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CFR Citation: 50 CFR Part 17

FWS ID: [FWS-R8-ES-2008-0002; 1111 FY07 MO;ABC Code: B2]

NOTICE: Part III

DOCUMENT ACTION: Notice of 12-month petition finding.

SUBJECT CATEGORY: Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition To List the Siskiyou Mountains Salamander (Plethodon stormi) and Scott Bar Salamander (Plethodon asupak) as Threatened or Endangered

DATES: We made the finding announced in this document on January 24, 2008.

DOCUMENT SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 12month finding on a petition to list the Siskiyou Mountains salamander (Plethodon stormi) and Scott Bar salamander (Plethodon asupak) as threatened or endangered, under the Endangered Species Act of 1973, as amended (Act). After a thorough review of all available scientific and commercial information, we find that listing the Siskiyou Mountains salamander and Scott Bar salamander is not warranted. We ask the public to continue to submit to us any new information concerning the status of, and threats to, these species. This information will help us to monitor and encourage the ongoing management of these species.

SUMMARY: Interior Department, Fish and Wildlife Service,

SUPPLEMENTAL INFORMATION

Section 4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq.) requires that, for any petition to revise the Lists of Endangered and Threatened Wildlife and Plants that contains substantial scientific and commercial information that listing may be warranted, we make a finding within 12 months of the date of our receipt of the petition on whether the petitioned action is: (a) Not warranted, (b) warranted, or (c) warranted, but the immediate proposal of a regulation implementing the petitioned action is precluded by other pending proposals to determine whether any species is threatened or endangered. Such 12month findings are to be published promptly in the Federal Register. Section 4(b)(3)(C) of the Act requires that we treat a petition for which the requested action is found to be warranted but precluded as though resubmitted on the date of such finding, and we must make a subsequent finding within 12 months.

Previous Federal Actions

On June 18, 2004, we received a petition dated June 16, 2004, from the Center for Biological Diversity, KlamathSiskiyou Wildlands Center, and Noah Greenwald, to list the Siskiyou Mountains salamander (Plethodon stormi) as a threatened or endangered species on behalf of themselves and five other organizations. The petition clearly identified itself as such and included the requisite identification information for the petitioners, as required in 50 CFR 424.14(a). In their petition, the petitioners assert that there are three separate distinct population segments (DPSs) of the Siskiyou Mountains salamander, one of which consists of the Scott Bar salamander. Alternatively, the petitioners assert that the Scott Bar salamander is a separate species and request that it be considered independently for listing. Since the time the petition was submitted, the Scott Bar salamander (Plethodon asupak) has been recognized as a species separate from the Siskiyou Mountains salamander (Mead et al. 2005, pp. 169171), and we have reviewed it separately in making this finding. The petitioners also requested the Service to consider whether the Siskiyou Mountains salamander (and therefore the Scott Bar salamander, as well) warrants listing throughout a significant portion of its range, and requested designation of critical habitat for both species concurrent with their listing. In a July 19, 2004, letter to the petitioners, we responded that we reviewed the petition for both species and determined that an emergency listing was not warranted, and that because of inadequate funds for listing and critical habitat designation, we would not be able to otherwise address the petition to list the Siskiyou Mountains salamander and Scott Bar salamander at that time.

On June 23, 2005, we received a 60day notice of intent to sue and on August 23, 2005, the Center for Biological Diversity and four other groups filed a Complaint for Declaratory and Injunctive Relief in Federal District Court for the District of Oregon (Center for Biological Diversity et al. v. Norton et al., No. 3:05CV1311BR), challenging our failure to issue a 90day finding on the petition to list the Siskiyou Mountains salamander and Scott Bar salamander. On December 28, 2005, we reached an agreement with the plaintiffs to complete the 90day finding by April 15, 2006, and if we determined that the petition presented substantial information that listing may be warranted, to complete the 12month finding by January 15, 2007.

On April 17, 2006, the Service made its 90day finding (71 FR 23886, April 25, 2006), concluding that the petition did not present substantial scientific or commercial information to indicate that listing the Siskiyou Mountains salamander and Scott Bar salamander may be warranted.

On July 6, 2006, the Center for Biological Diversity and others filed suit in the United States District Court for the Northern District of California (Center for Biological Diversity et al. v. Dirk Kempthorne et al., No. C064186WHA), challenging the merits of that finding. On January 19, 2007, the District Court determined the 90day finding was arbitrary and capricious, vacated and remanded the finding, and ordered the Service to make a new finding by March 23, 2007.

A new 90day finding was signed on March 22, 2007, and we published it in the Federal Register on March 29, 2007 (72 FR 14750). In that 90 day finding, we concluded that the petition presented substantial scientific or commercial information to indicate that listing the Siskiyou Mountains salamander and Scott Bar salamander may be warranted, announced the initiation of a status review of these taxa, and solicited comments and information to be provided in connection with the status review by May 29, 2007. This notice constitutes our 12 month finding regarding the petition to list these two species.

To ensure that this finding is based on the latest information and incorporates the opinions of the scientific community, the Service entered into a
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Cooperative Agreement with the U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, in Corvallis, Oregon, to provide a technical report addressing taxonomy, biology, habitat associations, detectability, and effects of habitat alteration on the salamanders. The technical report was authored by Douglas DeGross and R. Bruce Bury, and reviewed by species experts in the U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center; U.S. Forest Service (USFS) Pacific Northwest Research Station and Pacific Southwest Research Station; and Rogue RiverSiskiyou National Forest. The technical report (DeGross and Bury 2007), information provided by the public, and additional information and data in our files provided the basis for this status review for the Siskiyou Mountains salamander and Scott Bar salamander. In addition, Service staff involved in the development of this finding have several years of combined experience surveying for and researching the distribution and habitat associations of Siskiyou Mountains salamander.

Foreseeable Future

The principal difference between an ``endangered'' and a ``threatened'' species under the Act is whether the species is currently in danger of extinction, or if it is likely to become so ``within the foreseeable future.'' The Act does not define the term foreseeable future; however, we consider the foreseeable future to be affected by the biological and demographic characteristics of the species, as well as our ability to predict or extrapolate the effects of threats facing the species in the future. Quantification of the time period corresponding to the forseeable future is challenging because it necessitates making predictions about inherently dynamic political, legal, and social mechanisms that influence the degree and immediacy of potential threats to the species.

Population dynamics of the Siskiyou Mountains salamander and Scott Bar salamander are poorly known, and we are unaware of data sufficient to support estimates of longevity, generation times, or recruitment rates for these species. For example, Nussbaum et al. (1983, p. 103) state that both sexes ``are thought to'' mature at 5 to 6 years of age, but provide no basis for this estimate. Likewise, estimates of population and genetically effective population (Ne) size are unavailable for these species (DeGross and Bury 2007, p. 9). Because the demographic and biological characteristics of these species are so poorly understood, we must base our estimate of foreseeable future on our ability to predict or extrapolate the effects of the future threats facing these species.

