Selected publications:

Frey, W., Kürschner, H. 2011. Asexual reproduction, habitat colonization and habitat maintenance in Bryophytes. A review. - Flora 206: 173-184.

Frey, W., Stech, M. 2009. Marchantiophyta, Bryophyta, Anthocerotophyta. - In: Frey, W. (ed.): Syllabus of Plant Families, pp. 1-257. - Borntraeger, Stuttgart.
Stech, M., Frey, W. 2008. A morpho-molecular classification of the mosses (Bryophyta). - Nova Hedwigia 86: 1-21.
Frey, W. 2006. Hornworts and liverworts. In: Blockeel, T.L. ed.: The liverworts, mosses and ferns of Europe. Pp. 6-127. - Harley, Colchester.
Yin-Long Qiu et al. (21 authors) 2006. The deepest divergences in land plants inferred from phylogenomic evidence. - PNAS 103: 15511-15516.
Frey, W., Stech, M. 2005. A morpho-molecular classification of the liverworts (Hepaticophytina, Bryophyta). - Nova Hedwigia 81: 55-78.
Frey, W. 2004. Leber- und Hornmoose. In: Frahm, J.-P., Frey, W.: Moosflora. S. 6-157. 4. Aufl. - Ulmer, Stuttgart.
Frey, W., Hofmann, M., Hilger, H.H. 2001. The gametophyte-sporophyte junction: unequivocal hints for two evolutionary lines of archegoniate land plants. - Flora 196: 431-445.
Frey, W., Hilger, H.H., Hofmann, M. 1996. Water-conducting cells of extant Symphyogyna-type Metzgerialean taxa: ultrastructure and phylogenetic implications. - Nova Hedwigia 63: 471-481.
Frey, W. 1981. Morphologie und Anatomie der Laubmoose. - In: W. Schultze-Motel (ed.): Adv. Bryol. 1: 399-477.
Frey, W. 1977. Neue Vorstellungen über die Verwandtschaftsgruppen und die Stammesgeschichte der Laubmoose. - In: Frey, W., Hurka, H., Oberwinkler, F. (Hrsg.): Beiträge zur Biologie der niederen Pflanzen, s. 117-139. Stuttgart.
Frey, W. 1970. Blattentwicklung bei Laubmoosen. - Nova Hedwigia 20: 463-556.

Vegetation of South West Asia (Near and Middle East)

• In the context of Special Research Division TAVO (1974–1985). Acquiring of the 18 vegetation maps of “Tübingen Atlas of Near and Middle East”. Publication of several papers on the vegetation of the area.
• Implementation of several accompanying research projects [e.g., Fenan, Dur Katlimmu (environment reconstruction) or on desert bryophytes].
• Establishment of a herbarium with ca. 20.000 specimens (now in Herbarium Tubingense, TUB).

Selected publications:

Frey, W., Kürschner, H. 1989. Vorderer Orient. Vegetation/Near and Middle East. Vegetation. 1:8 000 000. - Karte/map A VI 1 Tübinger Atlas Vorderer Orient. Wiesbaden.
Frey, W., Kürschner, H. 1989. Die Vegetation im Vorderen Orient. Erläuterungen zur Karte A VI 1 Vorderer Orient. Vegetation 1:8 Mill. des Tübinger Atlas des Vorderen Orients. - Beih. Tübinger Atlas Vorderer Orient, Reihe A (Naturwiss.), Nr. 30, 92 pp. Wiesbaden.
Baierle, H.U., Frey, W. 1986. A vegetational transect through Central Saudi Arabia (at-Ta'if - ar-Riyad). - In: Kürschner, H. (ed.): Contributions to the vegetation of Southwest Asia. - Beih. Tübinger Atlas Vorderer Orient, Reihe A (Naturwiss.), Nr. 24: 111-136. Wiesbaden.

Frey, W., Probst, W. 1986. A synopsis of the vegetation of Iran. - In: Kürschner, H. (ed.): Contributions to the vegetation of Southwest Asia. - Beih. Tübinger Atlas Vorderer Orient, Reihe A (Naturwiss.), Nr. 24: 9-43. Wiesbaden.
Frey, W., Kürschner, H., Probst, W. 1985. Südkaspisches Tiefland und Elburzgebirge (Iran). Vegetation. / Southern Caspian lowlands and Elburz Mountains. Vegetation. 1:500000. - Karte/map A VI 5 Tübinger Atlas Vorderer Orient. Wiesbaden.
Frey, W., Probst, W. 1978. Vegetation und Flora des Zentralen Hindukuš (Afghanistan). - Beih. Tübinger Atlas Vorderer Orient, Reihe A (Naturwiss.), Nr. 3, 126 pp. Wiesbaden.
Breckle, S.-W., Frey, W. 1974. Die Vegetationsstufen im Zentralen Hindukusch. - Afghanistan J. 1: 75-80.

