18 and NR42); (ii) a degraded forest fragment (FFD); (iii) pasture (P), and (iv) sugarcane (SC). The hydraulic soil conductivity characterization was performed using the Beerkan method. Dry soil bulk density (BD), total porosity (Pt), macroporosity (Mac), microporosity (Mic), penetration resistance (PR), mean aggregate diameter (MWD), and soil organic carbon (OC) were also determined. The comparative analysis of the hydrophysical attributes of the soil superficial horizon in agricultural land uses (P and SC), restored forests (NR18 and NR42), and a degraded forest (DFF) confirms that the recovery of soil hydrological functioning in ongoing forest restoration processes can be a relatively slow process. In addition, the intensity of previous land use leaves footprints that can affect passive restoration areas for decades after agriculture abandonment, increasing the time for the recovery of Ks and soil hydrophysical attributes.

Highlights

A substantial increase in the area of secondary tropical forests has been occurring in the last 20 years [1,2]
That the impact of passive restoration on the soil hydrophysical functioning is still little known, this study aimed to answer the following question: Is passive restoration capable of improving soil Ks, as well as the physical attributes of the soil superficial horizon? To answer this question, we investigated the behavior of Ks and some soil physical attributes of the soil superficial horizon in forests of different ages undergoing passive restoration by natural regeneration, a degraded forest fragment, a pasture, and a sugarcane field
Among the different types of land use studied in this investigation, there were statistically significant differences for the variables Ks, Mic, penetration resistance (PR), means weight diameter (MWD), and organic carbon (OC) (Table 2 and Figure 3)

Summary

Introduction

A substantial increase in the area of secondary tropical forests has been occurring in the last 20 years [1,2]. Especially those that have not been subjected to many years of monoculture, are recovered using passive restoration techniques. One of these techniques is natural forest regeneration, which takes advantage of the resilience of degraded areas by stimulating the germination of local seed banks, seed dispersal processes, regrowth of trunks, or seedlings that resisted the disturbances. Soil is the substrate for forest restoration, and the knowledge of its functioning is essential for understanding and managing restoration processes

Objectives

Methods

Results

Discussion

Conclusion