| Abstract: | State-dependent strategies (SDSs) are the most general form of harvest policy because they allow the harvest rate to depend, without constraint, on the state of the system. State-dependent strategies that provide an optimal harvest rate for any system state can be calculated, and stochasticity can be appropriately accommodated in this optimization. Stochasticity poses 2 challenges to harvest policies: (1) the population will never be at the equilibrium state; and (2) stochasticity induces uncertainty about future states. We investigated the effects of 2 types of stochasticity, environmental variability and management control error, on SDS harvest policies for a white-tailed deer (Odocoileus virginianus) model, and contrasted these with a harvest policy based on maximum sustainable yield (MSY). Increasing stochasticity resulted in more conservative SDSs; that is, higher population densities were required to support the same harvest rate, but these effects were generally small. As stochastic effects increased, SDSs performed much better than MSY. Both deterministic and stochastic SDSs maintained maximum mean annual harvest yield (AHY) and optimal equilibrium population size (Neq) in a stochastic environment, whereas an MSY policy could not. We suggest 3 rules of thumb for harvest management of long-lived vertebrates in stochastic systems: (1) an SDS is advantageous over an MSY policy, (2) using an SDS rather than an MSY is more important than whether a deterministic or stochastic SDS is used, and (3) for SDSs, rankings of the variability in management outcomes (e.g., harvest yield) resulting from parameter stochasticity can be predicted by rankings of the deterministic elasticities. |
| Genre: | Article |
| ProdID: | 5224328 |
| Citation Author: | Hunter, C.M.; Runge, M.C. |
| Citation Contributing Office: | Patuxent Wildlife Research Center |
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| Citation End Page: | 594 |
| Citation Issue: | 3 |
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| Citation Language: | English |
| Citation Larger Work Title: | Journal of Wildlife Management |
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| Citation Number Of Pages: | 10 |
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| Citation Phsyical Description: | 585-594 |
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| Citation Public Comments: | 6191_Hunter.pdf |
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| Citation Search Results Text: | The importance of environmental variability and management control error to optimal harvest policies; 2004; Article; Journal; Journal of Wildlife Management; Hunter, C.M.; Runge, M.C. |
| Citation Start Page: | 585 |
| Citation Volume: | 68 |
| Citation Year: | 2004 |
| Type: | citation/reference |
| Text: | The importance of environmental variability and management control error to optimal harvest policies; 2004; Article; Journal; Journal of Wildlife Management; Hunter, C.M.; Runge, M.C. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DOCUMENT): | http://www.bioone.org/perlserv/?request=get-abstract&doi=10.2193%2F0022-541X%282004%29068%5B0585%3ATIOEVA%5D2.0.CO%3B2 ; http://www.jstor.org/stable/3803392 |
| Date Other: | Wed, 16 Jun 2010 12:18 -0500 |
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