Change in natural complexes of Bolshezemelskaya tundra and the Polar Urals under the impact of construction of "Bovanenkovo-Ukhta" gas pipeline

The landscapes of European Northeast of Russia have recently been exposed to increasing anthropogenic impact from exploitation and transportation of energy resources from the Far North regions to the central parts of the country. At that roads, gasand oil-pipelines are the main industrial facilities, which have impact on natural systems of Bolshezemelskaya tundra and the Polar Urals regions. Data on the influence of linear constructions on tundra ecosystems are sporadic. The purpose of this study was to evaluate the state of components of natural ecosystems in the area of the pipeline “Bovanenkovo-Ukhta". Field studies were carried out in summer 2013. Terrestrial and aquatic ecosystems along linear constructions of the gas pipeline in the Kara river basin, its tributaries: Bolshaya Lyadgei-Yaha, Nyarma-Yaha rivers, Kosmatu lake and unnamed thermokarst lake No.1 - were investigated. Samples (herbarium, the leaves of shrubs, water, sediments, algae, zoobenthos) were collected according to standard methods. The remote sensing of the surface and graphic algorithms for visualization of temporary changes were applied. The water samples from rivers were taken up (station 1 - background site) and down the stream (station two - the site under the influence) from the bridges and river crossings. The saprobity index for diatom algae was calculated. It is used to evaluate the degree of pollution caused by easily oxidized organic substances.The radius of dust pollution from road exploitation ranges from 250 m to 1000 m in terrestrial ecosystems. The dust pollution leads to transformation of natural ecosystems towards simplicity. The components of phytocoenoses which are most vulnerable to pollution (protected species of vascular plants, lichens, and moss) disappear from the communities. The change from natural tundra cenoses to antropogenic grassy complexes occurs in the area of mechanical disturbance. The dust pollution affects food resources for domestic reindeers. The concentration of heavy metals was higher in the samples from plots near the road and pipeline in comparison with background plots.The water ecosystems (rivers, lakes) located along the pipeline and road undergo changes as well due to anthropogenic influence. The analysis shows that in gene-ral the lakes of the studied region maintain their natural properties, however, the trace of technogenic pollution by oil, mercury, and heavy metals could be seen in water and sediments. The hydrological regime is altered which results in compositional and structural changes of aquatic communities. The diversity of algal communities changes. The analysis of saprobiological groups showed that the diversity and proportion of diatoms (indicators of clear waters) decrease in parts of the river under impact. The proportion of weak and strong indicators of water pollution by easily oxidizable organic substances increases. The index of saprobity ranges in rivers from 1.85 to 2.03, thus, the water of the studied rivers can be characterised as moderately polluted (III quality class)The studies have shown that water and terrestrial ecosystems near the rivercrossings of Kara, Bolshaya Lyadgei-Yaha, and lake Komatu experience the greatest impact from the exploitation of gas pipeline “Bovanenkovo-Ukhta”. Dust pollution is one of the main factors of impact on adjacent ecosystems.