Comparing Ecoregional Classifications for Natural Areas Management in the Klamath Region, USA
Sarr, D. A., Duff, A., Dinger, E. C., Shafer, S. L., Wing, M., Seavy, N. E., & Alexander, J. D. (2015). Comparing Ecoregional Classifications for Natural Areas Management in the Klamath Region, USA. Natural Areas Journal, 35(3), 360-377. doi:10.3375/043.035.0301
10.3375/043.035.0301 Natural Areas Association
Version of Record http://cdss.library.oregonstate.edu/sa-termsofuse R E S E A R C H A R T I C L E ABSTRACT: We compared three existing ecoregional classification schemes (Bailey, Omernik, and World Wildlife Fund) with two derived schemes (Omernik Revised and Climate Zones) to explore their effectiveness in explaining species distributions and to better understand natural resource geography in the Klamath Region, USA. We analyzed presence/absence data derived from digital distribution maps for trees, amphibians, large mammals, small mammals, migrant birds, and resident birds using three statistical analyses of classification accuracy (Analysis of Similarity, Canonical Analysis of Principal • Coordinates, and Classification Strength). The classifications were roughly comparable in classification accuracy, with Omernik Revised showing the best overall performance. Trees showed the strongest fidel- Comparing ity to the classifications, and large mammals showed the weakest fidelity. We discuss the implications for regional biogeography and describe how intermediate resolution ecoregional classifications may be Ecoregional appropriate for use as natural areas management domains. Index terms: Bailey ecoregions, Klamath Region, management domains, Omernik ecoregions, World Classifications Wildlife Fund ecoregions for Natural Areas INTRoduCTIoN Management in the • Increasingly, natural resource management involves multipartner collaboration across Klamath Region, landscapes and regions, often with complex arrays of administrative and ecological USA 2Wildlife Survey Data Management boundaries. Typically, the conceptual and Wildlife Science Division spatial domains for natural areas manage- Washington Dept. of Fish and Wildlife ment (hereafter management domains) are not clearly defined. Ideally, management 1,7,8 600 Capital Way North daniel A. Sarr Olympia, WA 98501-1091 domains would be grounded in biogeog- raphy, and potentially relevant to a wide 1Klamath Network–National Park array of ecological patterns, processes, and Service 3US Geological Survey suites of species. When exploring alternate 1250 Siskiyou Boulevard 3200 SW Jefferson Way management domains for a region, natural Ashland, OR 97520 Corvallis, OR 97331 areas managers may wish to know answers to a number of practical questions, such as: (1) Which classifications best describe 2 ecologically significant boundaries? (2) Andrew duff 4 Engineering, Resources and How do such boundaries correspond to 1 Eric C. dinger Management Department biotic distributions of different species? Sarah L. Shafer3 Peavy Hall 215 And (3) how do patterns of biogeography Oregon State University Michael Wing4 and biodiversity affect conservation and Corvallis, OR 97331 management? Nathaniel E. Seavy5 John d. Alexander6 Large scale classification of biotic commu- 5Point Blue Conservation Science nities has long been a goal of naturalists and 3820 Cypress Drive #11 biogeographers, whose works have yielded Petaluma, CA 94954 a diverse array of maps and classifications • of the world’s flora and fauna (Wallace 1869; Holdridge 1947; reviewed in Welsh 7 Corresponding author: [email protected]; 6 1994). At the same time, climatologists (928) 556-7250; Fax: (928) 556-7092 Klamath Bird Observatory have been converging upon regional clas- 8 Current address: USGS Grand Canyon PO Box 758 sifications of climate, with a number of Monitoring and Research Center, 2255 N. Ashland, OR 97520 Gemini Dr., Flagstaff, AZ 86001 studies focused in the western United States (Baker 1944; Mitchell 1976; Mock 1996). Formal ecoregional classifications • have been developed in North America by US federal agencies (e.g., Bailey 1983, Natural Areas Journal 35:360–377 1998; Omernik 1987, 2011), with subse- quent refinement by states (Welsh 1994)
360 Natural Areas Journal Volume 35 (3), 2015 and nongovernmental entities such as the into integrated and holistic approaches tance of each factor will vary depending World Wildlife Fund (WWF; Ricketts et that cover many species simultaneously upon the life history of the organisms al. 1999). and span large spatial scales (Johnson et involved. Moreover, any classification al. 1999; Vander Schaaf et al. 2004). For used should ideally offer sufficient gen- The causes of variation among ecoregions managers, this broader focus requires an erality to be easily recognized and used include both biological and physical fac- understanding of the biodiversity and bio- by natural area managers. Thus, lessons tors, of which climate is usually considered geography of major species assemblages learned from evaluating ecoregional clas- to be an overarching control (Bailey 1998). in the areas they manage, as well as the sification schemes in this diverse region For plants, other abiotic factors, such as ability to make sound hypotheses of eco- will provide examples of challenges that geology, have long been known to be fun- managers in many parts of the world may logical responses to management actions. expect to confront. damental to the distributions of species and In complex landscapes with many land- communities (Merriam and Steineger 1890; owners, ecoregional classifications may Our initial survey of ecoregion classifi- Whittaker 1960; Walter 1973; Woodward be essential for developing meaningful cations revealed several alternatives to 1987; Ohmann and Spies 1998). For other ecological units for collaborative manage- compare for potential use in our region. taxa, these biophysical controls have typi- ment (Host et al. 1996) and bioassessment Of these, we chose the Bailey (Bailey cally been less clearly understood, but a (Hawkins et al. 2000). 1983, 1998), Omernik (Omernik 1987, number of studies suggest these controls 2011), and WWF (Ricketts et al. 1999) may be important (Root 1988; Hansen and Managers and applied conservation classifications. We also noted that although Rotella 2002; Shine et al. 2002; Duff and scientists often must develop and apply the existing ecoregional classifications Morrell 2007). Upon the coarse biophysi- standardized inventory and monitoring appeared to capture a number of broad cal template, finer habitat divisions arise techniques across large and heterogeneous landscape boundaries across the Klamath Region as a whole, they did not adequately from vegetation structure, successional landscapes. For instance, the Klamath Net- differentiate climate zones within the most variation, interspecific competition, and a work Inventory and Monitoring Program complex part of our region, the Klamath host of other biologically mediated effects of the National Park Service is currently Mountains subregion, where biodiversity (Grinnell 1917). Animals further subdivide developing a long term monitoring program is particularly high and climatic gradients the landscape into breeding territories, for six park units (three national parks, are especially pronounced. Therefore, in foraging and staging areas, and other two national monuments, and one national addition to evaluating the existing ecore- functional spaces (Palik and Engstrom recreation area) in the Klamath Region of gional classifications, we decided to ana- 1999). Consequently, ecoregional varia- northern California and southern Oregon lyze available climate data to see if more tion is best viewed as a multiscale concept that vary tremendously in climate, geol- refined climate zones could be identified containing a complex array of controls on ogy, plant and animal species, and a host for our study area. Our objective was to spatial patterns. of ecological processes (Sarr et al. 2007). compare the three existing ecoregional An integrated and rigorous monitoring pro- Recent research (Wright et al. 1998; classifications and two derived classifica- gram requires a basic understanding of how McDonald et al. 2005; Thompson et al. tion schemes for the Klamath Region using important functional relationships change 2005) has demonstrated that ecoregional a suite of biological and physical datasets across landscapes and where important boundaries may not correspond closely to compare their effectiveness in represent- boundaries or semi-homogeneous regions with compositional changes in individual ing ecologically significant boundaries for occur. Such an understanding also would be life forms, which may change at dif- our region. More specifically, we sought helpful for fostering collaboration among ferent rates across landscape gradients. to better understand the biophysical and reserves and with adjacent landowners to Therefore, it may be useful to explore address issues of mutual interest. biogeographic patterns within our region how differing ecological classifications by investigating the following four research fit varied species geography. For instance, To evaluate the utility of ecoregional questions: highly vagile organisms (birds) may show classification for describing ecological more dispersed distributions and partition patterns, processes, and suites of species, 1. Which ecoregional classifications best the landscape more coarsely than sessile we investigated the performance of several describe ecologically significant boundar- organisms (trees) or species with limited classification schemes for the Klamath ies in the Klamath Region? dispersal abilities (amphibians) (McDonald Region of North America (Figure 1). 2. How might the ecoregional classification(s) be revised to better de- et al. 2005). The Klamath Region is one of the most scribe variation in the Klamath Region? biophysically complex regions in western 3. How do ranges of selected groups of Ecoregional Classifications and North America (DellaSala et al. 1999). organisms with different vagility and life Natural Areas Management In such heterogeneous regions, the selec- history correspond to different ecoregional tion of general landscape boundaries can classifications? In recent years, environmental manage- be challenging because there are many 4. What are the general biogeographic ment activities have evolved from single possible factors that might be used for linkages between ecoregional units within disciplines, such as fisheries or forestry, ecoregional classification, yet the impor- and outside the Klamath Region?
