scholarly journals Increasing silicon concentrations in Bohemian Forest lakes

2005 ◽  
Vol 9 (6) ◽  
pp. 699-706 ◽  
Author(s):  
J. Veselý ◽  
V. Majer ◽  
J. Kopácek ◽  
J. Safanda ◽  
S. A. Norton
Keyword(s):  
Surface Waters ◽  
Acidic Deposition ◽  
Sharp Decrease ◽  
Inhibitory Effect ◽  
Bohemian Forest ◽  
Long Term Trends ◽  
Marked Decline ◽  
The Bohemian Forest ◽  
Dissolved Silicon

Abstract. Long-term trends of dissolved silicon (Si) concentrations in five glacial lakes in the Bohemian Forest, Czech Republic, recovering from acidification show higher mobility of Si from the soil to surface waters despite lower atmospheric deposition of acids. Si increased by 0.95 to 1.95 µmol yr-1 (36 to 51%) from 1986-2004 and with increasing pH. A change in soil solution conditions because of a sharp decrease in acidic deposition has led to marked decline in Al mobility and to considerable decreases in dissolved Al, especially Al3+. The increase in Si may be related to: (1) unblocking of the inhibitory effect of dissolved Al on weathering of aluminosilicates, (2) biogenic opal (phytoliths) dissolving faster, and/or (3) lower Si precipitation as secondary aluminosilicates in soil. The change in Al speciation on the dissolution rate of biogenic silica is critical. A lack of change in Si at sites outside central Europe may be explained by small or no decline in mobility of dissolved Al. The effect of a long-term increase in temperature was probably minor.

scholarly journals Long-Term Trends of Hazel Grouse (Tetrastes bonasia) in the Bohemian Forest (Šumava), Czech Republic, 1972-2019

2021 ◽  
Author(s):  
Siegfried Klaus ◽  
Tobias Ludwig
Keyword(s):  
Czech Republic ◽  
Clear Cutting ◽  
Hazel Grouse ◽  
Bohemian Forest ◽  
Open Forest ◽  
Winter Food ◽  
Long Term Trends ◽  
The Bohemian Forest ◽  
Beetle Damage

The population dynamics of Hazel Grouse was studied by presence/ absence recording at stationary sites along fixed routes (110 km) during 1972-2019 in the central part of the Bohemian Forest (Šumava, Czech Republic). The 100-km² study area covered altitudes between 600 m (Rejstejn) and 1,253 m a.s.l., (mount Sokol). Our data base contained indices of Hazel Grouse occupancy: positive sites/ controlled sites for a yearly increasing number of Hazel Grouse occurrence sites (N = 134) for 48 years. We used a loglinear Poisson-regression method to analyze the long-term population trend for Hazel Grouse in the study area. In the period 1972 to 2006 we found a stable Hazel Grouse population (p = 0.83). From 2006-2007 to 2019, the population index dropped (-3.8% per year, p < 0.05) for the last 13 years. This decline is assumed to be influenced by habitat loss due to succession resulting in older, more open forest stands, by strongly increasing forestry and windstorm “Kyrill” followed by clear cutting, bark-beetle damage, and removal of pioneer trees in spruce plantations, which diminished buds and catkins, the dominant winter food. The influence of disturbance by increasing touristic activities and/or predation is discussed. Our results could help to optimize conservation efforts for Hazel Grouse in the Bohemian Forest.

scholarly journals Long-Term Trends of Hazel Grouse (Tetrastes bonasia) in the Bohemian Forest (Šumava), Czech Republic, 1972–2019

Birds ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 127-137
Author(s):  
Siegfried Klaus ◽  
Tobias Ludwig
Keyword(s):  
Czech Republic ◽  
Clear Cutting ◽  
Hazel Grouse ◽  
Bohemian Forest ◽  
Open Forest ◽  
Winter Food ◽  
Long Term Trends ◽  
The Bohemian Forest ◽  
Beetle Damage

The population dynamics of Hazel Grouse were studied by presence/absence recording at stationary sites along fixed routes (110 km) in the central part of Šumava (Bohemian Forest, Czech Republic) from 1972 to 2019. The 100 km2 study area covered altitudes between 600 m (Rejštejn) and 1253 m above sea level (Mt. Sokol). Our database contained indices of Hazel Grouse occupancy: positive sites/visited sites for a yearly increasing number of Hazel Grouse occurrence sites (n = 134) for 48 years. We used a loglinear Poisson regression method to analyze the long-term population trend for Hazel Grouse in the study area. In the period from 1972 to 2006 we found a stable Hazel Grouse population (p = 0.83). From 2006–2007 to 2019, the population index dropped (−3.8% per year, p < 0.05). This decline is assumed to be influenced by habitat loss due to succession, resulting in older, more open forest stands, by strongly increasing forestry and windstorm “Kyrill”, followed by clear cutting, bark beetle damage, and the removal of pioneer trees in spruce plantations, which diminished buds and catkins, the dominant winter food of Hazel Grouse. The influence of disturbance by increasing tourist activities and/or predation is also discussed. Our results could help to optimize the conservation efforts for Hazel Grouse in the Bohemian Forest.

