amphibian macrohabitat associations on a private industrial forest in western washington

Amphibian Macrohabitat Associations on a Private Industrial Forest in Western WashingtonAuthor(s): Thomas BosakowskiSource: Northwestern Naturalist, Vol. 80, No. 2 (Autumn, 1999), pp. 61-69Published by: Society for Northwestern Vertebrate BiologyStable URL: http://www.jstor.org/stable/3536930 .

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NORTHWESTERN NATURALIST 80:61-69 AUTUMN 1999

AMPHIBIAN MACROHABITAT ASSOCIATIONS ON A PRIVATE INDUSTRIAL FOREST IN WESTERN WASHINGTON

THOMAS BOSAKOWSKI1

Beak Consultants Incorporated, 12931 NE 126th Place, Kirkland, WA 98034 USA

ABSTRACT Landscape scale macrohabitat variables associated with amphibian communities were addressed in a private industrial forest in Washington. A GIS (Geographic Information System) analysis including 8 macrohabitat types was conducted within a 200-m radius around the center of survey sites. Multiple regression analysis was conducted to examine macrohabitat area associations for each species. Amphibians were sampled in 50 stream reaches, 29 wetlands, and 8 talus slopes (uplands) over a 3-yr period (1994 to 1996). A total of 14 species of amphibians was detected, which represents the full complement of species known to occur in the region. Regression models produced for 11 species included associations with the following habitat types (number of species): mature conifer (5), pole conifer (4), sapling conifer (4), recent clearcuts (4), alder-hardwoods (2), brush (0), rock (2), and open wetland (5). Results suggest that stream and riparian amphibians require closed-canopy forest cover from mature conifers, pole conifers, and / or alder-hardwoods. In contrast, pond-breeding amphibians were not restricted to areas with a closed canopy, at least during the breeding season.

Key words: amphibians, landscape ecology, habitat, GIS, forestry, wildlife, surveys

Most quantitative habitat studies of amphibians from the Pacific Northwest have focused on old-growth studies of national forests (see review by Walls and others 1992), and only a few have made comparisons to clearcuts or other early successional stages created by industrial logging (Bury and Corn 1988a; Raphael 1988; Corn and Bury 1989; Gomez and An- thony 1996; Aubry 1997). Furthermore, timber management is usually less intense on national forests than on private industrial forests (Franklin and Foreman 1987), and constraints at the landscape level could influence amphibian populations differently. For example, the U.S. Forest Service typically uses smaller, more widely distributed clearcuts than private forests, causing higher levels of forest fragmentation (Franklin and Foreman 1987; Li and others 1993), but limiting gap size and retaining habitat connectivity (between remaining stands). In this light, Li and others (1993) warned that the effects of forest fragmentation on wildlife may not become apparent until forests are clearcut on more than 30 to 40% of the landscape. Thus, amphibians could occur in

1 Present address: 19 Somerset Drive, Suffern, New York 1 0901 USA.

any habitat type on a national forest if late-successional patches are not far apart and evenly distributed.

In this study, I examined the distribution of the amphibian community on a private industrial forest using Geographic Information Sys- tem (GIS) to assess macrohabitat correlates at the landscape level. This type of approach on intensively managed forests yields comple- mentary information about habitat use than comparable studies in mature and old-growth forest conditions.

METHODS

The study area was conducted on the Min- eral Tree Farm located in central Lewis County, Washington, positioned between the towns of Mineral, Morton, and Randle. It is an industrial tree farm of about 21,600 ha in total area, which is owned by Murray Pacific Corporation. About 19,600 ha of the tree farm are capable of sup- porting forest growth, with the remaining area containing rocky ridgetops, alpine meadows, cliff and talus slopes, roads, brush, standing water, and gravel pits. These timberlands are in the Tsuga heterophylla Forest Zone (Franklin and Dyrness 1984), which is dominated by Doug- las-fir (Pseudotsuga menziesii) and western hem-

61



62 NORTHWESTERN NATURALIST 80(2)

lock (Tsuga heterophylla ). Western redcedar (Thuja plicata) is locally abundant, and Pacific silver fir (Abies amabilis) and noble fir (A. pro- cera) are present at higher elevations. A detailed description of the study area is available in Bo- sakowski (1997).

