This map shows the major vegetation types in Mexico. Monarch butterflies form their winter colonies in Mexico's rare oyamel forest, shown in black. The oyamel fir trees are found only at high elevations, at least 10,000 feet above sea level. Scientists think monarchs select the oyamel forest because of its unique microclimate. Up high, temperatures are cooler and there is more precipitation than at lower elevations.

• Why is it so important to conserve Mexico's oyamel forests? Include information revealed by this map in your answer.