rivers.clone().
addElement(basicTaiga, -1, 0.14f).
addElement(VanillaBiomes.FROZEN_RIVER, 0.14f, 1);
// taiga land
final BiomeSelectorLayer taiga =
frozenOceans.clone().
addElement(subTaiga, -1, 0.4f).
addElement(VanillaBiomes.FROZEN_OCEAN, 0.4f, 1);
// tundra
final BiomeSelectorLayer basicTundra =
hills.clone().