Alexander Archipelago Research Articles

Evolutionary diversity and ecology of endemic small mammals of southeastern Alaska with implications for land management planning

The dynamic geological history and naturally fragmented landscapes of southeastern Alaska create an environment with a high potential for endemism. The temperate rainforest of the region regenerates and develops slowly, and old-forest characteristics do not appear until ≥300 years following disturbance. The challenges of managing forest resources are intensified in island archipelagos because of the increased sensitivity of indigenous biota to disturbance and higher rates of extinction, especially among endemic organisms. Early expeditions of the large islands of the Alexander Archipelago (≈1% of all named islands) documented 27 endemic mammalian taxa. More recent studies with modern techniques found that some reputed endemics showed nominal levels of genetic divergence from other conspecific populations, but more divergence existed among several taxa than was reflected in the current taxonomy. Furthermore, the mammal fauna of southeastern Alaska has a nested structure with complex phylogeographic patterns suggesting multiple colonization events. Of eight taxa examined through phylogeographic analyses, five species showed acute genetic variation and divergence in mitochondrial sequences. Four species were comprised of coastal and continental clades (i.e. populations of recent common descent), whereas the fifth species showed a third clade. Conversely, the northern flying squirrel ( Glaucomys sabrinus) and southern red-backed vole ( Clethrionomys gapperi) were represented by relatively shallow divergent lineages. Still, G. sabrinus showed a distinct mitochondrial lineage on 11 islands (Prince of Wales Island complex), which exhibited severely reduced genetic variation. Moreover, flying squirrels in southeastern Alaska are genetically distinct from populations in the Pacific Northwest; as different as each is from the southern flying squirrel ( G. volans). Recent ecological studies of endemic populations of the northern flying squirrel and the southern red-backed vole (reputed old-growth associates) suggest that risk of extirpation in managed landscapes is likely less than was presumed during recent land management planning in the region because: (1) abundant noncommercial forests apparently contribute to breeding populations of northern flying squirrels, which appear to have a more general lifestyle than populations in the Pacific Northwest; and (2) red-backed vole populations may be able to exist in managed young-growth stands that originated from clearcut logging. Still, there are essential questions for both species regarding the influence of annual population fluctuations on habitat distribution and population demography, stand and landscape features that restrict dispersal, and vegetative and structural characteristics of second-growth stands that will sustain breeding populations of both species.

Maintaining wildlife habitat in southeastern Alaska: implications of new knowledge for forest management and research

We review results and implications from recent wildlife studies that followed from the 1997 Tongass Land Management Plan (TLMP) and identify information needs and directions for research, development, and application. Sustained population viability of wildlife species was identified as a major issue in the TLMP planning process. Several species were identified as management indicator species, and research was conducted to determine their potential sensitivity to forest management. Southeastern Alaska was found to be a region with an especially high degree of endemism in its small mammal fauna, principally because of the combination of its archipelago geography combined with highly dynamic glacial history. Two species of endemic small mammals selected for demographic study, however, appeared to be less dependent on old-growth forests than had been suspected at the time TLMP was written: the northern flying squirrel ( Glaucomys sabrinus) because of relatively high suitability of noncommercial, low-volume, mixed-conifer forest; and the southern red-backed vole ( Clethrionomys gapperi) because of relatively high suitability of precommercially thinned young-growth forest. The northern goshawk ( Accipiter gentilis) was found to be problematic for “management indicator” status because of logistical difficulties involved in monitoring this relatively rare, highly mobile species that frequently changes nest sites. Sampling protocols were developed for marbled murrelet ( Brachyramphus marmoratus), although murrelet populations do not appear to be in trouble on the Tongass. The conservation strategy of TLMP for American marten ( Martes americana) appeared to be sound on Chichagof Island where marten have been studied intensively, but implications for the rest of southeastern Alaska were unclear without further work. Studies of the Alexander Archipelago wolf ( Canis lupus ligoni) indicated that population density of black-tailed deer ( Odocoileus hemionus) and road access (to wolf hunters) were the predominant factors affecting wolf productivity and mortality, respectively. Finally, studies of bird community response to timber-harvest alternatives to clearcutting indicated that although creation of forest “edge” may increase nest predation rates, the actual response depends on a broad array of factors and is highly variable. We suggest that research, development, and application focus on plant and animal communities and management of vegetation to achieve specific objectives for wildlife habitat. We suggest that such efforts emphasize silviculture of second-growth forests, understanding old-growth reserves, distribution of endemic small mammals, and alternatives to clearcutting. Models for evaluating black-tailed deer habitat and populations are needed for subsistence-hunting management, and some work needs to be directed at interactions between tourism and selected wildlife species.