Volume 35 (3), 2015 Natural Areas Journal 361 Figure 1. Klamath area and delineated ecoregions. (A) Bailey’s Ecoregions, (B) World Wildlife Fund (WWF) Ecoregions, (C) Omernik Level III Ecoregions, and (D) Klamath Climate Zones. Klamath area National Park Service units are shaded (CRLA = Crater Lake National Park, LABE = Lava Beds National Monument, LAVO = Lassen Volcanic National Park, RNSP = Redwood National and State Parks, WHIS = Whiskeytown National Recreations Area, and ORCA = Oregon Caves National Monument). Numbers in bold are the original numeric codes for named ecoregions. See Appendix for ecoregion names.
METhodS sification systems as spatial datasets. united-states/; Figure 1A); (2) World These were: (1) Bailey’s Ecoregions and Wildlife Fund’s Terrestrial Ecoregions Compiling Ecoregional Classifications Subregions of the United States, Puerto of the World (http://www.worldwildlife. for the Klamath Region Rico, and the U.S. Virgin Islands (McNab org/science/data/terreco.cfm; Olson et al. and Avers 1994; http://www.fs.fed.us/ 2001; Figure 1B); and (3) Omernik’s Level We used three existing ecoregional clas- rm/ecoregions/products/map-ecoregions- III Ecoregions of the Continental United
362 Natural Areas Journal Volume 35 (3), 2015 States (Omernik 1987, 2011; http://www. elevation removed, we sought to generate Evaluating Biological Patterns across epa.gov/wed/pages/ecoregions/level_iii_ distinct climatic zones to identify important the Klamath Region iv.htm; Figure 1C). boundaries that might have been missed by the existing ecoregional classifications. Species distributions The Bailey system incorporates climate, Spatial resolution of all climate data was topography, and vegetation (Bailey 1983, 1000 m. 1998). The Omernik system, from which We selected four taxonomic groups for the WWF system is also partly derived We performed an unsupervised classifica- which digital range maps were available to test relationships between species distribu- (Olson et al. 2001), integrates soils, land tion in ArcGIS Spatial Analyst (Version 9.3, tions, ecoregions, and climate zones across surface form, potential natural vegetation, ESRI 2003) to delineate climate zones. To the Klamath Region. The groups were: (1) land use, and other variables (Omernik ensure our variables were weighted equally, Trees; (2) Amphibians; (3) Birds; and (4) 1987, 2011). The WWF system, along all six climatic variables were scaled to an with the other classifications to a degree, Mammals. For each group, we developed 8-bit data range. We performed a migrating presence/absence grids of 402 points using also involved the subjective assessment of means clustering procedure, utilizing the experts to delineate meaningful ecoregional 10-minute grids derived from subsam- IsoCluster routine, followed by maximum pling digital range maps obtained from boundaries (Olson et al. 2001). Ultimately, likelihood classification. The isocluster- all ecoregional classifications involve NatureServe (http://www.natureserve. ing routine procedure uses an ISODATA professional judgment and qualitative org) for amphibians, birds, and mammals, (Iterative Self-Organizing Data Analysis determinations of ecoregional units and and from the US Geological Survey for Techniques; Ball and Hall 1965) clustering boundaries, usually informed by a broad trees (US Geological Survey 1999). For algorithm for defining natural groupings array of physical and biological factors. vertebrates, NatureServe range maps are of data points in attribute space. It is a built from scientific literature, web sites, commonly used algorithm in satellite im- experts, and information from local data developing Climate Zones for the age classification to determine classes of centers. Many of the same sources used for Klamath Region multiple wavebands. In this procedure, the taxonomy and nomenclature are consulted user dictates the number of clusters, and for distribution information. In turn, much The Klamath Region is considered a transi- we performed a series of analyses using of the published information is based on tional area between maritime, continental, different numbers of clusters to arrive at a museum specimen records and, especially temperate, and Mediterranean air masses scheme that was readily interpretable and for birds, reliably documented observation in western North America (Mitchell 1976). ecologically meaningful. records. Review of the available literature In mountainous regions, identification of and other sources is done by NatureServe climate zones is often complicated by zoologists and by other experts con- the local effects of elevation on climate A Refined Ecoregional Classification tracted to develop this information, who (Mitchell 1976). Elevation neutral climate for the Klamath Region supplement their literature research with grids can be created to overcome the strong personal knowledge. Such range maps are confounding effect of local elevation in After looking at the most recent Omernik known to contain errors of commission, climate by projecting all sites to sea level (2011) classification, we developed a as real ranges are porous, especially in using spatially explicit regression equations revised version for our region, which we mountainous or otherwise complex terrain from existing climate data (Henderson called Omernik Revised (Figures 2–7; (Hurlbert and White 2005). Nonetheless, 1997). We used a gridded spatial dataset of Appendix). This change was based on they are often the only available data in six climatic variables that were projected our preliminary review of climate and areas with sparse or inconsistent surveys, to provide sea-level characteristics: (1) vegetation patterns in published literature and are considered a primary resource for Mean annual temperature at sea level; (McLaughlin 1989), which suggested that large-scale analyses. (2) Total precipitation at sea level (data the northern and southern portions of the Two secondary data filtration steps were from Henderson 1997), or were largely Cascade Range differ in important ways. elevation neutral; (3) Total precipitation performed that resulted in splitting the taxo- Because of climate and geographic affinity, days; (4) Average diurnal temperature nomic groups: (1) we separated birds into we hypothesized that the southern portion range (average daily maximum minus migratory breeders (which leave the region of the Cascade Range (Figure 1C, ecore- average daily minimum); (5) Annual air during winter) and year-round residents gion 4) would be more aligned biologically temperature range (July average minus that breed and winter in our region, on the January average); and (6) July maximum with the Sierra Nevada (Figure 1C, ecore- premise that the migratory breeding and temperature adjusted based on a spatially gion 5), despite being geologically part of year-round residents may respond to the constant lapse rate of 7.3 degrees Celsius the Cascade Range. For this revision, we factors underlying ecoregional boundaries per 1000 meters (all data were for the combined the southern Cascades ecoregion differently; and (2) we separated mammals period 1980–1997 from Thornton et al. with the Sierra Nevada ecoregion, retaining into “large” and “small” based on func- 1997; DAYMET 2007). With the effect of the original boundaries of both. tional species groupings, on the principle
Volume 35 (3), 2015 Natural Areas Journal 363 from different ecoregions. If, on average, the similarities between ecoregions and within ecoregions are the same, the R value will be approximately zero. In this regard, the R statistic is a measure of ecoregion classification success, with high values indicating stronger classification and low values indicating weaker classification. A permutation of the ecoregion allocation can be used to test the significance of the classification, but this is separate from the effect size, R. Statistical significance of the ANOSIM permutation is sensitive to even weak grouping effects, so that comparisons of significance level in assessing ecoregion classification is limited (e.g., when all grouping schemes are significant).
