Effects of Timber Harvesting on Southern Appalachian Salamanders

We compared the species richness and abundance of salamanders on six recent clearcuts (< 10 years old) with that of salamanders on 34 mature forest stands (>50 years old) in southern Appalachian forests in western North Carolina, U.S.A. Catches of salamanders from plots in mature forest stands were about five times higher than those on recent clearcuts. Almost all species and major taxonomic groups of salamanders were adversely affected by timber removal. Mean number of species collected per plot was about twice as great in mature forest stands as in clearcuts. Analyses of stand age versus salamander catch for 47 plots indicate that 50–70 years are required for populations to return to predisturbance levels following cutting. We conservatively estimate that clearcutting in U.S. national forests in western North Carolina results in a loss of nearly 14 millton salamanders annually. It also is chronically reducing regional populations by more than a quarter of a billion salamanders (9%) below that which could be sustained if mature forests were not cut.     

Forest Roads as Partial Barriers to Terrestrial Salamander Movement

Abstract:  Roads can fragment animal populations by disrupting movement among formerly continuous habitats. Although models have demonstrated that disrupted movement can contribute to long-term extinction, there are few empirical data on the effects of roads on animal movement. We used displacement and homing experiments to determine whether forest roads are barriers to the movement of terrestrial salamanders. We displaced 1471 red-backed salamanders ( Plethodon cinereus ) across five forest roads and compared return rates to those of salamanders displaced equal distances toward the forest interior. Roads significantly reduced the return rate of salamanders, with a mean reduction of 51%. Steep roadside verges further reduced return rates, particularly for salamanders moving downhill across verges. The permeability of roads to salamander movement did not appear to be related to road surface type. Gravel roads had both the highest and lowest observed permeability with the two paved roads intermediate between these. We conclude that narrow forest roads are partial barriers to salamander movement and that steep roadside verges may exacerbate these effects.     

Effects of timber harvesting on pond-breeding amphibian persistence: testing the evacuation hypothesis.

Numerous studies have documented the decline of amphibians following timber harvest. However, direct evidence concerning the mechanisms of population decline is lacking and hinders attempts to develop conservation or recovery plans and solutions for forest species. We summarized the mechanisms by which abundance of amphibians may initially decline following timber harvest into three testable hypotheses: (1) mortality, (2) retreat, and (3) evacuation. Here, we tested the evacuation hypothesis within a large-scale, replicated experiment. We used drift fences with pitfall traps to capture pond-breeding amphibians moving out of experimental clearcut quadrants and into control quadrants at four replicate arrays located within the Daniel Boone Conservation Area on the upper Ozark Plateau in Warren County, Missouri, USA. During the preharvest year of 2004, only 51.6% of the 312 individuals captured were moving out of pre-clearcut quadrants, and movement did not differ from random. In contrast, during both postharvest years of 2005 and 2006, the number of captures along the quadrant edge increased, and a higher proportion of individuals (59.9% and 56.6%, respectively, by year) were moving out of clearcut quadrants than entering. Salamanders moved out of clearcuts in large percentages (Ambystoma annulatum, 78.2% in 2005, 78.2% in 2006; A. maculatum, 64.0% in 2005, 57.1% in 2006). Frogs and toads also moved out of clearcut quadrants, but in lower percentages (Bufo americanus, 59.6% in 2005, 53.3% in 2006; Rana clamitans, 52.7% in 2006). Salamanders moved out of clearcuts with low-wood treatments more than out of clearcuts with high-wood treatments. Movement of salamanders out of clearcuts was independent of sex. Estimated movement out of clearcuts represented between 8.7% and 35.0% of the total breeding adults captured for two species of salamanders. Although we recognize that some portion of the amphibian population may retreat underground for short periods and others may not survive the effects of timber harvest, these data are the first direct evidence showing that individuals are capable of leaving clearcuts and shifting habitat use.     

