Morphological differentiation across the invasive range in Senecio madagascariensis populations

Vegetation of a hill grassland of the Paititi Natural Reserve (Pampa biome) and early detection of non-native species acting as invasive

Background and aims: Invasive species are the greatest threat to conservation. The objectives of this study were to identify the flora that thrive in a hill grassland of the Paititi Natural Reserve, to perform an early detection of non-native plant species that might be acting as invasive, and to establish the current situation of the native species considered threatened. M&M: Following the altitudinal gradient, 14 sites were selected; the environmental characteristics and cover-abundance of the vascular plant species were recorded in each site. With the collected data, a Principal Coordinate Analysis (PCooA) was performed to group the sites into vegetation units that were later described considering environmental characteristics, identified species and plant community type. Additionally, the threatened species were specified, as well as the most abundant exotic ones, therefore considered invasive.  Results: Total richness reached 370 species, 26.5% corresponding to non-native ones. Thirty threatened species were identified. The PCooA grouped the sites into eight vegetation units. The non-native species considered invasive were Dactylis glomerata, Senecio madagascariensis, Holcus lanatus and Racosperma melanoxylon, these last two reached the highest coverage-abundance values. Conclusions: To conserve biodiversity and minimize the invasion process, management efforts should be focused on monitoring the threatened species and controlling the advance of the non-native species acting as invasive. Early detection of those species in similar environments would be fundamental to facilitate rapid responses towards reducing invasions.