| BEN |
| BOTANICAL ELECTRONIC NEWS |
|---|
| ISSN 1188-603X |
| No. 172 September 27, 1997 | aceska@victoria.tc.ca Victoria, B.C. |
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Lloydia serotina (L.) Rchb. (Liliaceae) is found in a number of alpine and arctic locations throughout the northern hemisphere, ranging from alpine tundra in the Rocky Mountains and the European Alps to near coastal situations in Alaska and Siberia. It is not found in the European arctic however and in Britain it is a rare and protected species, only occurring on a very few cliff faces in the Snowdonia Mountains of North Wales. Concern at the vulnerable nature of these peripheral populations, together with the fact that very little was known about the species, prompted research into the ecology, population dynamics, reproductive ecology, habitat and genetic variation of populations in Wales, the European Alps and North America, including British Columbia and Washington State. The main aim was to assess the performance of the Welsh populations against that of the large populations at the centre of the species range, however, interesting results also emerged regarding all the populations studied, especially those in peripheral situations such as the Pacific north-west, Wales and the Southern Rocky Mountains.
The characteristics of the habitat vary throughout its range, influenced by latitude, climate and land use, with the more 'typical' habitat consisting of gently sloping alpine tundra, exemplified by the localities in the Rocky Mountains in Colorado. Further north however, the preferred habitat becomes more rocky, with the cliff bound populations in Wales providing an extreme example. These more northerly populations also tended to be much smaller than those in the centre of its range. Demographic studies revealed that vegetative reproduction appears to predominate over sexual reproduction in all populations, with +rhizome' type structures issuing from the bulb and forming daughter plants. The smaller, more peripheral populations showed slightly lower flowering and seeding levels than the larger populations studied during a three year period, but sexual reproduction does occur and seed produced is viable.
All populations studied had large percentages of male flowers as well as hermaphrodites, raising interesting questions regarding the possibility of androdioecy in the species. Initial investigations into pollen production and viability suggest that the theoretical requirements for double fertility in male flowers in androdioecious populations is not met with in Lloydia, but it may be possible that males are maintained in a population if they have an increased vegetative reproductive capability.
A survey of protein polymorphisms in 16 populations, including one from Vancouver Island, one from southern British Columbia and one from the Olympic Peninsula, showed lower levels of isozyme variation in the smaller populations, especially the most northerly and southerly ones in North America, suggesting the occurrence of genetic drift. The Welsh populations are the most isolated, but they show levels of variation which are slightly higher than those in the Pacific north-west. This could be due to a number of reasons involving the glacial history of the areas concerned and the size and viability of the populations studied. The two main Welsh populations studied were larger than some of those in the Pacific north-west where the very small populations there may be losing genetic variability due to inbreeding, lack of gene flow and genetic drift. Random Amplified Polymorphic DNA (RAPD) analysis of four Welsh populations produced evidence for clonal growth and consequent genetic structuring within these populations. This type of growth could help to maintain some genetic diversity in larger, more scattered populations which exhibit occasional gene flow between relatively isolated groups or 'clones', but in smaller, more compact populations, it can result in an increase in homozygosity (one population in the Olympic Mountains for example covered an area of only two square metres).
One major omission from the research was the investigation of material from the Queen Charlotte Islands. Lloydia from this locality is considered to constitute a subspecies Lloydia serotina subsp. flava, due to its larger size and different colouration. This has not been proven however, and so far my attempts to obtain material from these remote Islands have been unsuccessful. Genetic analysis of these populations would provide fascinating results, not only to confirm or otherwise the designation, but also to throw more light onto the glacial history of the area and its effects on speciation and past movement of vegetation communities. If anyone is visiting the Islands this year and is able to collect material for me, preferably seed, which will survive posting better than leaves, then I would be eternally grateful.
Bad news travels fast so many of you probably already know that the Geological Survey of Canada in its latest blood-letting has discontinued all paleoecological research (including pollen, wood and macrofossils) and has surplused everybody working in that realm. Evidently the GSC is walking away from an important area of Global Change research, just when the public is becoming aware of its importance.
The National Forestry Database Program is pleased to announce that the complete version of the sixth edition of the Compendium of Canadian Forestry Statistics, 1996 is now available on the World Wide Web at:
The Compendium contains national and provincial forestry information (more than 55 tables, 117 graphs, background information and terminology). All data files can be downloaded as ASCII text and can easily be manipulated using software such as Excel. The site provides historical tables as well as detailed tables by ownership (1990-1995) for the following areas:
We encourage you to provide feedback in order to help us develop a product that will best serve your needs.
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