MAPPING OF LICHENS in Koblenz
carried out by a biology set, class 13 of the
BISCHÖFLICHES CUSANUS-GYMNASIUM KOBLENZ


Copyright 1996 Hansjörg Groenert


IMG of the students of the biology set,
class 13 of  the
Bischöfliches
Cusanus Gymnasium Koblenz

The students of the biology set, class 13 of the Bischöfliches Cusanus Gymnasium Koblenz mapped the distribution of lichens in the Koblenz area. Our procedure was to examine four stripes of land which were 1 kilometre wide: -two stripes in west-east direction (from the Mühlental in Güls to the military training area at the Wintersborner rivulet in Arzheim an from Lay to the Siechhaustal) -two stripes in north-south direction (from the Rauental to the Siechhaustal and from the town centre to the Oberwerth).

map

Map:
red = only one lichen
yellow = zone of leaf-shaped lichens (crusty and leaf-shaped lichens)
green = zone of shrublike lichens (crusty, leaf-shaped and shrublike lichens)



map of trees

map of trees:
withe = only Pleurococcus sp.
red = crusty lichens
yellow = leaf-shaped lichens
green = shrublike lichens











Each student was in charge of one square kilometre of the examined area. First, he/she choose ten isolated, regularly spread deciduous trees with acid bark, such as birch trees, oak trees, black alders, pears, beeches, apple trees, lime trees, elms or maple trees, especially taking into account the different living spaces (differences in ground and micro-climate) in his/her grid square. Then he/she photographed the lichens on the bark at a height of 1.80 m, classified them and estimated their frequency. In case of finding lichens on neighbour trees too, those lichens were also recorded.

Mapping of lichens 1994/95 - location of the grid squares
red = crusty lichens / green = leaf-shaped lichens / blue = shrublike lichens

Picture: Mapping of
lichens
1994/95
Abundance: 1= individual finding, 3= little, 4=strong, 5=very large quantities







Under the guidance of their biology teacher, StD Groenert, the individiual results were evaluated: Lichens simply live on air, which provides water and nutrient salts, but also pollutants. Naturally caused, the barks have a pH-value between 3.4 and 7. A higher pH-value normally causes an intensified vegetation of the lichens. Acid rain diminishes the pH-value auf the bark, this could endanger the growth of the lichens. Because of their bigger surface, the shrublike lichens react more sensitive to environmental influences (pollutants and dryness) than the leaf-shaped lichens, and those, consequently, more sensitive than the crusty lichens. If even the crusty lichens can't survive, only Pleurococcus will be found.

All in all, the result of the examination was the following distribution of the different types of lichens:

1. West-east-distribution of lichens between Güls and Arzheim:
red = crusty lichens / green = leaf-shaped lichens / blue = shrublike lichens

Mapping out of lichens
west-east-comparison
                examination 1994/95













2. West-east distribution between Lay and Siechhaustal:
red = crusty lichens / green = leaf-shaped lichens / blue = shrublike lichens

Mapping out of lichens west-east
comparison: Lay
- Siechhaustal













3. North-south distribution between Rauental and Siechhaustal:
red = crusty lichens / green = leaf-shaped lichens / blue = shrublike lichens

 Mapping out of lichens north-south
comparison:
Rauental - Siechhaustal













4. North-south distribution: Town centre-Oberwerth:
red = crusty lichens / green = leaf-shaped lichens / blue = shrublike lichens

 Mapping of lichens Koblenz-city (n-s): City - Oberwerth













We suspected that there is a correlation between the different quantities of lichens and typical factors, such as emissions and changings of the microclimate, caused by road traffic, residential areas, sport fields etc..... In the town and along the Hunsrückhöhenstraße, the vegetation of lichens was strongly impaired. Even in comparison with a measurement in 1991, the shrublike and leaf-shaped lichens had been displaced. In the city, only one individual finding on one tree could be detected.

Xanthoria parietina - indicator of eutrophication:
Xanthoria parietina     -  
indicator of
eutrophication













The yellow leaf-shaped lichen "Xanthoria parietina" is an indicator of eutrophication. It can be detected in places where organic scrops are stored or where fertilizers are used. The students found these lichens for example on the waterfront of the Rhine and the Moselle, on the sports field of Asterstein, the Post-Sport tennis courts in Moselweiß, the tank street and very frequently in Lay

Distribution at the extreme locations town centre "left" and Remstecken "right" (1):
- average of 10 trees per 1 sqkm -
red = crusty lichens / green = leaf-shaped lichens / blue = shrublike lichens

Distribution at the extreme
locations town centre and
Remstecken (1)














Distribution at the extreme locations town centre "blue" and Remstecken "red" (2):
Distribution at the extreme locations town centre and
Remstecken (2)













For 1 year, the BCG and the Waldökostation Remstecken measure hourly the wind direction, the wind force, humidity, temperature and exposure to sunlight. Therefore, we had the possibility to compare the composition of sorts and the frequency of lichens at the extrem locations Remstecken and town centre with the measured climate factors.

Relative humidity (%) in august 1995  relative humidity in august 1995














The computational analysis showed, that every day the relative humidity in the city "blue graph" fluctuates significantly strong between the extreme values, it even reaches the 0% limit. That could be a mortal danger for the lichens in the city. This fluctuation, isn't so strong at Remstecken "red graph".

Further information about lichens as bioindicators from the university of Salzburg
Further information about this work: Hansjörg Groenert
home to homepage