DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 3-4/2015 str. 50     <-- 50 -->        PDF

Results
Rezultati
Classification – Klasifikacija
Cluster analysis clearly differentiated three groups of relevés (Figure 2). Cluster A consists of 20 relevés dominated by Acer negundo, while cluster B includes 11 relevés dominated by Fraxinus pennsylvanica. The third cluster (C) consists of four relevés and represents the stands of the ass. Sambuco nigrae–Aceretum negundo from Austria. Although Acer negundo is dominant species in this association, its relevés are separated and allocated from those of cluster A and B. In the relevé 34, Prunus spinosa L. is a dominant species, hence this relevé is singled out and has no relevance in characterization of described invasive forest communities.
From a total of 107 taxa that are present in clusters A and B, 50 appears only in cluster A, and 27 only in cluster B, while 30 species are common for both groups. The most common and abundant species in both analyzed groups are: Acer negundo, Rubus caesius L., Fraxinus pennsylvanica, Urtica dioica L., Symphytum officinale L., Aristolochia clematitis L. and Iris pseudacorus L.
Based on the results of the cluster analysis and also the analysis of the dominant and diagnostic species, we consider the first two groups (clusters A and B) specific and different enough, to be defined as associations.
Syntaxonomical treatment – Sintaksonomska interpretacija
Ass. Rubo caesii–Aceretum negundi ass. nova hoc loco (Holotypus Table 1, reléve 6, Figure 3)
Dominant species: Acer negundo L.(1 – 4) (Ic = 66.67) and Rubus caesius L.(+ – 3) (Ic = 37.22)
Diagnostic species: Fraxinus angustifolia Vahl. subsp. oxycarpa (Bieb ex Willd) Franco & Rocha Afonso (Φ = 0.48), Dactylis glomerata L. (Φ = 0.44).
Diagnosis: Ass. Rubo caesii–Aceretum negundi is developed on marshy, gley (eugley), hypogley, saline soils, on altitudes between 73 – 78 m on a flat surface, rarely on small slopes (up to 10°). Individuals of the dominant species Acer negundo are predominantly present in the canopy layer, up to 15 m high, and also in the shrub and herb layers. Total cover in different stands of this association is 30 – 100 % (average 69.5 %). Total of 80 taxa are present in all 20 relevés, average number of species per relevé is 13. Since the dominant and nominal species Acer negundo, is invasive, the association has an invasive character itself. The fact that individuals of this species are present in shrub and herb layers, indicate that this community is in progradation, and the final stage will, most probably, result in the development of the monodominant forest. The other invasive species also present in this association are: Bidens frondosa L., Echinocystis lobata (Michx) Torrey & A. Gray, Fraxinus pennsylvanica and Gleditsia triacanthos L.
Ass. Carici otrubae–Fraxinetum pennsylvanicae ass. nova hoc loco (Holotypus Table 2, reléve 8, Figure 4)
Dominant species: Fraxinus pennsylvanica Marshall(3 - 4) (Ic = 82.83) and Carex otrubae Podp.(r - 2) (Ic = 27.27)
Diagnostic species: Carex otrubae (Φ = 0.73), Lycopus europaeus (Φ = 0.66), Glyceria maxima (Hartman) Holmberg