Ecological Archives A012-007-A1

William F. Morris, Philip L. Bloch, Brian R. Hudgens, Leonie C. Moyle, and John R. Stinchcombe. 2002. Population viability analysis in endangered species recovery plans: past use and future improvements.  Ecological Applications 12:708-712.

Appendix A. Interpretations of survey responses to specific survey questions when analyzing the use of PVA in recovery plans.

Interpretation:       Response to survey questions:
 
1) Information on PVA was:
A. Presented in the plan.  105A = 1
B. Not presented because the  
plan stated that such information  
did not exist.     105A = 2
C. Not mentioned.     105A = 3
 
2) The plan stated that some or more information on PVA would be beneficial for recovery efforts:
A. Yes  105F = 1         
B. No        105F = 0
 
3) The plan assigned recovery tasks to collect some/more information on PVA:
A. Yes  
146G > 0        
B. No             146G = 0
 
4) The plan assigned monitoring tasks to collect all the necessary data needed to perform a “count-based” PVA:
A. Yes   (141G > 0 or 348OO > 0) and (143G > 0 or 349OO > 0)
B. No The above condition is not satisfied.
 
5) The plan assigned monitoring tasks to collect all the necessary data needed to perform a “structured” PVA:
A. Yes     

(152G > 0 or 354OO > 0) and (153G > 0 or 353OO > 0) and 355OO > 0

B. No   The above condition is not satisfied.
 
6) The plan assigned monitoring tasks to collect all the necessary data needed to perform a “metapopulation” PVA:
A. Yes       

(142G > 0 or 350OO > 0) and (35100 > 0 or 352OO > 0)and (160G > 0 or 357OO > 0)

B. No           The above condition is not satisfied.
 
7) The plan assigned monitoring tasks to collect all the necessary data needed to perform a “spatially  explicit” PVA:
A. Yes  139G > 0 and (145G > 0 or ((152G > 0 or 354OO > 0) and (153G > 0 or 353OO>))) and (160G > 0 or 357OO > 0)
B. No   The above condition is not satisfied.

    Note:  Questions are numbered as in the original survey form (see Hoekstra et al. [2002], opening paper in the Special Feature).                                                                             

A note on the units for statistical analyses -- plans vs. species: In asking how often recovery teams or individuals charged with developing recovery plans acknowledge or call for the use of PVA, the appropriate unit of analysis is the plan, rather than the individual species (because whether or not PVA is to be applied is not independent for two species within the same plan).  However, determining how often plans call for the collection of the appropriate combination of data to perform a PVA must be done at the species level.  For example, because projection matrix models require data on both fecundity and mortality rates, a multispecies plan that calls for the collection of fecundity data for one species and mortality data for a second species would not enable a PVA to be performed for either species, even though the plan specifies somewhere that all the correct data are to be collected.  Hence we analyzed questions 1-3 above using the plan as the sample unit and questions 4-7 above using the species as the sample unit.

Literature cited

Hoekstra, J. M., J. A. Clark, W. F. Fagan, and P. D. Boersma. 2002. A comprehensive review of Endangered Species Act recovery plans. Ecological Applications 12:630-640.



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