Message - 7th IAL Symposium

Lichen: from genome to ecosystem in a changing world
5I-O
5I: Global Change and lichen biology
(5I-O1) Submission ID: IAL0142-00001
ALTITUDINAL DISTRIBUTION OF CAUCASIAN LICHENS SUPPORTS THE KEY ROLE
OF CLIMATE IN HOLARCTIC DISTRIBUTION PATTERNS
Otte V. 1 , Ritz M. S. 1
1 Botany, Senckenberg Museum of Natural History, Goerlitz, Germany
Distribution of many lichen species spans both Holarctic continents (Eurasia and North America). Nevertheless,
it appears not stochastic, but can be assigned to certain types, which resemble those known from
vascular plant species. One distribution type frequently observed in lichens is the Asa Gray disjunction (East Asia
– Eastern North America), which is known from vascular plants mostly on the level of higher taxonomic units.
Distributions of this type are commonly linked with extinction events during the Quaternary. Their representatives
(or, in vascular plants, their close relatives) often have small isolated outposts in southeastern Europe and are
considered as Tertiary relicts, which were pushed back to their current occurrences during the Pleistocene. Our
study aimed to test whether occurrence of lichens of this distribution type can be explained by factors other than
history. We studied the allocation of epiphytic lichens of different distribution types in the north-western Caucasus
along an altitudinal gradient, which resembles a climatic gradient from warm-dry (lowlands) via warm-wet (middle
altitudes) up to cold-wet summers (higher mountains). Our results show that lichens with a global distribution of
the Asa Gray disjunction type clearly prefer the middle (warm-wet in summer) altitudinal belt in the Caucasus.
The more pronounced the preference of the relictic areas on a global scale, the stricter the confinement to the
middle altitudes in the Caucasus. Conversely, lichens that avoid the Asa Gray relictic areas on a global scale are
substantially rarer or lacking at the middle altitudes of the Caucasus, occurring instead below as well as above.
Species without pattern related to the Asa Gray areas do also not express an altitudinal pattern in the Caucasus.
We conclude that preference or avoidance of the Asa Gray relictic areas does not need historical explanations,
but can be put down to ecophysiological preferences related to the combination of moisture and temperature.
This should be kept in mind also in interpreting distribution of representatives of other taxonomic groups. Also, it
implies considerable distribution dynamics when climate changes.
(5I-O2) Submission ID: IAL0191-00001
RECONSTRUCTING HISTORIC BIODIVERSITY LOSS: LICHENS AS
A POWERFUL NEW ARCHAEOLOGICAL TOOL
Ellis C. J. 1 , Belinchon R. 1 , Yahr R. 1 , Coppins B. 1
1 Cryptogamic Botany, Royal Botanic Garden Edinburgh, Edinburgh, United Kingdom
We report the exceptional preservation of lichen epiphytes on historic wooden building materials in
southern England, representing an entirely novel archaeobotanical tool. These building materials were harvested
from the landscape during the pre-industrial period (< 1,750), with lichen and bryophyte epiphytes preserved
intact on both bark of large timbers and smaller diameter poles and rods. By using this resource to quantify
historic lichen diversity, we can demonstrate: (i) shifts in the biogeographic range of lichens across the threshold
of industrialisation, and (ii) changes in epiphyte community structure, both consistent with a severe depletion in
epiphyte diversity. We can robustly quantify the difference between pre-industrial biodiversity (prior to Linnaean
taxonomy and a modern conservation ethic), and biodiversity and environmental indicators developed during the
post-industrial period. In conclusion, modern indicators represent ‘soft targets’ for early-to-industrialise western
regions (e.g. southern England), which may be based on the recalcitrant subset of persisting species. These
results should cause the re-evaluation of conservation goals when looking for equity across developed and developing
nations.
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