Life History as a Predictor of Salamander Recovery Rate from Timber Harvest in Southern Appalachian Forests,U.S.A

Forest management often represents a balance between social, economic, and ecological objectives. In the eastern United States, numerous studies have established that terrestrial salamander populations initially decline in abundance following timber harvest, yet the large‐scale and long‐term consequences are relatively unknown. We used count data from terrestrial survey points to examine the relation between salamander abundance and historic timber harvest while accounting for imperfect detection of individuals. Overall, stream‐ and terrestrial‐breeding salamanders appeared to differ by magnitude of population decline, rate of population recovery, and extent of recolonization from surrounding forest. Specifically, estimated abundance of both species groups was positively associated with stand age and recovery rates were predicted to increase over time for red‐legged salamanders (Plethodon shermani) and decrease in stream‐breeding species. Abundance of stream‐breeding salamanders was predicted to reach a peak by 100 years after timber harvest, and the population growth rate of red‐legged salamanders was predicted to undergo a significant increase 100 years after harvest. Estimated abundance of stream‐breeding salamanders in young forest stands was also negatively associated with the distance to adjacent forest, a result that suggests immigration has a role in the recovery of these species. Our results indicate that salamander abundance in young forest stands may be only modestly lower than in more mature forest but that full recovery from timber harvest may take a substantial amount of time and that species life history may affect patterns of recovery. Historia de Vida como un Vaticinador de la Tasa de Recuperación de una Salamandra a la Colecta de Madera en los Bosques del Sur de los Apalaches, E.U.A     

Effects of Clearcutting on Habitat Use and Reproductive Success of the Ovenbird in Forested Landscapes

We studied Ovenbirds ( Seiurus aurocapillus ) in northern New Hampshire during 1992 and 1993 to determine whether edge-related changes in habitat use and reproductive success reported in fragmented landscapes exist in predominantly forested landscapes. Six study plots were placed adjacent to four recent clearcuts (2.1–5 ha) and extended 400 m into the forest interior. Nests, territories, and territorial males obtaining mates were equally distributed in edge (0–200 m) and interior (201–400 m) areas. Nest survival was higher in the forest interior in 1992 and for 1992 and 1993 combined. The proportion of pairs fledging ≥ 1 young, fledgling weight, and fledgling wing-chord did not differ between edge and interior in either year. Number of young fledged per pair was slightly lower in edge areas, but these differences were not significant. We conclude that clearcutting in extensively forested landscapes can affect Ovenbird reproductive success. Nevertheless, the effect on Ovenbird populations is moderated by the abundance of mature forest cover in the region and by the tendency of Ovenbirds to renest after initial nest failure.     

A Case for Using Plethodontid Salamanders for Monitoring Biodiversity and Ecosystem Integrity of North American Forests

Abstract: Terrestrial salamanders of the family Plethodontidae have unique attributes that make them excellent indicators of biodiversity and ecosystem integrity in forested habitats. Their longevity, small territory size, site fidelity, sensitivity to natural and anthropogenic perturbations, tendency to occur in high densities, and low sampling costs mean that counts of plethodontid salamanders provide numerous advantages over counts of other North American forest organisms for indicating environmental change. Furthermore, they are tightly linked physiologically to microclimatic and successional processes that influence the distribution and abundance of numerous other hydrophilic but difficult-to-study forest-dwelling plants and animals. Ecosystem processes such as moisture cycling, food-web dynamics, and succession, with their related structural and microclimatic variability, all affect forest biodiversity and have been shown to affect salamander populations as well. We determined the variability associated with sampling for plethodontid salamanders by estimating the coefficient of variation (CV ) from available time-series data. The median coefficient of variation indicated that variation in counts of individuals among studies was much lower in plethodontids (27%) than in lepidoptera (93%), passerine birds (57%), small mammals (69%), or other amphibians (37–46%), which means plethodontid salamanders provide an important statistical advantage over other species for monitoring long-term forest health.     

Plethodontid Salamander Response to Silvicultural Practices in Missouri Ozark Forests

Abstract: There is little information on the effects of tree harvest on salamander populations in the midwestern United States. We present data on plethodontid salamander densities in replicated stands of three forest age classes in the southeastern Ozarks of Missouri. Forest age classes consisted of regeneration-cut sites <5 years old, second-growth sites 70–80 years old, and old-growth sites> 120 years old. Salamander abundance on 21, 144-m² plots was determined by area- and time-constrained searches. We also compared age-class habitat characteristics, including downed woody debris, canopy cover, ground area cover, herbaceous vegetation, and woody vegetation. Salamander density was lowest in newly regenerated forests and highest in forests> 120 years old. Comparisons of recently regenerated forests with mature forests> 70 years old indicated that terrestrial salamanders were reduced to very low numbers when mature forests had been intensively harvested. This reduction may result from a decrease in microhabitat availability. Forest age-class comparisons further indicated that salamander abundance slowly increased over time after forests had regenerated. Management decisions that take into account plethodontid salamander abundance and their response to forest structural diversity are important components in sustaining ecosystem integrity while maximizing economic yield.     

