Assessing Naturalness Changes Resulting from a Historical Land Use in Brazil South Region: An Analysis of the 1986-2016 Period

Ivan Luís Rovani,José Eduardo Dos Santos,Vanderlei Secretti Decian,Elisabete Maria Zanin

doi:10.4236/jep.2019.102010

Abstract

The effects of land use and cover changes and the application of the Urbanity Index were analyzed to identify critical or non-critical naturalness scenery in the Northern Region of Rio Grande do Sul (Brazil), over a period of 30 years. Between 1986 and 2016, the main significant land use change was the reduction of the agricultural anthropic and the increase of the natural vegetation land use areas. About 90% - 80% of the total study areas were characterized by anthropic pattern features, with a predominantly agricultural matrix. The conversion of agricultural anthropic into natural areas resulted in increased naturalness landscape and a gain in the stock of natural capital. The increase in the natural vegetation area, mainly to the north and east of the region, set in a steep relief, became remarkable after 1990. The Urbanity Index values evidenced a highest naturalness condition (natural vegetation areas) to the northern and eastern, while a smaller naturalness condition (agricultural and non-agricultural areas) to the southern and western and central of the Northern Region of Rio Grande do Sul. These changes are related to a non-impaired (northern and eastern) and a impaired scenery (southern, western and central portion) of the ecological sustainability of the Northern Region of Rio Grande do Sul, after a 30-year period (1986-2016). These results pointed out that land use transitions resulted in a consolidated farming scenario in which agricultural intensification coincided with the reduction of farming area and increased naturalness as a reverse trend to the agricultural frontier dynamics.

Highlights

The intensification of changes in land use and cover has been associated with one of the key aspects of socioeconomic development [1] [2] [3], as well as one of the factors responsible for changes in environmental conditions [4] [5].The conversion of natural vegetation into agricultural anthropogenic uses on a global scale has been pointed out as the main direct factor of pressure on biodiversity and ecosystem services losses, and the emission of greenhouse gases [6] [7], especially when related to the loss of naturalness [8] and forest fragmentation [9]
Over a 30-year period (1986-2016), a process of land appropriation was observed, with anthropic agricultural land use constituting the main responsibility of causing changes in the landscape composition of the Northern Region of Rio Grande do Sul
The landscape spatial composition resulting from the conversion and substitution of one land use type by another configured an increase in the stock of natural vegetation immersed in a predominantly anthropic matrix, with agriculture and bare soil as the most representative land cover types

Summary

Introduction

The conversion of natural vegetation into agricultural anthropogenic uses on a global scale has been pointed out as the main direct factor of pressure on biodiversity and ecosystem services losses, and the emission of greenhouse gases [6] [7], especially when related to the loss of naturalness [8] and forest fragmentation [9]. In this sense, the condition of naturalness for biodiversity and ecosystem services’ maintenance are fundamental to ecological sustainability, in order to support the resilience of ecosystems [10] [11]. The concept is increasing in importance in some reports, it is almost completely peculiar in others reports [16] [17]

Methods

Results

Conclusion