A total of 50 stream reaches, 29 wetlands, and 8 upland talus slopes (steep slopes with rocky soils, generally near the base of cliffs, sometimes with forest cover present) were surveyed for amphibians on the Mineral Tree Farm from 1994 to 1996. These surveys represented a nearly complete census of all available streams, wetlands, and talus slopes on the tree farm, so a random site selection was not nec- essary. Replication of survey sites was conducted at 7 streams (same stream reaches) and 3 wetlands. A total of 19 stream reaches were surveyed from 15 to 19 August 1994. In 1995, surveys were conducted on 20 streams reaches, 14 wetlands, and 3 talus slopes from 26 April to 6 June. In 1996, surveys were conducted on 11 stream reaches, 15 wetlands, and 5 talus slopes from 29 April to 30 May.

Survey Technigues Visual encounter surveys (Crisafulli 1997)

that were time-searched (Fellers 1997) were used to quantify amphibian abundance. In this study, 2 or 3 observers captured and/or observed amphibians for a 1.5-hour or l-hour period, respectively (total effort = 3 person-hours per site). On streams, this survey effort usually resulted in a linear search distance of about 200 m. Survey time did not include time taken to hike to the site and identify or photograph . , . speclmens ot rare specles.

During stream surveys, the survey crew worked upstream searching shallow water, splash and flood zones, and adjacent stream banks '30 m from the stream. Surveyors, equipped with potato rakes, overturned large (>10 cm) rocks, logs, and bark piles (modified from Corn and Bury 1990). At wetland sites, searches were conducted by examining shallow water, bank, and upland habitat (<30 m) and usually circling around all or part of the wetland. Talus slopes were observed just after snowmelt or rain when wet ground conditions would favor surface movement of Larch Moun- tain salamanders (Plethodon larselli). During surveys of talus slopes, the surveyors over-

turned rocks, logs, and bark and observed rock crevices and small openings along cliffs.

Amphibians were identified by observation or captured by hand for closer examination. All were identified in the field or photographed for later verification. All captured amphibians were released downstream or downhill of the survey crew to avoid double counting. In wetlands, amphibian egg masses were also identified and counted. Tadpoles were noted, but their numbers were not estimated. Occasion- ally, adult frogs escaped before being positive- ly identified, and these were recorded as unidentified frogs.

GIS Analysis

Habitat was assessed using a vector-based GIS (ARC/INFO) which was maintained by Murray Pacific Corporation for mapping stand inventory data. For amphibian surveys, the GIS was used to classify stand data for the entire Mineral Tree Farm into 8 recognizable habitat types: clearcut (0 to 5 yr), sapling conifer (6 to 26 yr), pole conifer (27 to 44 yr), mature conifer ('45 yr), alder-hardwood (all ages), brush, rock (cliffs, talus, rock quarries), and open wetlands (non-forested). After surveys were com- pleted, the GIS was queried to calculate the area of habitat polygons within a 12.5 ha circle (200-m radius) that was centered on each sampling site.

Statistical Analysis Environmental data can indicate the factors

related to the presence or relative abundance of amphibians (Fellers 1997). Crisafulli (1997) suggests that correlative approaches can be used to examine relationships among habitat attributes or among amphibian species. In this study, I used a linear multiple regression analysis with the ordinary least squares method to determine relationships between amphibian abundance and corresponding habitat attributes. There are no underlying assumptions on the distribution of the independent variables in multiple regression analysis (Kerlinger and Pedhazur 1973). For multivariate testing, Green (1979) suggested that a high correlation (r > 0. 7) among the independent variables could cause multicollinearity problems and recom- mended omitting these variables from the model. The highest simple correlation found in this study between the habitat variables was



AUTUMN 1999 BOSAKOWSKI: MACROHABITAT ASSOCIATIONS OF AMPHIBIANS 63

r = -0.56, so all of the independent variables were retained for further analyses.