Distribution of Carabid Beetles (Coleoptera, Carabidae) across a Boreal Forest–Clearcut Ecotone

Abstract: We studied the occurrence of carabid beetles (Coleoptera, Carabidae) in boreal forest fragments, their edges, and adjacent clearcuts in central Finland. Beetles were collected with pitfall traps along transects extending 60 m from the edge into clearcuts and 60 m into forest interior. Our main findings were that (1) species richness was significantly higher in the clearcut than in the forest fragments, (2) clearcuts hosted many open-habitat species, which increased overall species richness in these sites, (3) carabid assemblages in the edges were more similar to forest assemblages than to those found in the clearcuts, (4) no edge specialists were found, and (5) open-habitat species did not penetrate into the forest fragments from the clearcut. Because forest specialists occurred all the way to the edge on the forest side, it seems that edge effects per se do not adversely affect these species, at least in the short term. In the long term, however, habitat conditions in the edges may deteriorate for interior species because of trees falling over in strong winds, thereby reducing the size of the fragments and widening the edge zone.     

Declines in Woodland Salamander Abundance Associated with Non-Native Earthworm and Plant Invasions

Abstract:  Factors that negatively affect the quality of wildlife habitat are a major concern for conservation. Non-native species invasions, in particular, are perceived as a global threat to the quality of wildlife habitat. Recent evidence indicates that some changes to understory plant communities in northern temperate forests of North America, including invasions by 3 non-native plant species, are facilitated by non-native earthworm invasion. Furthermore, non-native earthworm invasions cause a reduction in leaf litter on the forest floor, and the loss of forest leaf litter is commonly associated with declines in forest fauna, including amphibians. We conducted a mark-recapture study of woodland salamander abundance across plant invasion fronts at 10 sites to determine whether earthworm or plant invasions were associated with reduced salamander abundance. Salamander abundance declined exponentially with decreasing leaf litter volume. There was no significant relationship between invasive plant cover and salamander abundance, independent of the effects of leaf litter loss due to earthworm invasion. An analysis of selected salamander prey abundance (excluding earthworms) at 4 sites showed that prey abundance declined with declining leaf litter. The loss of leaf litter layers due to non-native earthworm invasions appears to be negatively affecting woodland salamander abundance, in part, because of declines in the abundance of small arthropods that are a stable resource for salamanders. Our results demonstrate that earthworm invasions pose a significant threat to woodland amphibian fauna in the northeastern United States, and that plant invasions are symptomatic of degraded amphibian habitat but are not necessarily drivers of habitat degradation.     

Salamander Abundance along Road Edges and within Abandoned Logging Roads in Appalachian Forests

Abstract:  Roads may be one of the most common disturbances in otherwise continuous forested habitat in the southern Appalachian Mountains. Despite their obvious presence on the landscape, there is limited data on the ecological effects along a road edge or the size of the "road-effect zone." We sampled salamanders at current and abandoned road sites within the Nantahala National Forest, North Carolina (U.S.A.) to determine the road-effect zone for an assemblage of woodland salamanders. Salamander abundance near the road was reduced significantly, and salamanders along the edges were predominantly large individuals. These results indicate that the road-effect zone for these salamanders extended 35 m on either side of the relatively narrow, low-use forest roads along which we sampled. Furthermore, salamander abundance was significantly lower on old, abandoned logging roads compared with the adjacent upslope sites. These results indicate that forest roads and abandoned logging roads have negative effects on forest-dependent species such as plethodontid salamanders. Our results may apply to other protected forests in the southern Appalachians and may exemplify a problem created by current and past land use activities in all forested regions, especially those related to road building for natural-resource extraction. Our results show that the effect of roads reached well beyond their boundary and that abandonment or the decommissioning of roads did not reverse detrimental ecological effects; rather, our results indicate that management decisions have significant repercussions for generations to come. Furthermore, the quantity of suitable forested habitat in the protected areas we studied was significantly reduced: between 28.6% and 36.9% of the area was affected by roads. Management and policy decisions must use current and historical data on land use to understand cumulative impacts on forest-dependent species and to fully protect biodiversity on national lands     

Patterns of litter disappearance in a northern hardwood forest invaded by exotic earthworms.

