Gymnoderma insulare 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Fungi Ascomycota Lecanoromycetes Lecanorales Cladoniaceae

Scientific Name: Gymnoderma insulare Yoshim. & Sharp
Taxonomic Notes: This attractive macrolichen is easy to recognize by lichen specialists. The species can be identified in the field and because it has been recognized as an extremely rare species for decades, the species is relatively well documented in literature and herbaria.

Assessment Information [top]

Red List Category & Criteria: Endangered B2ab(i,ii,iii,v) ver 3.1
Year Published: 2014
Date Assessed: 2014-08-14
Assessor(s): Ohmura, Y., Nadyeina, O. & Scheidegger, C.
Reviewer(s): Dahlberg, A. & Nimis, P.L.
The global distribution of this species is limited to only five locations in Japan (for the period of 1926-2012) and Taiwan (discovered in 2007), with an area of occupancy (AOO) of 24 km2. This species grows in old-growth forests at the base of trunks of veteran trees of Cryptomeria japonica (in Japan) and Chamaecyparis obtusa (in Taiwan). Both host species are Near Threatened according to the IUCN Red List. Old forests with these two tree species were largely destroyed in the past by forestry or typhoons, and now only exist in limited protected areas. Hurricanes and other severe stand-level disturbances pose continuing threats to the species. It is assessed as Endangered.

Geographic Range [top]

Range Description:

The species is known from Japan (Honshu, Kyushu, Shikoku) and Taiwan.

Countries occurrence:
Japan (Honshu, Kyushu, Shikoku); Taiwan, Province of China (Taiwan, Province of China (main island))
Additional data:
Estimated area of occupancy (AOO) - km2:24Continuing decline in area of occupancy (AOO):Yes
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:167283
Continuing decline in extent of occurrence (EOO):Yes
Number of Locations:5Continuing decline in number of locations:Unknown
Extreme fluctuations in the number of locations:NoLower elevation limit (metres):800
Upper elevation limit (metres):1000
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:This species is considered very rare but no detailed assessments of population size and possible decline exist. One out of six locations (17%) was destroyed by a typhoon in 1991, i.e. within the last generation. The extinction of the subpopulation in Fukuoka led to a 66% reduction in the extent of occurrence (EOO) and, if EOO were used as a proxy for population size assuming all sites are equal, this could represent a 66% population reduction. However, there are no additional data concerning declines prior to and after this event and there is uncertainty as to whether this loss represents an ongoing decline. This species has a generation length of 33 years and so declines for criterion A would need to be measured over a period of 100 years. As a result this species will not be assessed against criterion A and further work on population size and trend is recommended. Hurricanes are a continuing threat to this species and it should be noted that there will be no compensation for lost habitats through natural forest regeneration as this species is limited to old growth forests within protected areas.
Current Population Trend:Decreasing
Additional data:
Continuing decline of mature individuals:Yes
Extreme fluctuations:NoPopulation severely fragmented:No
Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and Ecology:

This species occurs in old-growth forests at the base of trunks of  veteran trees of Cryptomeria japonica or Chamaecyparis obtusa in protected forests. Both tree hosts are Near Threatened according to IUCN Red List. It is an old-growth dependent species with an expected long generation time. 

Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):33
Movement patterns:Not a Migrant

Threats [top]

Major Threat(s):

All known localities are within the borders of protected areas. It is likely that intensive forestry has led to a population decline in previous decades. Natural hazards such as typhoons are known and continuing threats.

Conservation Actions [top]

Conservation Actions:

All locations of the species are within the borders of protected areas. Detailed assessments of local subpopulations (size and trends) are needed and the geographic distribution should be clarified in underexplored regions.

Citation: Ohmura, Y., Nadyeina, O. & Scheidegger, C. 2014. Gymnoderma insulare. The IUCN Red List of Threatened Species 2014: e.T58520980A58520984. . Downloaded on 14 August 2018.
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