May 15, 2019
Mimosa (Mimosa pigra) and Olive Hymenachme (Hymenachne amplexicaulis) are the most serious environmental weeds found in the Arafura Swamp region. Both are wetland invaders with the potential to irrevocably change the swamp’s ecosystem. While Mimosa is currently under control, Olive Hymenachme continues to spread, threatening not only wildlife but traditional economies based on the wetlands.
Upland areas are threatened by Mission grass (Cenchrus polystachios), Grader grass (Themeda quadrivalvis) and Gamba grass (Andropogon gayanus). These introduced grasses out-compete native grasses and increase fuel loads, resulting in more intense fires and the loss of fire-sensitive understory species, the death of mature trees and general loss of biodiversity. By altering fire regimes invasive grasses have the potential to disrupt lucrative and environmentally important savanna carbon projects. Through vigilance and priority eradication of outbreaks along roads ASRAC Rangers have to-date managed to control these grassy weeds.