Russian Journal of Biological Invasions

2012, issue № 3

CONTENTS

Species pool, species richness, density compensation and invisibility of natural plant communities - Akatov V.V., Akatova T.V. - The published data on resistance of plant communities to invasions are discussed. It is shown that variation in saturation with alien species on small areas of communities depends on the ratio: species richness - species pool. This ratio was used for estimation of the invasibility potential of the Western Caucasian natural plant communities (alpine heaths and low-grass meadows, subalpine middle-grass meadows on isolated by forest communities and not isolated high mountain ranges, tree layer of plain and mountain forests). The results show that the higher invasiveness potential is characteristic for communities with high species richness, and isolated, evolutionary young and broken in the historical past communities.

Invasive species in Lake Kenon (Zabaikalsky region) - Bazarova B.B., Gorlacheva E.P., Matafonov P.V. - This paper reviews the invasive species of Lake Kenon, which is used as a water reservoir-cooler of the Chita TPP-1. During the period from 1919 to 2011 it was revealed 11 alien species of aquatic organisms in the lake. In 2009, the Gnathopogon mantschuricus, and hydrophyte Elodea canadensis Mich. were recorded for the first time.

Bullhead Cottus gobio L. invasion in Utsjoki River (Northern Finland): parasitological aspects - Ieshko E.P., Shulman B.S., Lebedeva D.I., Barskaja Yu.Yu., Niemela E. - The first specimens of bullhead (Cottus gobio L.) were found in the Ustjoki River (the Teno River tributary) in 1979. The fish had distributed widely in the lake-river system during next years. The bullhead parasite fauna was studied in 1993 and 2007. Parasite species composition had not changed much during this period, only Diplostomum and Apatemon metacercaria invasion was increased.

On the whole, characteristics of occurrence and number distribution of plerocercoids Schistocephalus solidus in the population of bullhead did not changed. The observed increase in juvenile Atlantic salmon infection by trematoda Apatemon gracilis can be considered as the negative effects of bullhead invasion in the region.

Revelation of Echinococcus multilocularis (Leuckart 1856) in the muskrat (Ondatra zibethicus) of the delta of the Selenga River (Russia) - Masur O.E., Fomina A.S. - In the livers of muskrats from the delta of the River Selenga (Buryatiya Republic, Russia), metacestoda Echinococcus multilocularis (Leuckart, 1858) has been found for the first time. It is established that muskrat, as alien species in new ecosystems, takes part as an intermediate host in parasitic system of E. multilocularis. Alveolar hydatid disease was found in 4.4% of the animals.

Modeling of Eurasian beaver (Castor fiber L.) population dynamics in the basin of the small tributary of the Oka River, the Tadenka (Prioksko-terrasny nature biosphere reserve) - Petrosyan V.G., Golubkov V.V., Goryainova Z.I., Zavyalov N.A., Albov S.A., Khlyap L.A., Dgebudze Yu.Yu. - The parametric discrete (in time) model of the beaver population dynamics from the invasion (1948) to the present day (2011) in the Tadenka River basin is presented. It is shown that the dynamics of the population size tends to a steady state with quasi-periodic component of 14 to 26 years. The population model shows that the periodic component has a sawtooth form, with the number of beavers increasing from minimum to maximum for every 6 years, and reducing from maximum to minimum value for the rest of the period. The oscillation amplitude of the quasi-periodic component is about 6 beavers and has a slight tendency to increase. We assume that the further development of the beaver population will depend on many random events that contribute to the change in the beaver regulatory factors, such as geomorphologic features of the area, recovery rate of feed resources in abandoned habitats, the extent and rate of development of beaver settlements. Stability analysis of stationary solutions and the assessment of model adequacy suggest that the proposed discrete model can be used for quantitatively assessment of the dynamics of beaver populations on other territories depending on the food resources availability.

Increasing of Mediterranean non-native species findings in the Black Sea - Shiganova T.A., Musaeva E.I., Lukasheva T.A., Stupnikova A.N. , Zasko D.N., Anokhina L.L., Sivkovich A.E., Gagarin V.I., Bulgakova Yu.V. - We summarize own and published data on the Mediterranean species records in the Black Sea. Number of similar species findings has increased both in the southern Black Sea, where some of them always occurred, and in the other areas of the Black Sea due to a rise of the water surface layer temperature and increasing of shipping intensity during the last decades. Vectors of penetrations, possibility of establishment, and role in ecosystem are discussing.