DEMOGRAPHY OF TWO ENDEMIC FOREST-FLOOR MAMMALS OF SOUTHEASTERN ALASKAN TEMPERATE RAIN FOREST

We studied demography of the Keen’s mouse (Peromyscus keenimacrorhinus) and the Wrangell Island red-backed vole (Clethrionomys gapperi wrangeli) in the Alexander Archipelago during 1998–2000 because of concerns over population viability from extensive clear-cut logging of temperate rain forest in the region. We trapped 1-ha grids and assessment lines with live traps during spring and autumn to compare populations among gap-phase oldgrowth, multicohort old-growth, peatland mixed-conifer, and thinned young-growth (23-year-old) forests. Generally, gap-phase old growth and peatland mixed conifer supported the highest and lowest populations of voles, respectively. One notable exception was during autumn 1998, when vole population levels were highest and density was higher (P , 0.02) in young growth than gap-phase old growth. Mean body mass, minimum summer and overwinter survival, age and sex composition, and percentage reproductive females did not differ among habitats. For Keen’s mouse, density was highest in 1998; overall, populations were highest in young growth and lowest in peatland mixed conifer. Mean body mass and minimum summer and overwinter survival did not differ among habitats, but fewer reproductive females were recorded in multicohort than in gap-phase old growth, peatland mixed conifer, or young growth. Our results suggest that C. gapperi populations in southeastern Alaska are not as sensitive to canopy removal as has been indicated elsewhere in western coniferous forests and that P. keeni populations in southeastern Alaska flourish in a variety of habitats. If the results of our study can be generalized across southeastern Alaska, peatland mixed conifer likely contributes little to breeding populations of C. gapperi and thus is unlikely to mitigate any effects of broad-scale clear-cut logging of old-growth forests.

A nuclear perspective on endemism in northern flying squirrels ( Glaucomys sabrinus ) of the Alexander Archipelago, Alaska

We used microsatellites to examine populationstructure and genetic diversity in northernflying squirrels in the Alexander Archipelagoof Southeast Alaska, with an emphasis on theendemic Prince of Wales flying squirrel(Glaucomys sabrinus griseifrons). Previouswork showed this subspecific designationcoincided with a distinct mitochondrial lineageon eleven islands (the Prince of Wales [POW]complex). To obtain a nuclear perspective onthis lineage and to further investigate geneticdiversity among insular populations, weexamined six microsatellite loci in 233 flyingsquirrels representing eight populations inSoutheast Alaska and a population from interiorAlaska (seven island and two mainlandlocalities). Island populations have lowerheterozygosity and allelic diversity thanmainland populations. Overall, populationpairs show a pattern of isolation by distance,indicating there is little long-distance geneflow across the archipelago. Analyses ofmicrosatellite allele frequencies revealsignificant differences between the POW complexpopulations and others we examined, a findingcongruent with the mitochondrial data. Thepopulation from Mitkof Island, a non-POWcomplex island, also differs significantly fromother populations in allele frequencies. Thesix POW complex populations are geneticallyvery similar, suggesting current or recent geneflow among these islands, while there seems tobe no gene flow between the POW complex andother populations in Southeast Alaska. Ourdata corroborate mitochondrial DNA resultsindicating that G. s. griseifrons isgenetically distinct and suggest a generalpattern of isolation of insular flyingsquirrels in Southeast Alaska.

