The objective of this study was to evaluate the applicability of soil pH and chlorophyll content as predictive indicators of damage in paddy fields affected by HCl spills, based on causal relationships. Five doses of HCl (e.g., 1, 50, 100, 200, and 500-fold of PNEC) were added to the paddy mesocosm during the rice heading stage. In the 7th week after the acid addition, rice grain quality (e.g., 1000-grain weight and filled grain ratio), soil microbial diversity (e.g., Operational Taxonomic Units (OTUs) and Shannon index), and soluble nutrients (e.g., NH4+, NO3-, SiO2, P2O5, and basic cations) were measured. Causal relationships among variables were analyzed using the Partial Least Square Path Model (PLS-PM). At the dose of 500xPNEC, all rice plants lodged when pH < 4. At 100xPNEC and 200xPNEC, the number of immature grains increased, resulting in a reduction in grain quality of over 18%. At 200xPNEC, the microbial OTUs and the Shannon index decreased by 30%. Notably, the proportion of Planctomycetes, the dominant phylum in the control soil, decreased. The reduction of Planctomycetes led to excessive NH4+ accumulation in the soil, which leads to an undesirable increase of chlorophyll content thereby deteriorating grain quality. The causal relationship suggests that information of soil pH and leaf chlorophyll can aid us in predicting damage for grain quality and microbial diversity.

In recent years, the Grey heron Ardea cinerea has been expanding its range in the south of the taiga zone of Western Siberia. In the Tomsk region during the XX-XXI centuries, it went from being a rare vagrant to a nesting species. The Grey heron is included in the regional Red Book as a rare species with insufficiently studied biology. Interest in it is also associated with its biocenotic role- the impact on soils and vegetation. It can also be an indicator of climate change, since its expansion to the north coincides with the trend of climate warming in Western Siberia. The aim of this work was to study the biology of the Grey heron in the south of the taiga zone of Western Siberia- migration, seasonal dynamics, nesting biology, biocenotic role in ecosystems. Observations of migration and seasonal dynamics were carried out from 1998 to 2023. In spring we used the method of daily 2-hour morning observations in April-May. In summer and autumn (from July to October) we carried out route-area counting of birds in the same place with a frequency of once every 5-7 days. A total we have 15 seasons in spring and 8 in summer-autumn. The main observation area was located in the vicinity of the village of Kolarovo (56 degrees 19'47.29'' N, 84 degrees 56'49.61'' E) on the Tom River (right tributary of the Ob River) 15 km south of Tomsk. Additionally, in 2002-2003, observations were conducted on the Ob River in the southern (Kozhevnikovo District), middle (Kolpashevo District) and northern (Aleksandrovo District) parts of Tomsk region. The southern points (Tomsk and Kozhevnikovo districts) corresponded to the sub- taiga zone, the middle and northern points corresponded to the southern and middle taiga of Western Siberia, respectively. Nesting biology was studied at a Heron colony discovered on an island near the village of Kolarovo. We counted nests, colony structure, and clutch size (based on the eggs shells under the nests). Since some of the trees in the colony were dried out and dead, which is associated with herons, we assessed and compared the & rcy;H and chemical composition of the soils (phosphorus content, exchangeable bases etc.) under different trees in the colony (See Fig.1)- long-used (dead), still alive and outside the colony (control area). The study showed that the arrival dates over the past 25 years have shifted by about 2 weeks towards an earlier appearance- from April 25 in the 2000s to April 5 in the 2020s (See Table 1). The trend is confirmed by the Kendall correlation (0.61; p < 0.05). One of the reasons for this is climate warming, another is the formation of a large colony, to which the birds tend to return as quickly as possible, whereas at the beginning of the observations the colony was just appearing. It was also shown that the density of birds on the lakes during feeding in spring increased by 3-10 times compared to the early 2000s (See Table 1). The number of nests in the identified colony was 81. They were located on 54 trees, mainly on bird cherry trees. There was 1 nest on 38 trees, 2 on 9 trees, 3 trees had 3 nests, and 4 on 4 trees. The average distance between nests was 4.28 +/- 0.48 meter (from 0.5 to 9.7 m). The height of the nests above the ground was 7,26 +/- 0.2 m. Chicks hatched in late May- early June. Clutch size was 3,91 +/- 0.13 (n = 23). We found a badger Meles leucurus settlement under the colony on the island. The conditions here were favorable for it due to the possibility of eating fish that fell during feeding and probably chicks (we found heron bones). During the inspection of the colony, we found dace Leuciscus baicalensis and perch Perca fluviatilis. It was also shown that the excretory activity of herons negatively affects the properties of the soil, leading to its acidification and the death of the trees on which the nests are located. Compared to the control area (out of colony), the phosphorus content in the upper horizons of the soil under the nests is 3.5 times higher. The acidity indicators differed between the background and the control by 1.5 times. Under the nests 4.3 and in the control- 6.1 units, respectively (See Table 2). Despite the negative impact, the problem is local in nature and does not cause significant damage. The article contains 2 Figures, 2 Tables and 35 References.

