Ahti, T. 1962. Ecological investigations on lichens in Wells Gray Provincial Park with special reference to their importance to mountain caribou. Unpublished Report, B.C. Parks, Victoria. 69 pages. [key words: Wells Gray Park / lichens / Mountain Caribou / animals]
Ahti, T. 1969. Notes on brown species of Parmelia in North America. The Bryologist 72: 233-239. [key words: Melanohalea / Melanelixia / lichens / new lichen taxa]
Ahti, T. 1978. Two new species of Cladonia from western North America. The Bryologist 81: 334-338. [key words: Cladonia / lichens / new lichen taxa]
Ahti, T. 2007. Further studies on the Cladonia verticillata group (Lecanorales) in East Asia and western North America. Bibliotheca Lichenologica 96: 5-19. [key words: Cladonia / lichens / new lichen taxa]
Ahti, T., I.M. Brodo and W.J. Noble. 1987. Contributions to the lichen flora of British Columbia, Canada. Mycotaxon 28: 91-97. [key words: lichens / new lichen reports]
Ahti, T. and R. Fagerstén. 1967. Mosses of British Columbia, especially Wells Gray Provincial Park. Annales Botanici Fennici 4: 422-440. [key words: Wells Gray Park / mosses / plants / plant checklist] [download pdf]
Ahti, T. and S. Hammer. 2002. Cladoniaceae. In Nash, T. H., B. D. Ryan, C. Gries and F. Bungartz (eds.), Lichen flora of Greater Sonoran Desert Region, 1: 131-158. Lichens Unlimited, Tempe, AZ. [key words: Cladonia / lichens / new lichen taxa / lichen identification]
Ahti, T. and A. Henssen. 1965. New localities for Cavernularia hultenii in eastern and western North America. The Bryologist 68: 85-89. [key words: Cavernularia / lichens / lichen distribution]
Ahti, T., G.W. Scotter and H. Vänskä. 1973. Lichens of the Reindeer Preserve, N.W.T., Canada. The Bryologist 75: 48-76. [key words: lichens / new lichen reports / lichen checklists]
Brodo, I.M. and T. Ahti. 1996. Lichens and lichenicolous fungi of the Queen Charlotte Islands, British Columbia, Canada. 2. The Cladoniaceae. Canadian Journal of Botany 74: 1147-1180. [key words: lichens / Cladonia / Cladina / new lichen taxa]
Brodo, I.M., W.J. Noble, T. Ahti and S. Clayden. 1987. Lichens new to North America from the flora of British Columbia, Canada. Mycotaxon 28: 99-100. [key words: lichens / new lichen reports]
Goward, T. and T. Ahti. 1983. Parmelia hygrophila, a new lichen species from the Pacific Northwest of North America. Annales Botanici Fennici 20: 9-13. [key words: Parmelia / lichens / new lichen taxa] [abstract] [download pdf]
The lichen Parmelia (subg. Parmelia) hygrophila Goward & Ahti, sp. nova, is reported from Alaska, British Columbia (typus), Idaho and Washington, where it is a widespread epiphyte in humid and subhumid sectors at low and middle elevations. Salazinic acid and atranorin are its major phenolic constituents. A key to the species of the P. saxatilis group in the Pacific Northwest is presented.
Goward, T. and T. Ahti. 1992. Macrolichens and their zonal distribution in Wells Gray Provincial Park and its vicinity, British Columbia, Canada. Acta Botanica Fennica 147: 1-60. [key words: Wells Gray Park / lichens / lichen checklists / hypothesis generation / new lichen reports] [abstract] [download pdf]
The distribution and general ecology of 293 macrolichen taxa are recorded for approximately 600 000 ha of mountainous terrain in Wells Gray Provincial Park and its vicinity in south-central British Columbia, Canada. Thirty-one taxa are documented for the first time from British Columbia, including seven from Canada, and five (Leptogium subtile, Usnea wasmuthii, and the lichenicolous fungi Corticifraga fuckelii, Echinothecium reticulatum, and Refractothilum peltigerae) from North America. 74% of the taxa included are essentially circumpolar, whereas only 11% are restricted to North America, in most cases western North America. A high proportion (71%) of the latter group is accounted for by corticoles. The Bioclimatic Zone System is used to indicate zonal distribution for the lichen species considered. Summaries of total ranges in the northern hemisphere are also provided. Duration of snow cover is considered to play a critical role in the distribution of many species, particularly terricoles. Numerous primarily coastal, oceanic lichen species are found to occur in the study area, including Cavernularia hultenii, Cladonia umbricola, Dendriscocaulon intricatulum, Hypogymnia enteromorpha, Parmelia pseudosulcata, Peltigera pacifica, Platismatia norvegica, Polychidium dendriscum, Pseudocyphellaria anomala, Sticta limbata, and Normandina pulchella.