Reduced genetic variation in insular northern flying squirrels (Glaucomys sabrinus) along the North Pacific Coast

Nearshore oceanic archipelagos are natural laboratories that could provide valuable insight into the role of evolutionary processes such as founder effects and incipient speciation in biotic conservation. The Alexander Archipelago of Southeast Alaska is an example of such a complex, yet few biological investigations have been conducted. For the past 50 years, the region has experienced intense anthropogenic disturbances (particularly timber harvesting), causing habitat fragmentation and potential disruption of biotic communities. As part of a series of studies of mammals endemic to Southeast Alaska, we examined mitochondrial DNA sequences from 118 flying squirrels to investigate genetic diversity across Southeast Alaska. Mitochondrial sequence divergence corroborates the subspecific designation of the endemic Prince of Wales flying squirrel (Glaucomys sabrinus griseifrons). This island lineage exhibits severely reduced genetic variation and may be the result of an early Holocene founder event. Nearly all of the animals we examined on Prince of Wales Island and ten islands to the west had identical cytochrome b (52 of 53) and control region (21 of 21) sequences. In contrast, substantial polymorphism and little genetic structuring were found in comparable populations on the mainland of Southeast and Interior Alaska. Because flying squirrels in the Pacific Northwest are associated with old-growth forest, forest-use plans should aim to conserve this unique lineage of island squirrels.

A phylogeographic perspective on endemism in the Alexander Archipelago of southeast Alaska

Conservation plans for the North Pacific Coast are beginning to acknowledge that the old-growth forests remaining on the extensive archipelagos of the region may require a new management paradigm. Extensive timber harvesting activities on these islands may impact wildlife populations and be particularly detrimental to the large number of endemics. Because insular biotas have suffered a disproportionate number of documented extinctions worldwide, the documentation of taxonomic validity and spatial distribution of endemics should be a priority for management efforts. To date, few North Pacific coastal endemics have been reevaluated since their original descriptions. This study provides an independent view of endemism in the Alexander Archipelago of southeast Alaska through a phylogeographic assessment of eight species of mammals ( Sorex monticolus, Glaucomys sabrinus, Microtus longicaudus, Clethrionomys rutilus, Clethrionomys gapperi, Martes americana, Mustela erminea, Ursus americanus). The molecular data (mitochondrial sequence variation of the cytochrome b gene) suggest a dynamic history of faunal interchange in the region. While some purported endemics show minimal levels of genetic divergence from other conspecific populations, other taxa appear to be more divergent than recognized by current taxonomy. Some species in the region are comprised of multiple clades or evolutionarily significant units. These reciprocally monophyletic lineages may be the result of multiple Holocene invasions (neoendemics) or they may have persisted in refugia (paleoendemics) in the region during Pleistocene glacial advances. This emerging historical perspective should have direct implications for the management of these endemic taxa.

Skeleton of Extinct North American Sea Mink (Mustela macrodon)

Mustela macrodon (extinct sea mink) is known only from prehistoric and historic Native American shell middens dating less than 5100 years old along coastal islands of the Gulf of Maine, northeastern North America. The species is distinct from all known extant subspecies of M. vison (American mink) but still belongs to the North American subgenus Vison. Metric comparisons between M. macrodon and five subspecies of M. vison, using skull, mandible, humerus, radius, femur, and tibia skeletal elements, show that M. macrodon is larger in overall size and robustness and is proportionately larger in the dental region. Many habitat-related parallels exist between coastal island mink of the Gulf of Maine and those of the Alexander Archipelago, southeastern Alaska, where the overall largest living subspecies of mink is found (M. v. nesolestes).

Assessment of anadromous salmon resources in the diet of the Alexander Archipelago wolf using stable isotope analysis.

