Visiting Isla Isabela in the Galápagos Archipelago

Volcano Trip On Horseback (continued)

Hiking across the raw volcanic terrain of the Sierra Negra volcano, at the "business end" of the volcano.

Our intrepid group of explorers about to set out across the bleak moonscape.   Far in the distance I spotted another tour group wandering across the stark terrain. That part of the volcano has almost no vegetation since it's the secondary crater that was most recently active.

Richar led us a short distance through some dense brush and when we emerged from the underbrush we took in a startling scene—the wild, alien, moonscape of a recently active volcano crater. The terrain was very hummocky and hilly, and very rough and uneven. The surface was mostly rough, jagged lava rocks, ranging in color from black to reddish-brown, with lava tubes, collapsed tubes, collapsed lava chambers, tall cinder cones, and deep pits of fumaroles. Adding to the surreal appearance, the rain increased and became a steady downpour; ragged gray and white clouds drifted across the landscape.

The volcanic landscape wasn't completely barren; in fact, there were plants growing here and there. These were the endemic species, that over millions of years have adapted to the very harsh conditions on the volcanic islands. According to Richar, in the harshest environments, only the specialized endemic species can establish a toehold. Once they colonize an area, other native species move in, followed finally by the introduced species. People brought the introduced species to the islands mostly for agriculture or as ornamental plants, so the introduced species are not adapted to the harsh volcanic environment. But they are good at opportunistically invading a favorable habitat that has been painstakingly established by endemic and native species. As Richar explained to us, endemic species are found only in the Galápagos, native species grow here naturally but are also found elsewhere, introduced species have been brought to the islands by man and normally grow elsewhere. Much of the fertile highlands has been taken over by introduced species, which can out-compete the more specialized endemic and native species.

Some of the plants we saw out on the volcano crater.

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