Coastal wetland soils are frequently underlain by sulfidic materials. Sea level fluctuations can lead to oxidation of sulfidic materials in acid sulfate soils (ASS) and increased acidity which mobilises trace metals when water levels are low, and inundation of coastal wetland soils and reformation of sulfidic materials when water levels are high. We measured the effect of surface water level fluctuations in soils from coastal wetland sites under four different vegetation types: Apium gravedens (AG), Leptospermum lanigerum (LL), Phragmites australis (PA) and Paspalum distichum (PD) on an estuarine floodplain in southern Australia. We assessed effects of fluctuating water levels on reduced inorganic sulfur (RIS) in terms of acid volatile sulfide (AVS), chromium reducible sulfur (CRS) and trace metals (Fe, Al, Mn, Zn, Ni). Intact soil cores were incubated under dry, flooded and wet-dry cycle treatments of 14 days for a total of 56 days. The flooded treatment increased RIS concentrations in most depths in the AG, PA and PD sites. Lower CRS concentrations occurred in all sites in the dry treatment due to oxidation of sulfidic materials when the surface layer was exposed to lower water levels. CRS was positively correlated with SOC in all treatments. The highest net acidity occurred in the dry treatment and lowest occurred in the flooded treatment in most sites. Inundation with seawater caused SO42- reduction and decreased soluble Fe in the PA and PD sites. General decreases in Al, Zn and Ni concentrations in flooded treatments may have been due to adsorption onto colloids or co-precipitation with slight increases in pH. SO42- concentrations decreased in the LL, PA and PD sites in the flooded treatment due to reformation of pyrite. In general, accumulation of RIS in soils under different vegetation types following brackish water inundation varied according to vegetation type, which may be linked to differences in organic material input and particle size distribution. Geochemical characteristics reflected whether oxidation or reduction processes dominated at each site in the wet-dry cycle treatments, with oxidation dominating in the LL and PA sites and reduction dominating in the AG and PD sites. This is likely due to more readily decomposable organic matter forming sulfidic materials during short periods of inundation.

We use GEOS-Chem chemical transport model simulations of sulfate-ammonium aerosol data from the NASA ARCTAS and NOAA ARCPAC aircraft campaigns in the North American Arctic in April 2008, together with longer-term data from surface sites, to better understand aerosol sources in the Arctic in winter-spring and the implications for aerosol acidity. Arctic pollution is dominated by transport from mid-latitudes, and we test the relevant ammonia and sulfur dioxide emission inventories in the model by comparison with wet deposition flux data over the source continents. We find that a complicated mix of natural and anthropogenic sources with different vertical signatures is responsible for sulfate concentrations in the Arctic. East Asian pollution influence is weak in winter but becomes important in spring through transport in the free troposphere. European influence is important at all altitudes but never dominant. West Asia (non-Arctic Russia and Kazakhstan) is the largest contributor to Arctic sulfate in surface air in winter, reflecting a southward extension of the Arctic front over that region. Ammonium in Arctic spring mostly originates from anthropogenic sources in East Asia and Europe, with added contribution from boreal fires, resulting in a more neutralized aerosol in the free troposphere than at the surface. The ARCMS and ARCPAC data indicate a median aerosol neutralization fraction [NH4+]/(2[SO42-] + [NO3-]) of 0.5 mol mol(-1) below 2 km and 0.7 mol mol(-1) above. We find that East Asian and European aerosol transported to the Arctic is mostly neutralized, whereas West Asian and North American aerosol is highly acidic. Growth of sulfur emissions in West Asia may be responsible for the observed increase in aerosol acidity at Barrow over the past decade. As global sulfur emissions decline over the next decades, increasing aerosol neutralization in the Arctic is expected, potentially accelerating Arctic warming through indirect radiative forcing and feedbacks. (C) 2011 Elsevier Ltd. All rights reserved.

Simultaneous measurements on physical, chemical and optical properties of aerosols over a tropical semi-arid location, Agra in north India, were undertaken during December 2004. The average concentration of total suspended particulates (TSP) increased by about 1.4 times during intense foggy/hazy days. Concentrations of SO4 (2-), NO3 (-), NH4 (+) and Black Carbon (BC) aerosols increased by 4, 2, 3.5 and 1.7 times, respectively during that period. Aerosols were acidic during intense foggy/hazy days but the fog water showed alkaline nature, mainly due to the neutralizing capacity of NH4 aerosols. Trajectory analyses showed that air masses were predominantly from NW direction, which might be responsible for transport of BC from distant and surrounding local sources. Diurnal variation of BC on all days showed a morning and an evening peak that were related to domestic cooking and vehicular emissions, apart from boundary layer changes. OPAC (Optical properties of aerosols and clouds) model was used to compute the optical properties of aerosols. Both OPAC-derived and observed aerosol optical depth (AOD) values showed spectral variation with high loadings in the short wavelengths (< 1 A mu m). AOD value at 0.5 A mu m wavelength was significantly high during intense foggy/hazy days (1.22) than during clear sky or less foggy/hazy days (0.63). OPAC-derived Single scattering albedo (SSA) was 0.84 during the observational period, indicating significant contribution of absorbing aerosols. However, the BC mass fraction to TSP increased by only 1% during intense foggy/hazy days and thereby did not show any impact on SSA during that period. A large increase was observed in the shortwave (SW) atmospheric (ATM) forcing during intense foggy/hazy days (+75.8 W/m(2)) than that during clear sky or less foggy/hazy days (+38 W/m(2)), mainly due to increase in absorbing aerosols. Whereas SW forcing at surface (SUF) increased from -40 W/m(2) during clear sky or less foggy/hazy days to -76 W/m(2) during intense foggy/hazy days, mainly due to the scattering aerosols like SO4 (2-).