Levantamento de plantas invasoras na província de Manica e modelação da distribuição potencial da vernonanthura phosphorica

Abstract

Invasions by exotic species have raised great concern worldwide, as they constitute the greatest threat to biodiversity loss. In Mozambique, these species are mostly introduced intentionally and for commercial purposes, as was the case with Vernonanthura phosphorica. However, there are no studies in the country on their actual distribution and impacts. Therefore, this research was conducted with the aim of evaluating the distribution of invasive species along the highways of Manica province and identifying areas prone to invasion by V. phosphorica at a national level. The study was carried out in May 2023, following access roads to the districts of Gondola, Manica, Sussundenga, Mossurize and Machaze, where surveys of tree, shrub and herbaceous species were carried out on a plot of 1000 m2 (50 m x 20 m). For the first two groups of plants, the diameter of the height at the base (DBH) criterion was used, including those with DBH≥5 cm, and the rest were counted and recorded. For the last group, a 1 m x 1 m grid was used, where they were launched 10 times at each point. The recorded plants were identified and classified as invasive and non-invasive, describing their growth habits, distribution and determining their phytosociological indices. A total of 162 species distributed across 131 genera and 43 families were inventoried. Of the species recorded, 90 are herbaceous, 31 are shrubs and 41 are trees, of which 40 are invasive. The families Fabaceae, Poaceae and Asteraceae were those that recorded the largest number of species with 36, 32 and 17 respectively. Among the herbaceous species, Hyparrhenia hirta was the most frequent (10.65%), the most abundant and registered the highest importance index (13.15%), and the species Lasiacis divaricata was the one with the greatest coverage (76 to 100%). Among the tree species, Vernonanthura phosphorica was the most frequent (9.52%), the one with the greatest coverage (57.06%) and the most important (69.92%). Julbernardia globiflora was the one that showed the greatest dominance (36.34%) in relation to the other plants observed. Currently, the area potentially prone to invasion by this species in the country is estimated at around 30.71%, and could reach 32.65% in 2050, if measures are not taken to control it (TRADUÇÃO NOSSA)