Changes in shrub invasion in South America protected temperate native forests

Abstract

Detecting invaded areas and mapping the extent and spatial pattern of invasive plants are important. The aim of this work was: a) to know the spatial changes in the invasion of shrub species protected by temperate native forests of the Mesopotamian Spinal using statetransition models, and b) to establish a future prediction model on the level of shrub invasion depending on the intensity of the current cattle grazing system. The study was carried in Protected Area ‘El Caraya’ (Argentina), hereinafter, PA ‘El Caraya’. Field sampling was carried out with 85 sites in 2011 and 82 sites in 2018 both located randomly and geo-referenced with GPS. At each sampling point, the level of shrub invasion was recorded. To map the distribution of shrub invasive classes, we obtained two Landsat images recorded on 2011 and 2017. Changes in the level of shrub invasion were evaluated with the change analysis model and the future trend using the Markov model. More than 30% of the PA ‘El Caraya’ territory did not present changes in the levels of shrub invasion, which indicates that the structural components such as herbaceous, shrub and tree are balanced. The results of this research have shown that remote sensors are a simple and useful tool that allow us to know what the spatial changes in the levels of invasion of shrub species in protected temperate native forests of southern South America, as was also possible to predict the future state under the same conditions of the study period.