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Dr. Darwyn Coxson
A major research interest of Dr.
Darwyn Coxson is studying the diverse contribution of non-vascular plants, such
as lichens and mosses, to ecosystem function along elevational gradients in
Western Canada. This research draws on experimental approaches from many
fields, including lichenology, plant environmental physiology, forest ecology,
and conservation biology. These approaches are now being applied by Dr. Coxson
and his students in the study of canopy epiphyte communities from inland
wet-temperate rainforests in British Columbia, where they have been examining
the potential use of canopy lichens as indicators of forest health and
ecosystem change.
One group of canopy lichens in
particular, namely Lobarion assemblage lichens (a globally threatened group of
canopy lichens from wet-temperate ecosystems), may be especially sensitive to
environmental changes. As a consequence, Dr Coxson's research group has been
examining Lobarion response to changes in canopy environments; both from
natural causes, such as single-tree gap-dynamics or small-patch insect
outbreaks, and from human influences, for instance, "edge effects" imposed by
the fragmentation of previously continuous forest cover.
A related component of Dr. Coxson's
research examines how alternative forest harvesting practices, such as
partial-cutting silvicultural systems, can be used to maintain conservation
values associated with canopy lichens, including biodiversity (in Lobarion
assemblage lichens), wildlife habitat (as a food source for endangered caribou
populations), and ecosystem function (especially nitrogen-fixation by
cyanolichens). Current research study areas include watersheds in the Upper
Fraser River Valley, as well as in other sites along elevational gradients in
Alberta and British Columbia. Additionally, Dr. Coxson has recently initiated
parallel studies looking at ecosystem contributions of nitrogen-fixing lichens
in south-temperate rainforests (see description of research in New Zealand ).
Dr. Coxson and his students work closely with government agencies, industries, and other non-governmental groups in applying the results of their research to problems in forest conservation and management. Dr. Coxson also incorporates these concepts into his teaching, including UNBC courses in Ecology, Conservation Biology and Systematic Botany. In 2011 Dr. Coxson taught the UNBC Biology course "Systematic Botany" (Biology 301) as a field camp based in Terrace, B.C. This course included a class project in Rapid Biodiversity Assessment in the coastal salt marshes at Cassiar Cannery, at the mouth of the Skeena River estuary (see description of Systematic Botany 2011 field course). This course will be taught in a field camp format again in 2013.
Contact:
Dr. Darwyn Coxson
Professor, Ecosystem Science and Management Program
University of Northern British Columbia
3333 University Way, Prince George,
British Columbia, Canada
V2N 4Z9
Phone: 250-960-6646
Email: darwyn@unbc.ca
Selected Publications:
Campbell, J., Bengtson, P.E., Fredeen, A.L., Coxson, D., and C.E. Prescott. 2013.
Does exogenous carbon extend the realized niche of canopy lichens? Evidence from sub-boreal forests in British Columbia. Ecology. In press.
Available from dx.doi.org.
Boudreault, C., Coxson, D., Bergeron, Y., Stevenson, S., and M. Bouchard. 2013.
Canopy openings by partial cutting do not provide growth conditions similar to old-growth forests for epiphytic lichens. Biological Conservation Vol. 159:458-467.
Available from dx.dvi.org.
Coxson, D.S., Goward, T., and D. Connell. 2012.
Analysis of ancient western redcedar stands in the upper Fraser River watershed and scenarios for protection. B.C. Journal of Ecosystems and Management Vol. 12 (3): 1-20.
Availabe from jem.forrex.org.
Gauslaa, Y., Coxson, D.S., and K.A. Solhaug. 2012.
The paradox of higher light tolerance during dessication in rare old forest cyanolichens than in more widespread co-occurring chloro- and cephalolichens. New Phytologist. 195: 812-822.
Available from the online Wiley library.
Stevenson, S., Armleder. H., Arsenault. A., Coxson, D., DeLong, C., and M. Jull. 2011.
British Columbia's Inland Rainforest: Ecology, Conservation and Management. UBC Press. 432 pages.
Gauslaa, Y., and D. Coxson 2011.
