Invasive palm image
P.T. Green. Symbols used courtesy of the Integration and Application Network, University of Maryland Center for Environmental Studies

Warmer winter temperatures in the deciduous forests of southern Switzerland in recent years have allowed the invasive palm, Trachycarpus fortunei, to flourish (A), altering the plant composition of the forest. On Easter Island, the introduction of yellow crazy ants by humans during the early 20th century caused the demise of the red land crab, the island's dominant omnivore. As a result, scientists say, the island's rainforest ecosystem shifted from an open (B) to a dense understory (C).