We conducted ANOSIM analyses for each taxonomic group for each ecoregion classification scheme, so that for each taxonomic group we could identify which ecoregion provided the strongest classifica- tion. ANOSIM analyses were performed in Primer (version 6.1.12, Primer-E Ltd., Plymouth, UK).
Canonical Analysis of Principal Coordinates
Figure 2. Map of Omernik Revised ecoregions showing misclassified plots based onamphibian assemblages. We used Canonical Analysis of Principal Large bold numbers indicate a misclassified plot, and the number indicates the erroneous ecoregion Coordinates (CAP) to assess the relative assignment based on the discriminant analysis function of Canonical Analysis of Principal Coordinates merits of each ecoregional classification (CAP). The actual ecoregion numbers follow the ecoregion names (e.g., Klamath Mountains / California scheme (ecoregions and climate zone) High North Coast Range: 78). across the six taxonomic groups. CAP is an ordination technique that maximizes a that small mammals, with typically smaller each approach are detailed below. priori group differences (e.g., ecoregion home ranges and less migration, may show groups) in a multivariate data cloud of more fidelity with ecoregions than larger Analysis of Similarity sites in species space. In this sense, CAP mammals with greater vagility and larger is a constrained ordination based on the home ranges. These steps resulted in six Analysis of similarity (ANOSIM) is a ecoregion classification, which attempts to separate taxa groups being analyzed. permutational test of a priori groups based produce axes that best separate the a priori on community assemblage data (Clarke groups (Anderson et al. 2008). data Analysis and Green 1988). Similarities between plots (here, we used Bray-Curtis distance The CAP ordination then can be used as a For the species distribution presence/ab- similarities, where a value of 1 indicates discriminant-type analysis, in an iterative sence datasets, we used three methods to 100% similarity and 0 indicates no simi- process, as follows: (1) the entire ordination evaluate the adequacy of the ecoregional larity) are used to calculate average rank is performed, but one plot is left out; (2) the and climate classifications: (1) Analysis of similarities between ecoregions and within left-out plot is then added to the ordination, Similarity R values, (2) Canonical Analysis ecoregions. A test statistic (R) comparing and assigned to the region with the closest of Principal Coordinates misclassification, the observed difference in the between and centroid; and (3) the original a priori class and (3) Classification Strength. These three within rank similarities is computed (see is then compared to the newly assigned measures provide a broad-based analysis Clarke and Warwick (2001) for details). class and, where there are discrepancies, of ecoregion congruence with biological An R value of 1 indicates plots are more the corrected class is recorded. This process pattern. The strengths and weakness of similar within ecoregions than to any plots is iterated so that eventually every plot has
364 Natural Areas Journal Volume 35 (3), 2015 Classification Strength
Classification strength (CS) is a simple metric developed by Van Sickle and Hughes (2000) in assessing the best ecoregional classification of aquatic vertebrates in Or- egon. A resemblance matrix of site similari- ties is created based on Bray-Curtis simi- larity measures (Van Sickle and Hughes 2000). CS is then the weighted mean of the within class similarities (W) minus the mean of all between class similarities (B). This metric is a function of within-class homogeneity and between-class separation, with high values indicating strong classifi- cation success. For all taxonomic groups and ecoregion classification schemes, we calculated CS with MEANSIM6 software (version 6.0, available at http://www.epa. gov/wed/pages/models/dendro/mean_simi- larity_analysis.htm). Values close to 0 in- dicate weak classification and values close to 1 indicate strong classification.
RESuLTS
A Climate Zone Classification for the Klamath Region
After classifying climate grids at multiple Figure 3. Map of Omernik Revised ecoregions showing misclassified plots based on resident land bird levels of resolution, we found a classifica- assemblages. Large bold numbers indicate a misclassified plot, and the number indicates the erroneous ecoregion assignment based on the discriminant analysis function of Canonical Analysis of Principal tion of five climate zones provided a readily Coordinates (CAP). The actual ecoregion numbers follow the ecoregion names (e.g., Klamath Mountains interpretable and ecological sensible classi- / California High North Coast Range: 78). fication, with minimal scatter across bound- aries (Figure 1D). These zones broadly corresponded to: (1) a Coastal zone; (2) a been excluded and reassigned, and the total Bailey ecoregion classification provide a Western Klamath zone; (3) a Californian number of misclassifications is used for an stronger classification for resident birds zone; (4) an Eastern Klamath/Cascades overall misclassification error. than amphibians?). Finally, and perhaps zone; and (5) a Great Basin zone. most importantly, mapping the locations A strong ecoregional classification will of plots that were misclassified can offer minimize the number of misclassifications, insights into where ecoregion classifica- Evaluating Ecoregional and Climate whereas a weak classification will be char- tions may be improved. We performed CAP Classifications acterized by many misclassifications. This analyses using the software Permanova+ method of assessing ecoregions is strongly (version 1.0.2, Primer-E Ltd., Plymouth, Based on average ANOSIM R values for affected by the total number of ecoregion all six taxa groups, the Omernik Revised groups (e.g., an ecoregion scheme with a UK). Because CAP analysis requires at large number of groups is more likely to least two replicates of each group, where classification had the strongest average have misclassifications than an ecoregion there was only a single sample for a region, grouping strength (R = 0.61) (Table 1). scheme with a low number of groups). we considered the bordering points in the The Climate Zones had the weakest aver- Despite this limitation, the CAP misclas- cardinal directions to be a part of that re- age R value (0.50). For individual taxa, sification rate still provides an estimate of gion to increase the nominal sample size the Climate Zones and WWF had the potential error rates associated with each of that group (this occurred only once in strongest grouping strength for Breeding scheme. It can also be used to assess the the Omernik classification, where the Sierra Birds, while the Climate Zones had the relative success of ecoregion schemes Nevada zone in the southeastern corner of strongest grouping strength for Resident across taxonomic groups (e.g., Does the the study area only had a single point). Birds. Amphibians had the strongest
Volume 35 (3), 2015 Natural Areas Journal 365 to Omernik’s classification increased the average percent correct allocation from 60% to 65% (with a constant number of ecoregions; 7).
