(CNN) — Lake Naivasha, northwest of Nairobi, Kenya is becoming increasingly unnavigable. Water hyacinth, the world’s most widespread invasive species, is blanketing the lake, choking its fish and ...

More than 2,500 plant species have the potential to invade the Arctic at the expense of the species that belong there. Norway is one of the areas that is particularly at risk.

Many mountain ranges contain semi-natural habitats that have been little human interference. They are home to many animal and plant species, some of them endemic and highly specialized. Mountains have ...

Introduction: Nonnative species in the world / David Pimentel -- The impacts of alien plants in Australia / Richard H. Groves -- Environmental and economic costs of invertebrate invasions in Australia ...