Interspecific and intraspecific variations in water storage in epiphytic old forest foliose lichens. Botany 89: 787–798.
Document in pdf format (786 kb)
Stewart, K.J., Coxson, D.S. and P. Grogan. 2011.
Nitrogen inputs by associative cyanobacteria across a low arctic tundra landscape. Arctic, Antarctic and Alpine Research: Arctic, Antarctic, and Alpine Research 43: 267–278
Document in pdf format (856 kb)
Stewart, K.J., Lamb, E.G. and S.D. Siciliano. 2011.
Bryophyte-cyanobacterial associations as a key factor in N2-fixation across the Canadian Arctic. Plant Soil
Document in pdf format (320 kb)
Stewart, K.J., Coxson, D.S., and S.D. Siciliano. 2011.
Small-scale spatial patterns of N2 fixation and nutrient availability in an arctic hummock-hollow ecosystem. Soil Biology and Biochemistry 43: 133-140. doi:10.1016/j.soilbio.2010.09.023
Document in pdf format (301 kb)
Coxson, D.S. 2010.
World Heritage Sites in the Upper Fraser River Watershed? Legislation not Guidance Needed to Help Forest Professionals Protect These Sites. B.C. Forest Professional Magazine. May-June. pp. 22-24.
Document in pdf format (511 kb)
Doering, M., and D. Coxson. 2010.
Riparian alder ecosystems as epiphytic lichen refugia in sub-boreal spruce forests of British Columbia. Botany 88:144-157.
Document in pdf format (462 kb)
Boudreault, C., Y. Bergeron, and D.S. Coxson. 2009.
Factors controlling epiphytic lichens biomass during postfire succession in black spruce boreal forests. Can. J. For. Res. 39: 2168-2179.
Document in pdf format (227 kb)
Radies, D.N., D.S. Coxson, C.J. Johnson, and K. Konwicki. 2009.
Predicting canopy macrolichen diversity and abundance within old-growth inland temperate rainforests. Forest Ecology and Management 259: 86-97.
Document available at Sciencedirect.com
Coxson, D.S. and D.R. Radies 2009.
Old-Forest Conservation Strategies in Wet-Trench Forests of the Upper Fraser River Watershed. Chapter 20 In: Ecosystem Management in the Boreal Forest. (Editors Sylvie Gauthier, Marie-Andrée Vaillancourt, Alain Leduc, Louis De Grandpré, Daniel Kneeshaw, Hubert Morin, Pierre Drapeau, Yves Bergeron). Presses de l'Université du Québec, pp. 501-518.
Document in pdf format (473 kb)
Stevenson, S.K. and D.S. Coxson. 2009.
Effects of partial cutting on forage lichens for caribou in a subalpine forest: The Pinkerton Mountain silvicultural system trial revisited 10 years after harvesting. NRES Research Extension Note: No. 3 , 11p.
pdf file (528 kb)
Stevenson, S.K. and D.S. Coxson 2008.
Growth responses of Lobaria retigera to forest edge and canopy structure in the inland temperate rainforest, British Columbia. Forest Ecology and Management: 256: 618-223.
Document at sciencedirect.com (308 kb)
Boudreault, C., D.S. Coxson, E. Vincent, Y. Bergeron, and J. Marsh. 2008.
Variation in epiphytic lichen and bryophyte composition and diversity along a gradient of productivity in Populus tremuloides stands of northeastern British Columbia, Canada. EcoScience 15:101-112.
Document in pdf format (965 kb)
Coxson,D.S. and S.K. Stevenson.
2007.
Influence of high-contrast and low-contrast forest edges on growth rates of Lobaria pulmonaria in the inland rainforest, British Columbia. Forest Ecology and Management 253: 103-111.
Document at sciencedirect.com (392 kb)
Stevenson, S.K. and D.S. Coxson.
2007.
Arboreal forage lichens in partial
cuts - a synthesis of research results from British Columbia, Canada. Rangifer
17: 155-165.
Document in pdf format (392 kb)
Coxson,D.S. and S.K. Stevenson.
2007.
Growth rate responses of Lobaria
pulmonaria to canopy structure in even-aged and old-growth cedar-hemlock
forests of central-interior British Columbia, Canada. Forest Ecology and
Management 242: 5-16.
