Phytosociological analysis of forest communities in the Vrbas River Canyon (Bosnia and Herzegovina)

Abstract

This study deals with the floristic and ecological diversity of the forest and scrub communities in the Vrbas River canyon. Vrbas is the river in the western part of the B&H with the main flow direction from the south to the north. In the mid parts of its flow, it cuts the relatively deep canyons and gorges through the limestone bedrock. Mainly steep slopes, soils of various depth, variety of expositions, human impact and influence of mild Submediterranean climate from the south have caused the diverse, but mainly thermophilous forest vegetation to develop. Around 100 relevés were collected in the field and analyzed by the classification and ordination methods. Preliminary results suggest the existence of thermophilous and calciphilous forest vegetation dominated by Quercus pubescens, Carpinus orientalis, Ostrya carpinifolia and Fraxinus ornus of the Carpinion orientalis and Fraxino orni-Ostryion. However, these habitats were often under negative anthropogenic influence, which resulted in degraded scrub, dominated mainly by Carpinus orientalis and Fraxinus ornus. At the bottom of the slopes, there are often scree and ravine forests of Ostryo-Tilion developed. At the higher elevations there are thermophilous beech forests of Aceri obtusati-Fagetum.

Full text

Phytosociological analysis of forest communities in the Vrbas River
Canyon (Bosnia and Herzegovina)
Ognjen Lukić1*, Vladimir Stupar1
1University of Banja Luka, Faculty of Forestry, Stepe Stepanovića 75A, 78000 Banja Luka, Bosnia and Herzegovina
*e-mail: ognjen_lukic1994@outlook.com
INTRODUCTION
Bosnia and Herzegovina is a country in southeastern Europe located on the Balkan Peninsula (Fig. 1).
Vrbas River is located in the western part of Bosnia and Herzegovina with the main flow direction from
the south to the north. The South of Banja Luka, Vrbas creates a fantastic canyon in which there is a series
of natural rarities. Rapids, waterfalls, cascades, beaches, surrounding rocks as well as the wealth of flora
and fauna make this area special (Fig. 2). Vegetation of the canyon is relict and was not explored into
detail until now. This study deals with the floristic and ecological diversity of the forest and scrub
communities in this area. In the mid parts of its flow, it cuts the relatively deep canyons and gorges
through the limestone bedrock. Mainly steep slopes, soils of various depth, variety of expositions, human
impact and influence of mild Submediterranean climate from the south have caused the diverse, but
mainly thermophilous forest vegetation to develop.
MATERIAL AND METHODS
RESULTSAND CONCLUSIONS
Total of 96 phytosociological relevés were made by the standard Braun-Blanquet’s method and stored into
TURBOVEG Database and imported to JUICE for the further analysis. We excluded mosses from the data
set before numerical analysis. Taxa recorded for more than one layer were merged into one layer because
of inconsistent sampling. Records of species determined to the genus level were deleted. Plant
nomenclature follows Euro+Med. Species from taxonomically critical groups that were not always
identified by the relevé authors were combined into aggregates (agg.).
The data set was subjected to numerical classification in PC-ORD using presence-absence data, Euclidean
distances and Ward’s method. We obtained nine clusters of relevés, which were ecologically and
floristically best interpretable (Fig. 3). Species ecological indicator values (EIVs) for temperature, light,
moisture, soil reaction and nutrients (Pignatti et al. 2005) were used as explanatory ecological variables
