Plethodon ouachitae

Shepard and Burbrink (2008) sequenced two mitochondrial genes in a study of geographic variation in the species and found seven subgroups but did not suggest changes in the taxonomy (Crother 2017).

Regional endemic, found only in a portion of the Ouachita Mountains of Oklahoma and Arkansas (currently known only from four counties). Small range, even if treating Plethodon fourchensis as a conspecific and including its occurrences as part of P. ouachitae’s range. Generally locally abundant with moderate, or possibly, high threat risk.

Restricted to the Ouachita Mountains of Arkansas and Oklahoma. Primarily found within the Winding Stair, Rich, and Black Fork Mountains, and the eastern portion of the Kiamichi Mountains. Also found on Buffalo Mountain, in Latimer County, Oklahoma. Minimum range is about 1650 km sq. when encompassing all known occurrences of Plethodon ouachitae. Maximum range is likely only about 2500 km sq., which includes known occurrences of P. ouachitae as well as the range of P. fourchensis, in case that species is downgraded to a subspecies or variant of P. ouachitae. Maximum range extent could have been calculated at about 19000 km sq. if all mountains in the Ouachita Highlands are included, but that inclusion does not appear to be warranted for this species, as it is likely that the species does not occur on additional mountains, nor in areas below about 250 meters elevation.

Blair and Lindsay (1965) divided the species into four distinct populations based on size and color pattern; one of those populations is now considered to be Plethodon fourchensis. More recently, sequencing of two mitochondrial genes indicated there are seven well-supported lineages within the species, geographically structured across 5-6 major mountains, depending upon how one wants to divide the topography within the species’ range (Shepard and Burbrink 2008). There are 29 distinct occurrences for this species when calculated using separation distances suggested by NatureServe (1km for suitable habitat, 3km for unsuitable).

The majority of the species’ range is protected within the Ouachita National Forest. A major threat with mesic forest salamanders is logging that causes direct habitat loss as well as soil desiccation from a more open canopy and edge effects. Self-reported logging records within the Ouachita National Forest indicate that there has been minimal overlap of logging with known occurrences for Plethodon ouachitae (USFS Timber Harvest, reported years 1820-present; https://data.fs.usda.gov/geodata/edw/datasets.php). Future logging in the National Forest should continue to avoid areas where P. ouachitae is found. If that is not done, then the threat level should be raised. Additional threats to the species include herbicide, pesticide, and other chemical use, and being killed on roadways. Climate change will likely be a future threat if it produces more xeric conditions and the species is unable to find sufficient refugia. More erratic temperatures, droughts, and storms would also impact this species, the latter by causing flash flooding that may wash away the softer topsoils upon which this species appears to depend.

Particular conservation attention should be paid to the genetically distinct population on Buffalo Mountain, Latimer County, Oklahoma. Currently the mountain appears to be privately owned and remains undeveloped and unlogged, but there is no guarantee that land use will not change in the future.