Document in pdf format (1,021 kb)
Piercey-Normore, M.D., Coxson, D.S., Goward, T. and Goffinet, B. 2006
Phylogenetic position of a Pacific
Northwest North American endemic cyanolichen, Nephroma occultum
(Ascomycota, Peltigerales). The Lichenologist 38:441-446.
Document in pdf format
(1,467 kb)
Marsh, J., Nouvet, S., Sanborn, P.
and D.S. Coxson. 2006.
Composition and function of
biological soil crust communities along topographic gradients in grasslands of
central interior British Columbia (Chilcotin) and southwestern Yukon (Kluane).
Canadian Journal of Botany 84:717-736.
Document in pdf
format (4,812 kb)
Coxson, D.S. and S.K. Stevenson.
2005.
Retention of canopy lichens after
partial-cut harvesting in wet-belt interior cedar-hemlock forests, British
Columbia, Canada. For. Ecol. and Manage. 204:99-114.
Document in pdf
format (566 kb)
Radies, D.N. and D.S. Coxson.
2004.
Macrolichen colonization on 120-140
year old Tsuga heterophylla in wet temperate rainforests of central-interior
British Columbia: a comparison of lichen response to even-aged versus
old-growth stand structures. Lichenologist 36:235-247.
Document in pdf
format (308 kb)
Stevenson, S.K. and D Coxson. 2003.
Litterfall, growth and turnover of
arboreal lichens after partial cutting in an Engelmann spruce-subalpine fir
forest in north-central British Columbia. Canadian Journal of Forest Research
33:2306-2320.
Document in pdf format (417 kb)
Coxson, D.S. and M. Coyle. 2003.
Niche partitioning and photosynthetic
response of alectorioid lichens from subalpine spruce–fir forest in
north-central British Columbia, Canada: the role of canopy microclimate
gradients. The Lichenologist 35(2):157-175.
Document in pdf
format (423 kb)
Coxson, D.S. and M. Curteanu.
2002.
Decomposition of hair lichens
(Alectoria sarmentosa and Bryoria spp.) under snowpack in montane forest,
Cariboo Mountains, British Columbia. The Lichenologist. 34: 395-402.
Document in pdf
format (115 kb)
Coxson, D.S, S. Stevenson, and J.
Campbell. 2002.
Short-term impacts of partial cutting
on lichen retention and canopy microclimate in an Engelmann Spruce - Subalpine
Fir forest in north-central British Columbia. Canadian Journal of Forest
Research. 33: 830-841.
Document in pdf format (488 kb)
Benson, S. and D. Coxson. 2002.
Lichen colonization and gap dynamics
in wet-temperate rainforests of northern interior British Columbia. The
Bryologist. 105: 673-692.
Document in pdf format (519 kb)
Coxson, D.S. and J. Marsh. 2001.
Lichen Chronosequences (Post-fire and
Post-harvest) in Lodgepole Pine (Pinus contorta) Forests of Northern-Interior
British Columbia. Canadian Journal of Botany. 79: 1449-1464.
Document in pdf
format (2427 kb)
Campbell, J., and D.S. Coxson. 2001.
Canopy microclimate and arboreal
lichen loading in subalpine spruce-fir forest. Canadian Journal of Botany 79:
537-555
Document in pdf format (2238
kb)
Sulyma, R. and D. Coxson. 2001.
Microsite Displacement of Terrestrial
Lichens by Feather Moss Mats in Late Seral Pine-Lichen Woodlands of
North-central British Columbia. The Bryologist 104:505-516.
Document in pdf
format (177 kb)
Wilson, J. And D. Coxson.
1999.
Carbon flux in a subalpine spruce
forest: Pulse Release from Hylocomium splendens feather-moss mats. Canadian
Journal of Botany 77: 564-569.
Document in pdf format (89 kb)
Coxson, D.S., and N.M. Nadkarni.
1995.
Ecological Roles of Epiphytes in
Nutrient Cycles of Forest Ecosystems. Chapter 20. In Forest Canopies. Academic
Press. pp 495-543. |