The Alexander Archipelago wolf (Canis lupus ligoni) is unique to southeast Alaska, occurring on islands south of Frederick Sound and along the mainland between Dixon Entrance and Yakutat Bay. Sitka black-tailed deer (Odocoileus hemionus sitkensis) are an important prey species for wolves across the southern part of the region. Spawning salmon (Onchorynchus sp.) are seasonally available but their presence in wolf diets has not previously been quantified. We examined the range of bone collagen δ13C and δ15N values for wolves throughout southeast (n = 163) and interior (n = 50) Alaska and used a dual-isotope mixing model to determine the relative contribution of salmon-derived marine protein in the diet. Southeast Alaska wolves consumed significantly more salmon (mean ± SE: 18.3 ± 1.2%) than did wolves from interior Alaska (9.1 ± 0.6%, P<0.001). Wolves on the southeast Alaska mainland appeared to have higher marine isotopic signatures than island wolves, although this difference was not significant. Variation among individual wolf diets was higher for southeast than for interior Alaska wolves, and variation was highest in coastal mainland wolf diets (P<0.001). Marine resources may augment the diet of southeast Alaska wolves during seasonal or annual fluctuations in the availability of deer, particularly in those areas on the mainland where densities of terrestrial ungulates are relatively low.

Mammalian biogeography of the Alexander Archipelago of Alaska: a north temperate nested fauna

Summary Aim A large number of studies have analysed the distribution of mammals within archipelagos, yet few have focused on islands that were heavily glaciated and subsequently colonized following deglaciation. Location We explored the relative effects of island area and isolation on faunal composition based on twenty‐three mammalian taxa of twenty‐four islands of the Alexander Archipelago, Southeast Alaska. Methods We used regression of log‐transformed variables and several indices of nestedness. Results These faunas showed significant nested structure using tests of nestedness and regression models. Unlike most landbridge and mainland archipelagos studied previously, isolation appears to be the primary factor determining patterns of species richness. Main conclusions Colonization ability of particular taxa, rather than extinction, has determined this nested structure. We suggest that other higher latitude archipelagos may show similar historical patterns.

Implications of cytochrome b sequence variation for biogeography and conservation of the northern flying squirrels (Glaucomys sabrinus) of the Alexander Archipelago, Alaska

The Alexander Archipelago of southeast Alaska is a highly fragmented landscape that is suspected to support a relatively large number of endemic mammals. At least two subspecies of northern flying squirrels (Glaucomys sabrinus) have been recognized from the region, the endemic Prince of Wales Island flying squirrel, Glaucomys sabrinus griseifrons, and the Alaska Coast flying squirrel, G. s. zaphaeus. We examined 56 northern flying squirrels from Alaska, Washington State, and Yukon Territory, using the DNA sequence from the mitochondrial cytochrome b gene to assess geographic variation. Flying squirrels from Washington were highly divergent (7.3%) from those of Alaska and Yukon Territory. Variation among Alaska and Yukon Territory populations was minimal, but five haplotypes were found. One predominantly "mainland" haplotype was widespread throughout Alaska, one island haplotype was confined to nine islands in southeast Alaska ("Prince of Wales complex"), and three haplotypes were unique. Flying squirrels of the Prince of Wales complex appear to be neoendemics and descended from a single founder population. Mitochondrial variation, although minimal, is consistent with the continued recognition of G. s. griseifrons. Our results, in light of increased habitat fragmentation in southeast Alaska, suggest that molecular data can provide important base-line information for effective management of insular populations.

