Nature Conservation Research

26–39

Authors: Fateryga V.V., Bagrikova N.A.

The results of a study of Opuntia humifusa and O. phaeacantha naturalised in the Karadag Nature Reserve (southeastern part of the Crimean Peninsula) are presented. There, the largest coenopopulations of Opuntia plants are confined to the «biostation» territory (bordering with the park, administrative buildings and housing estate). Twelve localities were described in the Karadag Reserve. These differ by phytocoenotic characteristics, area and floristic composition. Seven localities include only O. humifusa plants; four ones include only O. phaeacantha individuals; and both the species are present on the twelfth locality. The total number of individuals of each species and ontogenetic structure of the population were studied in each locality. The total number of O. humifusa individuals in the Karadag Reserve is more than 600 plants within the «biostation» territory, while the total number of O. phaeacantha plants is about 400 individuals. Studying of the plant communities has been carried out according to the Braun-Blanquet method. Opuntia plants form derivate communities within degraded steppes, phryganoid-steppes, and semi-desert badland phytocoenoses almost at all studied localities. A significant number of synanthropic species (including alien plants) was found within these communities. Opuntia plants are able to self-reproduce predominantly vegetatively. Self-seeding reproduction occurs less frequently. Both species can be considered as invasive plants because they have a high adaptive capacity.

53–77

Authors: Starodubtseva E.A., Grigoryevskaya A.Ya., Lepeshkina L.A., Lisova O.S.

The article deals with the analysis of alien species in local floras of the Voronezh region Nature Reserve Fund. The Voronezh Region is located on the border of the forest-steppe and steppe zones. 16 Model Protected Areas (PAs), having a different conservation status and a various size, have been chosen for the analysis. The article attempts to assess: a) the degree of biological contamination of PAs that protect forest-steppe and steppe ecosystems; b) features of the alien fractions of the PAs' flora of various categories. The characteristics of PAs with respect to the possibilities and conditions for the invasion of alien species of vascular plants are given. The alien fraction of the PAs' flora comprises 262 taxa: 255 species, 5 hybrids, 1 subspecies and 1 variety, referring to 178 genera and 66 families. For the typological analysis, alien species were divided into groups in accordance with the time of the invasion, the way of invasion and the naturalisation level. The average proportion of invasive species in PAs floras is 11.1% (in different local floras it varies from 4.4% to 16.8%). When considering stable flora elements only (excluding ephemerophytes and colonophytes), then the PAs' local flora contamination ratio will make the average of 6.1% (from 3.5% to 8.9%). The largest number of alien species is noted in the floras of state reserves and state nature sanctuaries, regional PAs are characterised by a smaller proportion of alien plants. The analysis of the ways of alien species' invasion has shown that human activity on introduction of plants makes an important contribution to the replenishment of the alien flora in protected areas: 31.7% of alien species had left the cultivation area, 15% were deliberately planted in the PAs. Transformer plants are of the greatest coenotic significance, out of 19 such alien species 11 are xenophytes, the other 8 species are ergasiophytes. The conclusion is made about the necessity to move from the monitoring of alien species to practical work on managing the process of alien plant invasion in state reserves.

90–95

Authors: Kirilenko E.V., Shemonaev E.V.

The article presents data on the species composition of fish in the waterbodies of the Mordovo floodplain of the Saratov Reservoir in the territory of the Samarskaya Luka National Park. The ichthyofauna of the investigated reservoirs was studied for the first time. The species structure of fish catches in five floodplain lakes and in one channel was analysed. Typological habitat conditions in waterbodies (for example, the flowage of floodplain waterbody and its connection with the Reservoir) effect the species diversity of fish. In four of the six investigated bodies of water, an alien species, the Chinese sleeper, was discovered. The biotope of the species is confined to the thickets of aquatic vegetation, regardless of the depth and place of its growth in the reservoir.

102–108

Authors: Dumalisile L., Somers M.J.

Alien plants have invaded most ecosystem types (terrestrial, fresh water and marine) and are responsible for the loss of irreplaceable natural services on which humankind relies. They alter food quantity, quality and accessibility, and may result in declines in native species richness, which may ultimately result in extinction. For an effective management of invasive alien plants, it is important to understand the effects that such plants have on all levels of biodiversity. However, the effects that invasive alien plants, such as the Triffid weed (Chromolaena odorata), have on mammalian biodiversity, especially large mammalian species, are not well-known, although they play major ecological roles in areas such as nutrient cycling. Also, little is known about the recovery of the ecosystem following alien plant removal. This study investigated the effects of C. odorata invasion on large mammalian herbivores in Hluhluwe-iMfolozi Park and whether clearing of this plant helped in rehabilitating the habitat. We used track counts to estimate and compare species richness, diversity and abundance indices for large mammalian species between areas with differing C. odorata invasion durations (ca 2 years, ca 10 years, ca 20 years), areas with differing clearing times (cl < 2 years, cl 3–5 years) and an area without any history of C. odorata invasion as a control. The results from this study show that large mammalian species utilised the uninvaded and the cleared areas more than the invaded areas. Species richness, abundance and diversity decreased with increasing invasion duration and cleared areas showed an increasing species richness and abundance. We conclude that this invasive alien plant modifies habitats and their removal does aid in the restoration of the ecosystem.