Invasion status of alien weeds in the historical Chobhar area of Kathmandu valley, Nepal.
Invasive alien weeds in Nepal have become a great problem. Many of them have been naturalized and threatening native ecosystems and biodiversity. This assessment was carried out to measure the density, frequency and coverage of four major invasive weeds in a historical place, Chobhar of Kathmandu, Nepal. It was found that Ageratina adenophora had the highest density, frequency, and cover in the Pine forest. Similarly, Ageratum conyzoides, Bidens pilosa, and Parthenium hysterophorus were dense and frequent with high cover along the roadside. The frequency of B. pilosa and P. hysterophorus was comparatively high in the fallow land. It shows that the ecological parameters of the particular invasive alien weeds vary with land-use types and aspects. These weeds should be regularly monitored and appropriate methods of controlling them should be implemented in the study area.