of the Monarch Butterfly's Forest in Mexico
These maps show the changes in the monarch forest from 1971 to 1999.
"What in 1971 was nearly continuous high quality forest is now a series of islands with large spaces of degraded forest between them. This study of aerial photographs taken in 1971, 1984 and 1999, shows that 44% of conserved, dense forests were degraded between 1984 and 1999," say Dr. Lincoln Brower and Monica Missrie, World Wildlife Fund-Mexico.
"Causes for this forest degradation are multiple, including excessive and illegal commercial logging, wood harvesting for domestic use, forest conversion to agriculture, and damage from periodic fires. These multiple negative effects on the oyamel forest ecosystem are incompatible with the needs of the monarch butterfly and, over the long term, those of the local inhabitants as well."
in Personal and Social Perspectives
National Geography Standards