scholarly journals Land use influences on acidification and recovery of freshwaters in Galloway, south-west Scotland

2001 ◽  
Vol 5 (3) ◽  
pp. 451-458 ◽  
Author(s):  
R. C. Helliwell ◽  
R. C. Ferrier ◽  
L. Johnston ◽  
J. Goodwin ◽  
R. Doughty
Keyword(s):  
Surface Waters ◽  
Chemical Recovery ◽  
Dry Period ◽  
Sulphur Deposition ◽  
South West ◽  
Recovery From Acidification ◽  
Long Term Trends ◽  
Acid Status ◽  
Annual Discharge

Abstract. The long term response of surface waters to changes in sulphur deposition and afforestation is investigated for three upland river systems in the Galloway region of south-west Scotland. From 1984-1999, these rivers exhibited a statistically significant decline in non-marine sulphate concentrations in response to reduced acid deposition. This reduction in non-marine sulphate was, however, insufficient to induce a pH recovery over the period. A statistically significant increase in river pH was observed between 1956-1970 (0.05 yr-1) when subsidised agricultural lime payments were at a maximum. In 1976, this subsidy ceased and surface waters have progressively acidified. In addition, climatic change is found to influence long-term trends in pH. Mean annual pH was greatest during a dry period between 1969-1973 when total annual discharge was low. Thereafter, pH declined gradually in response to higher rainfall and increased total annual discharge. Overall, surface waters draining the afforested catchments of the Rivers Cree and Bladnoch are more acid than those draining the moorland catchment of the Luce. These results indicate that in afforested catchments, current reductions in sulphur emissions have not led to an observed improvement in the acid status of surface waters. Forestry, therefore, represents a confounding factor with regard to chemical recovery from acidification in this region. Keywords: acidification, afforestation, deposition, rivers, lochs, non-marine sulphate, pH

Hypolimnion Injection of Nutrient Effluents as a Method for Reducing Eutrophication

1980 ◽  
Vol 37 (3) ◽  
pp. 320-327 ◽  
Author(s):  
D. W. Schindler ◽  
T. Ruszczynski ◽  
E. J. Fee
Keyword(s):  
Surface Waters ◽  
Standing Crop ◽  
Nutrient Concentrations ◽  
Precambrian Shield ◽  
Water Interaction ◽  
Anoxic Hypolimnion ◽  
Long Term Trends

Injection of nutrients into the anoxic hypolimnion of a small Precambrian Shield lake for 5 yr caused less of a eutrophication problem than discharging nutrients into surface waters. Phytoplankton standing crop and production in the whole lake averaged only 10–21% of values in a nearby lake fertilized at the surface. Five-year averages for the epilimnion only were still lower: 5–8% of those in the surface-fertilized lake. Analysis of long-term trends in chlorophyll and nutrient concentrations revealed much slower rates of increase than in surface-fertilized lakes.Key words: eutrophication, hypolimnion injection, sediment–water interaction, nutrients, experimental lakes

scholarly journals Management of the Incidence of Infectious Diseases by Applying Preventive Measures in the Weakest Period in Its Cyclicity

2021 ◽  
Vol 76 (1) ◽  
pp. 20-27
Author(s):  
Evgeny D. Savilov
Keyword(s):  
Infectious Diseases ◽  
Preventive Measures ◽  
Self Regulation ◽  
Cost Effective ◽  
Risk Groups ◽  
Disease Occurrence ◽  
Long Term Trends ◽  
Marked Decline ◽  
Positive Effect

