BC’s Coast Region: Species & Ecosystems of Conservation Concern 1

This semi-erect arboreal lichen forms cushiony structures about 2 cm across,

with many irregularly branched lobes. The stiff lobes are short to slightly elongated, and quite thin (0.5-2 mm wide). The top surface is usually a faint greenish-white colour but can also have a deep blue appearance. The smooth upper surface is strongly convex with occasional warts and whitish spots. The lower surface has a white colour and cottony texture. Urn-shaped reproductive structures and minute wispy hair-like structures rim the upper edges of the lobes.

There are similar macro-lichens to seaside centipede such as those in the genus

Hypogymnia including dog bone and beaded bone lichen. These species commonly grow throughout the Pacific Northwest on tree branches in association with H. sitchensis, are similar in colour and possess tubular structures with some branches ending in terminal cups as with seaside centipede. However the hair-like structures, large urn-shaped outgrowths and cottony lower surface distinguish seaside centipede from these other lichens.

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Description

Look’s Like?

Notes on Heterodermia sitchensis: A member of the family Physciaceae (“lichens”), this species is also referred to as “Sitka shield lichen”. Lichen are composite organisms consisting of a fungus and a photosynthetic partner, usually an algae, which form a symbiotic relationship. Lichens are generally assigned to one of four groups: “Foliose Macrolichens” (such as seaside centipede), “Mesolichens”, “Fruticose Lichens” and “Crustose Lichens”. These groups reflect the ecology and physical attributes of the species within each group.

Lichen anatomy

Dog Bone Lichen

BC’s Coast Region: Species & Ecosystems of Conservation Concern 2

Elevation 0-50 m. Unique to North America, seaside centipede is known only from 12 locations (mostly in Pacific Rim National Park), on the west coast of Vancouver Island in BC, and one site on the Oregon coast

(Cape Lookout). Nearly 70 percent of this lichen’s area of occurrence in BC is confined to the seaside forests, coves and inlets that range along the coastline of the Mission Group Islands in Kyoquot Sound to Folger Island in Barkley Sound.

Seaside Centipede (Heterodermia sitchensis), known and potential population occurrences (red-dotted line) for the Coast Region

Distribution

Coast Region occurrence range in relation to associated forest districts

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Critical Features

Seasonal Life Cycle

Threats

Habitat Preferences

Seaside centipede has an extremely narrow tolerance range

of habitat and nutrient requirements revolving around wind exposure, humidity, substrate and temperature. Ideal conditions appear restricted to localized micro-climates found on the lower branches of maritime variant Sitka spruce trees in association with undisturbed old-growth western hemlock-dominated forests. There is some indication that this species can survive desiccation and dryer, exposed conditions. Prolonged ability to tolerate significant changes projected to occur with climate change is unknown.

Proximity to the marine

environment is a critical factor as this lichen depends on moisture provided by sea-spray drift or fog. Protection from direct exposure may also be important. Nutrient sources appear to be a key requirement. Strong associations occur in locations where base-rich nutrients are abundant (e.g. areas where guano accumulates below bird perches or seabird flyways or scat on sea lion haul-outs), or where the host trees grow on, and therefore takes up, high levels of base minerals (e.g., calcium-rich bedrock, First Nations shell middens). It has been suggested that a minimum buffer at least 60 meters wide is required to reduce harvesting impacts to sensitive lichens such as Heterodermia sitchensis.

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

This lichen may live 10-15 years.

A short lifespan, poor dispersal ability, highly specific habitat requirements, ephemeral nature of its preferred habitat

and limited suitable habitat availability contribute to this species rarity and vulnerability. This species has a life history that suggests a strong dependence on local micro-climate factors and a need for stable

habitat not vulnerable to sudden change. Development, clearing, forestry and silviculture management practices, collection of branches for community purposes

(e.g. firewood) and other disturbance factors remain a significant issue. Recovery and recolonization rates for disturbed, damaged or destroyed colonies could take decades in order for suitable

host tree maturation to occur. Impacts from changes to the critical nutrient regimes this species requires (e.g. reduction in seabird or marine mammal

populations that produce nutrient sources) is unknown. Increased severity of weather events (precipitation, storm surges) and related impacts from climate change (potential

loss of critical moisture regimes) are difficult to project and manage for.

Seaside centipede is only associated with small defoliated twigs in the lower canopy of Sitka spruce within several meters of the high tide zone.

