Volume 49, Nº 6 (2018)

We estimated when the edge effect appears in the herb–dwarf shrub layer of pine forests near Yekaterinburg (Central Urals; Southern Taiga subzone) on 14 transects (series of 6–10 plots of 400 m², conjugated in a line 140–260-m long from the edge into the forest, perpendicularly to the forest boundary). The boundaries of forests have differed in time of occurrence (less than nine years and older than 20 years) and type (adjacent to motorways and wastelands). The edge effect on the herb–dwarf shrub layer is manifested in the increasing diversity but not total abundance of herbs. The main components of the edge effect is manifested through an increase in species richness and abundance of plants of nonforest, meadow, and ruderal cenotic groups. The richness and abundance of alien plants and graminoids (cereals and sedges) also increased near forest edges. The depth of the edge effect was, on average, 32 m. For some characteristics, the edge effect contrast increased with time or at added transformation in conditions near highways.

Subrecent spore–pollen spectra have been analyzed for the occurrence Carpinus, Fagus, Tilia, and Quercus pollen in the East European Plain to evaluate the possibility of long-distance pollen transfer. Analysis was based on the material from the Russian Palynological Database on 250 points in different regions of European Russia and neighboring countries and on data from published sources. Pollen of oak, linden, and hornbeam has been found in surface samples taken within the natural ranges of these species and in regions of their introduction, with linden and oak pollen being transferred by air for several tens of kilometers, and hornbeam pollen, for about 200 km. Beech pollen can be transferred by wind for long distances, and its presence in spectra has been recorded farther than 1000 km from the species range boundaries. The proportion of components transferred from long distances increases in spore–pollen spectra from regions with sparse or poorly developed plant cover, and single occurrences of broadleaf tree pollen are also possible in such regions.

Parkinsonia aculeata and Prosopis juliflora are two of the most problematic invasive plant species in the Brazilian tropical seasonal dry forest, but the mechanisms driving the biological invasion of this ecosystem is virtually unknown. This study assessed the role of arbuscular mycorrhizal symbiosis, in particular of Funneliformis mosseae, on the biological invasion process by P. aculeata and P. juliflora. F. mosseae is a cosmopolitan arbuscular mycorrhizal fungus (AMF) frequently found in association with plants of different regions of the world. The present study was conducted to determine if F. mosseae is present in the soils from two invaded areas by P. aculeata and P. juliflora and to evaluate its contribution to the growth of these invasive plant species. Firstly, AMF colonization and AMF spore abundance was assessed in the roots and rhizosphere of both species in the field. Spores of F. mosseae were obtained from the soil samples and used to set up a greenhouse experiment to evaluate its effect on plant dry biomass and plant phosphorus concentration for both exotic plant species. We found that F. mosseae inoculation promoted the growth of the invaders and lead to a higher P concentration. Our results demonstrate that (a) AMF play an important role in the biological invasion process of the Brazilian tropical seasonal dry forest by P. aculeata and P. juliflora and (b) F. mosseae might be an important AMF species during the biological invasion process.

Paternity analysis, carried out on 13 microsatellite loci, was used to investigate pollen dispersal and mating patterns in an invasive population of Solanum rostratum in China. We determined a high outcrossing rate (0.81 ± 0.02) and found that all 174 offspring for which the father could be identified were outcross progeny. The mean pollen dispersal distance was 13.66 m (range 0.41–71.67 m); however, 59.2% of effective pollination events occurred at <10 m. Our results indicate substantial near-neighbor pollen dispersal and imply that successful invasion of S. rostratum is facilitated by a high level of pollen flow within the population.

Based on data from camera traps installed throughout the model territory in southwest Primorye, information was received during an annual cycle on the presence of individually identified Amur leopards in the area of study. Analysis of the data using a combination of different techniques has determined the mutual spatial arrangement and sizes of approximated home ranges for both male and female leopards. The dataset of individually identified animals proves sufficient in describing the social organization of the studied group of Amur leopard using the spatial overlapping of individual home ranges as a characteristic of social relationships. Each individual home range overlaps with several home ranges belonging to both individuals of the opposite and same sex, with the overlapped portion larger in males than in females.

The long-term dynamics of the parasitic infection of two coregonid species with different food specializations, peled Coregonus peled (Gmelin, 1789) and Siberian whitefish Coregonus lavaretus pidschian (Gmelin, 1788), during spawning migration in the Synya River (a Polar Urals tributary of the Lower Ob) has been studied. The differences in the parasite species composition and infection of the two fish species are determined their food spectra features, as well as by their use of different biotopes in feeding water bodies and the interannual dynamics of the fish age composition. A trend towards a decrease in the rate of peled infection by myxosporidium and cestode with a simultaneous decrease in its abundance due to intensive catches has been revealed. The stability of the composition of the coregonid parasite fauna in the Ob lower reaches indicates stable relationships between parasites and hosts and a relatively stable state of the ecosystem of the Lower Ob.

This work aims to examine the spatial pattern of bird species richness at broad landscape-scale and to determine the key factors correlated to this pattern in the mainland of China. We divided the mainland of China was divided into 241 quadrats, 2° latitude by 2° longitude. The number of bird species occurring in each quadrat was counted based on available records. Plant species richness was also measured and net primary productivity estimated for each quadrat. Climatic data of each quadrat were based on 30-year records from 830 county’s meteorological stations. The results showed that bird species richness was significantly correlated to most factors examined. Factors of food, water and habitat resources such as plant species richness, primary productivity, annual mean precipitation, and longitude were most significantly related to bird richness in China. Other factors such as monthly mean temperature of January, frost-free period, minimum temperature, annual mean temperature, latitude showed somewhat indirect effects on bird species richness, i.e. specifically, they directly influenced plant richness and productivity, which then influenced bird richness. The maximum bird species richness occurs in the south of Yunnan province close to Yarlung Zangbo Grand Canyon probably in response to rich food resources, while the minimum plant species richness was found on Qinghai-Tibetan Plateau where food resources and habitats are limited. Based on our results, we suggest that the protection and development of food and habitat resources should be a priority to conserve bird diversity in China.

The paper is aimed in ants’ preference among seeds with elaiosomes. Seeds with elaiosomes of plants Asarum europaeum, Viola arvensis, Symphytum officinale, Chelidonium majus, and Ficaria verna were offered to red wood ants (Formica rufa) near two observed anthills. Monitored characteristics were the number of seeds collected by ants depending on the plant species, the presence of elaiosome, the orientation and the distance from anthill. The obtained data were processed by factorial ANOVA including PCA analysis. Seeds without elaiosomes were less preferred than the seeds with elaiosomes at statistical level. This experiment confirmed that elaiosomes attached to the seeds had significantly influenced transport of seeds by red wood ants. On the contrary, the influence of orientations (north–south) between seeds and the anthill were not proved. A distance of seeds from the anthill may play a certain role, but the results were not significant. Data indicated that ants had preferred seeds with elaiosomes of two plant species (A. europaeum and V. arvensis) from five species offered. The authors recommend to store seeds in a freezer before a similar experiment, because the elaisomes from different plant species will be fresh.