Our ability to predict the effects of future threats is limited to our knowledge of the time frame of the threats potentially facing the species (e.g., timber harvest, wildfire, roads and road construction, mining and rock quarrying, disease, stochastic events, and climate change) and of any conservation activities taking place to address these threats. For example, the rate of timber harvest has declined on Federal lands (which constitute over 85 percent of the combined ranges of both species) during the last 30 years (USDA and USDI 1994, 2005) and we have no information that would lead us to predict a dramatic increase in the rate and intensity of timber harvest such that large areas of habitat will be affected to such a great degree that these species will suffer adverse impacts. In the event that the rate and intensity of timber harvesting were to increase dramatically, it would take some period of time (depending on the actual increase of the rate and intensity, and the impact of the harvesting at issue on the salamanders) for the cumulative impact of the timber harvesting to have a significant effect on the species. Because the available evidence suggests that the salamanders recover for even intensive disturbances such as clearcutting (from 11 years (Bull et al. 2006, p. 21) to 30 years (Welsh et al. 2007b) for Siskiyou Mountains salamanders), the species would only become in danger of extinction if that increased level and intensity of harvest lasted long enough to effect sufficient habitat at nearly the same time such that it overcame the apparent resiliency of the species to such disturbances. Further, while scientists predict that the rate of temperature change will continue to increase throughout the present century (EPRI 2003, p. 3; Hayhoe et al. 2004, p. 12423; Cayan et al. 2006, pp. 1114, 31; Maurer 2007, p. 317), the effects of climate change on these species are uncertain and estimation of the timing of potential effects would be speculative.

We do not have sufficient demographic information on Siskiyou Mountains salamanders or Scott Bar salamanders, nor on the trajectory of potential threats when combined with existing regulatory mechanisms, on which to base a precise definition of foreseeable future. Given the stability of Federal Land and Resource Management Plans and the Northwest Forest Plan (NWFP) since its establishment in 1994, we assume that significant changes to current land management practices on Federal lands are not likely to occur within 20 years. We note that the changes in Federal land management that we can anticipate may happen in the short term, including termination of the Survey and Manage Program and Western Oregon Plan Revision, discussed below, are unlikely to result in the sort of significant changes that might have an important effect on the conservation status of the species. If a significant change were to occur, we estimate that, because of logistical and regulatory limitations imposed on the rate of planning and implementing significant land management actions, actual management activities could take an additional 20 years to reach a magnitude of effect that would measurably affect salamander populations. Therefore, we conclude that the foreseeable future for the salamanders does not extend beyond 40 years. In other words, we have sufficient confidence in our estimates of the threats and reaction of the two species to those threats to draw a conclusion as to the likelihood of endangerment over only at most 40 years. Beyond that period, our level of confidence is such that any conclusions we drew would be too speculative on which to base current action. We find that this estimate of the foreseeable future is both reasonable and appropriate because it focuses this status review on the time frame in which current social and political change may affect species management, which we consider to have the most likely potential for meaningful nearterm influence on the status of these species. Species Descriptions

Like others in the Family Plethodontidae (the lungless salamanders), the Siskiyou Mountains salamander and Scott Bar salamander are completely terrestrial, mediumsized, slenderbodied salamanders with short limbs and a dorsal stripe. Both species are found in or near talus (loose surface rock) and fissured rock outcrops where moisture and humidity are high enough to allow respiration through their skin (Feder 1983, p. 296; Nussbaum et al. 1983, pp. 73, 90, and 102; Stebbins 2003, p. 168). Both species are endemic to the KlamathSiskiyou Mountains of southern Oregon and northern California, where they are considered as part of a species complex that includes and is named for the similar Del Norte salamander (Plethodon elongatus).

Members of the Plethodon elongatus Complex differ physically from other regional members of the genus
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Plethodon. Species in the Plethodon elongatus Complex have webbed toes, while Dunn's salamander (P. dunni) and western redbacked salamander (P. vehiculum) do not (Highton 1962, pp. 255256). The larger number of trunk vertebrae and costal grooves (vertical creases along the side of the body), as well as the smaller number of vomerine teeth (teeth on the vomer bone in the roof of the mouth) further distinguish the Plethodon elongatus Complex from the rest of the western Plethodon species (Highton and Brame 1965, p. 1; Brodie 1970, pp. 503505; Nussbaum et al. 1983, p. 102; Mead et al. 2005, pp. 163166).

The Siskiyou Mountains salamander was described in 1965, two years after it was first identified (Highton and Brame 1965, p. 1). It is characterized by a modal number of 17 costal grooves and 4 to 5.5 intercostal folds (folds of skin between the costal grooves) between the toes of adpressed limbs (limbs firmly pressed against the sides of the body) (Nussbaum et al. 1983, p. 102; Leonard et al. 1993, p. 78). Adults have a light to purplishbrown dorsum, and the body is sprinkled with a moderate to dense array of white to yellow flecks, concentrated on the sides and limbs and away from the lightbrown dorsal stripe (Highton and Brame 1965, p. 1; Nussbaum et al. 1983, p. 102). Juveniles are black and have an olivetan dorsal stripe that extends onto the tail.

The Scott Bar salamander is more robust and has a wider head and longer limbs than the Del Norte salamander and Siskiyou Mountains salamander. It has fewer intercostal folds between adpressed limbs (2.5 to 3.5) than either the Del Norte salamander (5 to 6) or Siskiyou Mountains salamander (4 to 5.5), and the modal number of costal grooves (17) is one less than in the Del Norte salamander (18). The Scott Bar salamander has a longer body relative to its tail length and longer forelimbs and hindlimbs than the Siskiyou Mountains salamander or Del Norte salamander. The coloration of the Scott Bar salamander is similar to that of the Siskiyou Mountains salamander and is described in Mead et al. (2005, p. 170). Despite the morphological differences described in Mead et al. (2005, pp. 169171), the two species are difficult to distinguish in the field.

Taxonomy

The Siskiyou Mountains salamander was first identified in 1963, adding the second form to what is now referred to as the Plethodon elongatus Complex (Highton and Brame 1965, p. 1). Early distinctions between Siskiyou Mountains salamanders and Del Norte salamanders were based on morphological traits and coloration (Highton and Brame 1965, p. 1; Brodie 1970, pp. 503505; Bury 1973, p. 57). However, it is now clear that field identification of these species based on coloration is unreliable because both species exhibit geographic variation in coloration (Brodie 1970, p. 503; Bury 1999, pp. 910).

