Exsertotheca crispa, (Hedw.) S. Olsson, Enroth & D. Quandt (Hedw.)

Alataş, Mevlüt, Ezer, Tülay, Erata, Hüseyin, Batan, Nevzat & Ursavaş, Serhat, 2023, The Epiphytic Bryophyte Vegetation of Buxus sempervirens L. forests in the Fırtına Valley (Rize, Turkey), Cryptogamie, Bryologie 20 (5), pp. 123-132 : 127-130

Exsertotheco crispae - Allenielletum besseri ass. nov. typicum Alataş, Ezer, Batan & Erata, subass. nov.

( Table 3A )

HOLOTYPE. — Turkey. Rize Province, Fırtına Valley, 1026 m, Buxus sempervirens forest .

NOMENCLATURAL TYPE. — Table 3A , relevé no. 13, holotype.

CHARACTERISTIC SPECIES. — Exsertotheca crispa , Alleniella besseri .

COMMENTS

The new typical subassociation is represented by a total of seven relevés from tree trunks. It occurs from 956 to 1061 m, and is mainly found on the central parts of trunks of Buxus sempervirens in the northern part of the study area. While the general bryophyte coverage varies between 83% and 97%, the canopy cover, in the forest where it was found, was 100%. The average number of taxa within the community varies from five to ten. The subassociation consists of a total of 18 taxa. Of these, two are liverworts and 16 are mosses. Fifteen of the mosses are pleurocarpous and one is acrocarpous.

Within the relevés, the mesophylous Exsertotheca crispa , with a constancy of 100%, together with the mesophylous Alleniella besseri , with a constancy of 71%, are the main characteristics of the association and the taxa with the highest frequency. Both characteristic species grow on tree trunks and on rock surfaces, especially in humid and semi-neutral shaded habitats ( Dierssen 2001).

There are class, order and alliance characteristic species such as Alleniella complanata , Anomodon attenuatus (Hedw.) Huebener , A. viticulosus (Hedw.) Hook. & Taylor , Homalia trichomanoides , Isothecium alopecuroides (Lam. ex Dubois) Isov. , Pseudoamblystegium subtile (Hedw.) Vanderp. & Hedenäs , Pterigynandrum filiforme Hedw. , Radula complanata (L.) Dumort. and Sciuro-hypnum flotowianum (Sendtn.) Ignatov & Huttunen in Exsertotheco crispae - Allenielletum besseri . Therefore, the new association was synhierarchically classified in the Neckeretea complanatae, Neckeretalia complanatae, and Neckerion complanatae ( Table 3A ).

Exsertotheco crispae -Allenielletum besseri leucodontetosum sciuroidis Alataş, Ezer, Batan & Erata, subass. nov.

( Table 3B )

HOLOTYPE. — Turkey. Rize Province, Fırtına Valley, 1061 m, Buxus sempervirens forest .

NOMENCLATURAL TYPE. — Table 3B , relevé no. 9, holotype.

CHARACTERISTIC SPECIES. — Leucodon sciuroides .

COMMENTS

Exsertotheco crispae -Allenielletum besseri leucodontetosum sciuroidis is represented by a total of 10 relevés collected mostly from the middle parts of the trunks, at an altitude between 1061 and 1275 m. The coverage of bryophytes within the subassociation varies between 88% and 99%, while the canopy cover varies between 80% and 100%.

The community includes a total 22 taxa, of which 17 are mosses and five are liverworts. Pleurocarpous mosses are especially dominant. The average taxa number within this sub-association is nine. The high number of pleurocarpous and liverworts indicates that the community develops in more humid conditions than the sub-association typicum. Moreover, the low number of acrocarpous members indicates that the habitats are moist and shaded ( Kürschner 2004).

The mesophylous-xerophylous Leucodon sciuroides (Hedw.) Schwägr. distinguished the sub-association from the Exsertotheco crispae -Allenielletum besseri subass. typicum. It has the highest frequency, and its constancy is 90% within the relevés ( Table 3B ). The large pleurocarpous moss Leucodon sciuroides grows on tree trunks and on rock surfaces. It also prefers acidic and semi-arid open habitats ( Dierssen 2001).

As the typical sub-association, the leucodontetosum sciuroidis sub-association contains the characteristic species of Neckeretea complanatae, Neckeretalia complanatae, and Neckerion complanatae ( Table 3B ).

The large pleurocarpous moss Palamocladium euchloron , endemic to the forests of the Black Sea and Caspian Sea coasts ( Hofmann 1997), distinguished Alleniello besseri - Palamocladietumeuchloronis from Exsertothecocrispae -Allenielletum besseri . Palamocladium euchloron , the characteristic species of the new association, shows basiphytic and mesophylous affinities ( Dierssen 2001). While Alleniello besseri -Palamocladietum euchloronis was found on the north and northeast aspects of the trunks of relatively young boxwood trees (the maximum tree trunk circumference was 0.45 m), Exsertotheco crispae - Allenielletum besseri was mostly found on the northern aspect of the trunks of relatively middle-aged and old boxwood trees (the maximum tree trunk circumference was 0.70 m). Therefore, although both syntaxa are similar to each other in terms of floristic composition, Alleniello besseri -Palamocladietum euchloronis was described as a separate association in the present study due to both the presence of the characteristic species P. euchloron and its preference for relatively young boxwood trees.

The high number of pleurocarpous mosses and liverworts within Exsertotheco crispae -Allenielletum besseri leucodontetosum sciuroidis indicated that it developed in more humid conditions than in the subass. typicum. Moreover, the frequency and constancy of the large pleurocarpous and strong competitor moss Leucodon sciuroides within the sub-association distinguished it from the Exsertotheco crispae -Allenielletum besseri typicum. In addition, Exsertotheco crispae -Allenielletum besseri typicum is floristically similar to Neckeretum crispae (Kaiser, 1926) Herzog & Höffler, 1944 (syntaxa: Anomodonto viticulosi -Leucodontetum sciuroidis Wisniewski, 1930) determined from the trunks of the Buxus sempervirens trees in Mount Musa (southern Turkey) by Ezer (2008). Hovewer, Exsertotheco crispae -Allenielletum besseri is more sciophytic than Neckeretum crispae, and grows in more humid environments.