(Fig. 4). All 96 relevés, together with the EIVs, were projected onto a DCA plot (Fig. 5). Diagnostic
species were determined using phi coefficient in the JUICE.
Fig. 1. Location of Bosnia and Herzegovina in Europe and the Vrbas River.
Red dots represent localities of 96 relevés used in this study. Fig. 2. Summer aspect of the Vrbas River Canyon.
Fig. 3. Numerical classification yielded nine ecologically sound clusters of relevés
(vegetation types), which are presented in the dendrogram.
Fig. 4. Relevés ecological indicator values (EIVs) for temperature, light, moisture, soil raction and nutrients (Pignatti et al. 2005).
The floristic numerical analysis distinguished six known associations and three new communities
(constant species in every community are: Carpinus orientalis, Fraxinus ornus, Cornus mas, Cyclamen
purpurascens and Helleborus odorus):
2. Cruciato glabrae-Carpinetum orientalis
Secondary succession stage of the previous community
1. Cerex hallerianae-Quercetum pubescentis
Extrazonal forest of Oriental hornbeam and Downey oak
Fig. 5. DCA plot of 96 classified relevés of TDF with passively projected EIVs.
Diagnostic and constant species:
Sorbus torminalis
Rosa arvensis
Ligustrum vulgare
Crataegus monogyna
Brachypodium sylvaticum
Potentilla micrantha
Cruciata glabra
Glechoma hirsuta
Viola hirta
Diagnostic and constant species:
Quercus pubescens
Acer monspessulanum
Coronilla emerus
Crataegus monogyna
Euonymus verrucosus
Carex halleriana
Sesleria autumnalis
Viola hirta
Veronica chamaedrys
Glechoma hirsuta
3. Asplenium scolopendrium-Carpinus orientalis comm.
Degradation of Ostryo-Tilion community
Diagnostic and constant species:
Tilia tomentosa
Asplenium scolopendrium
Asplenium trichomanes
Veratrum nigrum
Veronica chamaedrys
Symphytum tuberosum
Peltaria alliacea
Saxifraga rotundifolia
Silene dioica
Carex digitata
Dactylis glomerata
Lathyrus venetus
Hepatica nobilis
4. Seslerio autumnalis-Ostryetum carpinifoliae
Syndinamicaly connected to thermophilous beech forests
Diagnostic and constant species:
Ostrya carpinifolia
Quercus pubescens
Sorbus aria/torminalis
Acer obtusatum
Coronilla emerus
Sesleria autumnalis
Veratrum nigrum
Lathyrus venetus
Viola hirta
Symphytum tuberosum
Carex digitata
5. Rusco aculeati-Ostryetum carpinifoliae
Ostrya carpinifolia forests on rocky slopes
Diagnostic and constant species:
Quercus petraea
Ostrya carpinifolia
Pyrus pyraster
Prunus avium
Acer campestre
Rosa arvensis
Crataegus monogyna
Festuca heterophylla
Tamus communis
Viburnum lantana
Cruciata glabra
6. Cotinus coggygria-Quercus pubescens comm.
Structurally degraded variant of C. hallerianae-Q. pubescentis
Diagnostic and constant species:
Quercus pubescens
Acer obtusatum
Cotinus coggygria
Ostrya carpinifolia
Crataegus monogyna
Viola hirta
Clinopodium vulgare
Asplenium ceterach
7. Aceri obtusati-Quercetum petraeae
Thermo-mesophilous forests of Quercus petraea
Diagnostic and constant species:
Quercus petraea
Acer obtusatum
Carpinus betulus
Sorbus torminalis
Rosa arvensis
Sanicula europaea
Symphytum tuberosum
Aposeris foetida
Anemone nemorosa
8. Lathyro nigri-Quercetum petraeae
Basophilous forests of Q. petraea and C. orientalis
Diagnostic and constant species:
Tilia tomentosa
Staphylea pinnata
Ulmus glabra
Acer obtusatum/campestre
Corylus avellana
Ruscus hypoglossum
Ilex aquifolium
Polystichum setiferum
Lathyrus vernus
Hedera helix
Asarum europaeum
9. Staphylea pinnata-Tilia tomentosa comm.
Ravine and scree forests of Tilia tomentasa in canyons
Diagnostic and constant species:
Ostrya carpinifolia
Euonymus verrucosus
Asplenium trichomanes
Clematis vitalba
Carex digitata
Sedum maximum
Aremonia agrimonioides
Potentilla micrantha
Melica nutans
Wrocław (Poland), 23-26 May 2018