Engel, T., Frey, W. 1996. Fuel resources for copper smelting in antiquity in selected woodlands in the Edom highlands to the Wadi Arabah/Jordan. - Flora 191: 29-39.
Baierle, H.U., Frey, W., Jagiella, C., Kürschner, H. 1989. Die Brennstoffressourcen im Raum Fenan (Wadi Araba, Jordanien) und die bei der Kupfererzverhüttung verwendeten Brennstoffe. - Archäometallurgie der Alten Welt. - Der Anschnitt. Zeitschrift für Kunst und Kultur im Bergbau, Beih. 7: 213-222. Bochum.
Ergenzinger, P.J., Frey, W., Kühne, H., Kürschner, H. 1988. The reconstruction of environment, irrigation and development of settlement on the Habur in North-East Syria. - In: Bintliff, J.L., Davidson, D.A., Grant, E.G. (eds.): Conceptional Issues in Environmental Archaeology, pp. 108-128. Edinburgh.

Kürschner, H., Frey, W. 2011. The Liverworts, Mosses and Hornworts of Southwest Asia (Marchantiophyta, Bryophyta, Anthocerotophyta). - Nova Hedwigia, Beih. 139: 1-240.
Frey, W., Kürschner, H. 1998. Wüstenmoose: Anpassungen und Überlebensstrategien im täglichen Kampf mit der Sonne. - Biologie in unserer Zeit 28: 231-240.
Frey, W., Kürschner, H. 1991. Conspectus Bryophytorum Orientalum et Arabicum. An annotated catalogue of the Bryophytes of Southwest Asia. - Bryoph. Bibl. 39: 1-181, Berlin, Stuttgart.
Frey, W., Herrnstadt, I., Kürschner, H. 1990. Verbreitung und Soziologie terrestrischer Bryophytengesellschaften in der Judäischen Wüste. - Phytocoenologia 19: 233-256.
Frey, W., Kürschner, H. 1988. Bryophytes of the Arabian Peninsula and Socotra. Floristics, phytogeography and definition of the Xerothermic Pangaean element. Studies in Arabian Bryophytes 12. - Nova Hedwigia 46: 37-120.
Frey, W., Probst, W. 1973. Die Polstermoosvegetation im Karadj-Tal (Elbursgebirge, Iran). - Bot. Jahrb. Syst. 93: 404-423.

• Comparative analysis of plant communities, life forms, life strategies and ecomorphological structures of trunk epiphytic bryophytes on Borneo (Mt Kinabalu), in Zaire/Rwanda (eastern border of the Kongo basin) and Peru (eastern Andean slopes).
• Corresponding adaptive trends (functional types) and evolutionary strategies in comparable elevation zones of tropical mountains.

Selected publications:

Kürschner, H., Frey, W., Parolly, G. 1999. Patterns and adaptive trends of life forms, life strategies and ecomorphological structures in tropical epiphytic bryophytes - a pantropical synopsis. - Nova Hedwigia 69: 73-99.
Frahm, J.-P., Frey, W., Kürschner, H., Menzel, M. 1991. Mosses and liverworts of Mt. Kinabalu. - Sabah Parks Publication, No. 12: 1-91. Kota Kinabalu.
Frey, W. (Hrsg.) 1987. Moosflora und -vegetation in Regenwäldern NO-Perus. Ergebnisse der Bryotrop-Expedition nach Peru 1982. - Nova Hedwigia, Beih. 88: 1-159. Stuttgart.
Frey, W., Kürschner, H. 1991. Lebensstrategien epiphytischer Bryophyten im tropischen Tieflands- und Bergregenwald am Mt. Kinabalu (Sabah, Nord-Borneo). - Nova Hedwigia 53: 307-330.

• Geomolecular divergence patterns of Gondwanan and Palaeoaustral bryophytes.
• The overwhelming richness of mosses in the South Hemispheric temperate rain forests (New Zealand, Tasmania, Patagonia/Chile) and the phylogeographic relationships of the species were the focus of this research project.

Selected publications:

Frey, W., Pfeiffer, T., Stech, M. 2010. Geomolecular divergence patterns of Gondwanan and Palaeoaustral bryophytes. - An overview. Studies in austral temperate rain forest bryophytes 34. - Nova Hedwigia 91: 317-348.
Villarreal, J.C., Frey, W., Cargill, D.C. 2010. Bryophyte biology, phylogeography, systematics and evolution in the Southern Hemisphere, A posthumous tribute volume in honour of Dr. Gabriela Hässel de Menéndez. - Nova Hedwigia 91: 279-532.
Stech, M., Pfeiffer, T., Frey, W. 2008. Phylogenetic relationships within Dendroligotrichum and Polytrichadelphus (Polytrichaceae, Polytrichopsida) in the Palaeoaustral region. Studies in austral temperate rain forest bryophytes 32. - Austr. Syst. Bot. 21: 39-49.
Schaumann, F., Frey, W., Pfeiffer, T., Stech, M. 2005. Molecular circumscription, intrafamilial relationships and biogeography of the Gondwanan liverwort family Pallaviciniaceae (Hepaticophytina, Bryophyta). Studies in austral temperate rain forest bryophytes 27. - Pl. Syst. Evol. 252: 27-48.
Schaumann, F., Frey, W., Hässel de Menendez, G.G., Pfeiffer, T. 2003. Geomolecular divergence in the Gondwanan dendroid Symphyogyna complex (Pallaviciniaceae, Hepaticophytina, Bryophyta). Studies in austral temperate rain forest bryophytes 22. - Flora 198: 404–412.
Pfeiffer, T., Kruijer, H., Frey, W., Stech, M. 2000. Systematics of the Hypopterygium tamarisci complex (Hypopterygiaceae, Bryopsida): Implications of molecular and morphological data. Studies in austral temperate rain forest bryophytes 9. - J. Hattori Bot. Lab. 89: 55-70.
Frey, W., Stech, M., Meissner, K. 1999. Chloroplast DNA-relationship in palaeoaustral Lopidium concinnum (Hypopterygiaceae, Musci). An example of stenoevolution in mosses. Studies in austral temperate rain forest bryophytes 2. - Pl. Syst. Evol. 218: 67-75.

