Foreign invasive plants[edit]
In 2014, there are as many as 25 non-native plants in Mount Semeru National Park, which threaten the endemic local plants. The foreign plants were imported by a Dutch botanist named Van Steenis, in the colonial era. They include Foeniculum vulgare mill, Verbena brasiliensis, chromolaena odorata, and Salvinia molesta.[5]
Vegetable plantations[edit]
Mud erosion from surrounding vegetable plantations are also making problem of silting of Ranu Pane Lake, which the lake becomes smaller and shallower. Research predicted the lake will disappear in about 2025, except the kind of vegetables plantation is replaced with more ecological plantations.[6]