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BEN # 222
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No. 222 April 28, 1999
aceska@freenet.victoria.bc.ca Victoria, B.C.
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Dr. A. Ceska, P.O.Box 8546, Victoria, B.C. Canada V8W 3S2
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MEADOWLARK FESTIVAL, OKANAGAN VALLEY - B.C., MAY 21-24
From: Lisa Scott <lscott@vip.net>
On May 21-24 join us in celebrating spring and experience the
unique landscapes of the south Okanagan and lower Similkameen
Valleys during the second annual Meadowlark Festival. The
Meadowlark Festival was initiated by the Okanagan Similkameen
Conservation Alliance to encourage people of all ages to ex-
perience, discover and explore our natural environment. The
Okanagan-Similkameen hosts a rare mosaic of natural habitats,
among them is one of Canada's most endangered ecosystems - the
hot, dry shrub-grasslands.
Festival events range from lively slide shows and discussions on
nature and conservation topics, to canoe trips, horseback
riding, a photography workshop, and a wide variety of bird and
wildflower explorations.
Events occur in a wide variety of locations throughout the
Okanagan-Similkameen and involve some of BC's and Canada's
leading experts, including Mark Brigham, Geoff Scudder, Dick
Cannings, Terry McIntosh and Bill Barlee. You can learn to
identify bird species by their songs with John Neville, who
produced the CD 'Bird Songs of the Okanagan Valley'. And join
other festival participants during the banquet and silent auc-
tion on Saturday evening, and be entertained by a stunning
audio-visual presentation by Graham Osborne, hailed as one of
BC's and Canada's best photographers.
The price for taking part in the festival has been kept very low
to encourage broad public involvement, but pre-registration is
required as space for many events is limited, to protect the
fragile areas we will visit. The aim is for people to have a
wonderful weekend outdoors, to learn more about our diversity of
wildlife and to work together to conserve our valuable wildlife
habitat.
For further information and to register for events contact the
Meadowlark office:
phone: (250) 492-LARK (5275)
write: 27A Front St., Penticton, B.C.
e-mail: meadowlark@img.net
http://www.meadowlarkfestival.bc.ca
HELP TO TRACK THE DISTRIBUTION OF GORSE (ULEX EUROPAEUS) IN B.C.
Gorse (Ulex europaeus) is a dense spiny shrub that invades the
Pacific Northwest. The Pacific Forestry Centre in Victoria, B.C.
is currently documenting any sightings of this invasive shrub.
Be careful not to confuse it with broom (Cytisus scoparius). At
this time of year, they both have yellow pea-like flowers. Upon
closer inspection you will notice large sharp spines on gorse.
The spines make access to colonized areas almost impossible, and
the stems contain oils which create a fire hazard.
Have you seen gorse in your area?
Please contact:
Art Robinson: 250-363-0729 - arobinson@pfc.forestry.ca
Dr. Raj Prasad: 250-363-0747 - rprasad@pfc.forestry.ca
Canadian Forest Service, Pacific Forestry Centre
506 W. Burnside Rd., Victoria, B.C., Canada V8Z 1M5
PLANT DIVERSITY IN BARKLEY SOUND [Part 3 of 3]
From: Martin L. Cody <mlcody@ucla.edu>
POPULATION TURNOVER, ISLAND ADAPTATION AND EVOLUTION
Incidence functions tell only part of the story, and in par-
ticular omit the dynamics. With repeated censuses of specific
islands, many instances of colonization and extinction have been
uncovered, allowing measurement of population turnover rates;
these can be calculated as the proportion of islands which are
different in name, because of yearly colonization of "new"
islands and extinction on "old" islands. In the composites,
values range from a low of 0.066 (in Achillea millefolium, which
is very persistent) to a high of 0.974 (in Anaphalis mar-
garitacea, in which populations wink in and out very rapidly).
Of course most trees and shrubs are long-term persistent, but
not necessarily so on the smaller islands. Species with general
similarity in incidence functions, e.g. Anaphalis and Lactuca
muralis, can differ dramatically in turnover rates.
For adaptation and evolution to occur in situ on islands,
reasonably persistent populations are prerequisite; we have
shown (Cody & Overton 1996) that strong selection for reduced
dispersal, in terms of lower ratios of pappus to achene volume,
is detectable in island Lactuca populations within a decade
after initial colonization. In other candidates for such evolu-
tion, it is precluded in Hypochaeris radicata because of low
turnover rates (and therefore very few newly initiated island
populations to sample), and in Senecio vulgaris by a combination
of few persistent populations and a nonsignificant relationship
between propagule morphology and drop time (i.e. lack of cor-
relation between morphology and dispersal potential).
A second interesting example of island evolution is provided by
the ubiquitous fern Polypodium scouleri, in which frond size,
thickness, and degree of dissection varies conspicuously with
the size of the island the population occupies. On small, dry
islands the fronds are short, thick, and possess as few as three
pinnae, but on larger islands and in wetter or more shaded sites
fronds are long, thinner, and have perhaps 8 times as many
pinnae. In fact this species is a useful bioassay of the local
island climates.
REFERENCES
Cody, M.L. 1992a. Plant species turnover and microevolution on
continental islands off NW and SW North America. Amer. J.
Bot. 79(6) Suppl: 50.
Cody, M.L. 1992b. Some theoretical and empirical aspects of
habitat fragmentation. J Keeley (ed.) Proc. So. Calif. Acad.
Sci. 1991 Symposium, Occidental College.
Cody, M. L. 1999. Assembly rules in bird and plant communities.
Ch. XX in Keddy, P., & E. Wieher (eds), The Search for As-
sembly Rules in Ecological Communities. In press, Cambridge
Univ. Press.
Cody, M. L., & J. M. Overton. 1996. Short-term evolution of
reduced dispersal in island plant populations. J. Ecol.
84(1): 53-61.
Cody, W. J., & D. M. Britton. 1989. Ferns and Fern Allies of
British Columbia. Publ. Research Branch, Agriculture Canada.
Ottawa.
Dawson, A. G. 1992. Ice Age Earth: Late Quaternary Geology and
Climate. Routledge, London & NY.
Diamond, J. M. 1975. Assembly of species communities. pp. 342-
444 in M. L. Cody & J. M. Diamond (eds.), Ecology and Evolu-
tion of Communities, Belknap Press of Harvard Univ. Press,
Cambridge, MA.
Friele, P. A., & I. Hutchinson. 1993. Holocene sea-level changes
on the central west coast of Vancouver Island, British Colum-
bia. Canad. J. Earth Sci. 30: 832-840.
Hitchcock, C.L., & A. Cronquist. 1973. Flora of the Pacific
Northwest. Univ. WA Press, Seattle.
Klinka, K., V.J. Krajina, A. Ceska, & A.M. Scagel. 1989. Indi-
cator Plants of Coastal British Columbia. Univ. Brit. Colum-
bia Press, Vancouver.
Muller, J.E. 1983. The Tertiary Olympic Terrane, SW Vancouver
Island and NW Washington. Field Trip #12, Geol. Assn. Canad.
(Victoria, BC).
Pojar, J. & A. MacKinnon. 1994. Plants of Coastal British Colum-
bia. B.C. Ministry of Forests and Lone Pine Publ., Vancouver,
BC.
Stebbins, G. L. 1950. Variation and Evolution in Plants. Colum-
bia Univ. Press, NY.
Yorath, C. J. 1995. The Geology of southern Vancouver Island.
Orca Bk. Publ., Victoria, BC.
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