Existing preventive measures have not been entirely efficient. Mainly they are aimed at solving social and economic issues, which demands both time and money. Considering this, it is necessary to find and sustain additional effective measures, based on patterns of development of infectious diseases, which could be more cost-effective. One of such approaches could be based on the theory of self-regulation of parasitic systems, which directs epidemiologists to conducting preventive measures before the rise of the number of cases to prevent increase in the agents virulence. Yet this theory does not provide the optimum time for preventive measures. Based on the main statements of the theory of self-regulation of parasitic systems and analysis of annual and/or long-term cyclicity, the article provides substantiation of the theory that the lowest level of incidence is the weakest period in its development. Epidemiological experiments, using bacterial dysentery as an example, showed that preventive administration of polyvalent dysenteric bacteriophage in risk groups (children going to preschool institutions) during two months of the lowest incidence level of the disease appeared to be effective. The positive effect took place in the stages of cyclic increase and decrease of long-term trends. The effect appeared in the groups of children and population in general with most marked decline in disease occurrence in its seasonal peak. The hypothesis that the lowest incidence level is directly related to seasonal climbs of the disease was proved by our earlier studies when we investigated influence of technogenic pollution of the environment on annual incidence rate of more than ten most common infectious diseases with different ways of transmission. Thus, the lowest incidence level of infectious diseases defines their future growth and/or decline, and, therefore, it can be used to conduct preventive measures.

scholarly journals Seasonal variation in aragonite saturation in surface waters of Puget Sound – a pilot study

Elem Sci Anth ◽  
2018 ◽  
Vol 6 ◽  
Author(s):  
Gregory Pelletier ◽  
Mindy Roberts ◽  
Mya Keyzers ◽  
Simone R. Alin
Keyword(s):  
Pilot Study ◽  
Surface Waters ◽  
Puget Sound ◽  
Phytoplankton Production ◽  
Carbonate System ◽  
Saturation State ◽  
Aragonite Saturation ◽  
Spatially Distributed ◽  
Long Term Trends

A pilot study of sampling, using monthly marine flights over spatially distributed stations, was conducted with the aim to characterize the carbonate system in Puget Sound over a full year-long period. Surface waters of Puget Sound were found to be under-saturated with respect to aragonite during October–March, and super-saturated during April–September. Highest pCO2 and lowest pH occurred during the corrosive October–March period. Lowest pCO2 and highest pH occurred during the super-saturated April–September period. The monthly variations in pCO2, pH, and aragonite saturation state closely followed the variations in monthly average chlorophyll a. Super-saturated conditions during April–September are likely strongly influenced by photosynthetic uptake of CO2 during the phytoplankton growing season. The relationship between phytoplankton production, the carbonate system, and aragonite saturation state suggests that long-term trends in eutrophication processes may contribute to trends in ocean acidification in Puget Sound.

scholarly journals Trends in soil solution dissolved organic carbon (DOC) concentrations across European forests

2016 ◽  
Author(s):  
M. Camino-Serrano ◽  
E. Graf Pannatier ◽  
S. Vicca ◽  
S. Luyssaert ◽  
M. Jonard ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Atmospheric Deposition ◽  
Soil Solution ◽  
Surface Waters ◽  
European Forests ◽  
Icp Forests ◽  
Level Ii ◽  
Long Term Trends

Abstract. Dissolved organic carbon (DOC) in soil solution is connected to DOC in surface waters through hydrological flows. Therefore, it is expected that long-term dynamics of DOC in surface waters reflect DOC trends in soil solution. However, a multitude of site-studies has failed so far to establish consistent trends in soil solution DOC, whereas increasing concentrations in European surface waters over the past decades appear to be the norm, possibly as a result from acidification recovery. The objectives of this study were therefore to understand the long-term trends of soil solution DOC from a large number of European forests (ICP Forests Level II plots) and determine their main physico-chemical and biological controls. We applied trend analys is at two levels: 1) to the entire European dataset and 2) to the individual time series and related trends with plot characteristics, i.e., soil and vegetation properties, soil solution chemistry and atmospheric deposition loads. Analyses of the entire dataset showed an overall increasing trend in DOC concentrations in the organic layers, but, at individual plots and depths, there was no clear overall trend in soil solution DOC across Europe with temporal slopes of soil solution DOC ranging between −16.8 % yr−1 and +23 % yr−1 (median= +0.4 % yr−1). The non-significant trends (40 %) outnumbered the increasing (35 %) and decreasing trends (25 %) across the 97 ICP Forests Level II sites. By means of multivariate statistics, we found increasing DOC concentrations with increasing mean nitrate (NO3−) deposition and decreasing DOC concentrations with decreasing me an sulphate (SO42−) deposition, with the magnitude of these relationships depending on plot deposition history. While the attribution of increasing trends in DOC to the reduct ion of SO42− deposition could be confirmed in N-poorer forests, in agreement with observations in surface waters, this was not the case in N-richer forests. In conclusion, long-term trends of soil solution DOC reflected the interactions between controls acting at local (soil and vegetation properties) and regional (atmospheric deposition of SO42− and inorganic N) scales.

scholarly journals Trends in nitrogen deposition and leaching in acid-sensitive streams in Europe

