COS 28-9 - Predicting the locations of breeding pools to assess landscape connectivity for a rare amphibian

Tuesday, August 4, 2009: 10:50 AM
Grand Pavillion III, Hyatt
William R. Fields, Biology, North Carolina State University, Raleigh, NC and Matthew C. Simon, Geography, University of North Carolina, Chapel Hill, NC
Background/Question/Methods

The effects of habitat loss and fragmentation on rare species can be mitigated by increasing landscape connectivity. However, knowledge of the distribution and connectivity of suitable habitats for rare species is often incomplete. We used a geographic information system and field validation to identify suitable breeding habitat for a rare amphibian, the tiger salamander (Ambystoma tigrinum), at Fort Bragg, NC. We used generalized additive models to predict the locations of breeding pools with data derived from a high-resolution elevation model.   

Results/Conclusions

We found that breeding pools were more likely to be located at greater distances from streams and roads.  While our best model included some sites that were not actually breeding pools, it correctly identified all 34 previously known suitable breeding pools, and it led to the discovery of 3 new suitable breeding pools.  After validating our model, our analysis of landscape connectivity for these sites indicated that most breeding pools were rather isolated from their nearest neighbors, so persistence of local populations likely depends more on local recruitment than emigration from other populations in the landscape.  Reestablishing additional populations in breeding pools that are currently unoccupied and creation of new artificial pools could enhance landscape connectivity and viability for this species.

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