In primary succession following deglaciation at Glacier Bay, Alaska, we tested the hypothesis that the major effect of initial nitrogen-fixing colonizers is to facilitate establishment oflate-successional dominants and that other possible causes of successional change (e.g., life history factors governing seed rain and competitive interactions among species) need not be invoked. Environment changed dramatically through the first 200 yr of succession. Soil organic matter increased 10-fold in the upper mineral soil with corresponding increases in soil moisture, total nitrogen (N), and capacity to support plant growth and declines in bulk density, pH, and total phosphorus (P). Plant growth in pioneer soils tended to be simultaneously limited by both N and P, as well as by unknown factors (perhaps lack of mycorrhizae), whereas only P limited growth in older soils. Light availability to seedlings declined through succession.Early-successional species (Epilobium /atifolium, Dryas drummondii) had smaller seeds, younger age at first reproduction, shorter life-span, and shorter height at maturity than did mid-successional (alder, Alnus sinuata) and late-successional species (sitka spruce, Picea sitchensis). Seed rain of alder and spruce was negligible in the pioneer stage, increased prior to the stage in which a species was dominant, and was greatest in the stage in which a species dominated. Vegetation in each successional stage inhibited germination and initial establishment of sown alder and spruce seeds (except a tendency of the "black-crust" algal/microbial community in the pioneer stage to enhance survivorship). Removal of the surface litter layer generally enhanced germination and survivorship, particularly of alder. Comparisons of germination in the greenhouse and the field indicated that climatic or indirect vegetation effects (e.g., differential seed predation) and allelopathy also reduced germination and establishment in vegetated communities.Naturally occurring spruce seedlings grew most rapidly in the Dryas and alder stages and most slowly in the spruce stage. Similarly, growth of spruce seedlings transplanted into each successional stage was facilitated by the Dryas (nonsignificantly) and alder stages but inhibited by the spruce stage, relative to earlier successional stages. Facilitation of growth of natural and transplanted spruce seedlings by Dryas and alder stages was associated with higher N and P uptake and tissue nutrient concentrations, whereas nutrient uptake and concentration in spruce seedlings declined in the spruce stage. By contrast, transplanted alder seedlings grew rapidly and accumulated most nutrients in the pioneer stage and were strongly inhibited by subsequent stages.The facilitative effect of Dryas and alder comes primarily from inputs of organic matter and associated N. Addition of alder litter stimulated nutrient uptake and growth of transplanted spruce seedlings in the pioneer and Dryas stages, whereas shading had no effect on growth of spruce seedlings. Root trenching and planting o...

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Monitoring patterns in biodiversity and phenology have become increasingly important given accelerating levels of anthropogenic change. Long‐term monitoring programs have reported earlier occurrence of spring activity, reflecting species response to climate change. Although tracking shifts in spring migration represents a valuable approach to monitoring community‐level consequences of climate change, robust long‐term observations are challenging and costly. Audio recordings and metrics of bioacoustic activity could provide an effective method for monitoring changes in songbird activity and broader biotic interactions. We used 3 years of spring and fall recordings at six sites in Glacier Bay National Park, Alaska, an area experiencing rapid warming and glacial retreat, to examine the utility of bioacoustics to detect changes in songbird phenology. We calculated the Acoustic Complexity Index (ACI), an algorithm representing an index of bird community complexity. Abrupt changes in ACI values from winter to spring corresponded to spring transition, suggesting that ACI may be an effective, albeit coarse metric to detect the arrival of migrating songbirds. The first peak in ACI shifted from April 16 to April 11 from 2012 to 2014. Changes in ACI were less abrupt in the fall due to weather events, suggesting spring recordings are better suited to indicate phenology. To ensure changes in ACI values were detecting real changes in songbird activity, we explored the relationship between ACI and song of three species: varied thrush (Ixoreus naevius), Pacific wren (Troglodytes pacificus), and ruby‐crowned kinglet (Regulus calendula). ACI was positively related to counts of all species, but most markedly with song of the varied thrush, the most common species in our recordings and a known indicator of forest ecosystem health. We conclude that acoustic recordings paired with bioacoustic indices may be a useful method of monitoring shifts in songbird communities due to climate change and other sources of anthropogenic disturbance.

Lichens are widely acknowledged to be a key component of high latitude ecosystems. However, the time investment needed for full inventories and the lack of taxonomic identification resources for crustose lichen and lichenicolous fungal diversity have hampered efforts to fully gauge the depth of species richness in these ecosystems. Using a combination of classical field inventory and extensive deployment of chemical and molecular analysis, we assessed the diversity of lichens and associated fungi in Glacier Bay National Park, Alaska (USA), a mixed landscape of coastal boreal rainforest and early successional low elevation habitats deglaciated after the Little Ice Age. We collected nearly 5000 specimens and found a total of 947 taxa, including 831 taxa of lichen-forming and 96 taxa of lichenicolous fungi together with 20 taxa of saprotrophic fungi typically included in lichen studies. A total of 98 species (10.3% of those detected) could not be assigned to known species and of those, two genera and 27 species are described here as new to science: Atrophysma cyanomelanos gen. et sp. nov., Bacidina circumpulla, Biatora marmorea, Carneothele sphagnicola gen. et sp. nov., Cirrenalia lichenicola, Corticifraga nephromatis, Fuscidea muskeg, Fuscopannaria dillmaniae, Halecania athallina, Hydropunctaria alaskana, Lambiella aliphatica, Lecania hydrophobica, Lecanora viridipruinosa, Lecidea griseomarginata, L. streveleri, Miriquidica gyrizans, Niesslia peltigerae, Ochrolechia cooperi, Placynthium glaciale, Porpidia seakensis, Rhizocarpon haidense, Sagiolechia phaeospora, Sclerococcum fissurinae, Spilonema maritimum, Thelocarpon immersum, Toensbergia blastidiata and Xenonectriella nephromatis. An additional 71 ‘known unknown’ species are cursorily described. Four new combinations are made: Lepra subvelata (G. K. Merr.) T. Sprib., Ochrolechia minuta (Degel.) T. Sprib., Steineropsis laceratula (Hue) T. Sprib. & Ekman and Toensbergia geminipara (Th. Fr.) T. Sprib. & Resl. Thirty-eight taxa are new to North America and 93 additional taxa new to Alaska. We use four to eight DNA loci to validate the placement of ten of the new species in the orders Baeomycetales, Ostropales, Lecanorales, Peltigerales, Pertusariales and the broader class Lecanoromycetes with maximum likelihood analyses. We present a total of 280 new fungal DNA sequences. The lichen inventory from Glacier Bay National Park represents the second largest number of lichens and associated fungi documented from an area of comparable size and the largest to date in North America. Coming from almost 60°N, these results again underline the potential for high lichen diversity in high latitude ecosystems.