Vol 9, No 2 (2018)

In 2016–2017, in the forests and parks of Kyiv, 22 points of spontaneous spread of selfsown plants of six species of Juglans L., namely, J. ailantifolia Carrière, J. cinerea L., J. mandshurica Maxim., J. nigra L., J. regia L., and J. subcordiformis Dode (Juglandaceae DC. ex Perleb), were found. In eight locations, 919 selfsown individuals and 45 maternal trees of these species were examined. Local populations are left-side in most cases; they have different spatial and ontogenetic structures and some of them contain young reproductive individuals. According to our data (abundance, size, and ontogenetic composition), the points of selfseeding spread are spontaneous self-reproducing populations. Schematic maps of distribution of Juglans species have been created. These results expand the concept of naturalization of representatives of the genus Juglans in urban forests and parks. The collected factual information and maps can serve as the basis for a strategy of monitoring the invasions of exotic trees.

The genetic diversity of the first Baltic population of the bivalve mollusk Rangia cuneata (G.B. Sowerby I, 1831) is studied on the basis of mtDNA COI gene sequences. It is shown that a single population of this alien species with a high level of genetic diversity inhabits the whole Vistula Lagoon. It is assumed that common rangia penetrated to the Vistula Lagoon at the larval stage with ballast waters. The first European R. cuneata population from the North Sea is regarded as the most probable source of introduction. Information on the genetic diversity of population of introduced species may be useful for forecasting of further ways of dispersal of the species.

The invasion of the European mink Mustela lutreola in Omsk oblast continued about 100 years; it was reported for the first time in 1886 and last in 1984. Changes in numbers of the European mink in Omsk oblast were in a direct weak relationship to abiotic factors, such as indicators of solar activity (W, Wolf number) and different moisture conditions within the territory and water level in water bodies. Changes in the area of distribution and population density were in a weak relationship to the timing of spring and fall onsets and the amount of precipitation and snow cover in winter. The average annual harvest amount from professional hunting was rated at ~25% of the individuals living within the territory.

For the first time in the Republic of Moldova, adults of the phytophagous thrips identified as Echinothrips americanus Morgan were caught in a greenhouse in 2013. Some systematic morphological particularities of the structure of adults of this invasive species originating from the subtropics of the southeastern part of the American continent are given. The probability of adaptation of E. americanus to the open ground in the Republic of Moldova is discussed. The conclusion is made that the risks of accumulation and spreading of the E. americanus increase in the process of conjoint cultivation of ornamental plants and seedlings of vegetable crops in commercial greenhouses and hothouses. It is proposed to include this pest in the list of quarantine alien insects of the Republic of Moldova. The necessity of the monitoring species of Thysanoptera in the commercial hothouses and greenhouses is justified.

A map of the current distribution of Heracleum sosnowskyi Manden. on the territory of Russia was composed. It reflects the space and time dynamics of the widening of the secondary range of the weed including the data on the territories not favorable for its invasion. It was shown that intentional introduction was of the main importance in the modern formation of the secondary range of the weed. It led firstly to local distribution of the plant in agricultural areas in a few regions of the Soviet Union, which were the centers of cultivation of this plant as a fodder crop, and further to “escapement from culture” and distribution of the plant initially near the centers of its cultivation and then to uncontrolled widening of the invasive range of Heracleum sosnowskyi. The species is still more associated with synanthropic habitats than natural ones and forms monospecific thickets on large areas. It was noted that another species of the giant hogweeds—Heracleum mantegazzianum—was also intentionally introduced in the territory of Russia, although to a significantly lesser degree.

The species Moina micrura Kurz, 1875 (Crustacea: Cladocera), which is new for the Vistula Lagoon of the Baltic Sea, was recorded there for the first time. Over the past years, the species has formed a stable opportunistic population, which may become dominant under optimal abiotic and trophic conditions. The continuing eutrophication of the Vistula Lagoon and local climate warming in recent decades are, apparently, the main reasons for the successful naturalization of the species in this water body.

Common ragweed Ambrosia artemisiifolia L. is an aggressive adventive quarantine species that is widespread in the southern regions of Russia. In the Kabardino-Balkarian Republic, freshly-plowed meadows and fresh deposits after cereals in the foothill zone and weedy sites are the optimal conditions for the species spread. Common ragweed has recently actively penetrated into the mountain regions of the republic. On the basis of the study of the ecological–cenotic and ecological–biological features of A. artemisiifolia, a number of recommendations on limiting its distribution within Kabardino-Balkaria have been developed.