Implications of cytochrome &lt;i&gt;b&lt;/i&gt; sequence variation for biogeography and conservation of the northern flying squirrels (&lt;i&gt;Glaucomys sabrinus&lt;/i&gt;) of the Alexander Archipelago, Alaska

Implications of cytochrome &lt;i&gt;b&lt;/i&gt; sequence variation for biogeography and conservation of the northern flying squirrels (&lt;i&gt;Glaucomys sabrinus&lt;/i&gt;) of the Alexander Archipelago, Alaska

Late quaternary regional geoarchaeology of Southeast Alaska karst: A progress report

Karst systems, sea caves, and rock shelters within the coastal temperate rain forest of Alaska's Alexander Archipelago preserve important records of regional archaeology, sea level history, glacial and climatic history, and vertebrate paleontology. Two 14C AMS dates on human bone discovered in a remote cave (49-PET-408) on Prince of Wales Island document the oldest reliably dated human in Alaska to ca. 9800 B.P. A series of 14C AMS dates from cave deposits span the past 40,000 years and provide the first evidence of Pleistocene faunas from the northwest coast of North America. Other discoveries include sea caves and marine beach deposits elevated above modern sea level, extensive solution caves, and mammalian remains of species previously undocumented within the region. Records of human activity, including cave art, artifacts, and habitation sites may provide new insights into the early human colonization of the Americas. © 1997 John Wiley & Sons, Inc.

An Ice Age Refugium for Large Mammals in the Alexander Archipelago, Southeastern Alaska

Genetic and paleontological evidence are combining to provide a new and surprising picture of mammalian biogeography in southeastern Alaska. Prior to our study, the brown and black bears of the Alexander Archipelago were considered postglacial immigrants that never had overlapping ranges. Vertebrate fossils from caves on Prince of Wales Island now demonstrate that brown and black bears coexisted there (and even inhabited the same caves) both before and after the last glaciation. Differences in mtDNA sequences suggest that living brown bears of the Alexander Archipelago comprise a distinct clade and are more closely related to polar bears than to their mainland conspecifics. We conclude that brown bears, and perhaps other large mammals, have continuously inhabited the archipelago for at least 40,000 yr and that habitable refugia were therefore available throughout the last glaciation.

Vegetation History of Pleasant Island, Southeastern Alaska, since 13,000 yr B.P.

A 13,000-year history of late-Quaternary vegetational and climatic change has been derived from lacustrine sediments from Pleasant Island in the Glacier Bay region of southeastern Alaska. Early arrival of lodgepole pine and mountain hemlock, indicated by the presence of pollen and conifer stomata, suggests expansion from refugia in the Alexander Archipelago. A short-term climatic reversal, possibly correlated with the European Younger Dryas, is inferred from the expansion of tundra elements and deposition of inorganic sediments between 10,600 and 990014C yr B.P. Two peat cores from the lake catchment verify Holocene vegetation changes and aid in the separation of biogenic from climatic forces affecting vegetation history. Differences in pollen representation among the three cores illustrate the variation among pollen-collecting substrates, as well as the spatial heterogeneity of peatland development and its dependence on local hydrology. Initial peat accumulation and soil paludification, occasioned by increases in temperature and precipitation in the early Holocene, allowed western and mountain hemlock to replace sitka spruce 8500–8000 yr B. P. Open muskeg became widespread about 7000 yr B. P. and allowed lodgepole pine to reinvade the region after a 2000-yr absence. The extensive replacement of fen elements by bog taxa at 3400 yr B. P. suggests increased paludification due to changing hydrologic conditions; its correlation with the upland expansion ofTsuga heterophyllasuggests the onset of a cooler/wetter Neoglacial climate in southeastern Alaska.

Marine Vertical Distribution of Juvenile Chinook and Coho Salmon in Southeastern Alaska

