Foliar stable isotope ratios of carbon and nitrogen in boreal forest plants exposed to long-term pollution from the nickel-copper smelter at Monchegorsk, Russia

Long-term exposure to primary air pollutants, such as sulphur dioxide (SO2) and nitrogen oxides (NOx), alters the structure and functions of forest ecosystems. Many biochemical and biogeochemical processes discriminate against the heavier isotopes in a mixture; thus, the values of delta C-13 and delta N-15 (i.e. the ratio of stable isotopes C-13 to C-12 and that of (15) N to (14) N, respectively) may give insights into changes in ecosystem processes and identify the immediate drivers of these changes. We studied sources of variation in the delta C-13 and delta N-15 values in the foliage of eight boreal forest C3 plants at 10 sites located at the distance of 1-40 km from the Monchegorsk nickel-copper smelter in Russia. From 1939-2019, this smelter emitted over 14,000,000 metric tons (t) of SO2, 250,000 t of metals, primarily nickel and copper, and 140,000 t of NOx. The delta C-13 value in evergreen plants and the delta N-15 value in all plants increased near the smelter independently of the plant mycorrhizal type. We attribute the pollution-related increase in the foliar delta C-13 values of evergreen species mainly to direct effects of SO2 on stomatal conductance, in combination with pollution-related water stress, which jointly override the potential opposite effect of increasing ambient CO2 concentration on delta C-13 values. Stomatal uptake of NOx and root uptake of N-15-enriched organic N compounds and NH4+ may explain the increased foliar delta N-15 values and elevated foliar N concentrations, especially in the evergreen trees (Pinus sylvestris), close to Monchegorsk, where the soil inorganic N supply is reduced due to the impact of long-term SO2 and heavy metal emissions on plant biomass. We conclude that, despite the uncertainties in interpreting delta C-13 and delta N-15 responses to pollution, the Monchegorsk smelter has imposed and still imposes a great impact on C and N cycling in the surrounding N-limited subarctic forest ecosystems.Peer reviewe

New records of Lepidoptera from the Arkhangelsk oblast of Russia

Faunistic studies conducted in multiple localities across the Arkhangelsk oblast during 2014–2016 resulted in the discovery of 104 species of Lepidoptera not previously reported from this region. Especially noteworthy records include Phyllocnistis saligna, Depressaria ultimella, Dichrorampha insperata, Eversmannia exornata and Eublemma amasina.We also confirm records of 24 species which were known from old publications only, and we report new localities for 379 species. The known fauna of the Lepidoptera of the Arkhangelsk oblast now includes 1,140 species (604 species of microlepidoptera and 536 species of macrolepidoptera), which we presume to represent slightly more than a half of the potential diversity of Lepidoptera of the oblast

Lepidoptera of Arkhangelsk oblast of Russia: a regional checklist

The first regional checklist of moths and butterflies of Arkhangelsk oblast of Russia includes 1,036 species (538 species of microlepidoptera and 498 species of macrolepidoptera), 496 of which have been found in the oblast for the first time. The most interesting records include Gnorimoschema robustella, Caryocolum leucomelanella, Dichrorampha sequana, D. uralensis, Neptis rivularis and Melitaea phoebe. We also discovered several populations of Parnassius mnemosyne in the southern part of the oblast. The fauna of Arkhangelsk oblast appears poorer than the fauna of Northern Ural Mts. but still includes some Siberian taiga species which do not reach Fennoscandia. Also, the distribution limits of several species extend further north in Arkhangelsk oblast than in the more western parts of Europe.We estimate that 500 to 800 species remain to be found in the study region

The fluctuating asymmetry of the butterfly wing pattern does not change along an industrial pollution gradient

The rapid and selective responses to changes in habitat structure and climate have made butterflies valuable environmental indicators. In this study, we asked whether the decline in butterfly populations near the copper-nickel smelter in Monchegorsk in northwestern Russia is accompanied by phenotypic stress responses to toxic pollutants, expressed as a decrease in body size and an increase in fluctuating asymmetry. We measured the concentrations of nickel and copper, forewing length, and fluctuating asymmetry in two elements of wing patterns in Boloria euphrosyne, Plebejus idas, and Agriades optilete collected 1–65 km from Monchegorsk. Body metal concentrations increased toward the smelter, confirming the local origin of the collected butterflies. The wings of butterflies from the most polluted sites were 5–8% shorter than those in unpolluted localities, suggesting adverse effects of pollution on butterfly fitness due to larval feeding on contaminated plants. However, fluctuating asymmetry averaged across two hindwing spots did not change systematically with pollution, thereby questioning the use of fluctuating asymmetry as an indicator of habitat quality in butterfly conservation projects.</p

Decline of Eulia ministrana (Lepidoptera: Tortricidae) in polluted habitats is not accompanied by phenotypic stress responses

Environmental pollution is currently identified as one of the major drivers of rapid decline of insect populations, and this finding has revitalized interest in insect responses to pollution. We tested the hypothesis that the pollution-induced decline of insect populations can be predicted from phenotypic stress responses expressed as morphological differences between populations inhabiting polluted and unpolluted sites. We explored populations of the brassy tortrixEulia ministranain subarctic forests along an environmental disturbance gradient created by long-lasting severe impacts of aerial emissions of the copper-nickel smelter in Monchegorsk, northwestern Russia. We used pheromone traps to measure the population densities of this leafrolling moth and to collect specimens for assessment of three morphological stress indices: size, forewing melanization, and fluctuating asymmetry in wing venation. Wing length ofE. ministranaincreased by 10%, and neither forewing melanization nor fluctuating asymmetry changed from the unpolluted forest to the heavily polluted industrial barren. However, the population density ofE. ministranadecreased 5 to 10 fold in the same pollution gradient. Thus, none of the studied potential morphological stress indicators signaled vulnerability ofE. ministranato environmental pollution and/or to pollution-induced environmental disturbance. We conclude that insect populations can decline without any visible signs of stress. The use of morphological proxies of insect fitness to predict the consequences of human impact on insect populations is therefore risky until causal relationships between these proxies and insect abundance are deciphered

Is the small island effect observed in the courtyards of a historical city centre?