2001 ◽  
Vol 5 (3) ◽  
pp. 299-310 ◽  
Author(s):  
R. F. Wright ◽  
C. Alewell ◽  
J. M. Cullen ◽  
C. D. Evans ◽  
A. Marchetto ◽  
...  
Keyword(s):  
Surface Waters ◽  
Nitrogen Saturation ◽  
Inorganic Nitrogen ◽  
N Deposition ◽  
N Saturation ◽  
The Past ◽  
Run Off ◽  
Nitrate Concentrations ◽  
Long Term Trends

Abstract. Long-term records of nitrogen in deposition and streamwater were analysed at 30 sites covering major acid sensitive regions in Europe. Large regions of Europe have received high inputs of inorganic nitrogen for the past 20 - 30 years, with an approximate 20% decline in central and northern Europe during the late 1990s. Nitrate concentrations in streamwaters are related to the amount of N deposition. All sites with less than 10 kgN ha-1 yr-1 deposition have low concentrations of nitrate in streamwater, whereas all sites receiving > 25 kgN ha-1 yr-1 have elevated concentrations. Very few of the sites exhibit significant trends in nitrate concentrations; similar analyses on other datasets also show few significant trends. Nitrogen saturation is thus a process requiring many decades, at least at levels of N deposition typical for Europe. Declines in nitrate concentrations at a few sites may reflect recent declines in N deposition. The overall lack of significant trends in nitrate concentrations in streams in Europe may be the result of two opposing factors. Continued high deposition of nitrogen (above the 10 kgN ha-1 yr-1 threshold) should tend to increase N saturation and give increased nitrate concentrations in run-off, whereas the decline in N deposition over the past 5 – 10 years in large parts of Europe should give decreased nitrate concentrations in run-off. Short and long-term variations in climate affect nitrate concentrations in streamwater and, thus, contribute "noise" which masks long-term trends. Empirical data for geographic pattern and long-term trends in response of surface waters to changes in N deposition set the premises for predicting future contributions of nitrate to acidification of soils and surface waters. Quantification of processes governing nitrogen retention and loss in semi-natural terrestrial ecosystems is a scientific challenge of increasing importance. Keywords: Europe, acid deposition, nitrogen, saturation, recovery, water

scholarly journals Trends in soil solution dissolved organic carbon (DOC) concentrations across European forests

2016 ◽  
Vol 13 (19) ◽  
pp. 5567-5585 ◽  
Author(s):  
Marta Camino-Serrano ◽  
Elisabeth Graf Pannatier ◽  
Sara Vicca ◽  
Sebastiaan Luyssaert ◽  
Mathieu Jonard ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Atmospheric Deposition ◽  
Soil Solution ◽  
Surface Waters ◽  
N Deposition ◽  
Icp Forests ◽  
Level Ii ◽  
Long Term Trends ◽  
Increasing Trends

Abstract. Dissolved organic carbon (DOC) in surface waters is connected to DOC in soil solution through hydrological pathways. Therefore, it is expected that long-term dynamics of DOC in surface waters reflect DOC trends in soil solution. However, a multitude of site studies have failed so far to establish consistent trends in soil solution DOC, whereas increasing concentrations in European surface waters over the past decades appear to be the norm, possibly as a result of recovery from acidification. The objectives of this study were therefore to understand the long-term trends of soil solution DOC from a large number of European forests (ICP Forests Level II plots) and determine their main physico-chemical and biological controls. We applied trend analysis at two levels: (1) to the entire European dataset and (2) to the individual time series and related trends with plot characteristics, i.e., soil and vegetation properties, soil solution chemistry and atmospheric deposition loads. Analyses of the entire dataset showed an overall increasing trend in DOC concentrations in the organic layers, but, at individual plots and depths, there was no clear overall trend in soil solution DOC. The rate change in soil solution DOC ranged between −16.8 and +23 % yr−1 (median  = +0.4 % yr−1) across Europe. The non-significant trends (40 %) outnumbered the increasing (35 %) and decreasing trends (25 %) across the 97 ICP Forests Level II sites. By means of multivariate statistics, we found increasing trends in DOC concentrations with increasing mean nitrate (NO3−) deposition and increasing trends in DOC concentrations with decreasing mean sulfate (SO42−) deposition, with the magnitude of these relationships depending on plot deposition history. While the attribution of increasing trends in DOC to the reduction of SO42− deposition could be confirmed in low to medium N deposition areas, in agreement with observations in surface waters, this was not the case in high N deposition areas. In conclusion, long-term trends of soil solution DOC reflected the interactions between controls acting at local (soil and vegetation properties) and regional (atmospheric deposition of SO42− and inorganic N) scales.

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