Researchers have cited morphological differences as evidence of a taxonomic distinction between Siskiyou Mountains salamanders and Del Norte salamanders. Perhaps the most convincing support for distinguishing between these forms was provided by Mead et al. (2005, pp. 165166), who found that all three species in the Plethodon elongatus Complex differed in average measurements of male snoutvent length, forelimb length, and head width; and female snoutvent length, forelimb length, and internarial distance. Additionally, both Siskiyou Mountains salamanders and Scott Bar salamanders have a smaller modal number of costal folds and proportionally larger forelimbs than Del Norte salamanders, contributing to their more robust appearance (Highton and Brame 1965, p. 1; Mead et al. 2005, p. 170).

Phylogenetic studies of the Plethodon elongatus Complex have provided further support for classifying Siskiyou Mountains salamanders and Del Norte salamanders as closely related species (Mahoney 2001, p. 183; Mahoney 2004, pp. 155161; Bury and Welsh 2005, p. 842; Mead et al. 2005, p. 166). Phylogenetic studies of these species have also shown that early studies of the morphology of Del Norte salamanders along the Klamath River between Happy Camp and Seiad Valley, California, were in fact describing Siskiyou Mountains salamanders (Pfrender and Titus 2001, p. 15; DeGross 2004, pp. 1718; Mahoney 2004, p. 5; Mead et al. 2005, p. 173; Mead 2006, pp. 1516). In fact, Bury (1973, p. 57) proposed possible intergradation between these two species, and Stebbins (1985, p. 47; 2003, pp. 173174) demoted the Siskiyou Mountains salamander to a subspecies of Del Norte salamander. However, recent research suggests that little gene flow occurs between these species across their zone of contact in the Indian Creek drainage in western Siskiyou County, California (DeGross 2004, p. 40; DeGross et al. unpublished).

Phylogenetic studies of the Siskiyou Mountains salamander have indicated that this species consists of two distinct genetic lineages: North Clade (populations within the Applegate River drainage and on the crest of the Siskiyou Mountain Range) and South Clade (populations south of the Siskiyou Mountain Range crest and adjacent to the Klamath River) (Pfrender and Titus 2001, pp. 56; DeGross 2004, pp. 2444; Mahoney 2004, p. 8; Mead et al. 2005, pp. 163166). A third, more divergent, group was also identified and is now recognized as a separate species, the Scott Bar salamander.

Based on levels of genetic divergence between species in the Plethodon elongatus Complex, researchers estimated that the Del Norte salamander and Siskiyou Mountains salamander lineages diverged approximately 4 million years ago and that their shared ancestral lineage diverged from that of the Scott Bar salamander between 20 and 26 million years ago (Mahoney 2004, p. 15; Mead et al. 2005, p. 165). Therefore, the Scott Bar salamander lineage appears to be the basal (most primitive, from which others are derived) lineage of the Plethodon elongatus Complex. Given the time periods during which these species diverged, speciation within this complex was probably influenced by Pleistocene glaciation (Soltis et al. 1997, pp. 369370; Bury 1999, p. 22; DeGross and Bury unpublished).

Differences between Scott Bar salamanders and the other members of the Plethodon elongatus Complex are not limited to their genetic divergence. As noted above, Mead et al. (2005, pp. 165166) found differences in morphological measurements of all three species. Nonetheless, questions about the validity of the current classification of these species persist (sensu Wake and Jockusch 2000, p. 117). Further, the ranges of the Scott Bar salamander and Siskiyou Mountains salamander abut each other north of the Klamath River and south of Horse Creek, so it is possible that these species interbreed in this area. Measurements of gene flow between these species would be helpful to further clarify the taxonomy of southern populations of Siskiyou Mountains salamanders and Scott Bar salamanders and define the interspecific boundaries for each species range (DeGross and Bury 2007, p. 4; Wake and Jockusch 2000, p. 117).

The Service recognizes that questions about the taxonomy of the Plethodon elongatus Complex remain and that research on this topic is ongoing. However, for the purpose of this finding, we evaluated the threats to the Siskiyou Mountains salamander and Scott Bar salamander separately because the preponderance of available evidence currently supports recognition of these forms as separate species. Even so, the ecological research on these species was
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conducted prior to recognition of the Scott Bar salamander as a separate species, and since both species are members of the Family Plethodontidae, their life histories and habitat associations appear to be similar. Therefore, for the purpose of this finding, we use the current literature describing the biological characteristics and ecology of the Siskiyou Mountains salamander for both species.

For the purposes of this finding, we use the following hierarchy of taxonomic names:
(1) Plethodon elongatus Complex: Plethodon salamanders within the geographic region occupied by Del Norte salamander, Siskiyou Mountains salamander, and Scott Bar salamander.
(2) Siskiyou Mountains salamander Complex: The three known genetic entities previously classified as Siskiyou Mountains salamander, consisting of the Scott Bar salamander, Siskiyou Mountains salamander North Clade, and Siskiyou Mountains salamander South Clade. (3) Siskiyou Mountains salamander (North and South Clades combined), not including the Scott Bar salamander.
(4) Individual genetic subunits of Siskiyou Mountains salamander: North Clade (hereafter referred to as the Applegate salamander) and South Clade (hereafter referred to as the Grider salamander). Biology

Like other members of the Family Plethodontidae, Siskiyou Mountains and Scott Bar salamanders require contact with moisture for respiration through their permeable skin (Feder 1983, pp. 292293). Desiccation is lethal to Plethodon species and therefore, surface activity by Siskiyou Mountains and Scott Bar salamanders primarily occurs at night, when the air is cool and moist (Nussbaum 1974, p. 3; Nussbaum et al. 1983, p. 103; Clayton and Nauman 2005, p. 139; Mead et al. 2005, p. 118). Peak periods of surface activity occur during the rainy season (usually late fall and spring) (Clayton and Nauman 2005, p. 139; Mead et al. 2005, p. 118). These salamanders retreat to underground refugia during the extreme climatic conditions common during summer and winter in the eastern Klamath Mountains (Nussbaum 1974, p. 3). They may forage at the surface during the summer (Nussbaum et al. 1983, p. 103) but probably only in sites with relatively cool, moist microclimates. Little is known about these species' behavior, but many researchers assume that they are inactive underground and that foraging and reproduction only occur during brief periods of surface activity (Feder 1983, p. 305). However, it is possible that these activities also occur below the surface (Welsh and Lind 1992, p. 433). The limited surface activity by these species is reflected in survey protocols for Siskiyou Mountains salamanders, which require that surveys be restricted to periods of relative humidity above 65 percent, air temperatures between 39.2 and 68 [deg]F (4 to 20 [deg]C), soil temperatures between 38.3 and 64.4 [deg]F (3.5 to 18 [deg]C), and moist soil conditions (Clayton et al. 1999, p. 133).