Growing evidence suggests that biodiversity on small islands and fragments could be independent of island area, a pattern called the Small Island Effect (SIE). We searched for SIE among the floras of 19 courtyards completely enclosed by buildings in central St Petersburg, Russia, in 1993, 2003 and 2008. Despite the extremely small size of the studied habitats (125-3500 m(2); open ground area 0.1-700 m(2)), the number of native and naturalized vascular plant species generally increased with an increase in habitat area. Plant species richness was better explained by the open ground area than by the total courtyard area, and species-area relationships did not differ between ornamental and non-ornamental plants. The statistical support for SIE was obtained in 3 of 14 analyses. Both semi-log and log-log data demonstrated SIE in trees, but not in shrubs or herbs. We also found SIE in the 2008 data (all life forms combined), but only with a semi-log model. The threshold area for the detected SIE was 3-7 m(2). We conclude that SIE in urban green spaces may be an exception rather than the general rule. Its occurrence may be transient and may depend on the current balance of stochastic colonisation and extinction processes. Thus, even a minor increase in the area of open ground patches embedded in an urban matrix will increase the diversity of plants persisting in these patches. This finding justifies the importance of small local actions for maximizing the conservation of urban biodiversity and the retention of the ecosystem services it provides

Temperature and herbivory, but not pollution, affect fluctuating asymmetry of mountain birch leaves: Results of 25-year monitoring around the copper nickel smelter in Monchegorsk, northwestern Russia

Fluctuating asymmetry ( FA), which is defined as the magnitude of the random deviations from a symmetrical shape, reflects developmental instability and is commonly assumed to increase under environmental and genetic stress. We monitored the leaf FA of mountain birch, Betula pubescens subsp. czerepanovii, from 1993 to 2017 in individually marked trees at 21 sites around the copper nickel smelter at Monchegorsk, and we then analysed the results with respect to spatial and temporal variation in pollution, climate and background insect herbivory. Responses of leaf FA to different stressors were stressor specific: FA did not correlate with pollution load, it decreased significantly with an increase in June air temperature and it increased slightly but significantly with an increase in the previous-year leaf damage due to defoliating and leafmining insects. Our findings suggest that climate warming is unlikely to impose stress on the explored mountain birch populations, but even small increases in insect herbivory may adversely affect birch trees. However, these conclusions, since they are based on an observational study, should be viewed as tentative until confirmed by controlled experiments. We also demonstrated that the use of non-blinded measurements, which are prone to confirmation bias, was the primary reason for the earlier report of an increase in birch leaf FA near the Monchegorsk smelter. We hope that our findings will promote a wide use of blinded methods in ecological research and that they will contribute to debunking the myth that plant leaf FA consistently increases with increases in environmental pollution. (C) 2018 Elsevier B.V. All rights reserved

Insecticide application did not reveal any impact of herbivory on plant roots in boreal forests

The levels of belowground herbivory in natural ecosystems remain practically undetermined, and nothing is known regarding the geographic and/or climatic variations in belowground herbivory. We endeavoured to narrow this knowledge gap by exploring the latitudinal changes in the intensity of background root herbivory in boreal forest ecosystems by conducting a herbivore exclusion experiment in 10 forested sites from 60N to 69N in northwestern Russia. We found no statistically significant differences in fine root biomass between diazinontreated and control plots, nor did the differences show any latitudinal change. From biomass of root-feeding macrofauna we estimated that root herbivory in our sites averages 0.57 %. This low level of root herbivory could not be quantified reliably by herbivore exclusion experiments; therefore, we suggest that macroecological patterns in root herbivory are invoked from simultaneous measurements of the biomasses of fine roots and of root-feeders. More data on the efficiency of conversion of the food ingested by root-feeding invertebrates is needed to increase the accuracy of the suggested method of estimation of root herbivory

Variation in leaf size and fluctuating asymmetry of mountain birch (Betula pubescens var. pumila) in space and time: implications for global change research

Experimental, latitudinal, and historical approaches have been used to explore and/or predict the effects of global change on biota, and each approach has its own advantages and disadvantages. The weaknesses of these individual approaches can, potentially, be avoided by applying them simultaneously, but this is rarely done in global change research. Here, we explored the temporal and spatial variations in the leaf size and fluctuating asymmetry (FA) of mountain birch (Betula pubescens var. pumila) in the Murmansk region of Russia, with the aim of verifying the predictions derived from the responses of these traits to experimental manipulations of abiotic drivers of global change. The examination of herbarium specimens revealed that leaf length increased during the 20th century, whereas the FA in the number of leaf teeth decreased, presumably reflecting an increase in the carbon and nitrogen availability to plants in that century. Along a northward latitudinal gradient, leaf length decreased whereas FA increased, presumably due to the poleward decreases in air temperature. The study site, collection year, and latitude explained a larger part of the leaf length variation in mountain birch relative to the variation in FA. Leaf length is likely a better indicator than FA in studies addressing global environmental change impacts on plant performance