Impact of invasion: A case study on the ecological and socioeconomic impact of Lantana camara (L.) in Abay Millennium Park (AMP), Bahir Dar, Ethiopia

Lantana camara (L.), a highly aggressive exotic environmental weed in many countries, has significant adverse effects on biodiversity. It forms dense thickets, suppressing native vegetation and seedlings through shading, nutrient competition, smothering and allelopathy. This study was carried out to quantify ecological distribution, abundance and effects of L. camara on different land uses, and to assess the perception of the local community concerning its impacts on environment and biodiversity of the study area, Abay Millennium Park, Bahir Dar. To do so, 20 m x 20 m (trees) and inside which 5m x 5m nest plots (shrubs and saplings), 2mx2m (seedlings) were laid. Vegetation data were collected using purposive sampling technique with quantitative measurements (DBH, density, seedling and sapling count). Furthermore, semi-structured questionnaire was used to collect data about socio-economic and ecological impacts of the plant. Results revealed that L. camara has shown highest invasion (82.1%, grassland) and least invasion (34.6%, riverine forest), cultivated land being intermediate (57.5%). Plant species density was high at the lower class (<6 cm DBH, covering 83.94% of total plants sampled, showing the area was dominated by shrubs (1821 individuals/ha). At species level, L. camara exhibited an inverted J-shaped frequency distribution (62.21%, < 2 cm DBH), screening its greater regeneration potential. Also, there was high diversity and species richness (excluding L. camara) with H’=2.6980 & S=45, natural riverside forest, H’= 1.8173 & S=28 cultivated land, and H’=0.3446 & S=14, grassland. The socio-economic and ecological impact study as well, revealed L. camara was perceived as more disadvantageous (90% of the respondents), and therefore, they highly recommend, if possible, for its complete removal from the area.