180 likes | 284 Views
Missing collaborator. Conceptual Overview . Land use & landscape processes affect habitat. Land Use. Landscape Processes. Freshwater Habitat. Freshwater habitat affects productivity & capacity. SHIRAZ. Biological Response. The SHIRAZ model.
E N D
Conceptual Overview Land use & landscape processes affect habitat Land Use Landscape Processes Freshwater Habitat Freshwater habitat affects productivity & capacity SHIRAZ Biological Response
The SHIRAZ model • Developed for Muckelshoot Tribe in WA to evaluate ESA recovery planning for salmon • Uses flexible life history, with reach by reach specification of habitat characteristics • Basic structure can be simplified and adapted to meet various needs (i.e. it’s a framework) • Built with Visual Basic & integrates with Excel
Alternative life histories • Spawners • Adults • Spawners • Eggs • Fry • First winter residents • Smolts • Ocean residents • Adults
Relate life history to habitat Stage 1 Habitat Stage 2 Habitat Stage 3
Multistage Beverton-Holt Model (Mousalli & Hilborn 1986) Ns≡ individuals alive at stage s p ≡ max. survival rate from s s+1 ≡ “productivity” c ≡ max. N producible ats+1 ≡ “capacity”
Key Attributes In general • Freshwater survival driven by relationships between habitat, p, &c • c determined by quantity of habitat • p determined by quality of habitat Also assume • Freshwater survival is density-dependent • Marine survival is density-independent
Habitat Variables • Inherent “hard-wired” • spawning area • rearing area • % fines • % impervious • Generic • Increase or decrease c & p around a “reference” level • Multiplier specified by a general quadratic relationship • Based on difference between present state and reference Multiplier = exp[f1(state – ref) + f2(state – ref)2]
Changing habitat variables 1) Underlying trend (i.e. annual increase or decrease) Hmax trend>0 trend<0 0 2) Intervention (i.e. bulk addition or removal) Hmax (+) (-) 0 Time
Other model features Harvest strategies Hatchery influence Ocean survival
Integration with PRISM Land Use Landscape Processes PRISM Freshwater Habitat SHIRAZ Biological Response
Linking landscape to life history Stage 1 Climate FW Habitat Stage 2 Ocean Habitat Hydrology Stage 3 Land use Landscape Processes
Current status • Programming interactive improvements • Researching habitat-fish relationships • Researching hydrology-habitat relationships
Moving Forward • Choose watershed (Snohomish or Puyallip/White?) • Add variable hydrology inputs • Allow for various “what if” scenarios
Stream flow % fines Fry survival Precipitation Stream flow % fines Example scenario Ambient Decrease Increase ?
Ocean regime shifts • Evaluation of alternative harvest strategies should be robust to uncertainty about future ocean changes • May want to include known ocean changes based on historical data
SHIRAZSummary • It’s a modeling framework • Uses flexible life history • Spatially explicit habitat characteristics • Basic structure can be simplified and adapted