Environmental Problems in the Chaparral Biomes

The chaparral biome is predominantly found in coastal California, in the Sierra Nevada range. Similar plant communities are found in coastal regions of South Africa, South America, western Australia and the Mediterranean. Chaparral comprises hardy, woody shrubs that can withstand summer droughts, wet winters and occasional fires. Despite their hardy nature, however, chaparral biomes are subject to a number of natural and man-made environmental problems.

Habitat Loss

• "Soft" chaparral, also called coastal sage scrub, is threatened by the habitat loss caused by urban and suburban expansion. This is particularly true in California, where the coastal areas that contain the biome are being overdeveloped.

Fires

• Chaparral vegetation is highly affected by intense wildfires. As new areas are populated, the frequency of wildfires can increase due to human mistakes. For example, the U.S. Forest Service has observed that fire frequency in the California chaparral has increased from once every twenty years to once every sixteen years.

Erosion

• Chaparral tends to populate relatively steep slopes that can be prone to erosion. Mature areas of chaparral have significant plant cover and root penetration, which helps stabilize the soil. In spots where the plant community is younger---for example, where it is re-establishing itself after a fire---the soil is more vulnerable to erosion. The runoff from erosion can then affect nearby waterways, clogging them with excess silt.

Storm Runoff

• Denuded areas of chaparral can contribute to flooding. Well-vegetated areas will hold back rainfall and release it slowly after the plants and their root systems soak up a good portion of the water. Denuded areas will not do this, and the runoff from a typical storm could cause flooding.