Evaluating Biogeographic Linkages in the Klamath Region
Based on the success of the Omernik Re- vised classification in both ANOSIM R and Classification Strength techniques, its high percentage of correct classifications in the CAP analysis, and its closest congruence with the Climate Zone classification, we chose to use the Omernik Revised clas- sification as a framework upon which to map the location of misclassified plots and the reclassified grouping for each taxa group (Figures 2–7). The Omernik Revised classification is fairly coarse in scale (only seven ecoregions across our study region), but also biologically robust. The resulting maps provide insights into the biogeographic linkages between ecore- gions in the broader Klamath Region and, as discussed below, help identify areas for potential ecoregion refinements.
dISCuSSIoN
Figure 4. Map of Omernik Revised ecoregions showing misclassified plots based on migratory land bird This study illustrated that ecoregional assemblages. Large bold numbers indicate a misclassified plot, and the number indicates the erroneous variation differentially affects species with ecoregion assignment based on the discriminant analysis function of Canonical Analysis of Principal varied life history and vagility. Nonethe- Coordinates (CAP). The actual ecoregion numbers follow the ecoregion names (e.g., Klamath Mountains less, species distributions appear to provide / California High North Coast Range: 78). a coarse illustration of conceptual and spatial domains for natural areas manage- grouping strength in the Bailey classifica- and WWF) at 0.15 (Table 2). Breeding ment (hereafter management domains) in tion, and Small Mammals had the highest Birds and Large Mammals had the lowest the Klamath Region. The CAP analysis, grouping strength in the Omernik Revised classification strengths, demonstrating that in particular, illustrated areas of grada- classification. Grouping strength for Large these taxa have high amounts of similarity tion between adjacent zones, providing Mammals was generally low, and grouping (a large shared percentage of species) be- clues as to how the species distributions strength for Trees was generally high for tween ecoregions. Taxa groups with higher interface across ecoregional boundaries. all classifications except for the Climate classification strengths (typically Trees and In the following discussion, ecoregion Zones (Table 1). The reclassification of the Amphibians), however, have fewer shared names refer to the Omernik Revised clas- southern Cascades section of Omernik’s species between ecoregions. sification (Figures 2–7; Appendix) unless original scheme into an expanded Sierra otherwise stated. Nevada class in the Omernik Revised Percent correct allocation based on CAP classification improved the average group was sensitive to the number of ecoregions Ecoregional Classification Accuracy strength from the second weakest average in any one scheme, with Bailey ecoregions to being the strongest overall. having the worst overall average (53% If ecoregional classifications are judged on correct), but also the highest number of their ability to delimit internally homoge- Classification strength (W-B) results were regions (13) (Table 3, Appendix). Like- neous parts of the larger landscape, none similar to the ANOSIM R-value evalua- wise, the group with the highest average succeeded. Most of the ecoregions identi- tion, with the exception that the top two correct percentage was the Climates Zones fied showed important internal variation. If, strongest classifications were tied (Bailey (70%), with only five regions. The revision however, the goal is to identify interpretable
366 Natural Areas Journal Volume 35 (3), 2015 the distribution of amphibian species at the California–Oregon state border in the Eastern Cascades Slopes and Foothills ecoregion (Figure 2), which is likely due to differences in species inventory com- pleteness (it seems more complete for California) rather than the biogeography of amphibian species distributions. It should be noted that the Bailey classification has an ecoregion boundary in this vicinity (i.e., north of Klamath Falls, Figure 1A), but it is not clear at this time if this boundary identifies aspects of the environment that would affect amphibian species distribu- tions.
Although the Omernik Revised classi- fication (Figures 2–7) uses a somewhat coarser grain than the Bailey and WWF classifications (7 ecoregions, as opposed to 13 and 9 ecoregions for Bailey and WWF, respectively; Appendix), it seemed to capture the most important transitions across our region as a whole. We believe it provides a generalized and intuitive ecoregional framework for use by natural area managers in our region, recognizing that some applications would benefit from finer scale classifications (e.g., Bailey, WWF, and Omernik Level IV). Thus, with regards to research questions 1 and 2 that Figure 5. Map of Omernik Revised ecoregions showing misclassified plots based on large mammal as- we posed in the Introduction, we believe semblages. Large bold numbers indicate a misclassified plot, and the number indicates the erroneous the Omernik classification, revised to ecoregion assignment based on the discriminant analysis function of Canonical Analysis of Principal combine the southern Cascades with the Coordinates (CAP). The actual ecoregion numbers follow the ecoregion names (e.g., Klamath Mountains / California High North Coast Range: 78). Sierra Nevada ecoregion, provides the most ecologically relevant classification scheme for our region. transitions between ecoregions and to de- Bailey classification correctly described scribe the major landscape boundaries in the functional connection between the Species Vagility and Ecoregional the region, the ecoregional classifications California Cascade Range and the Sierra Classifications were roughly comparable in accuracy, and Nevada Range. Both the WWF and Bailey with the Climate Zones analysis, helped to classifications have especially large ecore- Species vagility appeared to be important paint a broad picture of the ecoregional gions (ecoregions 16 and 2 on Figures 1B for evaluating the fit between recorded structure of the Klamath Region. and 1A, respectively) that cover a large area species ranges and ecoregion classifica- of the Klamath Mountains, a region that tions (research question 3, Introduction). However, there were some boundaries that has great internal ecological heterogeneity. Trees showed the highest congruence with failed to capture ecological variation at our Neither classification recognized the con- all classifications (Tables 1–3), suggesting scale of analysis. For instance, Bailey’s siderable climatic diversity that we noted relatively fine scale correspondence with Klamath Mountains ecoregion extends all in the Climate Zone analysis for the central environmental variation. Studying species the way to the coast in southern Oregon part of our study region, specifically as distributions across geographic gradients (ecoregion 2 on Figure 1A), whereas all identified by the Eastern Klamath/Cascades in Patagonia, Monjeau et al. (1998) noted our analyses suggested the coastal zone has ecoregion and the westward peninsula of that plants responded more markedly to many distinctive qualities. The WWF clas- the Great Basin ecoregion (zones 4 and 5, climate variation than did small mammals. sification seemed to capture the coastal to respectively, Figure 1D). McDonald et al. (2005) also noted that Klamath Mountains transition particularly species turnover rate with distance was well (Figure 1B). On the other hand, the We noted a very implausible boundary in higher for trees than for land birds and
Volume 35 (3), 2015 Natural Areas Journal 367 robust for these groups. The preference of many birds for specific habitat types may be more intentional and fixed than for more wide ranging generalist species that establish territories across a broad range of habitats (e.g., CalPIF 2002a, 2002b, 2004, 2005). Migratory breeding birds showed somewhat weaker correspondence to the ecoregions than did resident species, due perhaps to their lower diversity and shorter period of residence in our region each year. Winter climate is typically considered one of the strongest factors limiting resident bird populations within temperate and boreal regions (Forsman and Mönkkönen 2003).
