Shallow Sandy Pediment 13-15 P.Z. JUOS/ARTRW8/ACHY-HECO26

Description

The Reference State 1.0 represents the natural range of variability of this site under pristine conditions. The reference state has four general community phases: an old-growth phase, a shrub-herbaceous phase, an immature tree phase, and an infilled tree phase. State dynamics are maintained by interactions between climatic patterns and disturbance regimes. Negative feedbacks enhance ecosystem resilience and contribute to the stability of the state. These include the presence of all structural and functional groups, low fine fuel loads, and retention of organic matter and nutrients. Plant community phase changes are primarily driven by: (a) fire, (b) periodic drought, or (3) insect or disease attack. Fires within this community are infrequent and likely small and patchy due to low fuel loads; for example, single tree death due to lightning strike. This fire type will create a plant community mosaic that will include all/most of the following community phases within this state.

Submodel

Description

This state is similar to the Reference State 1.0, with four general community phases: an old-growth tree phase, a shrub-herbaceous phase, an immature tree phase, and an infilled tree phase. Ecological function has not changed, however the resiliency of the state has been reduced by the presence of non-native species. These non-natives, particularly cheatgrass, can be highly flammable and promote fire where historically fire had been infrequent. Negative feedbacks enhance ecosystem resilience and contribute to the stability of the state. These include the presence of all structural and functional groups, low fine fuel loads and retention of organic matter and nutrients. Positive feedbacks decrease ecosystem resilience and stability of the state. These include the non-natives’ high seed output, persistent seed bank, rapid growth rate, ability to cross pollinate, and adaptations for seed dispersal. Fires within this community with the small amount of non-native annual species present are likely still small and patchy due to low fuel loads. This fire type will create a plant community mosaic that will include all/most of the following community phases within this state.

Submodel

Description

This state has two community phases that are characterized by the dominance of Utah juniper in the overstory. This state is identifiable by greater than 25 percent cover of Utah juniper. This stand exhibits a mixed age class. Older trees are at maximal height and upper crowns might be flat-topped or rounded. Younger trees are typically cone- or pyramidal-shaped. Understory vegetation is sparse due to increasing shade and nutrient competition from trees.

Submodel