The underlying assumption for the depen- dent variable is that it is normally distributed around each independent variable, but multiple regression analysis is ordinarily robust enough for most violations of normality, especially if data transformations are used for recalcitrant data (Kerlinger and Pedhazur 1973). Abun- dance levels did not conform to a normal distribution (D'Agostino 1990) and were subse- quently double square-root-transformed to sta- bilize variances, linearize responses, and nor- malize residuals. This powerful transformation also serves to reduce between-species and between-habitat sampling biases inherent in any relative abundance survey design for amphibians (Crisafulli 1997). I used a separate full- model (all variables included) multiple regression analysis for each species so that they would be directly comparable to each other and because stepwise procedures recently have been criticized for use in ecology by many investigators (James and McCulloch 1990). Ele- vation was not included in the regression models because it was based on a different dimen- sional scale (distance instead of area) and it was the only variable that did not have zero for its origin. The analysis was run using the multiple regression program in version 5.03 of NCSS (Number Cruncher Statistical System, Kaysville, Utah). A regression model is pre- sented only for species having at least 1 significant (P < 0.05) predictor.

RESULTS AND DISCUSSION

A total of 783 amphibians was recorded during the survey including 147 adult salamanders, 500 adult frogs, 1 adult toad, and 137 aquatic larval or neotenic salamanders (Table 1). Also, there were 644 egg masses of northwestern salamanders observed, but no adults and only 2 larvae were found. Overall, this survey documented the presence of 14 amphibian species on an industrial forest on the west side of the Cascade Mountains in Washington, which included the full complement of species expected for this geographic location (McAllis- ter 1995, pers. comm.).

Macrohabitat Correlates All but 2 of the multiple regression models

produced higher correlation coefficients than

simple correlation coefficients for single variables, suggesting that a combination of several variables was more important (explained more of the variation) than a single variable for these species (Table 2). The 2 exceptions were the Larch Mountain salamander and ensatina, which had significant simple correlations only with area of rock, albeit sample size was small for both species. Unidentified frogs displayed a non-significant regression model (R2 = O.Ooo, p = 0.597), which suggests that significant species models were not due to random noise in the data set (in other words, this group served as a negative control).

Several of the stream-associated amphibians (tailed frog, Pacific giant salamander, Cascade torrent salamander, Van Dyke's salamander) were found only in forested areas, and models showed associations for mature conifer, pole conifer, and alder-hardwood (Table 2). Several investigators have found tailed frogs primarily in older forests (>100 yr; Welsh 1990; Welsh and Lind 1991). Conversely, several studies did not observe tailed frogs in clearcuts (Bury 1968; Corn and Bury l991a). Corn and Bury (1989) found that tailed frogs were abundant in vari- ous forest stand ages >30 yr old, but were ab- sent or very rare in clearcuts. Gomez and An- thony (1996) captured tailed frogs in all 5 forest types sampled, but highest levels were in mature (110 to 200 yr) and old-growth conifer stands (>200 yr).

The Pacific giant salamander model showed an association with mature and pole conifer forests. This species breeds in streams surrounded by cool, moist coniferous forest (closed-canopy through old-growth stages) and red alder (Alnus rubra) forest (Brown 1985). Abundance of terrestrial adults has been reported to be nearly equal in young forest (30 to 80 yr), mature forest (80 to 200 yr) and old- growth forest (>200 yr) in Oregon (Bury and others l991a). Gomez and Anthony (1996) captured them in all 5 forest types sampled, but highest levels were in mature (110 to 200 yr) and old-growth conifer stands (>200 yr). Bury and Corn (1988b) found a much lower abundance in young 2nd-growth stands (14 to 40 yr) compared to older stands (60 to 500 yr).

Models for Van Dyke's salamander and western red-backed salamander showed associations with alder-hardwood, mature conifer, and pole conifer (Table 2), indicating that a



TABLE 1. Distribution of adult amphibians among three habitat survey types on a private industrial forest in the western Washington Cascades and correlations of abundance with elevation.

