Figure 1. Volcanically active islands of the Mariana Arc. A. Remains of a Japanese Zero at the former airfield on Pagan in the northern Mariana Islands. Grazing by feral cattle prevents trees from invading the field. Casuarina equisetifolia dominates the adjacent forest, while the active volcano, Mt. Pagan, dominates the skyline. Despite considerable recent volcanic activity, Pagan possesses the most diverse flora of the islands in the uninhabited northern archipelago. B. By contrast, the nearby island of Anatahan is blanketed in a thick layer of volcanic ash that has smothered its once lush vegetation. Extensive collections of plants from these and the other Mariana Islands are housed in the Guam Herbarium. Credits: Photo A, A.M. Kerr; Photo B, T. Schils.