Ecoregional Features and Biogeographic Linkages
Our results suggest that there are a number of biogeographic linkages among ecore- gions in our study area (research question 4, Introduction). Although the number of ecoregions in each classification varied, our analyses suggested that they can be viewed hierarchically, from a three-zone overview of the region that should be rel- evant to almost all species, to finer scale subdivisions for less widespread species or other ecological processes. Figure 6. Map of Omernik Revised ecoregions showing misclassified plots based on small mammal as- semblages. Large bold numbers indicate a misclassified plot, and the number indicates the erroneous All the classifications differentiated a coast ecoregion assignment based on the discriminant analysis function of Canonical Analysis of Principal Coordinates (CAP). The actual ecoregion numbers follow the ecoregion names (e.g., Klamath Mountains zone from the rest of the ecoregions (Figure / California High North Coast Range: 78). 1). Although latitudinal variation does oc- cur in this zone, it is muted within our study region. The uniquely cool, moist climates mammals. Because climatic variation was with the hypothesis that larger mammals, of the coastal zone are associated with notable across all the classifications, and which are highly mobile and can more ef- redwood (Sequoia sempervirens Endl.) and such variation is mechanistically linked fectively regulate their body temperature, Sitka spruce (Picea sitchensis (Bong.) Car- to plant species distributions (Woodward are less sensitive to some of the climatic rière) forests, as well as a number of other 1987), these results are not surprising. or habitat boundaries than are less mobile Pacific Northwest plant and animal species. and ectothermic organisms. However, this Interestingly, the summer climate appears Small mammal and amphibian distribu- finding may also have been affected by to be the primary factor differentiating this tions showed modestly high degrees of the low species richness of large mam- zone, as winter precipitation is matched in correspondence to the ecoregional clas- mals, so our results are not definitive for other areas of the western Klamath Region. sifications (Tables 1–3). Hess et al. (2006) this group. Other characteristic species of this region noted that congruence between ecoregional include trees such as red alder (Alnus ru- and species richness turnover for amphib- Resident and migratory birds showed an bra Bong.) and western hemlock (Tsuga ians was among the highest for terrestrial intermediate degree of correspondence heterophylla Sarg.), mammals such as wildlife indicators. In the Pacific North- with the ecoregional classifications we the white-footed vole (Arborimus albipes west, they also noted that mammal turn- tested (Tables 1–3), but appeared more Merriam) and yellow-cheeked chipmunk over was high. However, large mammals sensitive to such geographic differences (Neotamias ochrogenys Sutt. & Nadl.), showed the weakest correspondence with than did large mammals. However, we had and a rich array of salamander species, the ecoregional classifications we tested many more bird species to analyze, so we including California slender salamander (Tables 1–3). Our results are consistent believe our results are more likely to be (Batrachoseps attenuates Eschscholtz)
368 Natural Areas Journal Volume 35 (3), 2015 and Del Norte salamander (Plethodon elongatus Van Denburgh). Resident birds include the Marbled Murrelet (Brachyr- amphus marmoratus Gmelin) and many other coastal species. This zone’s eastern boundary is more definitive for plants than for most of the animals we studied.
Similarly, the easternmost zone is highly distinctive in our study area, showing a markedly different flora and fauna and much less forest cover than the rest of the region. Significantly, the climatic and topographic boundary of the Cascade Range appears to be a more pronounced boundary for small mammals than for many tree species, and although poor in tree species, areas east of the Cascade Range are surprisingly rich in animal species (Appendix). The biodiversity of the region is composed of species with broad distributions in the Great Basin and Intermountain West. Characteristic tree species include western juniper (Juniperus occidentalis Hook.) and curl-leaf mountain mahogany (Cercocarpus ledifolius Nutt.). Notable animal species include the Great Basin spadefoot toad (Scaphiopus inter- montanus Cope), pronghorn (Antilocapra Americana Ord), least chipmunk (Tamias minimus Bachman), and birds of open Figure 7. Map of Omernik Revised ecoregions showing misclassified plots based on tree assemblages. country, such as the ferruginous hawk Large bold numbers indicate a misclassified plot, and the number indicates the erroneous ecoregion (Buteo regalis Gray). assignment based on the discriminant analysis function of Canonical Analysis of Principal Coordinates (CAP). The actual ecoregion numbers follow the ecoregion names (e.g., Klamath Mountains / California High North Coast Range: 78). The central zone is an exceedingly complex area of major latitudinal and longitudinal transitions between wet coastal forests along the western and northern margins,
Table 1. Ecoregional classification strength as measured by analysis of similarity (ANOSIM) R values for each biota group and ecoregional classification. B = Bailey, C = Climate Zones, O = Omernik, O_R = Omernik Revised, and W = World Wildlife Fund. See text for more information on ANOSIM R values.
ANOSIM R Biota Group B C O O_R W Average Rank Order Amphibians 0.69 0.43 0.63 0.67 0.65 0.61 B = O_R > W > O > C Breeding Birds 0.49 0.6 0.54 0.56 0.6 0.56 C = W > O_R > O > B Resident Birds 0.61 0.69 0.62 0.67 0.66 0.65 C > O_R > W > O > B Large Mammals 0.4 0.19 0.3 0.35 0.34 0.32 B > O_R > W > O > C SmallSmall MMammalsammals 0. 63 0.63 0.65 0.68 0. 67 0.65 O_ R > W > O > B = C Trees 0.73 0.45 0.68 0.72 0.68 0.65 B > O_R > W = O > C Averages 0.59 0.5 0.57 0.61 0.6 0.57 O_R > W > B > O > C
Volume 35 (3), 2015 Natural Areas Journal 369 Table 2. Ecoregional classification strength as measured by Classification Strength values (the weighted mean of the within class similarities minus the mean of all between class similarities) for each biota group and ecoregional classification. B = Bailey, C = Climate Zones, O = Omernik, O_R = Omernik Revised, and W = World Wildlife Fund. See text for more information on Classification Strength.
Classification Strength Biota Group B C O O_R W Average Rank Order Amphibians 0.2 0.16 0.19 0.2 0.21 0.19 W > B = O_R > O > C Breeding Birds 0.07 0.06 0.06 0.06 0.07 0.06 W = B > C = O_R = O Resident Birds 0.07 0.07 0.06 0.07 0.07 0.07 W = B = O_R = C > O Large Mammals 0.06 0.04 0.04 0.05 0.05 0.05 B > W = O_R > C = O SmallSmall MMammalsammals 0. 16 0.14 0.14 0.15 0. 16 0.15 B = W > O_R > C = O Trees 0.31 0.22 0.28 0.31 0.31 0.29 W = B = O_R = C > O Averages 0.15 0.12 0.13 0.14 0.15 0.13 W = B > O_R > O > C
and dry forests, sagebrush steppe, Mediter- amabilis Douglas ex J. Forbes), Engelmann lowland California. These species include ranean shrublands, and grasslands along spruce (Picea engelmannii Engelm.), sub- a number of native oaks, such as blue oak the eastern and southern boundaries. The alpine fir (Abies lasiocarpa Endl.), such (Quercus douglasii Hook. & Arn.), valley three broad zones described above were iconic northern mammals as the wolverine oak (Q. lobata Née), interior live oak (Q. recognized by all the classifications, and (Gulo gulo L.) and lynx (Lynx canadensis wislizeni A. DC.), a rich array of chaparral compose the coarsest ecoregional classifi- Kerr), small mammals such as the water shrubs, such as toyon (Heteromeles arbuti- cation for our region. We next delineate and vole (Microtus richardsoni De Kay) and folia M. Roem.) and chamise (Adenostoma describe regions within the central zone. Pacific shrew (Sorex pacificusCoues), and fasciculatum Hook. & Arn.), small mam- high elevation birds, such as the Ameri- mals such as the California kangaroo rat At the northern edge of the central zone, can Three-toed Woodpecker (Picoides (Dipodomys californicus Merriam), and the Oregon Cascades subregion (Cascades dorsalis Baird) and Gray Jay (Perisoreus southern landbirds such as the California 4; Figures 2–7) appears to function as a canadensis L.). Thrasher (Toxostoma redivivum Gambel), southward-reaching high elevation pen- and Greater Roadrunner (Geococcyx cali- insula of circumboreal species that do Similarly, at the southern margin of the cen- fornianus Lesson). not occur elsewhere in our region. This tral zone, the Central California Foothills was especially notable for small mam- and Coastal Mountains ecoregion of the Our analyses suggested the California mals, which show a surprising richness Sacramento Valley (Figures 2–7) presents a Cascade Range is climatically and bio- in this subregion. Notable species of this northward-reaching peninsula for the rich geographically more closely allied with ecoregion include Pacific silver fir (Abies assemblage of species characteristic of the Sierra Nevada than the larger Cascades
Table 3. Ecoregional classification strength as measured by Canonical Analysis of Principal Coordinates (CAP) analyses for each biota group and ecore- gional classification. B = Bailey, C = Climate Zones, O = Omernik, O_R = Omernik Revised, and W = World Wildlife Fund. See text for more information on CAP.