Stream- Talus Elevation (m) Abundance riparian slope Wetland

Species n n-50 n = 8 n = 29 Mean (range) r P Western red-backed salamander (Plethodon vehiculum) 86 77 9 0 516 (354-890) -0.568 <0.001 Van Dyke's salamander (Plethodon vandykei) 42 38 4 0 444 (354-1067) 0.364 <0.2 Larch Mountain salamander (Plethodon larselli) 5 0 5 0 1188 (1127-1280) 0.262 NS Ensatina (Ensatinn eschscholtzii) 6 0 6 0 1163 (890-1200) 0.208 NS Pacific giant salamandera (Dicamptodorl tenebrosus) 140 140 0 0 739 (354-1146) -0.309 <0.001 Cascade torrent salamander (Rhyacotriton cascadae) 2 2 0 0 722 (688-755) Long-toed salamander (Ambystoma macrodacEylum) 1 0 0 1 1005 Northwestern salamanderb (Ambystoma gracile) 624 0 0 624 938 (365-1200) 0.402 <0.001 Rough-skinned newt (Taricha granulosa) 63 1 1 61 979 (737-1200) 0.398 0.001 Tailed frog (Ascaphus truei) 43 43 0 0 782 (426-1146) -0.108 NS Northern red-legged frog (Rana aurora) 57 10 0 47 831 (354-1005) 0.026 NS Cascades frog (Rana cascadae) 234 19 1 214 969 (677-1200) 0.539 <0.001 Pacific chorus frog (Pse7ldacris regilla) 166 3 3 160 871 (365-1200) 0.302 <0.001 Western toad (Buto bore:s) 1 0 0 1 610 Unidentified frogs 27 5 0 22 807 (365-994) 0.040 NS

a Includes mostly larvae and neotenes; only 5 adults. b Represents number of egg masses because no adults were found.

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TABLE 2. Multiple regression analysis of amphibian abundance with macrohabitat areas on a private industrial forest in the western Washington Cascades. > Values for each habitat represent standardized beta coefficients for a full-model analysis of all habitat areas. O

Mature Sapling Recent 7< conifer Pole conifer conifer clearcut Alder- Open Model Adjusted

n ('45yr)(27to44yr)(6to26yr) (Oto5yr) hardwood Rock Brush wetland P-value R2 g

Western red-backed salamander 86 0e313a 0.402a -0.007 -0.044 0.221a 0.093 -0.063 -0.002 <0.001 0.414 rr Van Dykets salamander 42 0.229a 0.2l6a -0.015 -0.064 0.361a 0.026 -0.042 -0.008 <0.001 0.272 0 Larch Mountain salamander 5 0.060 -0.026 0.046 0.085 -0.046 0.253a -0.006 -0.026 0.475 0.008 X Ensatina 6 0.147 -0.028 0.037 -0.010 -0.045 0.422a -0.092 -0.009 0.006 0.160 N Pacific giant salamanderb 140 0.654a 0.270a 0.021 0.054 0.116 0.020 -0.043 -0.046 <0.001 0.664 > Northwestern salamanderC 624 0.009 -0.094 0.480a 0.217a -0.044 -0.104 0.048 0.514a <0.001 0.727 3 Rough-skinned newt 63 0.046 -0.100 0.550a 0.208a -0.127 -0.122 0.021 0.205a <0.001 0.420 > Tailed frog 43 0.536a 0.248a 0.034 0.082 -0.061 -0.065 -0.020 -0.031 <0.001 0.335 v) Northernred-leggedfrog 57 0.058 0.004 0.126 0.024 0.158 -0.052 0.064 0.406a 0.001 0.222 ° Cascades frog 234 O.199a -0.024 0 495a 0.208a -0.165 -0.145 0.069 0.365a <:0.001 0.573 > Pacific chorus frog 166 0.026 -0.110 O.492a 0.241a -0.032 -0.106 0.023 0.358a CO.001 0.543 93 Unidentified frogs 27 0.074 -0.038 0.178 0.053 0.098 -0.063 0.050 0.036 0.597 0.001 ° Total amphibian s 1493 0.201a -0.028 0.497a 0.150 -0.031 -0.072 -0.011 0.40ga <0.001 0.626 uz Streamamphibians 311 0.567a 0.144 --0.030 0.002 0.126 0.046 -0.029 -0.012 <0.001 0.419 ° Wetland anrphibians 1144 0.049 -0.087 0.500a 0.160a -0.072 -0.108 0.001 0.444a <0.001 0.608 > Species richness 87 0.407a 0.170a 0.443a 0.214a 0.049 -0.072 0.040 0.325a <0.001 0.834 g

