Northwest Lichenologists

Mystery of Quadra Island

  • 21 Jul 2018 1:26 PM
    Message # 6391797
    Bruce McCune (Administrator)

    I recently spent some time on Quadra Island, B.C., on the east side of Vancouver Island, about half the way up. It's about 50 km long and 10-30 km wide. It seemed to me that the southern half of of the island is very poor in lichens (diversity, cover, biomass, etc.), while the northern part seems to have normal lichens for the PNW. Why are the lichens are so reduced in the southern part?

    Both conifers and hardwoods have sparse lichens in the southern parts of the island. I would expect dense young stands to be nearly barren of lichens anywhere in the PNW, but even places with more open forest structure were strangely barren on Quadra Island. Crustose lichens appeared to be suppressed too. For example, you can find stabilized beach logs high on the shore tend to have hardly any Xylographa, Lecanora, or other expected species. Some trees are dense with monospecies stands of Ramalina farinacea but almost nothing else.

    Air pollution? I saw no sign of industry nearby, but perhaps there was historic air pollution?

    Forest management? Perhaps the whole southern part was clearcut over a short period of time, creating a deficit of nearby propagule sources. The northern part has more rocky knobs and outcrop areas that haven't been logged. Perhaps the logging was less thorough in the north.

    I only spent a week there, so my observations may be off base. Maybe others can confirm or refute these impressions. Or maybe you have some clues to help solve the mystery.

  • 22 Jul 2018 9:16 AM
    Reply # 6392481 on 6391797


    Are the mosses also missing? You probably weren't there at the right time, but how about mushrooms?

  • 23 Jul 2018 7:22 AM
    Reply # 6393719 on 6391797
    Bruce McCune (Administrator)

    I'd say that mosses were well developed on the forest floor and low on the trees, but not as much moss on the branches and trunks as you might find on the west side of Vancouver Island and Olympic Peninsula.

  • 23 Jul 2018 9:57 AM
    Reply # 6394018 on 6391797

    Hi Bruce

    Marco's parents had a cabin on Cortes Island, the next island over from Quadra east towards the mainland of BC, so I've spent quite a bit of time there over the last 20 years. A few of us conducted a lichen/bryo bioblitz at our property in 2014. I've attached the species list if your interested. We did not focus on crusts though we did collect some and they are included in the list.

    In terms of pollution, there is a pulp mill in Campbell River very near to Quadra on Vancouver Island. It was still active at into the 2000's at least, although I'm not sure of its status now. But I remember seeing the smoke stacks from Cortes and thinking about that as a pollution source.

    Cortes is similar in that the northern half of the island is much more wild with few roads and no people. There are even some chunks of old growth left! The landscape is rocky with lots of bluffs so harder to clear cut. I do think much of Quadra and Cortes were clear cut at last once. Much of the forests are second growth. I also noticed that these islands are definitely not a place of high lichen abundance, although their are some impressive patches of reindeer lichens and other Cladonia's on the bluffs. I'm not sure if this is a big factor but Cortes was in a bit of a rainshadow, its much drier than one would expect for our bioregion.

    Anyway, hope that helps to shed some light on the Quadra Island Mystery!!

    Best wishes, Lalita

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  • 24 Jul 2018 8:49 AM
    Reply # 6395790 on 6391797

    I believe that would be the Elk Falls pulp mill that Lalita refers to.  It closed several years ago.  I think the property now has a power plant (nat gas or coal fired -- cant recall which)

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