The Banaue Rice Terraces in the northern Philippines are considered as the world's eighth wonder. But a new study says a bigger culprit is tourism. Actually an old problem, the earthworm menace has worsened since the early 1990s when water for the rice terraces began to dwindle. Some 300 kilometres north of Manila, the rice terraces are carved around steep mountains in Banaue town in Ifugao Province, one of six upland provinces in Luzon island's Cordillera region.
Earthworms reproduce more with less water.
The more earthworms there are, the more water is lost. As the topsoil dries up with the lack of water, the earthworms go deeper into the soil as they seek areas that are still moist. Water seeps through the holes earthworm bore, causing the soil and terrace walls to dry up and crack. Tourism has encouraged the commercial production of woodcarvings and handicrafts and this helped deplete local forest resources,' said the study. The study added that with a highly commercialised woodcarving industry, even Ifugao's indigenous forest and watershed management system is disintegrating.