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Cryic, Umbric Or Andic Slopes

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List model

Ecosystem states

State 1

Reference State

State 2

Degraded State

2784

Circle-spoke model

Ecosystem states

State 1

State 2

2784

Scenario model

Ecosystem states

Current ecosystem state

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State 1
Reference State
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State 2
Degraded State
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Management practices/drivers

Select a transition or restoration pathway

No transition or restoration pathway between the selected states has been described

Target ecosystem state

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State 1
Reference State
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State 2
Degraded State
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2784

State 1
Reference State

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Reference State

Description

The reference state occurs with a fire return interval of 10 to 50 years, and only moderate grazing. The fire regime allows for a spatially variable succession of plant communities to co-exist, and grazing impacts are not severe enough to cross an ecological threshold to a degraded state where the natural community dynamics no longer function.

Submodel

1.1. Reference Community

1.2. Early Fire Regeneration (Provisional)

1.3. Mid-Seral (Provisional)

State 2
Degraded State

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Degraded State

Community Phase 2.1

Community Phase 2.3

Description

This state develops when overgrazing and a lack of fire triggers an ecological threshold to be crossed where the natural community dynamics no longer function and cannot be restored without active intervention. Exploitative grazing practices from the 1850s to approximately 1930 caused this transition to occur in much of the range of this ecological site, especially the Lake Tahoe Basin (Elliot-Fisk et al. 1996, Taylor 2004). Heavy and pervasive sheep grazing in the Lake Tahoe Basin removed all grasses and palatable shrubs in some areas by 1900 (Sudworth, 1900, quoted in Fisk et al. 1996). Over a century later, many of these shrublands have not recovered, and remain heavily dominated by shrubs with a minimal grass component, and increased unpalatable forbs. Fire in this state is rare, and a grass-dominated community does not occur.

Submodel

2.1. Overgazed

2.2. Grazed + Burned (Provisional)

2.3. Eroded Community Phase

Model keys

Briefcase

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Natural Resources
Conservation Service

Cryic, Umbric Or Andic Slopes

List model

Circle-spoke model

Scenario model

Current ecosystem state

Management practices/drivers

Target ecosystem state

State 1
Reference State

Description

Submodel

State 2
Degraded State

Description

Submodel

Model keys

Briefcase

Ecological sites

Major Land Resource Areas

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Natural ResourcesConservation Service

Cryic, Umbric Or Andic Slopes

Model keys

Natural Resources
Conservation Service