A field study was conducted to evaluate the effects of exotic earthworm invasions on the rates of leaf litter disappearance in a northern hardwood forest in southcentral New York, USA. Specifically, we assessed whether differences in litter quality and the species composition of exotic earthworm communities affected leaf litter disappearance rates. Two forest sites with contrasting communities of exotic earthworms were selected, and disappearance rates of sugar maple and red oak litter were estimated in litter boxes in adjacent earthworm-free, transition, and earthworm-invaded plots within each site. After 540 days in the field, 1.7-3 times more litter remained in the reference plots than in the earthworm-invaded plots. In the earthworm-invaded plots, rates of disappearance of sugar maple litter were higher than for oak litter during the first year, but by the end of the experiment, the amount of sugar maple and oak litter remaining in the earthworm-invaded plots was identical within each site. The composition of the earthworm communities significantly affected the patterns of litter disappearance. In the site dominated by the anecic earthworm Lumbricus terrestris and the endogeic Aporrectodea tuberculata, the percentage of litter remaining after 540 days (approximately 17%) was significantly less than at the site dominated by L. rubellus and Octolasion tyrtaeum (approximately 27%). This difference may be attributed to the differences in feeding behavior of the two litter-feeding species: L. terrestris buries entire leaves in vertical burrows, whereas L. rubellus usually feeds on litter at the soil surface, leaving behind leaf petioles and veins. Our results showed that earthworms not only accelerate litter disappearance rates, but also may reduce the differences in decomposition rates that result from different litter qualities at later stages of decay. Similarly, our results indicate that earthworm effects on decomposition vary with earthworm community composition. Furthermore, because earthworm invasion can involve a predictable shift in community structure along invasion fronts or through time, the community dynamics of invasion are important in predicting the spatial and temporal effects of earthworm invasion on litter decomposition, especially at later stages of decay.     

Effects of Forest Management on Amphibians and Reptiles in Missouri Ozark Forests

Abstract:  As part of the Missouri Ozark Forest Ecosystem Project (MOFEP), we experimentally evaluated the impacts of forest management on the relative abundance of amphibians and reptiles in Missouri's Ozark forests (U.S.A.). Using large study sites (average size of 400 ha) as the experimental unit, we tested the effects of uneven-aged and even-aged forest management treatments compared with no-harvest management (i.e., control) on the relative abundance of 13 focal amphibian and reptile species. Within even-aged management sites, we also focused on the local-scale effects of clearcutting on these species by comparing relative abundance among plots located within clearcut stands, 50 m away from clearcut stands, and 200 m away from clearcut stands. Pretreatment sampling of species abundance occurred from 1992 through 1995, and post-treatment sampling occurred from 1997 through 2000. At the landscape scale, treatment significantly affected the abundance of Bufo americanus . This species declined less on even-aged management sites than on control sites, but the general decline on all sites suggests that other factors may have contributed to this result. Within even-aged management sites, most amphibian species declined and some reptile species increased relative to pretreatment abundances within clearcut stands. We found significant effects of distance from clearcut for two amphibian species, Ambystoma maculatum and Rana clamitans, and two reptile species, Scincella lateralis and Sceloporus undulatus . In general, we conclude that clearcuts within even-aged management sites locally affected amphibian and reptile species but, at a larger spatial scale, we did not detect significant effects of even-aged and uneven-aged forest management. These findings represent relatively short-term data but suggest that forest management and maintenance of biodiversity may be compatible when relatively small amounts of the landscape are disturbed.     

Response of a Reptile Guild to Forest Harvesting

Abstract:  Despite the growing concern over reptile population declines, the effects of modern industrial silviculture on reptiles have been understudied, particularly for diminutive and often overlooked species such as small-bodied snakes. We created 4 replicated forest-management landscapes to determine the response of small snakes to forest harvesting in the Coastal Plain of the southeastern United States. We divided the replicated landscapes into 4 treatments that represented a range of disturbed habitats: clearcut with coarse woody debris removed; clearcut with coarse woody debris retained; thinned pine stand; and control (unharvested second-growth planted pines). Canopy cover and ground litter were significantly reduced in clearcuts, intermediate in thinned forests, and highest in unharvested controls. Bare soil, maximum air temperatures, and understory vegetation all increased with increasing habitat disturbance. Concomitantly, we observed significantly reduced relative abundance of all 6 study species (scarletsnake [Cemophora coccinea] , ring-neck snake [Diadophis punctatus] , scarlet kingsnake [Lampropeltis triangulum] , red-bellied snake [Storeria occipitomaculata] , southeastern crowned snake [Tantilla coronata] , and smooth earthsnake [Virginia valeriae] ) in clearcuts compared with unharvested or thinned pine stands. In contrast, the greatest relative snake abundance occurred in thinned forest stands. Our results demonstrate that at least one form of forest harvesting is compatible with maintaining snake populations. Our results also highlight the importance of open-canopy structure and ground litter to small snakes in southeastern forests and the negative consequences of forest clearcutting for small snakes.     