a p < 0,50.

b Includes mostly larvae and neotenes; only 5 adults. a ' Includes egg masses only. >

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dense canopy cover was required with trees at least pole size in diameter. The Van Dyke's salamander is typically a close associate of small, shallow streams (Corn and Bury l991b; Leon- ard and others 1993), but it is also uses upland, north-facing slopes with heavy moss cover (Leonard and others 1993) and talus slopes (Herrington 1988). I found an equal proportion distributed between streamside and talus habitats (Table 1). Little information has been reported on forest cover preferences except for Jones and Atkinson (1989), who reported an association of these salamanders with riparian habitats in mature and old-growth coniferous forests of Long Island, Washington.

The pond-breeding amphibians (Cascades frog, northern red-legged frog, Pacific chorus frog, rough-skinned newt, and northwestern salamander) were highly associated with open wetland habitat (Table 2). These wetlands were surrounded by a wide variety of forest age classes, but the dominant forest type was sapling conifer. Forest associations of these pond- breeders are not well known. Aubry and Hall (1991) found Cascades frogs in old-growth (n =

10), mature stands (80 to 190 yr; n = 2), and young stands (55 to 75 yr; n = 1), noting positive correlations with well-decayed snags and deciduous and coniferous canopy cover on the landscape.

The red-legged frog model showed an association only for open wetlands (Table 2). While most adults were found near wetlands (n = 47), the 10 remaining adults were found along streams (Table 1) with canopy cover. Although abundance of red-legged frogs has not been correlated with specific forest age classes (Au- bry and Hall 1991; Bury and others 1991b; Au- bry 1997), positive associations have been reported for woody debris, density of broadleaf trees, percent cover of mid-canopy broadleaf trees (Aubry and Hall 1991), lower elevations, and flatter slopes (Bury and others 1991b).

The Pacific chorus frog model showed associations with sapling and clearcut habitats, possibly because there was little older forest around the majority of the breeding ponds where it was found. Raphael (1988) found highest abundance in early successional habitats (0 to 10 yr) as well as in 50 to 150 yr-old forests, and lower abundance in sapling-pole or old- growth forests. Welsh and Lind (1991) found that density increased from young forest (24 to

99 yr), to mature (100 to 200 yr), to old-growth, but they did not examine wetlands, clearcuts, or sapling stands in their study. The Pacific chorus frog is generally considered a habitat generalist (Brown 1985; Leonard and others 1993).

Models for rough-skinned newts and northwestern salamanders showed an association for open wetlands as well as early successional habitats (clearcut and sapling conifer; Table 2). Several investigators have found a higher abundance of these 2 species in older forests (>80 yr; Raphael 1988; Welsh and Lind 1988, 1991; Au- bry and Hall 1991; Corn and Bury l991a). How- ever, in younger forest seral stages between 0 and 80 yr, Aubry (1997) found little difference in abundance levels for these 2 species. Because few old forests were near the wetlands in my study, these 2 species might be surviving in suboptimal habitat by using subnivean space, or traveling extensive distances (>200 m) to reach these breeding ponds.