Plethodon salamanders are fully terrestrial amphibians and do not need standing or flowing water for any stage of their life cycle (Zug et al. 2001, p. 383). Eggs are thought to be laid in small clusters deep in moist, rocky substrates, but this has not been observed by researchers. Females have clutches of 2 to 18 eggs, with an average of 9 eggs per clutch (Nussbaum et al. 1983, pp. 2123). Juveniles emerge in late fall and early spring. Welsh and Lind (1992, p. 432) reported that juveniles captured in midspring were significantly larger than would be expected if newly hatched. These salamanders appear to become reproductively mature at 5 to 6 years and are relatively longlived (up to 15 years) (Nussbaum et al. 1983, p. 103; Clayton and Nauman 2005, p. 139). Females appear to breed every other year (Nussbaum 1974, p. 22).

Siskiyou Mountains and Scott Bar salamanders are `lieandwait' predators that prey on a variety of small terrestrial invertebrates, including spiders, pseudoscorpions, mites, ants, collembolans, and beetles (Nussbaum et al. 1983, p. 103). Seasonal changes in diet have been reported for these species (Nussbaum 1974, p. 24). Predators of these species have not been identified but may include snakes, shrews, or animals that opportunistically forage in spring leaf litter and debris (e.g., groundforaging birds). Several researchers have hypothesized that interspecific and intraspecific competition are important factors in the population ecology of Siskiyou Mountains and Scott Bar salamanders (Nishikawa 1985, p. 1290; Mathis 1989, p. 790; Griffis and Jaeger 1998, p. 2500). These species' ranges overlap with those of ensatina (E. eschscholtzii oregonensis) and black salamanders (Aneides flavipunctatus), and a recent study described one site where they are sympatric with Del Norte salamanders (Mead 2006, p. 8). We are not aware of any information about parasites or diseases affecting these species or information about symbiotic or mutualistic interactions with other organisms.

Habitat Associations

Siskiyou Mountains salamanders and Scott Bar salamanders occur on slopes with rocky soils or talus (loose surface rock) outcrops. These substrates provide interstitial spaces into which these animals can retreat from the climatic extremes of the eastern Klamath Mountains. These salamanders are occasionally found under other types of cover, such as bark, limbs, or logs, but only during wet weather when moisture is high and only in close proximity to suitable rocky substrates (Nussbaum 1974, p. 13; Nussbaum et al. 1983, p. 102). Like other plethodontids, Siskiyou Mountains salamanders and Scott Bar salamanders require contact with moisture for respiration through their skin. Therefore, habitat characteristics that influence forest microclimates, especially relative humidity and soil surface moisture, are likely important to these species. Based on these species' similar natural histories and physiologies (see ``Biology'' section), occurrence in the same region, and previous designation as one species, we assume that Siskiyou Mountains salamanders and Scott Bar salamanders have similar habitat requirements. As noted above, nearly all of the available information on these species comes from studies conducted on both species, prior to recognition of Scott Bar salamander as a separate species.

Early observational studies of Siskiyou Mountains salamanders found that these animals are highly associated with talus and other rocky substrates (Highton and Brame 1965, p. 1; Storm 1966, p. 1; Nussbaum 1974, p. 13; Clayton and Nauman 2005, p. 139; Mead et al. 2005, p. 118). Nussbaum (1974, p. 13) found that the densest populations were on heavily wooded, northfacing slopes that also had talus deposits or fissured rock outcrops. Many of the earliest known populations of Siskiyou Mountains salamanders occurred in talus road cuts, where the underlying rock substrate was exposed and detection of salamanders was facilitated (Nussbaum 1974, p. 13).

The degree to which Siskiyou Mountains salamanders and Scott Bar salamanders are associated with lateseral forest conditions has been the subject of considerable uncertainty and debate among scientists and land managers. Understanding this debate is essential to understanding the Service's finding for these species. The debate is exemplified by the salamander population at MuckaMuck Creek, the type locality from which the Scott Bar salamander was described (Mead et al. 2005, p. 169). Biologists and researchers
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use MuckaMuck as a ``reference site,'' a location with reliable salamander detections that can be checked prior to conducting surveys in other nearby areas to confirm that current weather conditions are within proper limits to conduct these surveys. However, even when survey conditions are adequate, salamanders may not be detected at this known reference site on any given single visit. Located adjacent to a road, the site experienced hydraulic mining in the late 1800s and currently supports a sparse overstory of young and early mature trees. These habitat conditions are representative of habitat at many locations occupied by apparently viable populations of Siskiyou Mountains salamanders (Bull et al. 2006, pp. 1922; CDFG 2005, p. 24; Farber 2007a, pp. 34). The regularly reported existence of salamander populations at sites like the MuckaMuck Creek site undercuts the conclusion of some researchers (based on the results of a single study) that the species is dependent on oldgrowth forest (Ollivier et al. 2001, pp. 2629; Welsh et al. 2007a, p. 31).

The results of studies of habitat relationships conducted to date are equivocal or provide limited inferences. Limited inferences result from either (1) lack of a random or systematic sampling design that allows inference to a larger population, or (2) singlevisit sampling that fails to incorporate the low and variable detection rates associated with these species. Two analyses of a single, relatively largescale, singlevisit, random, samplingbased study suggested an association with closedcanopy, older forest (Ollivier et al. 2001; Welsh et al. 2007a), whereas field studies evaluating habitat attributes at known (not randomly or systematically selected) locations demonstrated that the species are found in a wide range of forest structural conditions (Farber et al. 2001; Bull et al. 2006; Farber 2007a). We are not aware of any rigorous studies evaluating the species' demographic responses to forest conditions.

The most rigorous research of these species' habitat associations was conducted by Ollivier et al. (2001) and Welsh et al. (2007a). These studies used the same data set and somewhat different analytical techniques. The data used in both analyses were collected at 61 sites occupied by Siskiyou Mountains salamanders and possibly Scott Bar salamanders (a few sites were located within the range of what were later recognized as Scott Bar salamanders). These sites were compared with sites classified as unoccupied by salamanders (see below). These studies found that salamander populations on either side of the Siskiyou Crest appeared to occupy habitat based on different environmental factors (Welsh et al. 2007a, p. 28). The authors primarily attributed this result to geographic differences in precipitation, illumination (topographic variation in sunlight or shading), and vegetation (Welsh et al. 2007a, pp. 19, and 28). Based on these differences, they suggested that suitable habitat is less abundant and more patchily distributed on the south side of the crest than on the north side (Welsh et al. 2007a, p. 28). Although these results differed somewhat for salamanders on either side of the Siskiyou Crest, they generally indicated that sites occupied by salamanders contained attributes that likely moderate surface microclimates for these animals (e.g., greater canopy closure, more leaf litter cover, more decaying logs) or that are associated with moist, cool microclimates (e.g., less grass cover, more sword fern cover) (Ollivier et al. 2001, pp. 1721, 2629; Welsh et al. 2007a, pp. 24, 27). Both analyses concluded that Siskiyou Mountains (and possibly Scott Bar) salamanders are ``a mature to oldgrowthforestassociated species that exists at its biological optimum under conditions found primarily in later seral stages of mixed coniferhardwood forests in northwestern California and southwestern Oregon'' (Ollivier et al. 2001, p. 42; Welsh et al. 2007a, p. 31). However, the authors also state that ``[t]oday, information on the habitat requirements of this species is incomplete and conflicting'' (Welsh et al. 2007a, p. 16) and ``[m]any of the biotic and abiotic requirements necessary for longterm viability for the Siskiyou Mountains salamander remain undetermined'' (Welsh et al. 2007a, p. 31). It is important to note that the results of these studies only indicate correlations between forest attributes and the presence of salamanders; they do not actually demonstrate that these species select habitat based on olderforest characteristics (Welsh et al. 2007a, p. 31). For example, these salamanders may select habitat based on other factors (e.g., suitable microclimates) that often occur within older forests but that can also occur in other areas such as deep drainages and northfacing slopes.