CAP (%Correct) Biota Group B C O O_R W Average Rank Order Amphibians 55% 67% 66% 64% 61% 63% C > O > O_R > W > B Breeding Birds 55% 71% 66% 71% 64% 65% C = O_R > O > W > B Resident Birds 58% 83% 69% 68% 66% 69% C > O > O_R > W > B Large Mammals 16% 36% 14% 35% 29% 26% C > O_R > W > B > O SmallSmall MMammalsammals 62% 80% 66% 70% 66% 69% C > O_ R > W = O > B Trees 71% 82% 81% 84% 81% 80% O_R > C > W = O > B Averages 53% 70% 60% 65% 61% 62% C > O_R > W > O > B
370 Natural Areas Journal Volume 35 (3), 2015 ecoregion described by Omernik (2011). Although they are distinguished from the distinct combinations of climate, geology, The Bailey and WWF classifications both immediate coastal forests by greater plant and biodiversity, yet there is not a corre- define a Sierra Nevada ecoregion, but of diversity and endemism, western Klamath sponding level of site-specific management very different extents in our study region. Mountains sites were often misclassified as knowledge for many issues. Klamath Re- The California Cascades/Sierra Nevada coastal sites for resident land birds, small gion managers often must import concepts ecoregion we defined using the Omernik mammals, and amphibians, suggesting and resource management approaches boundaries (Sierra Nevada 5; Figures 2–7) strong connections between these moist, developed in adjacent regions, yet the is similar in distribution to the Bailey Sierra largely forested ecoregions (Figures 2, geographic domains of such management Nevada and Southern Cascades ecoregions, 3, and 6). approaches are rarely stated explicitly. but more closely matches the topography and recognizes an important disjunction The eastern Klamath Mountains subregion This study provides potential insights into between the Sierra Nevada and Cascades shows more varied biogeographic influenc- the relevant management domains of the ecoregions in far northern California. The es. The Climate Zone analysis suggested Klamath Region. For instance, the wet climatic, biogeographic, and biophysical that climates typical of the eastside of the and productive landscape of the coast, data suggest such a disjunction is im- Cascade Range extend nearly to the eastern western Klamath Mountains, and Oregon portant, despite the underlying volcanic foothills of the Marble Mountains (a high Cascades subregions seem to show strong geology. range in the central Klamath Mountains), connections to the management domain which mirrored western range extensions of the maritime Pacific Northwest (e.g., The Klamath Mountains/California High of many drought-adapted plant and animal Swanson and Franklin 1992; Carey 1998; North Coast Range ecoregion (hereafter species typically found east of the Cascade Naiman et al. 2000; Spies et al. 2002; Klamath Mountains ecoregion), the most Range. The eastern ridges and valleys Altman and Alexander 2012). These land- complex and centrally located ecoregion, show evidence of Sierran and Californian scapes are dominated by highly produc- shows a notable gradient from the wind- influences, respectively. In the northeast, tive conifer-dominated forests with many ward slopes of the major mountain ranges, Cascadian influences are also notable. shade-tolerant, moisture-adapted plant and where lower elevations are largely forested The general character is of great spatial animal species. Many of the ecological and receive 100–250 cm of precipitation per variability and surprising juxtapositions processes (e.g., large, relatively infrequent year, to the leeward slopes, which receive of different floras and faunas. fires, debris flows and geomorphic, flood, 40–80 cm of precipitation per year and and wind events, rafting and damming contain a rich mosaic of more open for- The strong influence of Sierran species of large wood in large perennial streams, ests, shrublands, pine-oak woodlands, and throughout the Californian Cascades and etc.) are well studied in this region. In this grasslands at lower elevations. This pattern into the eastern Klamath Mountains ecore- productive landscape, uniquely biodiverse suggests that the Klamath Mountains ecore- gion is most likely a result of the unique habitats, such as rare plant communities, gion might be viewed in terms of western evolutionary, geologic, and climatic history are likely to be associated with geologi- and eastern subregions, with quite varied of these adjacent ecoregions. The ancient cally distinct areas or relatively rare early environments and floras. Waring (1969) Klamath Mountains and Sierra Nevada, and late successional stages (Odion and proposed that the eastern portion of the with many shared geologic characteristics Sarr 2007). Siskiyou Mountains (a northern subrange and a great diversity of habitats, evolved a of the Klamath Mountains) composes globally distinct and uncommonly diverse East of the crest of the Klamath Mountains, a distinct ecological unit within which flora and fauna (Whittaker 1961; Stebbins the management domains become blurred many characteristic woody plant species and Major 1965). With the later rise of the and broadly overlapping. Southern and of the western Siskiyou Mountains are Cascade Range, the species-rich communi- low elevation zones, with open woodland, absent or rare. While many of the endemic ties of the adjacent Klamath Mountains and grassland, and chaparral environments and moisture-adapted woody species are Sierra Nevada were able to readily colonize have strong connections with Californian indeed restricted to the western Siskiyou the new volcanic landscapes, intermix, and and Sierran ecosystems and management Mountains, vascular plant species diver- with subsequent climate-driven migrations, literatures (e.g., SNEP 1996; Odion and sity is notably higher in the eastern zone establish a general biogeographic conti- Davis 2000; CalPIF 2002a, 2002b, 2004; (Whittaker 1960), with a greater array of nuity across the highlands of northeast Keeley 2002; Agee and Skinner 2005). Spe- plant communities, especially of drought- California. cies diversity and landscape heterogeneity adapted species. are very high, summer drought is severe, Implications for Natural Areas and fire and invasive species are major Viewed across all the taxa groups we Management in the Klamath Region concerns, especially at low and middle el- studied, the western Klamath Mountains evations. Although fire and fuels restoration subregion can be viewed as a major reser- The uniquely complex array of ecoregions approaches developed in the southwestern voir of mesic forest species with northern and environments within the Klamath United States are often applied to these fire- distributions into the maritime forests of Region creates practical challenges for adapted ecosystems (e.g., Covington et al. the coastal zone and Pacific Northwest. natural area managers. There are many 1997) in natural areas, it is important to note