Larch Mountain salamanders were rare and found only on upland talus slopes ("rock" in Table 2) at higher elevations (Table 1), although talus was rare at low elevations. Neither site with Larch Mountain salamanders had over- head tree cover, but mature forest was close (30 to 100 m) along the sides and top of the slope at both locations. Herrington (1988) found 95% of Larch Mountain salamanders in talus habitats. Brown (1985) and Herrington and Larsen (1985) indicated that partial or complete forest cover was usually present. Recent studies in the Washington Cascade Range have also found them to be numerous in contiguous old- growth forest without talus (C. Crisafulli, U.S. Forest Service, Amboy, WA, pers. comm.), thus talus slopes may not be as critical as formerly assumed. Bury and Corn (1988b) found a small sample of 14 individuals in old-growth forest (>195 yr), but none were in mature forest (105 to 150 yr), young forest (30 to 76 yr), or clearcuts (<10 yr).

Two other salamanders occurred occasion- ally in talus (Western red-backed salamander and Van Dyke's salamander). Herrington (1988) found these 2 species to be more numerous in talus than adjacent (>100 m) non-talus habitats, but he did not specifically target stream- banks in his "non-talus" searches. In this study, there was no significant difference in proportions for either of these species in




streamside habitat under a closed-canopy forest versus talus slopes (Fisher Exact Test, P > 0.25). McComb and others (1993a) and Gomez and Anthony (1996) did not find a significant difference in capture rates for red-backed salamanders in streamside versus upslope habitats.

Ensatinas were rare and were found only on upland talus slopes ("rock" in Table 2) at higher elevations (Table 1), higher than previously reported for the species (1168 m; Leonard and others 1993). Ensatinas were also more numerous in upslope habitats than riparian capture sites in Oregon (McComb and others 1993a, 1993b; Gomez and Anthony 1996).

Community Trends and Conservation Strategies

When all stream and streamside amphibians were combined, a model was produced with significance for mature conifer only. These results support other research that has suggested the retention of uncut buffer strips or patch re- serves along streams as a valuable conservation measure for aquatic and streamside amphibians (Bury and Corn 1988b; Welsh 1990; Diller and Wallace 1996). In contrast to stream dwell- ers, combining all wetland pond-breeding species produced a model for open wetland, clearcut, and sapling conifer. The general lack of correlation of canopy cover with pond-breeding amphibians, could be partly due to a bias in the study area because few ponds had mature stands nearby and the availability of ponds on the tree farm was limited, thereby increasing their priority. However, these pond-breeding species do not generally require cold, clear water and are capable of traveling large distances over land, especially during periods of rain, fog, and dew.

Using species richness of amphibians at each sample site, a model was produced for open wetland, clearcut, sapling, pole, and mature conifer. These results suggest that a variety of macrohabitat types on an industrial forest con- tributed to high species richness. As a management tool, I suggest that GIS data from other landowners could be used to produce habitat- based models to predict amphibian presence and abundance. Models should be field-veri- fied, and caution should be used in interpreting results due to the legacy of past disturbances and differences among recovering systems. Fi-

nally, models developed in different provinces may not be applicable elsewhere.

ACKNOWLEDGMENTS

Funding for this project was provided by the Murray Pacific Corporation, Tacoma, Washing- ton. We thank G. McCaul from Murray Pacific for the GIS calculations and mapping and B. McCullough, M. Scharpf, D. L. Olson, M. Rubi- no, and S. Turner for assistance with fieldwork.

LITERATURE CITED AUBRY KB. 1997. Influence of stand structure and

landscape composition on terrestrial amphibians. In: Aubry KB, West SD, Manuwal DA, Stringer AB, Erickson JL, Pearson S, editors. Wildlife use of managed forests: a landscape perspective. Vol- ume 2, Research Results. Olympia, WA: Timber, Fish and Wildlife, TFW-WL4-98-002. p 1-43.

AUBRY KB, SENGER CM, CRAWFORD RL . 1987. Dis- covery of Larch Mountain Salamanders Plethodon larselli in the central Cascade range of Washing- ton. Biological Conservation 42:147-152.

AUBRY KB, HALL PA. 1991. Terrestrial amphibian communities in the southern Washington Cas- cade Range. In: Ruggiero LF, Aubry KB, Carey AB, Huff MH, technical coordinators. Wildlife and vegetation of unmanaged Douglas-fir forests. Portland, OR: USDA Forest Service General Tech- nical Report PNW-GTR-285. p 327-340.