Life strategies, clonal reproduction, asexual multiplication, habitat colonization and habitat maintenance

• Life strategies. Common adaptive traits (functional types) acquired by parallel character differentiation and evolution. Functional characterization of species and plant communities.
• Clonal reproduction and consistent asexual multiplication are basic principles of exhaustive habitat colonization (patches) by species as well as habitat maintenance (e.g., ground covering species of Central European forests).
• Molecular techniques allow to reveal the evidence of genets (clones) after asexual multiplication in nature [e.g., Rhytidium rugosum (Rhytidiaceae, pleurocarpous moss) and Tussilago farfara (Asteraceae)].

Selected publications:

Frey, W., Lösch, R. 2010. Geobotanik. 3. Aufl., 616 S. - Spektrum Akad. Verlag, Heidelberg.
Pfeiffer, T., Günzel, G., Frey, W. 2008. Clonal reproduction, vegetative multiplication and habitat colonisation in Tussilago farfara (Asteraceae): A combined morpho-ecological and molecular study. - Flora 203: 281-291.

Pfeiffer, T., Fritz, S., Stech, M., Frey, W. 2006. Vegetative reproduction and clonal diversity in Rhytidium rugosum (Rhytidiaceae, Bryopsida) inferred by morpho-anatomical and molecular analyses. - J. Plant. Res. 119: 125-135.
Frey, W. 2000. Life strategies as a basis for functional characterization of plant species and plant communities: a case study. - Z. Ökologie u. Naturschutz 9: 35-41.
Frey, W., Hensen, I. 1995. Lebensstrategien bei Pflanzen: ein Klassifizierungsvorschlag. - Bot. Jahrb. Syst. 117: 187-209.
Frey, W., Hensen, I., Heinken, T. 2001. Life strategies in the xerothermous vegetation complex of the lower Unstrut valley (Saxony-Anhalt, Germany). - Feddes Repert. 112: 87-105.
Frey, W., Kürschner, H. 1991. Lebensstrategien von terrestrischen Bryophyten in der Judäischen Wüste. - Bot. Acta 104: 172-182.
Frey, W., Kürschner, H. 1991. Lebensstrategien epiphytischer Bryophyten im tropischen Tieflands- und Bergregenwald am Mt. Kinabalu (Sabah, Nord-Borneo). - Nova Hedwigia 53: 307-330.

Since 2007 the main research and scientific work was on the textbook of Geobotany and editing the 13. edition of the „Syllabus of Plant Families“, the classical Engler’schen Syllabus der Pflanzenfamlien“ (5 Parts).

Publication of more than 220 papers (compilation in Nova Hedwigia, Beih. 131: IX–XVIII, 2007. up to 2006). Charged with 14 dissertations, 75 diploma works, 27 state works and 5 habilitations.

Afghanistan (1965, 1974: Central Hindu Kusch), Iran (1969, 1972, 1975, 1976, 1977; Alborz Mountains, NE-Khorasan, Zagros, Maharlu-Lake (Shiraz), Coastal regions of the Persian-Arabian Gulf, Queshm), Türkei 1978, 1986; Tuz Gölü, Aladaglari, South Türkei), Israel, Palästina (1978, 1980, 1988, 1989, 1994; Judaen Desert, Arava, Negev), Jordan (1980, 1986, 1990, 1993; Azraq, Arava, Fenan, Edom), Saudi Arabia (1981, 1982, 1984, 1985, 1988; Asir, centr. Saudi Arabia, Thumama NP, Riyadh-Najran-Gizan, Hejaz, Jabal Tuwayq), Oman (1983; Muscat, Qurm NR), Syria (1983; Tell Schech Hamad, centr. Syria), Malaysia (1986; Malaysia, Sabah (Borneo), Zaire/Dem. Rep. Kongo, Rwanda (1991; Kivu), New Zealand (1992, 1994, 1998; North and South Island), Tasmania (1994), Chile (1995, 2001, 2003; South Chile, Patagonia, Tierra del Fuego), Madeira (2004, 2005, 2006, 2007; Laurisilva, coastal regions).