Goward, T. and T. Ahti. 1997. Notes on the distributional ecology of the Cladoniaceae (lichenized Ascomycetes) in temperate and boreal North America. Journal of the Hattori Botanical Laboratory 82: 143-155. [key words: Cladonia / Cladina / lichens / lichen distribution / hypothesis generation / lichen phytogeography] [abstract] [download pdf]
Based on the western North American distributions of 71 taxa and chemotypes of Cladina and Cladonia occurring at temperate and boreal latitudes, the Coast Mountains of British Columbia are shown to form a major phytogeographic barrier, dividing 21 oceanic taxa to the west from 24 continental taxa to the east. Maximum floristic diversity in these genera occurs between 52°N, in a region occupied by glacial ice until roughly 10,000 years ago. Following deglaciation, many Cladoniaceae must have colonized this region from south of the Cordilleran Icesheet, presumably deriving from regions that no longer support them. South of 52°N, modern-day rates of decline average between three and five taxa per degree of latitude, and appear to be correlated with a southward trend from summer-moist climatic conditions to summer-dry. By contrast, the present southern limits of Cladina stellaris, Cladonia macroceras and C. stricta are believed to reflect historical, as opposed to strictly ecological, factors. Such species may still be extending their ranges southward.
Goward, T., T. Ahti, J. Elix and T. Spribille. 2010. Hypogymnia recurva and Hypogymnia wilfiana spp. nov.: two new lichens from western North America. Botany 88:345 – 351. [key words: lichens / Hypogymnia / Wells Gray Park / new lichen taxa] [abstract] [request pdf]
Hypogymnia metaphysodes was first described from Japan and Sakhalin, and later reported from western North America. Here we show that the North American material currently referred to H. metaphysodes differs from that species not only morphologically and chemically, but also in ascospore size and shape. We also show that the North American material is in fact heterogeneous, and can be assigned to two well-defined species here described as new: Hypogymnia recurva sp. nov. and H. wilfiana sp. nov. Both of these lichens contain distinctive secondary metabolites: vittatolic acid in the case of H. recurva, and 2-methylene-3-carboxy-18-hydroxynonadecanoic acid (“apinnatic acid”), reported here for the first time from Hypogymnia, in H. wilfiana. Both of our new species are so far known only from western North America, where they occur primarily as epiphytes on the branches of conifers. Hypogymnia metaphysodes s. str. has not yet been reliably reported from this region and should be excluded from the North American lichen flora.
Goward, T., T. Spribille and T. Ahti. 2011. Four new sorediate species in the Hypogymnia austerodes group (lichens) from northwestern North America, with notes on thallus morphology. Submitted. [key words: Hypogymnia / lichens / new lichen taxa]
Hämet-Ahti, L. 1965. Vascular plants of Wells Gray Provincial Park and its vicinity, in eastern British Columbia. Annales Botanici Fennici 2: 138-164. [key words: Wells Gray Park / plants] [download pdf]
Hämet-Ahti, L. 1965. Notes on the vegetation zones of western Canada, with special reference to the forests of Wells Gray Park, British Columbia. Annales Botanici Fennici 2: 274-300. [key words: Wells Gray Park / plants / zonation] [download pdf]
Hämet-Ahti, L. 1965. Luzula piperi (Cov.) M.E. Jones, an overlooked woodrush in western North America and eastern Asia. Aquilo, ser. Bot. 3: 11-21. [key words: Wells Gray Park / plants / Luzula] [download pdf]
Hämet-Ahti, L. 1971. A synopsis of the species of Luzula, subgenus Anthelaea Griseb. (Juncaceae) indigenous in North America. Annales Botanici Fennici 8: 368-381. [key words: Wells Gray Park / Luzula / plants] [download pdf]
Hämet-Ahti, L. 1971. List of vascular plants collected in Alaska, the Yukon, northern British Columbia, and Alberta by Leena Hämet-Ahti and Teuvo Ahti in 1967. Mimeographed Papers of Botanical Museum, University of Helsinki 3: 1-17. [key words: plants / plant checklist]
Hämet-Ahti, L. 1972. Notes on Ustilago vuijckii Oudem. and Beijer. on some Luzula species in North America. Syesis 5: 83-85. [key words: Luzula / plants]
Hämet-Ahti, L. 1973. Notes on the Luzula arcuata and L. parviflora groups in eastern Asia and Alaska. Annales Botanici Fennici 10: 123-130. [key words: Luzula / plants]
Hämet-Ahti, L. 1975. Additional notes on Luzula subcongesta and L. parviflora (Juncaceae) in North America. Annales Botanici Fennici 12: 27-29. [key words: Luzula / plants]
Hämet-Ahti, L. 1979. The dangers of using the timberline as the “zero line” in comparative studies on altitudinal vegetation zones. Phytocoenologia 6: 49-54. [key words: vegetation / zonation]
Hämet-Ahti, L. 1978. Timberline meadows in Wells Gray Park, British Columbia, and their comparative geobotanical interpretation. Syesis 11: 187-211. [key words: Wells Gray Park / plants / subalpine meadows] [download pdf]
