A transformação da paisagem pastoril no Parque Natural Montesinho (1995 – 2022)

Abstract

Analyzing the transformation of agricultural and forestry uses of a territory is one of the most commonly used approaches to understand the effect of factors such as climate change and human activities on the evolution of a landscape. With this in mind, this study evaluates the evolution of the pastoral landscape in Montesinho Natural Park through the interpretation of aerial photographic records taken at different dates, aiming to quantify the main changes in land use and occupation of grazing areas from 1995 to 2021. The study was divided into two stages. The first stage involved adjusting the Map of Natural and Semi-Natural Vegetation of PNM (1995) to the current geometry of land structure, specifically using the geographic database known as "parcelário" provided by the installment identification system (iSIP), supported by orthophotos from 1995. The purpose of this stage was to correct and adjust the geometry of different land uses and occupations. The second stage was conducted to update the same cartography, using orthophotos from 2021 of the same area observed in the previous stage, in order to obtain the evolution of land use and occupation over these 26 years. The results were confirmed through field visits and interpretations of images from Google Earth Pro, during diferente seasons of the year. The findings allowed the creation of a transition matrix between these dates, enabling the interpretation of the trend of these transformations and extrapolating it to an equal future period (2047). The main transformations observed in the agricultural matrix were the replacement of rain-fed crops (-53%) by the establishment of perennial agriculture, such as chestnut (41%) and olive (3%). In the forestry matrix, there was na increase in oak forests (18%) and broom shrubs (30%), resulting from the depopulation of the studied region. If this transformation trend continues over the next 26 years, it will require protective measures from the management of PNM concerning both the landscape and the population, as well as investments in the agricultural matrix, particularly regarding the increased risk of wildfires associated with extreme phenomena linked to climate change.