Plant and animal diversity
Tierra Alta is an oak forest with an occasional pine tree. However, there is unusual biodiversity in both the plants and animals of this region – Mexico has more than 100 species of oak and 39 different pines. At Tierra Alta, a variety of wild orchids bloom in the spring, as do bromeliads and other epiphytes. There are many plant species endemic to the area.
This is because the Sierra Madre Occidental Mountains reach their endpoint very near Puerto Vallarta, leaving large gaps in mountain elevations. The mountains then resume their march to the south as the Sierra Madre del Sur range, well to the south of El Tuito, ultimately reaching the southern Mexican states of Guerrero and Oaxaca.
The unusual number of endemic species in this area is the result of isolation caused by the almost complete separation of the western Sierra Madre range from the Sierra Madre del Sur to the south. This gap has caused uniquely favorable ecological conditions for endemic species. Within the Jalisco coastal area alone, there are 18 mammal species endemic to Mexico, meaning they occur in no other country.