| BEN |
| BOTANICAL ELECTRONIC NEWS |
|---|
| ISSN 1188-603X |
| No. 265 March 2, 2001 | aceska@freenet.victoria.tc.ca | Victoria, B.C. |
|---|
Vegetation changes were monitored over a 13-year period (1982-1994) in the Campbell River estuary [eastern coast of Vancouver Island, British Columbia, Canada: 50 deg. 02' N, 125 deg. 15' W] following the development of marshes on four intertidal islands. The marshes were created to mitigate the loss of a natural estuarine marsh resulting from the construction of a dry land log-sorting facility. Plant species coverage was measured along 23 permanent transects in planted and unplanted blocks on the constructed islands, and in naturally occurring low-marsh and mid-to-high marsh reference communities on nearby Nunn's Island.
Five dominant species, Carex lyngbyei, Juncus balticus, Potentilla pacifica, Deschampsia cespitosa, and Eleocharis palustris established successfully and increased in cover in both planted and unplanted areas. The planted, unplanted, and Nunn's Island low-marsh sites had similar total plant cover and species richness by the 13th year. Principal components analysis of the transects through time indicated successful establishment of mid-to-low marsh communities on the constructed islands by the fourth year.
Vegetation fluctuations on the constructed islands were greater than in the mid-to-high and low-marsh reference communities on Nunn's Island. Results showed that substrate elevation and island configuration were major influences on the successful establishment and subsequent dynamics of created marsh communities.
Aboveground biomass estimates of marshes on the created islands attained those of the reference marshes on Nunn's Island between years 6 and 13. However, Carex lyngbyei biomass on the created islands had not reached that of the reference marshes by year 13. Despite the establishment of what appeared to be a productive marsh, with species composition and cover similar to those of the reference marshes on Nunn's Island, vegetation on the created islands was still undergoing changes that, in some cases, were cause for concern. On three of the islands, large areas devoid of vegetation formed between years 6 and 13, probably a result of water ponding.
Adaptive management has allowed us to modify the island configuration through the creation of channels to drain these sites in an attempt to reverse the vegetation dieback. These changes, occurring even after 13 years, further underscore the need for caution when considering the trading of existing natural, healthy, productive wetlands for the promise of created marshes that may or may not prove to be equal to the natural systems.
Where marsh creation is warranted, we recommend that management of created marshes be adaptive and flexible, including a long-term monitoring program that should continue at least until the annual variation in vegetation of the created marsh is similar to that of natural, nearby systems.
Please note that 1 cm discs of leaves give more reliable than 5 mm leaf discs. We only used this in one study as 5 mm cutters were widely available for collaborating schools. However 1 cm cork borers or punches give statistically more reliable results.
I would be most interested to hear what sort of leaf yeast colony numbers occur on the west coast, eg. on ash or maple leaves.
Here on the east coast [in Nova Scotia] numbers are very much lower than in the British Isles possibly because of the lack of grass as a winter resevoir for the leafyeasts.
New Publication in the Northwest Plant Hunters Series: Life of Botanist Louis F. Henderson
The Native Plant Society of Oregon proudly announces the publication of NPSO Occasional Paper Number 2, "Louis F. Henderson (1853-1942): the Grand Old Man of Northwest Botany," by Dr. Rhoda M. Love of Eugene.
The peer-reviewed paper has been formatted as a 64-page booklet with 56 historic and modern images -- many never before published. It is carefully researched, with 133 notes. Also included are a chronology of Henderson's life, notes on many of his important collections, a list of his publications, and a list of plants named for Henderson. The research took nearly three years and extended throughout the Pacific Northwest as well as to Mississippi, Cornell University, The Chicago Field Museum, the Smithsonian Institution, and the Jepson Herbarium at Berkeley. The Occasional Paper is a much-expanded version of Dr. Love's earlier essay on Henderson which appeared in Pacific Northwest Quarterly last year.
Henderson lived through the Civil War in Mississippi only to see his lawyer father murdered in New Orleans during the Reconstruction period. Young Louis was educated at Cornell, studying botany under David Starr Jordan, later President of Stanford. He came west in 1874 and moved to Portland in 1877 to take up a teaching post. He began his botanizing in Washington and Oregon at that time. Soon after, Henderson married fellow teacher Kate Robinson and the couple had two daughters. Henderson had several careers in botany in the Northwest including that of Professor of Botany at the University of Idaho from 1893 to 1908. It was during this time that his herbarium burned, destroying an estimated 85,000 specimens. At the age of seventy-one he became Curator of the Herbarium of the University of Oregon and remained for 15 years, greatly increasing the collection.
The Native Plant Society of Oregon, a non-profit organization, has advanced funds for the printing and mailing of 200 copies of the Henderson Occasional Paper. The Native Plant Society wishes to recoup its investment in a timely fashion, thus mail orders will be accepted starting immediately. The cost is US$10.00 per copy which includes mailing and handling. Orders will be filled as soon as received.
To order send a US$10.00 check, made out to NPSO, to: Occasional Papers, Native Plant Society of Oregon, P.O. Box 902, Eugene, Oregon, 97440-0902. Please include your full return address.