|
Golden eagles graciously soar over tall pine trees as tiny broad-handed moles burrow through leaf litter in search of grubs and worms. An "island" of forest in a "sea" of dry landscape, these pine-oak forests are home to many endemic and endangered species. These coniferous forests grow in two mountain ranges, the Sierra Juarez and Sierra de San Pedro Martir, in Baja California, Mexico. Altitudes range between 3,600 and 9,200 feet (1100 and 2800 m) and the climate is temperate subhumid with winter rains. Precipitation levels in these mountains are the second highest on the Baja peninsula (16-28 inches or 40-70 cm per year), and many rivers carve deep valleys as they flow down the slopes. Dominant tree species are pines, white fir, juniper, and oaks.
This relatively small ecosystem is the western equivalent to the "sky islands" of northern Mexico and southwestern Arizona. They are an elevational oasis in a mosaic of chaparral and desert. Rising up out of desert lands, the conifer forests are islands of unique species. At least 10 species of pine occur on the steep mountain slopes, including pinyon and Parry pines. This area is also considered special by scientists as one of the few Mediterranean-climate forests in the country. Some of the tallest pine trees in Mexico grow in Sierra de San Pedro Martir, such as the 230-foot (70-m) sugar pine, which produces 28-inch (70-cm) pine cones. The Tecate cypress and rare Cuyamaca cypress are found in scattered groves in these mountains. Many species of birds, like the pinyon jay, eat the pinyon nuts and help more trees sprout by burying the seeds in the ground.
Two members of the cat family occur in the coniferous forests-the puma and the bobcat. Coyotes can be heard howling in these woods and mountain sheep manage well on the steep slopes. Smaller creatures common here are the ornate shrew, California chipmunk and fringed myotis bat. The western pipistrelle bat, brush rabbit, Merriam's chipmunk, and mule deer are some of the many other species that can be seen here.
A large portion of these forests is still intact, mostly because it is inaccessible. However, cattle farming and intense fires have deteriorated some patches of land. In 1989 and 1996, fires consumed 27 square miles (70 square kilometers) and 23 square miles (60 square kilometers) of forest, respectively. Mistletoe and insects have also invaded and weakened older tree systems. The California condor once roamed the mountains of north Baja California, but disappeared around 1937 because of hunting and poisoning. For more information on this ecoregion, go to the World Wildlife Fund Scientific Report. All text by World Wildlife Fund © 2001
|