376
I.M. Munda
was dominated by fucoids. This is still the case in undisturbed sites,
distant from sources of pollution, where representatives of the
polymorphic genus Cystoseira colonize the grater part of the sublittoral
slopes and occupy a similar level (niche) as Laminarians from the Atlantic
coasts. In the lower sublittoral, Sargassum species were rather common
(Ercegovic 1952; Span 1972). In the eulittoral, the endemic fucoid Fucus
virsoides is common in the northern Adriatic (Zavodnik 1967; Munda
1972). It extends, however, as far south as to Dubrovnik, but is most
abundant in the northern regions. The northern Adriatic flora and
vegetation were investigated by us in the Gulf of Trieste, around Piran,
along the Istrian coast and on some islands in the Gulf of Quarnero.
Earlier, extensive floristic and vegetational data for the area around
Rovinj refer to unpublished diaries of P.Kuckuck and are based on his
field studies in the area between 1884 and 1901. Older published data for
the Adriatic are available in the classical works of Hauck (1885) and
Lorenz (1863), in the extensive compilatory contribution of Vatova
(1928) as well as in the works of Techet (1906), Schiller (1914), Vouk
(1914), Schiffner (1916), Schiffner and Vatova (1938), and some others.
More recent data dealing with a rather undisturbed flora and vegetation
refer to the surroudings of Rovinj (Munda 1972, 1973, 1975, 1979), the
Quarner region (Rizzi-Longo 1972) and the coast below Velebit (Zalokar
1942). Algal associations at Piran were studied by Vukovic (1980).
A complete floristic list for the Adriatic as a whole was published by
Giaccone (1978) and is based on different records through the last decades.
In undisturbed sites of the northern Adriatic, the level of the littoral
fringe is usually populated by Catenella caespitosa, which occurs in
patches. The most characteristic feature is, however, the Fucus virsoides
association (Zavodnik 1967; Munda 1972) which is prolific in moderately
exposed habitats. The Fucus settlements are less dense in exposed sites.
Their biomass varied between approximately 2000 g m -2 under optimum
conditions, and 200 g m -2 under conditions of strong exposure (Munda
1972, 1973, 1990).
In some highly exposed habitats Fucus settlements are replaced by
either Cystoseira compressa or C. adriatica. The floristic diversity within
these high-level Fucacean associations decreases with increasing exposure of the habitats, but is in all cases highest in spring, due to the
admixture of several seasonal floristic elements belonging to the genera
Ceramium, Callithamnion, Griffithsia, Champia, Chylocladia, Antithamnion, Polysiphonia, and Ectocarpus.
Cladophora dalmatica is common in spring, in both the epiphytic
cover of Fucus and in small eulittoral depressions. In the understorey
of the high-level Fucacean associations, several crustose floristic elements are common (Phymatolithon lenormandii, P. Polymorphum,
I.M. Munda
was dominated by fucoids. This is still the case in undisturbed sites,
distant from sources of pollution, where representatives of the
polymorphic genus Cystoseira colonize the grater part of the sublittoral
slopes and occupy a similar level (niche) as Laminarians from the Atlantic
coasts. In the lower sublittoral, Sargassum species were rather common
(Ercegovic 1952; Span 1972). In the eulittoral, the endemic fucoid Fucus
virsoides is common in the northern Adriatic (Zavodnik 1967; Munda
1972). It extends, however, as far south as to Dubrovnik, but is most
abundant in the northern regions. The northern Adriatic flora and
vegetation were investigated by us in the Gulf of Trieste, around Piran,
along the Istrian coast and on some islands in the Gulf of Quarnero.
Earlier, extensive floristic and vegetational data for the area around
Rovinj refer to unpublished diaries of P.Kuckuck and are based on his
field studies in the area between 1884 and 1901. Older published data for
the Adriatic are available in the classical works of Hauck (1885) and
Lorenz (1863), in the extensive compilatory contribution of Vatova
(1928) as well as in the works of Techet (1906), Schiller (1914), Vouk
(1914), Schiffner (1916), Schiffner and Vatova (1938), and some others.
More recent data dealing with a rather undisturbed flora and vegetation
refer to the surroudings of Rovinj (Munda 1972, 1973, 1975, 1979), the
Quarner region (Rizzi-Longo 1972) and the coast below Velebit (Zalokar
1942). Algal associations at Piran were studied by Vukovic (1980).
A complete floristic list for the Adriatic as a whole was published by
Giaccone (1978) and is based on different records through the last decades.
In undisturbed sites of the northern Adriatic, the level of the littoral
fringe is usually populated by Catenella caespitosa, which occurs in
patches. The most characteristic feature is, however, the Fucus virsoides
association (Zavodnik 1967; Munda 1972) which is prolific in moderately
exposed habitats. The Fucus settlements are less dense in exposed sites.
Their biomass varied between approximately 2000 g m -2 under optimum
conditions, and 200 g m -2 under conditions of strong exposure (Munda
1972, 1973, 1990).
In some highly exposed habitats Fucus settlements are replaced by
either Cystoseira compressa or C. adriatica. The floristic diversity within
these high-level Fucacean associations decreases with increasing exposure of the habitats, but is in all cases highest in spring, due to the
admixture of several seasonal floristic elements belonging to the genera
Ceramium, Callithamnion, Griffithsia, Champia, Chylocladia, Antithamnion, Polysiphonia, and Ectocarpus.
Cladophora dalmatica is common in spring, in both the epiphytic
cover of Fucus and in small eulittoral depressions. In the understorey
of the high-level Fucacean associations, several crustose floristic elements are common (Phymatolithon lenormandii, P. Polymorphum,