Vertical distributions of chinook salmon Oncorhynchus tshawytscha of marine ages x.0, x.1, and x.2 and coho salmon O. kisutch of age x.0 are reported for the marine waters of southeastern Alaska. (The number or letter preceding the decimal point indicates number of winters spent in freshwater, that following the decimal point indicates winters spent in salt water.) Understanding vertical distribution of prerecruit salmon may be useful in minimizing fishery bycatch. Salmon were caught to a depth of 36.6 m from chartered commercial power trollers fishing small hooks and lures. Sampling occurred throughout inside waters of the Alexander Archipelago and adjacent coastal waters during September 1986 and in inside waters near Ketchikan during February, May, and September 1987. Vertical distribution of salmon differed significantly by species and age-group: in September, age-x.0 coho salmon (mean fork length, 28.4 cm) were caught shallower than age-x.0 chinook salmon (27.3 cm); age-x.1 (44.2 cm) and age-x.2 (60.4 cm) chinook salmon were deeper than age-x.0 chinook salmon. Length of chinook salmon increased significantly with depth. Vertical distribution did not differ significantly between ocean-type and stream-type fish or between sexes. Chinook salmon were significantly deeper in February than in September or May and significantly deeper in September than in May. Our findings suggest that encounter rates of prerecruit chinook salmon and coho salmon in chinook salmon troll fisheries could be minimized by restricting fishing to depths of 30 m or more during selected periods.

Distribution and characteristics of metamorphic belts in the south‐eastern Alaska part of the North American Cordillera

The Cordilleran orogen in south‐eastern Alaska includes 14 distinct metamorphic belts that make up three major metamorphic complexes, from east to west: the Coast plutonic–metamorphic complex in the Coast Mountains; the Glacier Bay–Chichagof plutonic–metamorphic complex in the central part of the Alexander Archipelago; and the Chugach plutonic–metamorphic complex in the northern outer islands. Each of these complexes is related to a major subduction event. The metamorphic history of the Coast plutonic–metamorphic complex is lengthy and is related to the Late Cretaceous collision of the Alexander and Wrangellia terranes and the Gravina overlap assemblage to the west against the Stikine terrane to the east. The metamorphic history of the Glacier Bay–Chichagof plutonic–metamorphic complex is relatively simple and is related to the roots of a Late Jurassic to late Early Cretaceous island arc. The metamorphic history of the Chugach plutonic–metamorphic complex is complicated and developed during and after the Late Cretaceous collision of the Chugach terrane with the Wrangellia and Alexander terranes.The Coast plutonic–metamorphic complex records both dynamothermal and regional contact metamorphic events related to widespread plutonism within several juxtaposed terranes. Widespread moderate‐P/T dynamothermal metamorphism affected most of this complex during the early Late Cretaceous, and local high‐P/T metamorphism affected some parts during the middle Late Cretaceous. These events were contemporaneous with low‐ to moderate‐P, high‐T metamorphism elsewhere in the complex. Finally, widespread high‐P–T conditions affected most of the western part of the complex in a culminating late Late Cretaceous event. The eastern part of the complex contains an older, pre‐Late Triassic metamorphic belt that has been locally overprinted by a widespread middle Tertiary thermal event.The Glacier Bay–Chichagof plutonic–metamorphic complex records dominantly regional contact‐metamorphic events that affected rocks of the Alexander and Wrangellia terranes. Widespread low‐P, high‐T assemblages occur adjacent to regionally extensive foliated granitic, dioritic and gabbroic rocks. Two closely related plutonic events are recognized, one of Late Jurassic age and another of late Early and early Late Cretaceous age; the associated metamorphic events are indistinguishable. A small Late Devonian or Early Mississippian dynamothermal belt occurs just north‐east of the complex. Two older low‐grade regional metamorphic belts on strike with the complex to the south are related to a Cambrian to Ordovician orogeny and to a widespread Middle Silurian to Early Devonian orogeny.The Chugach plutonic–metamorphic complex records a widespread late Late Cretaceous low‐ to medium/high‐P, moderate‐ T metamorphic event and a local transitional or superposed early Tertiary low‐P, high‐T regional metamorphic event associated with mesozonal granitic intrusions that affected regionally deformed and metamorphosed rocks of the Chugach terrane. The Chugach complex also includes a post‐Late Triassic to pre‐Late Jurassic belt with uncertain relations to the younger belts.

