Abstract
Juvenile development from sown vegetative diaspores of the cyanobacterial lichen Lobaria scrobiculata and the green algal lichens Platismatia glauca and P. norvegica was studied through a four-year field experiment in a boreal spruce forest. All three species developed juvenile thalli within the period of observation. The largest lobules of L. scrobiculata and Platismatia were 0.4 mm and 1.3 mm, respectively, four years after sowing the diaspores. The first very tiny lobule (0.1 mm) of L. scrobiculata was observed 29 months after sowing the soredia. This period of juvenile development is the longest period so far reported for lichens. A long phase of dormancy, after the diaspores were attached to the substrate, was characteristic for the investigated species. Apical growth of the isidia of Platismatia glauca and P. norvegica was not observed until 21 months after sowing. Low light levels, low temperatures and snow covering the diaspores during winter, causes a short growth season in boreal spruce forests. These factors might explain the long period for juvenile development. The results indicate a slow rate of colonization of a new habitat for the investigated species since they need several years to grow to visible thalli.
Key words
Lobaria
-
Platismatia
- epiphyte - juvenile development - diaspore - forest
References
1 Ahmadjian, V.. (1993) The lichen symbiosis. New York; John Wiley and Sons
2
Ahlner, S..
(1948);
Utbredningstyper bland nordiska barrträdslavar.
Acta Phytogeographica Suecica.
22
1-157
3 Armstrong, R.. (1988) Substrate colonization, growth, and competition. CRC Handbook of Lichenology, Vol. II. Galun, M., ed. Boca Raton, Florida; CRC Press pp. 3-16
4
Armstrong, R..
(1990);
Dispersal, establishment and survival of soredia and fragments of the lichen Hypogymnia physodes .
New Phytologist.
114
239-245
5 Aune, B.. (1993) Air temperature normals, normal period 1961 - 1990. Det Norske Meteorologiske Institutt, Report 02/93 Klima 1-63
6 Bailey, R.. (1976) Ecological aspects of dispersal and establishment in lichens. Lichenology: Progress and Problems. Brown, D. H., Hawksworth, D. L., and Bailey, R. H., eds London; Academic Press pp. 215-247
7
Bowler, P. A., and Rundel, P. W..
(1975);
Reproductive strategies in lichens.
Botanical Journal of the Linnean Society.
70
325-340
8
Degelius, G..
(1964);
Biological studies of epiphytic vegetation on twigs of Fraxinus excelsior.
.
Acta Horti Gotoburgensis.
27
11-55
9 Direktoratet for Naturforvaltning .(1999) Nasjonal rødliste for truede arter i Norge 1998 (Norwegian redlist 1998). DN-report 3: pp. 1-161
10
Fremstad, E..
(1997);
Vegetasjonstyper i Norge.
NINA Temahefte.
12
pp. 1-279
11 Førland, E. J.. (1993) Precipitation normals, normal period 1961 - 1990. Det Norske Meteorologiske Institutt, Report 39/93 Klima pp. 1-63
12
Gauslaa, Y..
(1995);
The Lobarion , an epiphytic community of ancient forests threatened by acid rain.
Lichenologist.
27
59-76
13 Harris, L. D.. (1984) The fragmented forest: island biogeography theory and the preservation of biotic diversity. Chicago; University of Chicago Press
14
Hilmo, O..
(1994);
Distribution and succession of epiphytic lichens on Picea abies branches in a boreal forest, Central Norway.
Lichenologist.
26
149-169
15
Hilmo, O., and Såstad, S. M..
(2001);
Colonization of old-forest lichens in a young and an old boreal Picea abies forest: an experimental approach.
Biological Conservation.
102
251-259
16
Honegger, R..
(1987);
Isidium formation and the development of juvenile thalli in Parmelia pastillifera (Lecanorales, lichenized Ascomycetes).
Botanica Helvetica.
97
147-152
17
Honegger, R..
(1993);
Developmental biology of lichens.
New Phytologist.
125
659-677
18
Hyvärinen, M.,, Halonen, P.,, and Kauppi, M..
