Lava Flow by Julia and Briana

We're Julia and Briana, and we live on the island of Hawai'i, where lots of lava can be found! Lava flows are very unique environments. They look like a cross between the moon and a gigantic parking lot! Even though volcanoes have been erupting here for thousands of years, much of the big island is full of green plants. We stopped by the Volcanoes National Park Visitors Center to find out how that could be. Our question: How do plants return to an area wiped out by a lava flow?

What did we do?
To learn more about plants growing on lava flows, a park ranger suggested we walk the Mauna Ulu flow, which was active 40 years ago. Lava flows are very unique environments. They look like a cross between the moon and a gigantic parking lot! We soon spied the two kinds of lava: pahoehoe, which is smooth, and a'a, which is rough and jagged. We also noticed patches of jungle right in the middle of the flow. These patches of plants and trees, which the lava flowed around, but didn't harm, are called kipuka. We noticed three kinds of native plants in the kipuka: kupukupu ferns, ohelo berries, and ohi'a trees. We decided to look for these same plants around the Manua Ulu flow.

What did we find out?
We kept detailed field notes about the plants we saw on the lava flow. Then we took our notes back to the Visitor Center to analyze them with the park ranger. We saw smaller versions of the three kinds of plants we saw in the kipuka sprouting up sporadically through cracks in the lava. The ranger told us that birds eat the ohelo berries and spread the seeds in their poop. The kupukupu ferns and ohi'o tree seeds are spread by the wind. We were curious, how long until plants grow back after an active lava flow? Sounds like another DFTV investigation!

What can you do?

• A caldera is the name for the crater that develops when an underground lava pool empties, causing the ground above to collapse. You can model this process by putting a balloon under a mound of flour, all held in a large plastic tube. When you deflate the balloon, the flour above it sinks into a caldera. See if the caldera appearance changes if you use sand instead of flour.
   
  
• Ever notice plants growing out of cracks in concrete or pavement? Do a study of the kinds of plants that are able to take root in those cracks. Then look around for the plants that they probably came from. How did plant seeds get into the cracks? Does one kind of plant appear in those cracks more often than another?
   
  

	Go to the DFTV Boards, and tell us about your science investigation.