Volume 35 (3), 2015 Natural Areas Journal 371 that Mediterranean plant communities are Schaaf et al. 2004). Such evolutionary cies life history and other factors, such richer in endemic species than most Interior centers, refugia (Whittaker 1961; Tzedakis as environmental history and land use, West ecosystems, and warrant distinctive et al. 2002), and hot spots (Myers et al. can cause varied responses to landscape management approaches. Shrublands and 2000) may have exceptional importance for boundaries. Our findings supported the associated species, especially, are critical teaching us about the mechanisms whereby hypothesis that immobile species (plants, reservoirs for biodiversity (Cody 1986), species coexist and persist in space and fungi) and low vagility species (small mam- not simply ladder fuels or competitors with time. Tzedakis et al. (2002) demonstrated mals, amphibians) are likely to show nar- desired tree species. that many tree species survived Quaternary rower distributions than wider ranging taxa climate fluctuations in the mountains of (birds, large mammals). However, for most East of the Cascades and Sierra Nevada western Greece, a region with many paral- other taxa, inventories are not complete, ecoregions, the Interior West influence is lels to the Klamath Region. Much of the nor are range maps available (e.g., most increasingly important, although higher research to date in the Klamath Region arthropods). Thus, for many natural areas elevation areas have notable affinities with has been botanical. We need comparable management applications, managers may drier Sierran forest landscapes. The Eastern work for other life forms, especially the want to consider more general ecoregional Cascades Slopes and Foothills and North- less studied taxa (e.g., arthropods). classifications that are likely to be relevant west Basin and Range ecoregions in this to multiple species. area (Figures 2–7) have the strongest affini- Current climate figures strongly in the spa- ties with the other semiarid and subhumid tial structure of ecoregions in the Klamath It is also important to recognize that ecoregions of the Interior Northwest and Region and elsewhere; however, projected precise, taxon-specific classifications are Great Basin, and resource management lit- climate change will shift the geographic unlikely to be broadly relevant manage- erature from those regions (e.g., Hemstrom distribution of climate conditions (Wiens ment domains for natural area managers, et al. 2002; CalPIF 2005; Chambers et al. et al. 2011) and those shifts will likely who often must make decisions that are 2007) may be quite relevant for many of reshuffle existing ecoregional patterns suitable for many species and ecological the most pressing management issues. The (Stralberg et al. 2009). Landscapes that processes. In our study, we found that an notable summer drought in this area sug- have functioned as past refugia are likely intermediate level of resolution, as in the gests our eastern regions are likely to fall to be of exceptional importance during Omernik Revised classification, captured in the management domains of the western future changes (Ashcroft 2010). It seems sufficient ecoregional detail to be broadly Great Basin and Columbia Basin. reasonable to hypothesize that the Klam- relevant, yet easily understood and com- ath Region has the potential, if managed municated. Similar resolution ecoregional We found that a revision of the most re- well, to carry many native species into an classifications may be useful for natural cent Omernik ecoregional classification uncertain future (Olson et al. 2012). Major areas management applications in other (Figures 2–7) provided a relatively general goals for a Klamath Region management regions, particularly in other coastal moun- geographic framework that captured most domain might, therefore, be inventory, tainous regions with levels of ecoregional of the broad biogeographic zones and monitoring, and research that strengthens complexity comparable to that of the Klam- subregions of the Klamath Region. A more our understanding of the patterns and ath Region. precise delineation of western and eastern origins of native biodiversity and helps Klamath Mountains subregions appears to ensure it will be conserved for future ACKNoWLEdgMENTS worthy of future study, but awaits finer generations. scale data sources. The Omernik Revised classification we devised is sufficiently We thank Phillip van Mantgem and two general to be used by managers to place CoNCLuSIoNS ANd MANAgEMENT anonymous reviewers for their comments their protected areas in a larger regional RECoMMENdATIoNS on earlier versions of the text. S. Shafer context and to help identify linkages to was supported by the US Geological Survey more widespread ecoregions and manage- Our study of ecoregional structure and Climate and Land Use Change Research ment domains. biotic distributions in the Klamath Re- and Development Program. Any use of gion highlights the complex array of trade, firm, or product names is for de- Although the Klamath Region can be ecological patterns across the region. A scriptive purposes only and does not imply viewed as a nexus for more broadly distrib- hierarchical view of ecoregions, starting endorsement by the US Government. uted Maritime Temperate, Mediterranean, from a coarse three-region overview to and Interior West ecoregions and species finer ecoregional subdivisions, provides a assemblages, such a peripheral role does comprehensive and yet flexible framework Daniel Sarr is a Conservation Ecologist not fully capture its emergent properties. It suitable for understanding and managing who completed this research to help guide is important to recognize that it is also a re- for native biodiversity. At broad scales, the National Park Service’s Klamath Net- gion of globally significant biodiversity and general climate-driven patterns seem to work Inventory and Monitoring Program, endemism (Whittaker 1960; Stebbins and affect the distributions of most species in a program he helped to design and led for Major 1965; DellaSala et al. 1999; Vander the Klamath Region. At finer scales, spe- 13 years. He is now a Research Ecolo-
