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Part I: What’s the reference?. 1. 2. 3. 4. ?. 5. The rangeland health reference is based on what is possible (long-term ecological potential) for a particular soil and climate combination (i.e. ecological site )
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The rangeland health reference is based on what is possible (long-term ecological potential) for a particular soil and climate combination (i.e. ecological site) • S&T models indicate what is realistic (based on short-term potential and limited resource availability) (i.e. communities in an ecological state) 6
Knowing what’s possible provides: • Consistent standards for inventory, assessment & monitoring • Complete range of management options 7
Knowing what’s realistic provides: • A secondary standard for inventory, assessment & monitoring • Complete range of management options 8
Reference State Alternative State Community A Community Pathway Shrub/Exotic Annual Grass – Increased Fire Shrub/Native Perr. Grass Alternative State Thresholds (Relatively Irreversible Transitions) Exotic Annual Grass – Increased Fire 9
SUMMARY -- S&T models • Ecological site-basedstate & transitionconceptual models can be used in two ways. • The “reference state” = what is possible based on ecological site potential • Communities within a current state = what isrealistic 10
SUMMARY -- IIRH and S&T are used: • To determine departure from the reference state • None to Slight – expected for the ecological site and falls within the range of variation for the indicator (no threshold crossed) • SM, M, ME - indicates that a threshold is being approached or has already been crossed • Extreme to Total – Up to and including maximum possible departure for the indicator 11
SUMMARY -- IIRH and S&T are used: (cont) • To identify specific issues of concern (erosion, hydrology, biotic integrity) • To help identify and communicate management options 12
Part I: What’s the reference – using IIRH together with S&T modelsPart II: Reference sheet development overview 13
Reference sheet development (pages 21-25, 72-74) Capture spatial and temporal variability (including short-term disturbance effects)! Page 74 14
Reference sheet development (pages 21-25, 72-74) Reference Sheet defines the “None to Slight” Category in the Evaluation Matrix Page 25
Reference State Alternative State Community A Community Pathway Shrub/Exotic Annual Grass – Increased Fire Shrub/Native Perr. Grass A Reference Sheet is developed for the “Reference State” of each ecological site… Alternative State Exotic Annual Grass – Increased Fire 16
Page 74 Composition (indicators 10 and 12) based on:__ Annual Production, __ Foliar Cover, __Biomass 17
Page 74 Composition (indicators 10 and 12) based on:__ Annual Production, __ Foliar Cover, __Biomass 18
Generating the reference sheet • What do you need to define potential for an ecological site? • Ecological Site Descriptions • Soil survey information • Ecological Reference Area(s) • Expert knowledge (old timers and brilliant ecologists) • Other data (e.g. from LTER and other long-term studies) 19
What if I don’t have… • A state and transition model? • An ecological site description? • A soil survey? 20
Generating the Reference Sheet • How do you evaluate the quality of the information? • Go to the source, or people who knew it • Compare different sources 22
T.K. Stringham and others. 2003. State and transition modeling: An ecological process approach. Journal of Range Management 56: 106-113. J.E. Herrick and others. 2006. An integrated framework for science-based arid land management. Journal of Arid Environments 65: 319-335. No Reference Worksheet: don’t bother going to the field! 23