Consumption of aquatic subsidies by soil invertebrates in coastal ecosystems

Routes of aquatic allochthonous inputs (aquatic subsidies) to detrital food webs are studied, as is the effect of aquatic subsidies on the functional and taxonomic structure of soil invertebrate communities in coastal ecosystems. The study took place in the coastal zone of an oxbow lake of the Pra River in the Oka Reserve. The results indicate a strong dependence of soil animals in the coastal habitats on aquatic subsidies. Isotopic analysis shows that aquatic resources enter soil food webs not only via predators feeding on flying insects or aquatic prey, but also via saprophages decomposing organic debris of aquatic origin. The contribution of aquatic subsidies to the energy balance of soil invertebrates decreases rapidly with increasing distance from the lake. The fraction of aquatic carbon in tissues of collembolans and saprophages is negligible already a few meters from the water edge. The dependence of predatory invertebrates on aquatic resources can be traced at somewhat greater distance (tens of meters).     

Trophic-based diversification in benthivorous charrs (Salvelinus) dwelling littoral zones of Northern lakes

Charrs of the genus Salvelinus form distinct trophic morphs living in sympatry in numerous postglacial lakes. Here we demonstrate that charrs can diversify into amphipod foraging specialists and sedentary macrobenthos consumers in the shallow-water ecosystems. This pattern was revealed in three out of six lakes under exploration supported by differences in stomach content, trophic-transmitted parasite, and stable isotope ratio analyzes. The body shape and growth rate comparison indicates that this kind of trophic-based diversification emerges at a juvenile stage and is maintained throughout the whole life. The restriction in gene flow found between the morphs allows to propose the possibility for the hereditable-based specialization to evolve. We found that those diversification phenomena are possible only in the lakes situated in vicinity of the ocean coastline, while no evidence of this split was found for inland mountain lakes. We suggest that the trophic-based diversification in the littoral ecosystems is accounted for the heterogeneity in the ecological conditions and food resources’ distribution linked to coastal wind action. This phenomenon was previously reported for the charr in Lake Fjellfrosvatn, Scandinavia, so it seems to be some universal yet poorly described kind of disruptive selection pressure for northern latitude fishes.

     

The winter abundance and distribution of birds in western peter the Great Bay in the Sea of Japan

The data on the abundance and distribution of sea birds and waterfowl at the coast of southern Primorye and distribution diagrams of the sea ducks along the surveyed coast in winter season are given. The dependence of the presence of the birds in certain coastal areas on the winter ice condition was revealed.     

Dynamics of the abundance of seagulls (Charadriiformes: Laridae) in the northern Tatar Strait

Field observations on colonies of seagulls (Laridae) were carried out annually on islands of the northern Tatar Strait during 2001–2008. A general tendency towards a reduction in the number of nesting birds was observed on all islands surveyed. The anxiety factor and direct destruction of bird eggs and fledglings caused the whole or the greater part of colony to migrate to “quieter” sites on islands or the continental coast. The replacement of Larus crassirostris by L. schistisagus was observed in sites where the two species nest in neighborhood. Nesting specimens of L. schistisagus were found on islands of Lake Bolshoe Kizi, suggesting that the birds are in search of alternative nesting places that are less accessible to humans and predators.     

Isotopic signature (<Superscript>15</Superscript>N/<Superscript>14</Superscript>N and <Superscript>13</Superscript>C/<Superscript>12</Superscript>C) confirms similarity of trophic niches of millipedes (Myriapoda,diplopoda) in a temperate deciduous forest

The species composition, abundance, and isotopic signature of millipedes (Myriapoda, Diplopoda) were investigated in seven biotopes of Kaluzhskie Zaseki State Nature Reserve. Nine Diplopoda species were found in total, and the local species diversity (within a sampling plot) reached seven species. The Diplopoda tissues were similar to the plant litter in the isotopic composition of nitrogen (δ¹⁵N was by 0.4‰ higher, on average), but were strongly enriched in heavy carbon (δ¹³C was by 4‰ higher, on average). Removal of mineral carbon from the cuticle reduced δ¹³C of Diplopoda by about 1.4‰ on average. Differences in the δ¹⁵N and δ¹³C values between the species did not exceed 2.5‰. Differences in the isotopic compositions of the considered species were small, and, it is impossible to distinguish particular trophic guilds in the Diplopoda community. Analysis of the published data confirmed that isotopic differentiation of millipedes was much less pronounced than in other investigated groups of soil animals. Hence, millipedes of the deciduous forest form a uniform trophic group.     

吉林省发现长尾鼠耳蝠

在吉林省通化市采集到长尾鼠耳蝠(Myotis frater)样本9只,为吉林省蝙蝠科新纪录,鉴定为长尾亚种M.f.longicaudatus.本文给出了该蝙蝠的特征描述和相关测量数据,并与文献记录进行了比较.     

Facilitative interactions rather than resource partitioning drive diversity-functioning relationships in laboratory fungal communities

We manipulated the number of saprotrophic fungi in either a complex multi-resource substratum (sterilized forest soil), or a single-resource substratum (powdered cellulose). The substrates were inoculated with five common species of soil fungi in all possible combinations (from monocultures to five species in combination). In both substrates, the rate of organic matter decomposition was positively associated with species richness. The effect of fungal diversity was much stronger in the uniform single-resource substrate ( r ² = 0.455, P  < 0.0001) than in soil ( r ² = 0.154, P  < 0.0001). The results document that species richness of microbial decomposers strongly affects decomposition processes, at least at the species poor end of the diversity gradient. Both, 'sampling effect' and 'species complementarity effect' contributed to the community response with the latter being much more pronounced in uniform substrate than in soil. This indicates that facilitative interactions are more important than resource partitioning for positive effects of species richness.