prilagođeno pretraživanje po punom tekstu

ŠUMARSKI LIST 5-6/2014 str. 9     <-- 9 -->        PDF

Šumska vegetacija tektonskih udolina Pihlja i Vitra iznad Vinodola (Liburnijski krš, sjeverozapadna Hrvatska)
Forest vegetation of tectonic dolines Pihlja and Vitra above the Vinodol valley (Liburnian karst, NW Croatia)
Boštjan Surina
We studied floristic composition, structure and topology of forest stands in tectonic dolines Pihlja and Vitra above Vinodol valley (Liburnian karst, NW Adriatic). Floristically and structurally homogenous stands represent zonal forests of the association Aristolochio luteae-Quercetum pubescentis (=Ostryo carpinifoliae-Quercetum pubescentis, Ostryo-Carpinion orientalis) and cover 1,75 and 2,73 ha, each (85 and 70 % of tectonic dolines, respectively). Preliminary multivariate analyses revealed several incongruences in current synsystematics and forest topology within the alliance Ostryo-Carpinion orientalis and raised a need for a thorough revision. Unsettled synsystematics makes addressing the forest vegetation zonation of the area uncertain. We assume that various stands with Carpinus orientalis in northwestern Adriatic represent only secondary succession stages in several thermophytic vegetation types. Studied forests in tectonic dolines Pihlja and Vitra represent well preserved stands without any visible traces of wood cutting and are valuable in giving insights into patterns, processes and dynamics of northern-Adriatic vegetation. As such they are in need of a special protection.
Key words: Aristolochio luteae-Quercetum pubescentis, Liburnian karst, NW Adriatic, Ostryo-Carpinion orientalis, phytosociology, tectonic dolines, zonal vegetation, Vinodol valley
Increasing complexity of topographic, climatic and geological conditions of any given area results in higher degrees of biodiversity and rapid species turnover even on a smaller scale. However, along ecological gradients on various geographic scales, three types of natural vegetation generally develop in equilibrium with biotic, climatic and edaphic factors (e.g. Walter 1954; Dierschke 1994; Kovar-Eder and Kvaček 2007). Zonal (climax) vegetation (a), developed on a large-scale and more distinctly influenced by overall climatic rather than edaphic factors; for example: in the Liburnian karst (NW Dinaric Alps), Dinaric fir-beech stands (Omphalodo-Fagetum) are considered to represent a climax vegetation type forming a forest belt between 600 – 1300 m (e.g. Tregubov 1957; Puncer 1980; Vukelić 2012; Surina and Dakskobler 2013). Due to more extreme climatic conditions, usually at the geographic limits of their distribution areas, vegetation types may react with altitudinal shifts (e.g., from lower to higher elevation) and occupy areas with conditions atypical for the zone. Nice examples are stands of holm oak (Quercetum ilicis s.l.) in Northern (Trotter 1927; Mayer 1963; Poldini 1982; Poldini and Lasen 1989; Buffa et al. 1993) and Central Italy (Corbetta and Pirone 1992) and Slovenia (Dakskobler 1997), where they constitute the (b)