Geographic and sexual variation in the skull of Pacific coast marten (Martes americana)

From multivariate analyses of 25 cranial measurements, we assessed geographic and sexual variation in three island and two mainland samples of Pacific coast marten (Marten americana) from the caurina subspecies group. Three morphological groups were evident: the first from Queen Charlotte Islands, the second from Alexander Archipelago and Alaska Panhandle, and the third from Vancouver Island and the southern British Columbia coast. We concluded that the subspecies M. a. nesophila should be restricted to the Queen Charlotte Islands; Vancouver Island and southern British Columbia coastal marten are aligned with M. a. caurina. Alaskan marten showed some affinities with the americana subspecies group. The strong differentiation of M. a. nesophila is concordant with the isolation and unique selection regime of the Queen Charlotte Islands. Sexual dimorphism was most pronounced in island samples; possible explanations for this trend are discussed.

Holocene Sea Levels in Southeast Alaska: Preliminary Results

Natural raised marine deposits and archaeological sites recently discovered in southeastern Alaska have been measured relative to mean sea level and radiocarbon dated. Plots of sites on Heceta and Prince of Wales islands are compared to those developed for British Columbia. The Heceta Island curve is comparable to that of the Queen Charlotte Islands, in which pre-Holocene shorelines were lower than present until about 10,000 B.P. and then rose to a maximum of 15 m asl by 8500 B.P., when gradual emergence began to bring the sea level down to its present position. In contrast, the Prince of Wales Islands data indicate that sea level remained a few metres above its present position between 10,000 and 7000 B.P. - a time when the shores of mainland British Columbia were as much as 15 m below present sea level. Because Holocene sea levels are a function of isostatic rebound due to removal of glacial ice, as well as global sea level changes and tectonic activity, the implication is that whereas Heceta Island underwent processes and magnitudes of glaciation and isostatic rebound similar to the Queen Charlotte Islands, Prince of Wales Island was subjected to a pattern of glaciation and isostatic rebound different from that of the Queen Charlotte Islands and mainland of British Columbia.Key words: Alaska, Alexander Archipelago, archaeology, eustacy, geomorphology, glaciation, Holocene, isostacy, sea level, Quaternary

Physical and chemical response of understory vegetation to deer use in southeastern Alaska

Biomass of understory vegetation was sampled inside and outside four 19- to 21-year-old deer enclosures in the Alexander Archipelago of southeastern Alaska. Three sites were old-growth forests of western hemlock (Tsugaheterophylla (Raf.) Sarg.) –Sitka spruce (Piceasitchensis (Bong.) Carr.) and one site was an even-aged spruce–hemlock stand. In vitro dry-matter digestibility, fiber, nitrogen, and phosphorus concentrations of western hemlock seedlings and Alaska blueberry (Vacciniumalaskensis How.) inside and outside each exclosure also were compared. Analysis of variance indicated that Alaska blueberry and trailing bramble (Rubuspedatus Sm.) had greater biomass inside than outside the exclosures. No differences in chemical composition or digestibility of blueberry or hemlock inside and outside the exclosures occurred across sites. Results indicated that although deer may exert moderate to strong influence on the species composition and biomass of forest understories, their effect on dry-matter digestibility, fiber, nitrogen, and phosphorus concentrations of individual species may be negligible.

Anastrophyllum assimile and Marsupella revoluta, new to the interior of North America

Anastrophyllum assimile (Mitt.) Steph. and Marsupella revoluta (Nees) Lindb. are reported from the Keele Peak area, central-eastern Yukon Territory, Canada, and M. revoluta is also reported from Devon Island, Northwest Territories, Canada. These new localities extend a pattern of disjunct occurrences throughout the known range of both species, which further support the hypothesis of their relictual status. However, collections of A. assimile from coastal British Columbia and the Alexander Archipelago, Alaska, are indicative of strong oceanic affinities of North American populations of this species. Also, the arctic and alpine localities at which either A. assimile or M. revoluta might be expected to occur in the interior of Alaska and the Yukon are limited in number as both species invariably occur in association with siliceous substrates.