Hämet-Ahti, L. 1986. North American races of Juncus alpinoarticulatus (Juncaceae). Annales Botanici Fennici 23: 277-281. [key words: Juncus / plants]
Hämet-Ahti, L. and T. Ahti. 1969. The homologies of the Fennoscandian mountain birch forests in Eurasia and North America. Vegetatio 19: 208-219. [key words: zonation / plants / vegetation]
Hämet-Ahti, L. and V. Virrankoski. 1971. Cytotaxonomic notes on some monocotyledons of Alaska and northern British Columbia. Annales Botanici Fennici 8: 156-159. [key words: plants]
Hämet-Ahti, L. 1980. Juncus alpinoarticulatus: the legitimate name for Juncus alpines. Annales Botanici Fennici 17: 341-342. [key words: Juncus / plants]
Hammer, S. and T. Ahti. 1990. New and interesting species of Cladonia from California. Mycotaxon 37: 335-348. [key words: Cladonia / lichens / new lichen taxa]
McCune, B., E. Holt, P. Neitlich, T. Ahti and R. Rosentreter. 2009. Macrolichen Diversity in Noatak National Preserve, Alaska. North American Fungi 4(4):1-22. [key words: lichens / lichen checklists]
Noble, W.J., T. Ahti, G.F. Noble and I.M. Brodo. 1987. A second checklist and bibliography of the lichens and allied fungi of British Columbia. Syllogeus 61: 1-95. [key words: lichens / lichen checklists]
Otto, G.F. and T. Ahti. 1967. Lichens of British Columbia, preliminary checklist. Department of Botany, University of British Columbia, Vancouver. 40 pp. [key words: lichens / lichen checklists]
Piercey-Normore, M.D., T. Ahti and T. Goward. 2010. Phylogenetic and haplotype analyses of four segregates within Cladonia arbuscula s. l. Botany 88: 397-408. [key words: Cladina / lichens / species] [abstract] [request pdf]
Cladonia arbuscula (Wallr.) Flotow sensu lato is a widespread species complex traditionally divided among several subspecies on the basis of thallus morphology and secondary chemistry. Here we examine the evolutionary relationships of four of these segregates, C. arbuscula subsp. beringiana Ahti, C. arbuscula subsp. squarrosa (Wallr.) Burgaz, C. mitis Sandst., and an unnamed subspecies (referred to as C. arbuscula subsp. squarrosa PD – strain) in an attempt to link them to specific genotypes. The internal transcribed spacer regions of the nuclear ribosomal DNA (ITS rDNA) and the b-tubulin genes were sequenced for phylogenetic and haplotype analyses. In addition, the ITS2 RNA region was folded and changes were applied to the evolutionary hypothesis. We conclude that morphological differentiation within C. arbuscula s.l. is largely independent of variation in ITS rDNA and b-tubulin sequences, notwithstanding the distinct albeit incomplete clade formed by C. mitis. Compensatory base changes in the ITS2 RNA secondary structure could not support reproductive isolation. It is recommended that C. mitis be recognized at the subspecific rank as C. arbuscula subsp. mitis, and that subsp. squarrosa be included in subsp. beringiana. The apparent lack of correlation in C. arbuscula between genetic variability in the mycobiont and observed morphological variation in the thallus is intriguing, and requires explanation.
Thomson, J.W. and T. Ahti. 1994. Lichens collected on an Alaska Highway expedition in Alaska and Canada. The Bryologist 97: 138-157. [key words: lichens / lichen checklists / new lichen reports]
Thomson, J.W., G.W. Scotter and T. Ahti. 1969. Lichens of the Great Slave Lake Region, Northwest Territories, Canada. The Bryologist 72: 137-177. [key words: lichens / lichen checklists]
Tønsberg, T. and T. Ahti. 1980. Cladonia umbricola, a new lichen species from NW Europe and western North America. Norwegian Journal of Botany 27: 307-309. [key words: Cladonia / lichens / new lichen taxa]
Velmala, S., L. Myllys, P. Halonen, T. Goward and T. Ahti. 2009. Molecular data show that Bryoria fremontii and B. tortuosa (Parmeliaceae) are conspecific. Lichenologist 41: 231-242. [key words: lichens / lichen evolution / species / Bryoria / new lichen taxa] [abstract] [request pdf]
Bryoria fremontii and B. tortuosa are the only species in the lichenized ascomycete genus Bryoria known to contain the pulvinic acid derivative vulpinic acid. In B. fremontii this yellow pigment is restricted to the soralia and apothecia, while in B. tortuosa it can occur throughout the thallus. The actual amount of vulpinic acid produced by B. tortuosa isd rather variable, however with intermediate specimens bearing both white and yellow pseudocyphellae. We studied the relationship between the two species with parsimony analysis using four DNA regions: 1) the internal transcribed spacers of the nuclear rDNA including the 5.8S region (ITS), 2) partial sequences from the intergenic spacer of the nuclear rDNA (IGS), 3) partial sequences from the small subunit of the mitochondrial rDNA (mtSSU), and 4) partial sequences from the protein-coding glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH). Our phylogenetic analysis revealed that B. fremontii and B. tortuosa must be regarded as conspecific, but allowing for some genetic differentiation between European and North American populations. Bryoria tortuosa is therefore synonymized with B. fremontii.