BOSAKOWSKI T. 1997. Breeding bird abundance and habitat relationships on a private industrial forest in the western Washington Cascades. Northwest Science 71:244-253.

BROWN ER. 1985. Management of wildlife and fish habitats in forests of western Oregon and Wash- ington. Portland, OR: USDA Forest Service R6-F and WL-192, Pacific Northwest Region. 332 p.

BURY RB. 1968. The distribution of Ascaphus truei in California. Herpetologica 24:39-46.

BURY RB, CORN PS. 1988a. Douglas-fir forests in the Cascade Mountains of Oregon and Washington: relation of herpetofauna to stand age and mois- ture. In: Szaro RC, Severson KE, Patton DR, technical coordinators. Management of amphibians, reptiles, and small mammals in North America. Fort Collins, CO: USDA General Technical Report RM-166. p 11-22.

BURY RB, CORN PS. 1988b. Responses of aquatic streamside amphibians to timber harvest: a review. In: Raedeke KJ, editor. Streamside management, riparian wildlife and forestry interactions. Seattle, WA: Contribution No. 59, Institute of For- est Resources, University of Washington. p 165- 181.

BURY RB, CORN PS, AUBRY KB, GILBERT FF, JONES LLC. 1991a. Aquatic amphibian communities in




Oregon and Washington. In: Ruggiero LF, Aubry KB, Carey AB, Huff MH, technical coordinators. Wildlife and vegetation of unmanaged Douglas- fir forests. Portland, OR: USDA Forest Service General Technical Report PNW-GTR-285. p 353- 362.

BURY RB, CORN PS, AUBRY KB. l991b. Regional patterns of terrestrial amphibian communities in Oregon and Washington. In: Ruggiero LF, Aubry KB, Carey AB, Huff, MH, technical coordinators. Wildlife and vegetation of unmanaged Douglas- fir forests. Portland, OR: USDA Forest Service General Technical Report PNW-GTR-285. p 341- 352.

CAREY AB.1989. Wildlife associated with old-growth forests in the Pacific Northwest. Natural Areas Journal 9:151-162.

CORN PS, BURY RB . 1989. Logging in western Oregon: responses of headwater habitats and stream amphibians. Forest Ecology and Manage- ment 29:39-57.

CORN PS, BURY RB. 1990. Sampling methods for terrestrial amphibians and reptiles. In: Carey AB, Ruggiero LF, editors. Wildlife-habitat relationships: sampling procedures for Pacific Northwest vertebrates. Portland, OR: USDA Forest Service, General Technical Report PNW-GTR-256.

CORN PS, BURY RB. l991a. Terrestrial amphibian communities in the Oregon Coast Range. In: Rug- giero LF, Aubry KB, Carey AB, Huff MH, technical coordinators. Wildlife and vegetation of unmanaged Douglas-fir forests. Portland, OR: USDA Forest Service General Technical Report PNW-GTR-285. p 305-318.

CORN PS, BURY RB. l991b. Sampling methods for amphibians in streams. In: Carey AB, Ruggiero LF, editors. Wildlife-habitat relationships: sampling procedures for Pacific Northwest vertebrates. Portland, OR: USDA Forest Service, Gen- eral Technical Report PNW-GTR-275.

CRISAFULLI CM. 1997. A habitat-based method for monitoring pond-breeding amphibians. North- west Fauna 4:83-112.

D'AGosTINo, RB. 1990. A suggestion for using powerful and informative tests of normality. Ameri- can Statistician 44:316-322.

DILLER LV, WALLACE RL. 1996. Distribution and habitat of Rhyacotriton variegatus in managed, young growth forests in North Coastal California. Jour- nal of Herpetology 30:14-191.

FELLERS GM. 1997. Design of amphibian surveys. Northwest Fauna 4:23-34.

FRANKLIN JF, DYRNESS CT. 1984. Natural vegetation of Oregon and Washington. Corvallis, OR: Oregon State University Press. 452 p.