372 Natural Areas Journal Volume 35 (3), 2015 gist with US Geological Survey’s Grand As Klamath Bird Observatory co-founder, Beach, California. Accessed 7 January 2008 Canyon Monitoring and Research Center John Alexander has been working to
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374 Natural Areas Journal Volume 35 (3), 2015 with climate disruption: a no-analog future US Geological Survey. 1999. Digital represen- Waring, R.H. 1969. Forest plants of the eastern for California birds? PLoS ONE 4(9):e6825. tation of “Atlas of United States Trees” by Siskiyous, their environmental and veg- doi:10.1371/journal.pone.0006825. Elbert L. Little, Jr. US Geological Survey etational distribution. Northwest Science Swanson. F., and J.F. Franklin. 1992. New Professional Paper 1650, [Lakewood, CO]. 43:1-17. forestry principles from ecosystem analysis Accessed 19 May 2005
Volume 35 (3), 2015 Natural Areas Journal 375 Continued Small Mammals Trees Total Large Mammals Birds Resident Birds Breeding 2 5 ± 2.1 49 ± 0 84 ± 2.1 8 ± 0 40 ± 0.7 13 ± 1.4 197 ± 1 7 9 ± 1.1 50 ± 1.6 89 ± 1.2 5 ± 1 33 ± 1.1 12 ± 2.4 197 ± 3 4 11 ± 0.6 46 ± 1.2 89 ± 0.5 8 ± 0 35 ± 1 18 ± 4.2 205 ± 4 8 9 ± 1.5 50 ± 1.7 89 ± 1.2 5 ± 0.9 33 ± 1 12 ± 2.2 198 ± 3 535313 7 ± 0.8 7 ± 2.2 15 ± 2.7 51 ± 1.1 51 ± 1.9 47 ± 0.7 86 ± 1.7 89 ± 3.1 8 ± 1.1 86 ± 4 10 ± 0.8 39 ± 1.8 10 ± 0.3 39 ± 3.2 6 ± 3.6 41 ± 2.8 10 ± 4.6 195 ± 6 24 ± 2.5 205 ± 10 222 ± 5 1110 16 ± 0.7 15 ± 0.4 47 ± 1.6 81 ± 1.3 39 ± 1.1 8 ± 0.5 75 ± 1.3 37 ± 2.4 10 ± 0 35 ± 2.7 29 ± 1.2 222 ± 2 22 31 ± 2 198 ± 3 16 ± 0.6 44 ± 1.7 79 ± 1.2 8 ± 0.5 35 ± 1.6 32 ± 5.3 214 ± 6 19 16 ± 0.7 44 ± 1.8 79 ± 1.1 8 ± 0.5 35 ± 1.7 31 ± 5.3 213 ± 6 10 11 ± 0.7 48 ± 3.3 87 ± 2.7 7 ± 1.3 35 ± 1.1 19 ± 3.7 205 ± 4 28 14 ± 2.8 47 ± 1.2 86 ± 4.6 10 ± 0.4 41 ± 3.4 22 ± 3.9 219 ± 7 umber of plots Amphibians N orthern California Interior orthern California Coast orthern California Coastal N N N Oregon and Washington Coast Ranges Coast Ranges Ranges Forests California Central Valley Grassland Northern California Coast California Interior Chaparral and Woodlands Central and Southern Cascades Forests 1 23 Klamath Mountains 160 14 ± 1.9 44 ± 3.3 83 ±4.7 8 ± 1.1 37 ± 3.6 33 ± 6.7 219 ± 11 2 89 Great Valley Sierra Nevada Foothills 8 12 ± 0.5 52 ± 0.5 85 ± 1.6 5 ± 0.5 35 ± 2.1 17 ± 3.3 206 ± 5 8 9 Snake/Columbia Shrub Steppe 10 5 ± 0.3 51 ± 0.7 83 ± 2.5 9 ± 0.7 36 ± 2.1 5 ± 2.5 187 ± 7 27 Sierra Nevada Forests 24 8 ± 3.5 51 ± 2.0 83 ± 1.7 7 ± 1 37 ± 1.7 17 ± 5.8 202 ± 7 1011 Sierra Nevada 12 Southern Cascades Modoc Plateau 59 9 ± 3 50 ± 1.9 86 ± 2.8 8 ± 1.3 41 ± 3.9 17 ± 5.8 209 ± 10 1314 Eastern Cascades 28 Western Cascades Northwestern Basin and Range 3 5 ± 0 50 ± 1 81 ± 2 8 ± 0.6 34 ± 0.6 2 ± 0.6 180 ± 3 1012 Central Pacific Coastal Forests16 Eastern Cascades Forest19 Klamath-Siskiyou Forests 22 113 165 15 ± 0.7 39 ± 1.2 7 ± 1.2 14 ± 2.2 75 ± 1.6 51 ± 1.5 45 ± 3.2 10 ± 0.7 30 ± 1.5 88 ± 2.6 84 ± 4.1 32 ± 6.9 9 ± 1.5 8 ± 1 199 ± 7 40 ± 2.9 38 ± 3.4 8 ± 4.2 32 ± 6.9 201 ± 9 220 ± 9 168 164 1482 Zone Number Zone Name Bailey WWF Appendix. Appendix. Ecoregional classification schemes andaverage taxaVariance richnessfor isrepresented each as group examined. standard deviation. Number of plotsrefers to the number of points within each ecoregional polygon for that zone. Zone numbers are unique to each original ecoregional scheme and nohave inherent meaning other than their original context. Zone names come from the original ecoregional scheme as well.
376 Natural Areas Journal Volume 35 (3), 2015 Small Mammals Trees Total Large Mammals Birds Resident Birds Breeding 7 ± 2.2 50 ± 1.3 86 ± 1.9 8 ± 1.2 39 ± 2.4 10 ± 7.4 199 ± 11 5 ± 0 50 ± 0.7 83 ± 2.5 9 ± 0.7 35 ± 1.7 4 ± 2.5 186 ± 7 16 ± 0.7 42 ± 2.8 78 ± 2.6 9 ± 1 33 ± 3 35 ± 6.6 210 ± 10 15 ± 1.6 44 ± 2.6 82 ± 4.2 9 ± 1 37 ± 3.3 32 ± 7.4 219 ± 10 12 ± 2.6 48 ± 2.6 86 ± 2.6 7 ± 1.1 37 ± 2.5 25 ± 7.6 215 ± 11 1 3 49 85 8 40 12 196 4350 16 ± 0.8 42 ± 3.2 8 ± 2.7 77 ± 2.6 50 ± 1.8 9 ± 1.2 85 ± 2.2 32 ± 3.3 32 ± 5.9 7 ± 0.8 39 ± 3 207 ± 10 16 ± 6.1 204 ± 8 43 16 ± 0.8 42 ± 3.2 77 ± 2.6 9 ± 1.2 32 ± 3.3 32 ± 5.9 207 ± 10 77 10 ± 4.1 49 ± 2.4 85 ± 3.3 8 ± 1.6 40 ± 3.4 18 ± 6.2 210 ± 11 17 10 ± 1.4 49 ± 2.9 88 ± 2.4 6 ± 1.5 34 ± 1.7 15 ± 4 201 ± 5 99 7 ± 1.5 51 ± 1.5 88 ± 2.6 9 ± 1.5 40 ± 2.9 8 ± 4.7 201 ± 9 17 10 ± 1.4 49 ± 2.9 88 ± 2.4 6 ± 1.5 34 ± 1.7 15 ± 4 201 ± 5 28 14 ± 2.8 7 ± 1.1 86 ± 4.5 10 ± 0.4 41 ± 3.4 22 ± 3.9 220 ± 6 99 7 ± 1.5 51 ± 1.5 88 ± 2.6 9 ± 1.5 40 ± 2.9 8 ± 4.7 201 ± 9 65 63 93 156 14 ± 1.8 45 ± 3.1 84 ± 4.3 8 ± 1 37 ± 3.3 33 ± 6.6 221 ± 9 156 14 ± 1.8 45 ± 3.1 84 ± 4.3 8 ± 1 37 ± 3.3 33 ± 6.6 221 ± 9 112 umber of plots Amphibians N Coast Range Cascades Sierra Nevada Central California Foothills and Coastal Mountains Eastern Cascades Slopes and Foothills Klamath Mountains/California High North Coast Range Central California Foothills and Coastal Mountains Eastern Cascades Slopes and Foothills Klamath Mountains/California High North Coast Range Coastal Western Klamath Californian Great Basin ) 1 4 5 6 9 45 Cascades 6 Sierra Nevada 1 Coast Range 9 1 2 3 45 Eastern Klamath/Cascades 69 10 ± 2.8 49 ± 2.5 90 ± 2.1 10 ± 1.1 41 ± 3.4 19 ± 9.8 218 ± 9 78 80 Northern Basin and Range 9 78 80 Northern Basin and Range 9 5 ± 0 50 ± 0.7 83 ± 2.5 9 ± 0.7 35 ± 1.7 4 ± 2.5 186 ± 7 Zone Number Zone Name Continued Omernik Omernik Revised Climate Zones Appendix Appendix (
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