Protecting Biodiversity through Monitoring of Management Indicator Species: Questioning Designations of Ursus Americanus (black bear) and Plethodon jordani (Jordan's salamander)

Abstract

Loss of biological diversity is occurring on a global scale, with the southern Appalachians being no exception. As a result of legislation requiring all national forests to maintain viable plant and animal populations, the Forest Service incorporated use of Management Indicator Species (MIS). For an organism to be a good MIS, it must be easy to monitor, be associated with the community type or habitat it supposedly indicates, respond measurably to changes in habitat caused by management activities, and represent other species response to management activities. This study questions the designations of Ursus americanus and Plethodon jordani as MIS in Pisgah National Forest and investigates methods and indexes used in monitoring salamanders.

I found a high year-to-year repeatability in sampling of salamander abundances. Single sampling efforts at sites where highly correlated with the average of two or more sampling efforts at the same sites, indicating single searches are efficient in detecting abundances of salamanders at sites. In comparing two area-constrained search methods for salamanders, I found the two methods to produce different densities, Simpson diversity indexes, and species equitability, along with different abundances of most salamander species. Search methods are therefore not equivalent in detection of salamanders.

Searching at night was a more efficient sampling method for P. jordani than searches of natural cover during the day. I found P. jordani, which is designated as a MIS for woody debris special habitats, to be minimally associated with woody debris as a cover object during the day. Juvenile and small adult P. jordani preferred to use woody debris than rocks as a cover object during dry conditions. P. jordani were found to use all substrate types at night and preferred woody debris to understory, soil, and rocks. P. jordani did not use woody debris more than leaf litter or tree trunk substrates at night and their use of substrates did not differ from those of Desmognathus ocoee.

Black bears and salamanders prefer similar mature forest habitats, but whether black bears serve as a good MIS for mature forest salamanders is unclear. HSIs did not show many correlations with salamanders. Reduction of the black bear habitat suitability index model showed few habitat factors important for black bears were important for salamanders. Investigating the use of an animal existing on one scale to indicate for an animal on another scale merits further study.