FRANKLIN JF, FOREMAN RTT. 1987. Creating landscape pattern by forest cutting: ecological conse-

quences and principles. Landscape Ecology 1:5- 18.

GOMEZ DM, ANTHONY RG. 1996. Amphibian and reptile abundance in riparian and upslope areas of five forest types in western Oregon. Northwest Science 70:109-119.

GREEN RH. 1979. Sampling design and statistical methods for environmental biologists. New York, NY: Wiley and Sons. 257 p.

HERRINGTON RE. 1988. Talus use by amphibians and reptiles in the Pacific Northwest. In: Szaro RC, Severson KE, Patton DR, technical coordinators. Management of amphibians, reptiles, and small mammals in North America, Fort Collins, CO: USDA General Technical Report RM-166. p 216- 221.

HERRINGTON RE, LARSEN JH . 1985. Current status, habitat requirements and management of the Larch Mountain salamander Plethodon larselli in the central Cascade Range of Washington. Biolog- ical Conservation 42:147-152.

JAMES FC, MCCULLOCH CE. 1990. Multivariate analysis in ecology and systematics: panacea or Pan- dora's box? Annual Review of Ecology and S-s- tematics 21 :129-166.

JONES LLC, ATKINSON J. 1989. Plethodon vandykei. Herpetological Review 20:48.

KERLINGER FN, PEDHAZUR EJ. 1973. Multiple regression in behavioral research. New York, NY: Holt, Rinehart, and Winston, Inc.

LEONARD WP, BROWN HA, JONES LLC, McALLIsTER KR, STORM RM. 1993. Amphibians of Washington and Oregon. Seattle, WA: Seattle Audubon Soci- ety. 168 p.

LI H, FRANKLIN JF, SWANSON FJ, SPIES TA. 1993. De- veloping alternative cutting patterns: a simula- tion approach. Landscape Ecology 8:63-75.

McALLIsTER KR. 1995. Distribution of amphibians and reptiles in Washington State. Northwest Fau- na 3:81-112.

MCCOMB WC, McGARIGAL K, ANTHONY RG. 1993a. Small mammal and amphibian abundance in streamside and upslope habitats of mature Doug- las-fir stands, western Oregon. Northwest Science 67:7-15.

MCCOMB WC, CHAMBERS CL, NEWTON M. 1993b. Small mammal and amphibian communities and habitat associations in red alder stands, central Oregon Coast Range. Northwest Science 67:181- 188.

RAPHAEL MG. 1988. Long-term trends in abundance of amphibians, reptiles, and mammals in Doug- las-fir forests of northwestern California. In: Sza- ro RC, Severson KE, Patton DR, technical coordinators. Management of amphibians, reptiles, and small mammals in North America, Fort Col- lins, CO: USDA General Technical Report RM- 166. p 23-31.




WALLS SC, BLAUSTEIN AR, BEATTY JJ. 1992. Amphib- ian biodiversity of the Pacific Northwest with special reference to old-growth stands. North- west Environmental Journal 8:53-69.

WELSH HH. 1990. Relictual amphibians and old- growth forests. Conservation Biology 4:309-319.

WELSH HH, LIND AJ. 1988. Old-growth forests and the distribution of the terrestrial herpetofauna. In: Szaro RC, Severson KE, Patton DR, technical coordinators. Management of amphibians, reptiles, and small mammals in North America. Fort Collins, CO: USDA General Technical Report RM-166. p 439-458.

WELSH HH, LIND AJ. 1991. The structure of the her- petofaunal assemblage in the Douglas-fir/hardwood stands in northwestern California and southwestern Oregon. In: Ruggiero LF, Aubry KB, Carey AB, Huff MH, technical coordinators. Wildlife and vegetation of unmanaged Douglas- fir forests. Portland, OR: USDA Forest Service General Technical Report PNW-GTR-285. p 395- 414.

Submitted 1 September 1998, accepted 7 May 1999. Corresponding Editor: D. H. Olson.



amphibian macrohabitat associations on a private industrial forest in western washington

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