Effects of different mobilities of leaf and woody litters on litter carbon dynamics in arid ecosystems in Western Australia

Afforestation of arid land is a promising countermeasure against global warming. We had previously found, through modeling and mass balance analyses of an arid land afforestation experimental project in Western Australia, that a significant amount of litter could have been physically removed from the floors of natural forests. In order to analyze litter carbon dynamics in depth, we investigated the actual mobility of litter in several natural forests in Sturt Meadows in an arid region of Western Australia, and estimated the difference between the removal rate of leaf and woody (twigs and branches) litter on the forest floor. Then we redeveloped a litter carbon dynamics model by incorporating physical removal of litter to show the different mobilities of leaf and woody litters. We also analyzed carbon balances and the effect of differential litter mobility on litter carbon dynamics. Except for twigs in one plot in a high density forest, 29–100% of leaf litter and 10–100% of woody litter was removed annually, demonstrating the physical removal of litter in these natural forests. The main cause of litter removal was wind, not flooding. Decreases in leaf and woody litters could be approximated as first order decay functions in most plots; first order decay or disappearance rate constants were then determined. Estimated disappearance rate constants of leaf and woody litter ranged from 0.19 to 11 and 0.11–12 year⁻¹, respectively; most of the constants ranged from 0.19 to 2.0 and 0.11–0.74 year⁻¹, respectively. Based on the disappearance rate constant, the mobility of woody litter was estimated to be roughly 20% that of leaf litter, confirming that climatic factors move leaves more easily than twigs. The improved model, which took into account the different mobilities of leaf and woody litters, showed that annual physical removal of litter reached 70–82% of the annual litter fall in Acacia aneura forests, and that roughly 40–60% of the existing litter was removed annually from all sites. Incorporating into the model the difference in mobilities of leaf and woody litters showed that the ratio of annual litter removal to annual litter fall increased about 10% points compared with the assumption of that both litter types had equal mobility.     

Response of Red-Backed Voles to Recent Patch Cutting in Subalpine Forest

We examined the response of southern red-backed voles ( Clethrionomys gapperi ) to patch cutting in a forested landscape in which 23% of the forest cover had been removed by timber harvest. We live trapped voles in and around 18 patchcuts in one watershed of southern Wyoming. Although we found a significant difference in capture rates between patchcut interior and forest habitats in 1 of 2 years, voles did not strongly avoid the interior of patchcuts. This result contrasts with results from most studies of voles in clearcut ecosystems, which report that red-backed voles are generally rare or absent from clearcuts. Capture rates were highest on both sides of the patchcut edge, which also contrasts with studies of voles at the edges of forest remnants. The use of patchcut interior and edge habitats could not be explained as a consequence of juvenile voles dispersing to those habitats or males moving through the habitat in search of mates. We suggest that, despite similar physiognomy in patchcut and clearcut sites, the differences in landscape structure in perforated versus fragmented landscapes lead to very different patterns of vole movement. Understanding the scales at which voles perceive landscapes as coarse- or fine-grained will be key to developing predictive models to aid managers in designing timber sales that maintain high vole populations. Our results emphasize the importance of the spatial pattern and scale of disturbance in determining the response of vertebrates to landscape change and the need for more refined investigations of the consequences of deforestation.     

Effects of Clear-Cut Harvesting on Boreal Ground-Beetle Assemblages (Coleoptera: Carabidae) in Western Canada

We compared pitfall catches from four types of mature lodgepole pine—white spruce forest with those from five age classes of young forest regenerating subsequent to clear-cutting. Ground beetles were most abundant in the youngest sites (1–2 years since cutting) and in the mature stands on moist soil. Species richness was higher in regenerating sites than in mature forest. Cluster analysis grouped the ground-beetle fauna according to forest age and forest type, suggesting that there is a general pattern of recovery after logging. Responses of common species to forest cutting fell into three groups: (1) forest generalists (2 species) were not dramatically affected, (2) species of open habitat (27 species) appeared and/or increased in abundance, and (3) mature forest species (10 species) disappeared or decreased in abundance. Populations of many mature forest species appear to recover following logging, but several specialists did not recolonize even the oldest regenerating stands. Furthermore, fragmentation and creation of large areas of relatively homogeneous young forest stages through logging may have detrimental long-term effects even on the more abundant forest generalists. We must better understand subtle variations in habitat in order to maintain invertebrate diversity while harvesting the boreal forest.     

