Santa Cruz
Today we had the opportunity to visit Santa Cruz Island. It is the most humid and lush of all the places we have been. While we rode the bus up to the highlands we saw a variety of plants of which some were introduced and some were endemic. The story of how these plants got here is quite fascinating. Being volcanic in origin, the Galápagos Islands were basically just barren lava for a longtime. Yet these islands are now populated by several hundred different kinds of plants. In the case of the introduced plants, they are the result of human involvement. Some of these plants were brought here to provide food, while others were introduced for ornamental reasons. Still others arrived purely by accident.
The endemic and native flora of the Galápagos Islands is disharmonic in composition regarding their arrival and establishment. This means that certain types of plants known for their long-distance dispersal abilities are typically present in great numbers in comparison to those with poor dispersal techniques. For example, we observed several fern species today and they were just a handful of the 100 species found in the Galápagos. Ferns are plentiful here because their spores are easily carried by the wind. Some other plant families are highly represented because their seeds are a favorite food for many birds. Or, plants with seeds that are sticky and can be transported easily on birds’ feathers. On the other hand, palms are rare on these islands because their seeds can not withstand long distance ocean travel.
This phenomenon of disharmony is also seen in the animals that are found on Galápagos. Here reptiles “rule” and there are fewer mammals than one might expect. Seeing the giant tortoises, for which the islands were named, in the lush green pastures of the highlights of Santa Cruz today was a definite highlight.
Today we had the opportunity to visit Santa Cruz Island. It is the most humid and lush of all the places we have been. While we rode the bus up to the highlands we saw a variety of plants of which some were introduced and some were endemic. The story of how these plants got here is quite fascinating. Being volcanic in origin, the Galápagos Islands were basically just barren lava for a longtime. Yet these islands are now populated by several hundred different kinds of plants. In the case of the introduced plants, they are the result of human involvement. Some of these plants were brought here to provide food, while others were introduced for ornamental reasons. Still others arrived purely by accident.
The endemic and native flora of the Galápagos Islands is disharmonic in composition regarding their arrival and establishment. This means that certain types of plants known for their long-distance dispersal abilities are typically present in great numbers in comparison to those with poor dispersal techniques. For example, we observed several fern species today and they were just a handful of the 100 species found in the Galápagos. Ferns are plentiful here because their spores are easily carried by the wind. Some other plant families are highly represented because their seeds are a favorite food for many birds. Or, plants with seeds that are sticky and can be transported easily on birds’ feathers. On the other hand, palms are rare on these islands because their seeds can not withstand long distance ocean travel.
This phenomenon of disharmony is also seen in the animals that are found on Galápagos. Here reptiles “rule” and there are fewer mammals than one might expect. Seeing the giant tortoises, for which the islands were named, in the lush green pastures of the highlights of Santa Cruz today was a definite highlight.
