Assessment of alien invasive plant species along a distance gradient from dip tanks in a Highveld Area

Abstract

Long term dip tank use for livestock health management results in piosphere formation which presents a conducive environment for the proliferation of alien invasive plants. These invasive plants can alter soil edaphic properties, out-compete indigenous species, and change ecosystem functions, ultimately leading to rangeland degradation. Therefore, assessments of alien plants around dip tanks provide basis for studying their impact on rangelands. The objective of this study was to establish an inventory of alien plants around dip tanks. The assessments were conducted at three dip tanks in Marondera, Zimbabwe. A 1000 m transect was laid at the edge of each dip tank, and measurements on both woody and herbaceous species were taken at 50, 100, 200, 400 and 800 m along the transect. Results indicated that the common alien species were Lantana camara, Oxalis latifolia, Tagetes minuta, Cassia rotindifolia, Richardia scabra, Bidens pilosa and Datura stramonium. At all dip tanks there were significant differences (P<0.05) in L. camara density as well as richness of herbaceous species other than alien invasives. Significant differences (P<0.05) were also observed for C. rotindufolia, R. scabra, and D. stramonium. The results indicated the proliferation of invasive plants along a distance gradient from dip tanks. Therefore, early management of invasive species is recommended in order to curb serious long-term adverse impacts