(1999);
Habitat type and primary colonization of annual shoots of conifer saplings by epiphytic lichens.
Nordic Journal of Botany.
19
505-511
19
Jahns, H. M..
(1984);
Morphology, reproduction and water relations - a system of morphogenetic interactions in Parmelia saxatilis .
Beihefte Nova Hedwigia.
79
715-737
20 Jahns, H. M.. (1988) The lichen thallus. CRC Handbook of Lichenology, Vol. 1. Galun, M., ed. Boca Raton, Florida; CRC Press pp. 95-143
21
Jahns, H. M..
(1993);
Culture experiments with lichens.
Plant Systematics and Evolution.
187
145-174
22
Jørgensen, P. M..
(1978);
The lichen family Pannariaceae in Norway in Europe.
Opera Botanica.
45
1-124
23
Laundon, J. R..
(1978);
Haematomma chemotypes from fused thalli.
Lichenologist.
10
221-225
24 Nash, T. H.. (1996) Photosynthesis, respiration, productivity and growth. Lichen Biology. Nash III, T. H., ed. Cambridge; Cambridge University Press pp. 88-121
25
Ott, S..
(1987 a);
Differences in the developmental rates of lichens.
Annales Botanici Fennici.
24
385-393
26
Ott, S..
(1987 b);
The juvenile development of lichen thalli from vegetative diaspores.
Symbiosis.
3
57-74
27 Purvis, O. W.,, Coppins, B. J.,, Hawksworth, D. L.,, James, P. W.,, and Moore, D. M.. (1992) The lichen flora of Great Britain and Ireland. London; The British Lichen Society
28 Rose, F.. (1992) Temperate forest management: its effects on bryophyte and lichen floras and habitats. Bryophytes and lichens in a changing environment. Bates, J. W. and Farmer, A. M., eds. Oxford; Claredon Press pp. 211-233
29
Saunders, D. A.,, Hobbs, R. J.,, and Margules, C. R..
(1991);
Biological consequences of ecosystem fragmentation. A review.
Conservation Biology.
5
18-32
30
Scheidegger, C..
(1995);
Early development of transplanted isidioid soredia of Lobaria pulmonaria in an endangered population.
Lichenologist.
27
361-374
31
Scheidegger, C., and Zoller, S..
(1995);
Transplantation of symbiotic propagules and thallus fragments: Methods for the conservation of threatened epiphyitc lichen populations.
Mitteilungen der Eidgenössischen Forschungsanstalt für Wald, Schnee und Landschaft.
70
41-62
32
Schuster, G..
(1985);
Die Jugendentwicklung von Flechten - ein Indikator für Klimabedingungen und Umweltbelastung.
Bibliotheca Lichenologia.
20
1-206
33
Schuster, G.,, Ott, S.,, and Jahns, H. M..
(1985);
Artificial cultures of lichens in the natural environment.
Lichenologist.
17
247-253
34
Stocker-Wörgötter, E., and Türk, R..
(1989);
Artificial cultures of the cyanobacterial lichen Peltigera didactyla (Peltigeraceae) in the natural environment.
Plant Systematics and Evolution.
165
39-48
35 Thor, G., and Arvidsson, L.. (1999)
Rödlistade lavar i Sverige - Artfakta (Swedish Red Data Book of Lichens). Uppsala; ArtDatabanken SLU
36
Tørseth, K., and Semb, A..
(1998);
Deposition of nitrogen and other major inorganic compounds in Norway, 1992 - 1996.
Environmental Pollution.
102
299-304
37
Zoller, S.,, Frey, B.,, and Scheidegger, C..
(2000);
Juvenile development and diaspore survival in the threatened epiphytic lichen species Sticta fuliginosa , Leptogium saturninum and Menegazzia terebrata : Conclusions for in situ conservation.
Plant Biology.
2
496-504
O. Hilmo
Department of Botany Faculty of Chemistry and Biology Norwegian University of Science and Technology
7491 Trondheim Norway
Email: olga.hilmo@chembio.ntnu.no
Section Editor: H. M. Jahns