DESERT PATINA

Description

This state is representative of the natural range of variability under pristine conditions. Plant community phase changes are primarily driven by long-term drought. Insect attack and wildfire are infrequent, but have long-term impacts on the plant community. The plant communities of this site are dynamic in response to changes in disturbance regimes and weather patterns.

Submodel

Description

The Invaded State is characterized by the presence of non-native annuals in the understory. A biotic threshold has been crossed, with the introduction of non-native annuals that cannot be removed from the system. Ecological resiliency has been reduced by the presence of non-native annual species and a reduction in the cover of desert pavement. Non-native species have the potential to alter disturbance regimes significantly from their natural or historic range of variability.
Introduced annuals such as red brome, schismus and redstem stork's bill have invaded the reference plant community and have become a dominant component of the herbaceous cover. This invasion of non-natives is attributed to a combination of factors including: 1) surface disturbances, 2) changes in the kinds of animals and their grazing patterns, 3) drought, and 4) changes in fire history. These non-natives annuals are highly flammable and promote wildfires where fires historically have been infrequent.

Submodel