Effects of Warming Conditions in Eastern North American Forests on Red-Backed Salamander Morphology

Abstract:  Several studies have reported climate-associated changes in phenotypically plastic traits of amphibians, yet it remains unknown whether amphibians can manifest an evolutionary response to global climate change at the rate and magnitude that it is occurring. To assess this issue, we examined temporal change in the morphology of the red-backed salamander ( Plethodon cinereus ), a small, abundant woodland salamander distributed widely in eastern North America with two distinct morphotypes: striped individuals associated with cooler microclimates and unstriped individuals associated with warmer microclimates. We compiled morph frequencies for 50,960 individual salamanders from 558 sites as recorded in the published literature and in unpublished field notes of herpetologists between 1908 and 2004. We observed that striping probability increased with increasing latitude, longitude, and elevation and decreased (from 80% to 74% range wide) with time. The combined forces of regional climate warming and, particularly, forest disturbance have evidently been sufficient to cause morphological evolution in this amphibian over the last century.     

Edge Effects and Isolation: Red-Backed Voles on Forest Remnants

Negative effects of habitat edge have been advanced as an important proximate cause of extinction, and a growing literature calls attention to the matrix surrounding habitat remnants as a critical factor determining population persistence. I examined spatial distribution of California red-backed voles ( Clethrionomys californicus ) on 13 forest remnants and five control sites in southwestern Oregon. The species was virtually isolated on remnants, making little use of the regenerating clearcuts surrounding the remnants. The effects of the clearcut also impinged on the remnants as edge effects: six times more voles were captured per trap in the interior of remnants than on the edge. Consequently, the density of voles per unit area on remnants increased with remnant size, despite the potential buildup of population density in small isolates due to limited emigration. I explored potential mechanisms of the negative edge effect on voles and found that the biomass of coarse woody debris, per se, did not explain the vole distribution because both number and volume of logs increased from the interior to the edge of remnants. However, the distribution of the vole's primary food item, hypogeous sporocarps of mycorrhizal fungi, did correspond to the vole edge effect     

Effects of Forest Roads on Macroinvertebrate Soil Fauna of the Southern Appalachian Mountains

Abstract: Many forested landscapes are fragmented by roads, but our understanding of the effects of these roads on the function and diversity of the surrounding forest is in its infancy. I investigated the effect of roads in otherwise continuous forests on the macroinvertebrate fauna of the soil. I took soil samples along transects leading away from the edges of unpaved roads in the Cherokee National Forest in the Southern Appalachian mountains of the United States. Roads significantly depressed both the abundance and the richness of the macroinvertebrate soil fauna. Roads also significantly reduced the depth of the leaf-litter layer. These effects persisted up to 100 m into the forest. Wider roads and roads with more open canopies tended to produce steeper declines in abundance, richness, and leaf-litter depth, but these effects were significant only for canopy cover and litter depth. The macroinvertebrate fauna of the leaf litter plays a pivotal role in the ability of the soil to process energy and nutrients. These macroinvertebrates also provide prey for vertebrate species such as salamanders and ground-foraging birds. The effect of roads on the surrounding forest is compounded by the sprawling nature of the road system in this and many other forests. My data suggest that even relatively narrow roads through forests can produce marked edge effects that may have negative consequences for the function and diversity of the forest ecosystem.     

Relictual Amphibians and Old-Growth Forests

Abstract: Terrestrial and aquatic herpetofauna were sampled by pitfall traps, time-constrained searches, and area-constrained searches (stream sites only) over a three-year period to examine the importance of forest age to amphibians and reptiles. Fifty-four terrestrial and 39 aquatic sites in Douglas-fir—dominated, mixed evergreen forests were located in southwestern Oregon and northwestern California Mean age of trees on sites ranged in age from 30 to 560 years. Thirty-one species of amphibians and reptiles were detected from the 93 localities. Only three species were found primarily on older forest sites: the Del Norte salamander (Plethodon elongatus), the Olympic salamander (Rhyacotriton olympicus), and the tailed frog (Ascaphus truei). Paleoeco-logic evidence indicates an historical association between these three amphibians and the extant elements of ancient primeval coniferous forests of the Pacific Northwest. The life histories and habitat requirements of these species suggest that these forms are scarce in younger forests because the microclimatic and microhabitat conditions they require generally exist only in older forests. The long-term viability of these species in northern California and southern Oregon may depend upon developing forestry practices that protect these mitical microclimates and microhabitats.