Yu. V. Nabivailo, A. V. Skriptsova, E. A. Titlyanov - The interspecific relationships of seaweeds and their role in the formation of communities of Ahnfeltia tobuchiensis (Kanno et Matsubara, 1932) Makienko, 1970 (Rhodophyta)

BIOLOGIYA MORYA, 2014, Vol. 40, No. 5, pp. 353-363

The interspecific relationships of seaweeds and their role in the formation of communities of Ahnfeltia tobuchiensis (Kanno et Matsubara, 1932) Makienko, 1970 (Rhodophyta)

A.V. Zhirmunsky Institute of Marine Biology, Far East Branch, Russian Academy of Sciences, Vladivostok 690041

E-mail:

The character and intensity of interspecific relationships between common species of an Ahnfeltia bed community (Ahnfeltia tobuchiensis, Ahnfeltiopsis flabelliformis, Chondrus armatus, and Ptilota filicina) were investigated in relation to light levels and concentrations of dissolved inorganic nitrogen and phosphorus compounds. Growth and photosynthetic rates of seaweeds were measured in mono- and co-culture, as well as in the medium containing the metabolites of attendant species. Under low light conditions, A. tobuchiensis showed the highest competitive ability among the species studied. Experimental results indicated both negative (exploitation competition, allelopathic inhibition of production processes of a competitor) and positive (stimulation of growth and photosynthesis of attendant species) relationships between seaweeds. Increased nutrient concentrations and light levels resulted in a substantial reduction in the intensity of interspecific relationships. The dynamic system of positive and negative relationships may regulate the A. tobuchiensis community structure; the intensity of interspecific relationships depends on the availability of resources such as light and nutrients.

Key words: Ahnfeltia tobuchiensis, interspecific interactions, competition, allelopathy.