Our understanding of the habitat associations of Siskiyou Mountains salamander and their degree of ecological dependence on specific habitat conditions is hampered by the difficulty in detecting this species during surveys. Their brief, intermittent periods of surface activity, nocturnal habits, and secretive behavior make detection of Siskiyou Mountains salamanders and Scott Bar salamanders difficult (Nussbaum 1974, p. 3; Olson et al. 2007, pp. 78). Welsh et al. (2007a, p. 25) estimated that their detection rates for these species were 20 and 28 percent on the south and north slopes of the Siskiyou Crest, respectively. Detection rates for other Plethodon species are similarly low: 15 percent (Bailey et al. 2004, p. 21) and 2 to 32 percent (Taub 1961, p. 695). Because detection rates are low for these species, repeated surveys and estimation of the probability of false negatives during surveys are required to minimize or account for the probability of classifying occupied sites as unoccupied. The survey protocol developed for the NWFP Survey and Manage Guidelines (Clayton et al. 1999, p. 141) requires three survey visits to determine presence or absence of Siskiyou Mountains salamanders. Classifying occupied sites as unoccupied, or failing to account for the probability of doing so, can bias conclusions about relationships between salamanders and habitat characteristics. The presence or absence data analyzed by Ollivier et al. (2001) and Welsh et al. (2007a) were collected with a singlevisit protocol, so these studies cannot reliably infer absence at sites where detections were not obtained. In fact, the California Department of Fish and Game (CDFG) used a more intensive survey protocol to resurvey 13 clearcut or precanopy (0 to 30 yearsold) sites classified as unoccupied by Ollivier et al. (2001) and Welsh et al. (2007a) and found Siskiyou Mountains salamanders at 5 sites, Scott Bar salamanders at 2 sites, and Del Norte salamanders at 1 site (Bull et al. 2006, p. 25). While this finding does not appear to change the general conclusion described by Ollivier et al. (2001) and Welsh et al. (2007a) that salamanders were more likely to be detected in closed canopied older forest than in more open sites, it acts to substantially weaken the inference of Ollivier et al. (2001, p. 42) and Welsh et al. (2007a, p. 31), that these species are ecologically dependent on conditions primarily found in mature or lateseral stage forests.

Two other studies have examined potential relationships between habitat attributes and abundances of Siskiyou Mountains salamanders and Scott Bar salamanders. Farber (2007a) described sites occupied by Scott Bar salamanders on private timber company property and adjacent National Forest land. This study compared salamander abundances and habitat characteristics at 26 sites
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within a relatively small area (29 acres (ac) (11.7 hectares (ha))) and found that salamander abundance was only significantly related to percent rock cover. A large proportion of the occupied sites (94 percent) had evidence of at least one previous manmade or natural disturbance (Farber 2007a, p. 3). Bull et al. (2006) described CDFG surveys at 68 sites occupied by Siskiyou Mountains or Scott Bar salamanders. Eightyseven percent of these sites were on private timberlands, and the remaining sites were on Federal lands (Bull et al. 2006, p. 24). Like Farber (2007a), CDFG found evidence of previous disturbance at most (82 percent) occupied sites (Bull et al. 2006, p. 24). Roughly 83 percent of the sites occurred in forest stands with relatively open canopies (less than 60 percent canopy closure). They also found that salamander sites occurred within a wide range of environmental conditions, including all slope aspects and nearly all (16 of 18) California Wildlife Habitat Relationships tree size and canopy classes (Bull et al. 2006, p. 24). These studies' sampling designs preclude inferences about the habitat preferences of other Siskiyou Mountains salamander populations because they were focused on known salamander sites and did not take into account the broad range of habitat that is potentially available to these salamander species. However, both studies showed that Siskiyou Mountains salamanders and Scott Bar salamanders occur within a relatively wide range of forest conditions, and were not extirpated by the disturbances (timber harvest) that created those conditions.

To support their argument that the Siskiyou Mountains salamander is critically imperiled by habitat loss, the petitioners rely heavily on statements made by Welsh et al. (2007a) as providing new scientific information that the salamanders are highly associated with, and ecologically dependent on, oldgrowth forest conditions, and the petitioners highlight an ongoing debate between Dr. Welsh and the CDFG (Greenwald and Curry 2007, pp. 47). As discussed above, we conclude that the survey methodology employed by Ollivier et al. (2001) and Welsh et al. (2007a, p. 18) was inadequate to rigorously determine salamander absence as required for the presenceabsence statistical modeling method used to analyze the data. The singlevisit sampling methodology these authors employed is more appropriate for comparisons of relative abundance among habitat types, which is how we interpreted their results. The fact that salamanders were subsequently detected by CDFG at over half of the `absent' sites analyzed by Welsh et al. (2007a) does not negate the importance of this study or the habitat associations it describes; it does, however, limit the strength of inference regarding the degree to which Siskiyou Mountains salamanders may require oldgrowth forest conditions. We do not consider the field studies conducted by CDFG (Bull et al. 2006) as providing competing scientific research requiring reconciliation with the statistical design of the Welsh et al. (2007a) study. The CDFG field studies do, however, provide habitat results from a large sample of occupied salamander locations, which, in combination with similar data sets from Farber et al. (2001), constitute a significant source of information on these species.

A model was recently developed for predicting the occurrence of Siskiyou Mountains salamanders north of the Siskiyou Crest (Reilly et al. 2007). This model incorporated three variables reported by Ollivier et al. (2001) and Welsh et al. (2007a) to be positively related to occupancy by Siskiyou Mountains salamanders: rocky soil types, forest canopy closures above 70 percent, and conifer forest with average tree sizes greater than 17 inches (43 centimeters) in diameter at breast height (DBH) (Reilly et al. 2007, p. 1). An additional variable modeling topographical variation in sunlight or shading was also incorporated (Reilly et al. 2007, p. 2). Strategic surveys of sites that were predicted by the model to be occupied had 65 percent detection rates (34 of 52 sites were occupied), the highest ever reported for this species (Nauman and Olson 2004, p. 3). In addition to indicating the usefulness of presence or absence modeling as a scientific and management tool, this relatively high detection rate seems to support the associations described by Ollivier et al. (2001) and Welsh et al. (2007a).

