Physconio detersae–Phaeophyscion hirtuosae — the new alliance of epiphytic vegetation at Sakhalin Island
Authors: Kaganov V. V. , Korznikov K. A. , Ezhkin A. K. 
Published: December 2024

The paper presents the classification results for moss and lichen communities (synusiae) on the bark of living trees Populus suaveolens Fisch. in the southern part of Sakhalin Isl. The P. suaveolens was selected for study as a phorophyte species due to large trunk size and the high species diversity of epiphytes (Kaganov, Koroteeva, 2022), which provided the basis to trace the gradient of man impact since poplars are being actively used in settlement greening as well grow in natural riparian forests (Korznikov, Popova, 2018). Due to wide range of P. suaveolens our study opens perspectives for syntaxonomic generalizations in broader geographical comparison.

We sampled 110 relevés (0.16 m2, each consisting of a set of 4 vertical rectangle subplots 0.1×0.4 m faced to north, east, south, and west on a single tree) in urban parks and gardening, artificial forest stands on the periphery of an urbane zone, and natural riparian forests. The modified TWINSPAN algorithm (Roleček et al., 2009) from the JUICE 7.1.101 (Tichý, 2002) was used for relevé sorting. New syntaxa (Braun-Blanquet approach) were described based on TWINSPAN clustering according to the 4th edition of the International Code of Phytosociological Nomenclature (Theurillat et al., 2021).

Lecanoro pachycheilae–Collemetum furfuracei ass. nov. Holotypus: relevé 19 in Table 1; 27.10.2017; 46.9675° N 142.80194° E; natural riparian forest in the valley of the Rogatka River, V. V. Kaganov, A. K. Ezhkin.

Diagnostic combination: Bacidia sachalinensis, Buellia disciformis, B. erubescens, Caloplaca tarani, Collema furfuraceum, Eopyrenula intermedia, Heterodermia speciosa, Kurokawia isidiata, Lecanora allophana, L. pachycheila, Lecanora sp., Lepra amara, Lepraria incana, Leptogium burnetiae, L. cyanescens, Mikhtomia gordejevii, Opeltia flavorubescens, Pertusaria pertusa, Pylaisia condensata.

Ecology: subnitrophilous communities of mosses and lichens on Populus suaveolens bark in natural riparian forests or semi-natural forest stands.

Geographic distribution: southern part of Sakhalin Isl.

Lecanoro pachycheilae–Collemetum furfuracei typicum subass. nov. Holotypus: relevé 19 in Table 1.

Diagnostic combination: correspond with the association.

Ecology: subnitrophilous communities of mosses and lichens on Populus suaveolens bark in natural riparian forests.

Geographic distribution: correspond with the association.

Lecanoro pachycheilae–Collemetum furfuracei inops subass. nov. Holotypus: relevé 12 in Table 1; 17.11.2017; 47.02944° N 142.72194° E, forest stand in the riparian zone of the Rive Krasnoselskaya, urban zone of the Yuzhno-Sakhalinsk city, V. V. Kaganov, A. K. Ezhkin.

Diagnostic combination: absent.

Ecology: subnitrophilous communities of mosses and lichens on Populus suaveolens in artificial forest plantings on periphery of urban areas.

Geographic distribution: correspond with the association.

Physciello melanchrae–Candelarietum concoloris ass. nov. Holotypus: relevé 4 in Table 1; 01.10.2017; 46.93333° N 142.73333° E, Yuzhno-Sakhalinsk city, park area, V. V. Kaganov, A. K. Ezhkin.

Diagnostic combination: Candelaria concolor, Leskea polycarpa, Physciella melanchra.

Ecology: nitrophilous communities of mosses and lichens on Populus suaveolens bark in urban gardening.

Geographic distribution: settlements in the southern part of Sakhalin Isl.

Physconio detersae–Phaeophyscion hirtuosae all. nov. Holotypus: ass. Lecanoro pachycheilae–Collemetum furfuracei; this paper.

Diagnostic combination: Lewinskya sordidum, Mikhtomia gordejevii, Phaeophyscia hirtuosa, Physconia detersa, P. grumosa, P. kurokawae, Pylaisia condensata, P. polyantha.

Ecology: nitrophilous epiphyte communities and semi-nitrophilous epiphyte communities of mosses and lichens on tree bark in natural riparian forests, artificial plantings, and urban gardening.

Geographic distribution: southern part of Sakhalin Isl.

The new alliance is placed into the order Physcietalia Hadač in Klika et Hadač 1944 of the class Physcietea Tomaselli et De Micheli 1952 (Mucina et al., 2016):

The classification solutions proposed are well suited to the change in the composition of epiphytic communities on the gradient of the man impact increasing, from the natural habitats of Populus suaveolens in riparian forests to artificial plantings in the urban environment. Ass. Physciello melanchrae–Candelarietum concoloris unites epiphyte communities in the urban artificial plantings (parks, squares, alleys, street, yard landscaping) while the ass. Lecanoro pachycheilae–Collemetum furfuraecei does this outside of urbanized areas. The distribution of the subass. L. p.–C. f. typicum is limited to natural forests and the subass. L. p.–C. f. inops to semi-natural habitats — large forest parks or artificial forest plantings on the urbanized area periphery.