Bunmei Lava, Showa Lava

You will enter the Bunmei Lava zone just past the bend in the road past the Sonoyama Community Center building《園山公民館》. The Bunmei Great Eruption is the oldest of the four major eruptions, which occurred between 1471 and 1476. The lava in this area flowed out in 1471. The road resembles a graph of ｙ= | 𝑥 |  (though the slope may not be that steep …that’s just how it feels) because of the terrain formed by lava.

 

It may come as a surprise to learn that there was another great eruption with lava outflow in March 1946, shortly after the end of the war. Of course, it was much smaller in scale than the other three. The Showa Crater is where the lava flowed out at this time. That crater is still active now and sometimes erupts. The lava that flowed from the Showa Crater to the east was intercepted by Nabeyama and flowed north-south, and the one that split to the north is on this side. You may be able to see the difference in the recovery of vegetation because the Showa lava belt is beyond the Kurokami Elementary School 《黒神小学校》, but just before them is the Bunmei lava belt.

 

Once buried by lava, vegetation naturally disappears, but it recovers slowly and naturally over time. First, mosses (bryophytes) grow, then silver grass and ferns (pteridophytes), then Japanese black pines, then ring-cupped oaks, then chinquapins and oaks. That goes back to evergreen broadleaved forests. The Showa Great Eruption was only 70 years ago, so you can see that the trees are smaller than the vegetation of the Bunmei lava area, which is more than 500 years old.