Vol 7, No 2 (2016)

The results of the study of the dynamics of a biomass and production of treeless grass-shrub-sphagnum bog communities formed on the reclaimed site 20 years after the drainage and undisturbed mesotrophic shrub-Sphagnum bog community (excluding tree layer) on the Middle Amur River lowlands are compared. This bog is in a subclimax state and functions in conditions of sharply fluctuating hydrological regime. Significant fluctuations in the bog water level caused by the uneven atmospheric precipitation are very typical for mires on the Middle Amur depression, both in growing seasons and from year to year. They have shown that a biomass structure changed and a productivity of sphagnum moss and herbaceous plants increased, while production of psychrophilic shrubs reduced during secondary swamping as a result of changes in the hydrological regime. Live biomass was 1106 g× m-2 on undisturbed bog and 1640 g× m-2 on the secondary swamped site. In above-ground part and acrotelm mortmass increased up to 3561 g× m-2 on the secondary bog compared to 2272 g× m-2 on undisturbed bog. NPP on the secondary swamped site varies between 627-863 g × m-2 per year. It is significantly higher than NPP of undisturbed phytocenosis which ranges from 538 to 662 g× m-2 per year. The dominant indigenous mires Chamaedaphne calyculata is respond to waterlogging and stabilizing the hydrological regime by increase in the mass of roots that provide the greatest contribution to production in comparison with its above-ground live phytomass. The ratio of above-ground and underground phytomass of herbaceous plants thus remains constant, despite the change of species in phytocenosis. The species composition of moss layer changes and significantly increases its productivity. In general, peat accumulation endogenesis accelerates. On mesotrophic bogs of the Middle Amur River lowland it is hampered by recurrent fires on a big time trend, causing them to function in subclimax phase.

This paper discusses several controversial points from dissertation of Nikolai Andreevich Shnyrev «Regime investigations and estimate of gas exchange on the soil-atmosphere interface (methane fluxes from “Muhrino” wetland, West Siberia». Since methodological questions arised in the thesis are of special importance for greenhouse gas balance estimates from terrestrial ecosystems, correctness of their interpretation is required. In this regard, crucial question discussed in the thesis concerns applicability and accuracy of micrometeorological methods as an alternative to the classical chamber approach. It is shown that N.A. Shnyrev’s criticism of state-of-art eddy covariance technique is neither fundamental nor consistent; it disagrees with worldwide consensus riched by scientific community. The new classification scheme of gas exchange estimates on soil-atmosphere interface proposed by the author is quite pointless and not suitable for classifying some methods such as eddy covariance. Several issues of previous methane emission investigations in West Siberia and peculiarities of different flux measurement methods are also raised. Namely insufficient attention to methane emission studies conducted in West Siberian wetlands by automated chambers is pointed out.

The paper discusses several controversial points from thesis of Nikolai Andreevich Shnyrev «Regime investigations and estimate of gas exchange on the soil-atmosphere interface (methane fluxes from “Muhrino” wetland, West Siberia»). These points concern mainly previous estimates of regional methane emission from West Siberian wetlands, in particular, by Glagolev’s scientific group. The paper shows that “large variability of estimates as well as large disbalance in carbon cycle”, which was claimed in thesis to prove its relevance, contradict to modern investigations of the problem. We also discuss several methodological problems of static chamber method. In particular, it was proved that difference between methane emissions in the light and in the dark is negligible. In addition, we showed that N.A. Shnyrev’s suggestion on improvement the accuracy of static chamber method by reduction of chamber volume is unreasonable. Finally, we discuss if linearity of methane concentration dynamic is necessary for methane flux calculations.

Fungi are the important allergens, pathogens of plants, animals and humans, as well as they produce toxins and are
agents of biodegradation of natural and artificial materials. The publication summarizes the relatively few theoretical and
experimental papers devoted modeling the the dynamics of bioaerosols in the surface layer of the atmosphere. The emphasis
is done on processes and quantitative regularities that are important for the calculation of the dynamics of fungal aerosol,
which consist of fungal spores and mycelial fragments of various diameters. We describe the key processes determining the
dynamics of bioaerosols in the surface layer of the atmosphere, namely: emission, gravitational sedimentation, turbulent
diffusion, washing by precipitations, particle collision, and a number of other processes. We carried out the formulation of
the problem, introduced a number of equations, describing the dynamics of bioaerosols in the surface layer of the
atmosphere, we discussed the boundary conditions, necessary to carry out the calculations.