Summary of Habitat Associations

Few studies of the habitat associations of Siskiyou Mountains salamanders and Scott Bar salamanders have been conducted. These include only a single large, systematic sample effort, from which two analyses were conducted (Ollivier et al. 2001 and Welsh et al. 2007a). These analyses found positive relationships between detection of Siskiyou Mountains salamanders (and possibly Scott Bar salamanders) and habitat characteristics that likely moderate surface microclimates for them (e.g., high canopy closure, more leaf litter cover, more decaying logs). Studies by Farber et al. (2001), Farber (2007a), and CDFG (Bull et al. 2006) were smaller and less rigorous than the analyses by Ollivier et al. (2001) and Welsh et al. (2007a). However, they clearly showed that Siskiyou Mountains salamanders and Scott Bar salamanders occur within a wide range of habitat conditions, including clearcuts and young forest. The limited available evidence suggests that these species are highly associated with talus and fissured rock outcrops and are generally associated with moist, cool surface microclimates. These salamanders are likely more common in mature and oldgrowth forest than in other forest classes, but many salamander sites occur in other habitat types. Potential differences in the size and viability of populations in open or disturbed habitat and mature or oldgrowth habitat are discussed below under Factor A.
Range and Extant Distribution

Range

Currently known populations within the Siskiyou Mountains salamander Complex occur within Jackson County and the extreme southeast portion of Josephine County in southwestern Oregon, and in northern Siskiyou County in northwestern California. In Oregon, known populations occur in the Applegate Valley watershed north of the Siskiyou Crest. In California, the species complex occurs in the Klamath River drainage, south of the Siskiyou Crest, in the area bounded to the west by Indian Creek and the headwaters of Grider Creek, Kelsey Creek, and Canyon Creek; to the south by Scott Bar Mountain; and to the east by the headwaters of Mill Creek and the Horse Creek drainage. This range is subdivided into three areas based on genetically distinct populations. Siskiyou Mountains salamander North Clade (or Applegate Population) occupies the area north of the Siskiyou Crest; Siskiyou Mountains salamander South Clade (or Grider Population) occurs south of the Siskiyou Crest; and the Scott Bar salamander is found in the southeastern portion of the former range of Siskiyou Mountain salamander South Clade.

Boundary lines for the ranges of the members of the Siskiyou Mountains salamander Complex have been variously estimated by several authors (DeGross 2004, p. 15; Nauman and Olson 2004, p. 2; 2007, p. 4) and have changed through time as additional populations were discovered and results of genetic analyses were obtained. For the purposes of this finding, we delineated species' ranges and calculated landscape statistics based on
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range boundaries proposed by Nauman and Olson (2007, p. 4) but we slightly modified these boundaries based on new species locations, watershed boundaries, and distribution of suitable habitat. Based on the locations of genetic samples of Scott Bar salamanders, we estimated its range to incorporate the southeastern portion of the former Siskiyou Mountains salamander's range. However, the uneven distribution of surveys and small number of locations with genetic confirmation creates uncertainty as to the actual extent of the Scott Bar salamander. The resulting estimated range (136,740 ac (55,335 ha)) is considerably larger than previous estimates that were based on a small number of genetically confirmed locations; some of this expansion is the result of confirmation of one Scott Bar salamander location in the Walker Creek drainage (DeGross 2007). Several watersheds in the southern portion of the estimated range delineated by Nauman and Olson (2007, p. 4) do not have records of Siskiyou Mountains or Scott Bar salamander locations. Review of these areas by species experts (Cuenca 2007; Clayton 2007) indicated that surveys have not been conducted there, but suitable habitat is widespread. Additional surveys and genetic analyses are necessary to adequately delineate the southern boundary of the Scott Bar salamander and Siskiyou Mountains salamander. Our estimates of species' ranges are intended for use in evaluating species' distribution across various land ownership and Federal land allocations; they are not intended to represent precise estimates of occupied habitat.

Our understanding of the range and distribution of the Siskiyou Mountains salamander Complex is dynamic; the known range has roughly tripled between 1980 and 2007, doubling between 1993 and 1998 (Olson et al. 2007, p. 20). Biologists familiar with the species believe that the currently known range is welldefined to the east by xeric conditions and unsuitable soil types, and to the west by the range of the Del Norte salamander (Olson et al. 2007, p. 19). However, it is likely that the known range will continue to be refined and expanded through discovery of additional populations to the south in the Scott River, Canyon Creek, Kelsey Creek, and Upper Grider Creek drainages, and to the north in the Applegate River drainage. For example, two detections of salamanders described as Siskiyou Mountains salamanders were reported by a Survey and Manage Guidelines survey crew near the town of Rogue River in 2006 (DeGross 2007). If confirmed, these detections would represent a range expansion of roughly 5 miles (mi) (8.45 kilometers (km)).

We were unable to find any information suggesting that the occupied range of any member of the Siskiyou Mountains salamander Complex is different from its historical range. Many occupied locations exist within watersheds that have sustained considerable physical modification by historical mining, roadbuilding, and logging. As described above, the species' ranges appear to be defined by climatic conditions, soil and parent material type, and the adjacent Del Norte salamander (Olson et al. 2007, p. 19).

Distribution

The distribution of Siskiyou Mountains and Scott Bar salamander populations within their respective species' ranges is poorly known. With the exception of systematic surveys conducted by Ollivier et al. (2001) and Nauman and Olson (2004a and 2004b), the majority of surveys have been opportunistic or conducted in support of timber management planning activities. Large areas within the species' known ranges remain unsurveyed due to poor access or lack of planned projects requiring surveys. The lack of systematic surveys may result in biased estimates of population distribution. For example, because CDFG requires surveys for Siskiyou Mountains salamanders and Scott Bar salamanders during the Timber Harvest Plan (THP) review process, a high proportion (40 percent) of known Scott Bar salamander locations have been reported on private timberlands, which accounts for only 22 percent of the known range of the species (see Table 1 below). Table 1.Proportion of Land Ownership Within the Estimated Ranges of Siskiyou Mountains Salamanders (SMS) and Scott Bar Salamanders (SBS) Scott Bar Applegate Grider SMS salamander SMSSBS SMS (%) (%) (%) complex (%) Private Lands............................................... 15 9 22 15 Federal Lands:

USFS.................................................... 66 91 78 76

BLM..................................................... 19 0 0 9 Total Area (ac)..................................... 248,870 174,285 136,740 559,895 Total Area (ha)..................................... 100,712 70,529 55,335 226,578