Reproduction is asexual, lobes break off, disperse by wind or rain and colonize new Sitka spruce branch substrates

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Conservation & Management Objectives

Content for this Factsheet has been derived from the following sources

Apply conservation and management objectives for this species and its habitat as set out in the “Recovery Strategy for Seaside Centipede Lichen (Heterodermia sitchensis) in Canada.”

Integrate inventory recommendations and approaches developed in “Lichens of British Columbia: rare species and priorities inventory”. Collection activities should be limited and apply practices identified in the Province’s “Voucher Specimen Collection, Preparation, Identification and Storage Protocol: Plants & Fungi.” Inventory activities should consider approaches and references identified in E-Flora’s Protocols For Rare Vascular Plant Surveys.

Specific activities should include:

A targeted inventory is needed to determine if undiscovered populations exist elsewhere within the Coast Region and to update the status of all known populations.

Monitor existing populations on an ongoing basis to assess viability and reduce potential disturbance from land use activities. Where suitable habitat occurs, work with land managers and land owners to ensure development or recreational activities do not disturb or encroach on sensitive areas.

Conduct outreach to raise awareness of this species and how to identify it to improve distribution knowledge. Manage and restrict activities that will lead to changes to critical seaside centipede habitat requirements and reduce

viability of existing populations (e.g. kindling collection, clearing and slash removal).

B.C. Conservation Data Centre. 2010. [Internet] [Updated July 25 2007] Conservation Status Report: Heterodermia sitchensis. B.C. MoE. Bjork, Curtis et al. 2010. [Internet] Ways of Enlichenment: The Book (online). COSEWIC 2006. COSEWIC assessment and update status report on the seaside centipede Lichen Heterodermia sitchensis in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vi + 28 pp. E-Flora. 2010. [Internet] Electronic Atlas of the Plants of British Columbia Fairbarns, Matt. 2010. Aruncus Consulting [Personal comm.] Goward, Trevor. 2004. [Internet] SEASIDE CENTIPEDE (HETERODERMIA SITCHENSIS): PORTRAIT OF A LICHEN. In the Botanical Electronic News, No. 335 September 29. Goward, T. 1996. [Internet] Lichens of British Columbia: rare species and priorities inventory. Res. Br., B.C. Min. For. and Hab. Protect. Br., B.C. Min. Environ., Lands and Parks, Victoria, B.C. Work. Pap. 08/1996. National Recovery Team for Heterodermia sitchensis (Seaside Centipede Lichen). 2007. [Internet] Recovery Strategy for Seaside Centipede Lichen (Heterodermia sitchensis) in Canada. Species at Risk Act Recovery Series. Parks Canada Agency. Ottawa. vi + 19 pp. Proulx, Gilbert et al. 2003. A Field Guide to Species at Risk in the Coast Forest Region of British Columbia. Published by International Forest Products and BC Ministry of Environment. Victoria (BC). Ways of Enlichenment. 2010. [Internet].

Prepared by: Pamela Zevit of Adamah Consultants and Matt Fairbarns Aruncus Consulting for the South Coast Conservation Program (SCCP) in partnership with: International Forest Products (Interfor), Capacity Forestry (CapFor) and the BC Ministry of Environment (BC MoE), E-Flora and E-Fauna the Electronic Atlas of the Flora and Fauna of BC, Species at Risk & Local Government: A Primer for BC. Funding for this factsheet was made possible through the Sustainable Forestry Initiative (SFI): http://www.sfiprogram.org/ Every effort has been made to ensure content accuracy. Comments or corrections should be directed to the South Coast Conservation Program: info@sccp.ca. Content updated August 2010. Image Credits: Seaside centipede and close-up: Tim Wheeler, Dog bone lichen: Tim Wheeler, Habitat: Brian Reader Parks Canada, Lichen Anatomy graphic: Pamela Zevit modified from BJU press. Only images sourced from “creative commons” sources (e.g. Wikipedia, Flickr, U.S. Government) can be used without permission and for non-commercial purposes only. All other images have been contributed for use by the SCCP and its partners/funders only.

This species is listed under the Federal Species at Risk Act (SARA) and may be subject to protections and prohibitions under the BC Wildlife Act. Habitat for this species may also be governed under provincial and federal regulations

including the Fish Protection Act, Federal Fisheries Act, National Parks Act as well as Regional and local municipal bylaws.