Population distribution is strongly influenced by the abundance and distribution of suitable talus habitat. Using a Geographic Information System (GIS)based predictive model, the Survey and Manage Guidelines Species Review Panel for Siskiyou Mountains salamanders estimated that roughly 30 percent of the known range north of the Siskiyou Crest consisted of highquality talus habitat (USDA and USDI Species Review Panel 2002), but predisturbance surveys conducted in the same area found that 3 to 14 percent of a given planning area (10,000 to 15,000 ac (4,047 to 6,070 ha)) consisted of suitable rock substrate (USDA and USDI Species Review Panel 2001). Based on surveys and mapping of rock habitat, Timber Products Company estimated that approximately 18 percent of their surveyed lands within the range of the Scott Bar salamander was composed of suitable talus habitat (Farber 2006). Using a similar methodology, Fruit Growers Supply Company (2007) estimated that 19 percent of 2,615 ac (1,058 ha) surveyed within the range of the Applegate Population of the Siskiyou Mountains salamander was composed of suitable talus habitat.

The Siskiyou Mountains salamander Complex occurs within a roughly 500,000 ac (202,346 ha) area dominated by Federal lands (see Table 1). The range of the Applegate Population (North Clade) of the Siskiyou Mountains salamander occurs within 248,870 ac (100,712 ha), consisting primarily (85 percent) of Federal lands, and more than 90 percent of the 174,285 ac (70,529 ha) range of the Grider Population (South Clade) of the Siskiyou Mountains salamander occurs on Federal lands (see [[Page 4387]]
Table 1). The Scott Bar salamander has the smallest range, covering approximately 136,740 ac (55,335 ha), and occurs on the smallest proportion of Federal lands (78 percent) within the complex (see Table 1).

Known populations appear to be welldistributed across their respective species' ranges. To evaluate spatial distribution of salamander locations within each species' range at a coarse scale, we compared known locations to watershed boundaries within each species' range. Site locations of the Applegate Population of the Siskiyou Mountains salamander occur within 19 of the 21 watersheds that constitute the range of this group. The range of the Grider Population of the Siskiyou Mountains salamander is composed of 36 watersheds of which 23 (64 percent) contain known populations. The 13 watersheds without known salamander locations are primarily situated in Wilderness and Roadless areas where access is difficult and few surveys have been conducted. Known locations of Scott Bar salamanders occupy 17 of the 25 watersheds within their range. Of the eight watersheds without known locations, six are within Wilderness and Roadless areas where suitable habitat exists but surveys have not been conducted.

Nauman and Olson (2007) conducted surveys at a stratified random sample of points located on Federal lands within the range of the Grider Population of the Siskiyou Mountains salamander and the Scott Bar salamander. They found occupancy rates (presence or absence) to be similar at highelevation (greater than 4,000 feet (ft) (1,219 meters (m)) sites and lowelevation (less than 4,000 ft (1,219 m)) sites, but relative abundance (captures per person, per hour) at lowelevation sites was roughly twice that at high elevation. The authors conducted a single survey visit per site during one season, and did not evaluate the potential effect of variable detection probabilities at different elevations on their results, which, as noted above, may underestimate the number of animals actually present; however, their findings suggest that these salamanders may be less abundant or less detectable at higher elevations.

Population Size and Trend

Evaluation of potential population sizes for the Siskiyou Mountains salamander and Scott Bar salamander is strongly influenced by the species' low detectability and the amount and distribution of potentially suitable habitat. Because of their secretive habits, detection rates for these salamanders are very low, even though the species may be locally quite abundant (Nussbaum 1974, p. 3; Clayton et al. 1999, p. 133). Results of surveys within habitat known to be occupied are frequently negative (Clayton et al. 2004, p. 10; CDFG 2005, p. 10). Individual populations likely range in size from a few individuals to thousands of individuals (Nussbaum 1974, p. 16; Welsh and Lind 1992, p. 96). Based on extrapolation of salamander densities obtained during intensive field surveys, Nussbaum (1974, p. 16) provided a specieswide ``conservative estimate'' of over 3 million Siskiyou Mountains salamanders, and opined that the actual abundance could be 10 times as high. While the author acknowledged that a number of methodological problems may affect this estimate, it nonetheless suggests that the perceived rarity of this species may be more related to low detectability than to actual population size.

Our current understanding of population sizes for Siskiyou Mountains salamander and Scott Bar salamander is based primarily on the cumulative number of occupied sites or locations that have been reported over time. However, these numbers may be misleading for several reasons. At many locations, particularly sites detected during project surveys under Survey and Manage Guidelines, no attempt was made to determine population size; detection of a single individual was adequate to define an occupied site. Because of this, large habitat patches potentially supporting many individual salamanders are counted as equivalent to small habitat patches or detections of dispersing individuals. In addition, large areas of suitable habitat remain unsurveyed, particularly in Wilderness, Roadless Areas, and Late successional Reserves where access is poor or project surveys are typically not conducted (Latesuccessional Reserves are a NWFP land allocation designed to serve as habitat for latesuccessional and old growthrelated species). For example, approximately 10 percent and 26 percent of the range of the Scott Bar salamander and Grider salamander, respectively, is classified as ``Roadless Area.'' Finally, known locations are frequently spatially clumped, and no uniform effort to distinguish between individual populations has been undertaken. Agencies and researchers involved with these species employ several criteria (e.g., 164 to 492 ft (50 to 150 m) spacing, presence of perennial stream or area of unsuitable habitat) to imply separation between occupied locations or ``populations.'' For these reasons, the currently known numbers of Siskiyou Mountains salamanders and Scott Bar salamanders are more representative of the distribution and intensity of survey efforts than of actual salamander populations.

The numbers of known locations of Siskiyou Mountains salamanders and Scott Bar salamanders have increased steadily since the discovery of these species. For example, the number of known locations of Scott Bar salamanders on lands managed by Timber Products Company increased from 8 in 1997 to 36 in 2007 (Farber 2007c). To describe the number and distribution of known salamander locations, we obtained location data from Federal and State agencies and private timber companies and combined them into a single GIS layer. Because of variability in methods used by various agencies to delineate individual locations (many locations were clumped less than 328 ft (100 m) apart), we evaluated the proximity of adjacent locations and retained only locations greater than 328 ft (100 m) apart, to minimize the inclusion of multiple records at discrete locations. The resulting numbers are intended to represent individual populations, but likely still contain multiple records from large habitat patches and likely differ from previous estimates based on dissimilar mapping methods.

Within each of the genetic subunits in the Siskiyou Mountains salamander Complex, the number of locations with individuals that have been genetically confirmed to the species level is much smaller than the overall number of known locations. For example, the estimated range of the Scott Bar salamander is defined on the basis of 23 genetically confirmed locations from the samples of Mahoney, Mead, and DeGross; however, the defined range of the species contains 98 additional salamander locations previously attributed to the Grider salamander. Because populations of the two species tend not to overlap (Mead 2006, p. 10), it is reasonable to conclude that all salamander detections within what is now known to be the range of the Scott Bar salamander are Scott Bar salamanders. For the purposes of this finding, we used the total number of individual locations within each species' range, recognizing that ongoing genetic studies may modify the boundaries of these subunits, and therefore the number of known individual sites within each genetic subgroup.
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Table 2.Number of Known Locations and Percent of Total Known Siskiyou Mountains Salamanders (SMS) and Scott Bar Salamanders (SBS) on Federal and Private Lands Scott Bar SMSSBS Applegate SMS Grider SMS salamander \1\ complex Federal lands................................... 376 (85%) 74 (97%) 69 (60%) 519 (82%) Private Lands................................... 64 (14%) 2 (3%) 46 (40%) 112 (18%)

Total....................................... 440 76 115 631 \1\ Number of known Plethodon sp. locations within the presumed range of the Scott Bar salamander. Density

Population densities for the Siskiyou Mountains salamander Complex are poorly known. Estimation of population density for these salamanders is hindered by low detectability and highly variable environmental or habitat conditions during surveys (Nussbaum 1974, p. 15). Densities recorded during the habitat associations study conducted by Ollivier et al. (2001, p. 16) ranged from 1 to 13 animals per 527 ft\2\ (49m\2\) search plot (i.e., 0.02 to 0.33 animals per m\2\); whereas Nussbaum (1974, p. 16) recorded 0.53 animals per m\2\ during an intensive field study. Nauman and Olson (2007, p. 19) reported an average of 0.01 salamanders per m\2\ and 2.39 salamanders per person, per hour in California, with capture rates ranging from 2.83 salamanders per person, per hour at lower elevations to 1.25 salamanders per person, per hour at higher elevation sites. An inventory of all known Siskiyou Mountains salamander sites on the Applegate Ranger District in 1992 reported abundances of salamanders ranging from 0.3 to 11 salamanders per person, per hour (Olson et al. 2007, p. 13). None of these studies was designed to estimate salamander density, and markrecapture studies that would permit estimation of density have not been conducted.

Population Trend

We were unable to locate any information describing population trends for the Scott Bar salamander or Siskiyou Mountains salamander (or either of its constituent populations). Several authors have inferred population declines based on observations of habitat modification within occupied areas (Ollivier et al. 2001, p. 5; Welsh 2005, pp. 57), but their study design did not support this type of inference.

Land Management

Populations of Siskiyou Mountains salamanders and Scott Bar salamanders receive an added layer of security from several conservation efforts on Federal lands. The majority of the Siskiyou Mountains salamander Complex occurs within lands administered under the provisions of the NWFP (USDA and USDI 1994) (see Table 1 above), which was established to provide an ecosystembased management strategy for latesuccessional forests and the wildlife species that inhabit them (USDA and USDI 1994). The NWFP consists of two primary parts that concern salamander conservation: (1) A system of landuse allocations with associated Standards and Guidelines to guide land management; and, (2) until recently, the Survey and Manage Mitigation Measure Standards and Guidelines, which provided speciesspecific management guidance for certain groups of species. The NWFP Record of Decision (ROD) was implemented as amendments to all existing land and resource management plans for the Bureau of Land Management (BLM) and USFS within the range of the northern spotted owl.

Lands administered by the USFS and BLM are divided into five primary categories of land management under the NWFP: Latesuccessional Reserves, Congressionally Reserved Areas, Riparian Reserves, Adaptive Management Areas, and Matrix. Latesuccessional Reserves are established with an objective to protect and enhance conditions of latesuccessional and oldgrowth forest ecosystems, which serve as habitat for latesuccessional, forestrelated species. Forest management activities are highly restricted within Latesuccessional Reserves. Congressionally Reserved Areas, such as Wilderness Areas, Wild and Scenic Rivers, and National Monuments, are incorporated into the design of the Latesuccessional Reserve System. Riparian Reserves provide an area along all streams, wetlands, lakes, ponds, and unstable areas where ripariandependant resources receive primary management emphasis. Maintenance of forested conditions in Riparian Reserves for shading and water quality is also expected to contribute to dispersal and breeding habitat for latesuccessional species. Adaptive Management Areas (AMAs) are established to develop and test new management approaches and timber harvest methods to integrate and achieve ecological and economic health, and other social objectives. Matrix lands consist of those Federal lands outside of the four other categories described above. Production of timber and other commodities is an important objective for Matrix lands. However, forests in the Matrix also provide connectivity between Latesuccessional Reserves and function as habitat for a variety of forestdwelling species. The NWFP Matrix Standards and Guidelines are designed to provide for important ecological functions such as dispersal of organisms, carryover of some species from one stand to the next, and maintenance of ecologically valuable structural components such as logs, snags, and large trees. The Matrix also provides ecological diversity by providing early successional habitat. Within Matrix, other land use allocations such as Visual Emphasis Areas, Managed Wildlife Areas, and Retention Areas carry additional restrictions on timber harvest and to some degree function as reserves.
Table 3.Federal Land Allocations Within the Estimated Ranges of the Siskiyou Mountains Salamander (SMS) and Scott Bar Salamander (SBS) Applegate Scott Bar SMSSBS SMS Grider SMS salamander complex Total area in ac (ha)................................... 248,870 174,285 136,740 559,895 (100,712) (70,529) (55,335) (226,578) [[Page 4389]]
Private Lands (%)....................................... 15 9 22 15 Federal Lands (%):

Reserves............................................ 33 73 51 50

Adaptive Management Area \1\........................ 42 0 0 19

Matrixretention \2\................................ 1 13 19 9

Matrixgeneral forest \3\........................... 9 5 8 7 \1\ Experimental management to meet ecological, economic, and social goals. \2\ Timber harvest restricted to accommodate various other management goals. \3\ Timber production is a high priority.

Roughly 33 percent of the range of the Applegate salamander occurs within reserves (Latesuccessional Reserves, Wilderness, Riparian Reserves, and other land allocations withdrawn from scheduled timber harvest), 42 percent of the range within the Applegate Adaptive Management Area, 9 percent in Matrix, and 15 percent on private lands (see Table 3 above). Nearly threequarters of the range of the Grider salamander is in reserves, and 18 percent is in Matrix; however, almost threefourths of the Matrix is in landuse

FOR FURTHER INFORMATION CONTACT Phil Detrich, Field Supervisor, U.S. Fish and Wildlife Service, Yreka Fish and Wildlife Office (see ADDRESSES section). If you use a telecommunications device for the deaf (TDD), call the Federal Information Relay Service (FIRS) at 800877 8339.