No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Modeling and monitoring of long-term acidification in an upland catchment of the Western Ore Mountains, SE Germany
Abstract
Modeling and monitoring of acidification patterns in a limed forest catchment in the Ore Mountains, SE Germany are presented. A lumped-parameter model, MAGIC, satisfactorily reproduced the main parameters of stream water chemistry. Despite repeated whole-catchment liming, between 1993 and 1999 stream water pH increased from 4.3 to only 4.6, while calcium concentrations declined slightly. Stream water sulfate concentration declined from 687 to 396 microeq l(-1), and the pronounced effect of deposition decline during the 1990s was probably more important than liming.
... About 85% of the waters showed a rapid reversal from acidification, manifested by declining concentrations of protons, nitrate, sulfate, and reactive aluminum . Lorz et al. (2003) investigated another stream in a limed forest catchment of the Ore Mountains and satisfactorily reproduced the main trends (observation period 1993 to 1999) in pH, nitrate, sulfate, and aluminum concentrations using a lumped-parameter model for groundwater acidification (MAGIC). Despite the regular ameliorative liming of the catchment, calcium concentrations slightly declined. ...
... Despite the regular ameliorative liming of the catchment, calcium concentrations slightly declined. Lorz et al. (2003) concluded that in general, the short-term effects of ameliorative liming are low and recovery from acidification can only take place over long-term periods. Westermann (2000) analyzed 10 streams in Rhineland-Palatinate for the years 1983 to 1999 and found slowly weakening acidification conditions (large sulfate decrease, slightly increasing pH, reduction of aluminum peaks) whereas nitrate largely remained on a constant level. ...
... ents , the underlying bedrock has a low water permeability and fens developed in depressions and flat plateaus . The soils ( base - poor cambiols , haplic or cambic pozols , podzolic cambisols , peaty gleys , stagnog - ley , and gley ) are acid ( pH ( CaCl2 ) < 4 ) and have a low base saturation ( < 20% ) ( Alewell et al . 2001 ; Armbruster 1998 ; Lorz et al . 2003 ; Meesenburg et al . 2001 ; Moritz and Bittersohl 2000 ; Raben et al . 2000 ; Schaumburg et al . 2010 ) . Conse - quently , streams are poorly buffered . This study considers exclusively catchments with a forest percentage of at least 60% ( Appendix ) . Norway spruce ( Picea abies ) is the dominant forest tree , whilst beech ( Fagus syl ...
This study evaluates the acidification status and trends in streams of forested mountain ranges in Germany in consequence of reduced anthropogenic deposition since the mid 1980s. The analysis is based on water quality data for 86 long-term monitored streams in the Ore Mountains, the Bavarian Forest, the Fichtelgebirge, the Harz Mountains, the Spessart, the Black Forest, the Thuringian Forest, and the Rheinisches Schiefergebirge of Germany and the Vosges of France. Within the observation period, which starts for the individual streams between 1980 and 2001 and ends between 1990 and 2009, trends in chemical water quality were calculated with the Seasonal Mann Kendall Test. About 87% of the streams show significant (p < 0.05) negative trends in sulfate. The general reduction in acid deposition resulted in increased pH values (significant for 66% of the streams) and subsequently decreased base cation concentrations in the stream water (for calcium significant in 58% and magnesium 49% of the streams). Reaction products of acidification such as aluminum (significant for 50%) or manganese (significant for 69%) also decreased. Nitrate (52% with significant decrease) and chloride (38% with significant increase) have less pronounced trends and more variable spatial patterns. For the quotient of acidification, which is the ratio of the sum of base cations and the sum of acid anions, no clear trend is observed: in 44% of the monitored streams values significantly decreased and in 23% values significantly increased. A notable observation is the increasing DOC concentration, which is significant for 55% of the observed streams.
... Gunn et al. (2001) did not find a clear effect of liming on groundwater quality at a study site at Sudbury, Canada, within the first year. Peters et al. (1999) and Lorz et al. (2003) did not observe any effect of liming on stream water Ca concentration in two Czech shallow soil catchments. They ascribed that to ion exchange processes in the topsoil. ...
From a biogeochemical perspective, catchments can be regarded as reactors that transform the input of various substances via precipitation, deposition, or human activities as they pass through soils and aquifers towards receiving streams. Understanding and modeling the variability of solute concentration in catchment waters require the identification of prevailing processes, determining their respective contributions to the observed transformation of substances, their interplay with hydrological processes, and the determination of anthropogenic impacts. However, numerous biogeochemical processes often interact in a highly non-linear way and vary on temporal and spatial scales, resulting in temporally and spatially varying water chemistry in catchments. This is particularly true for riparian wetlands. Processes in this catchment area often superimpose the influence of the hill slope (and largest) area of the catchment on surface water quality. Accordingly, the first part of this thesis (Study 1 and 2), focuses on the temporal and spatial variability of biogeochemical processes at the catchment scale. Therefore, the first aim was to identify the prevailing biogeochemical processes which affect the quality of catchment waters in two forested granitic catchments. Based on these results, (i) the long-term behavior of these processes was determined (Study 1) and (ii) hot spots of these processes at the catchment scale along different flow paths were identified (Study 2). The second part (Study 3) focuses on the interplay between hydrological and biogeochemical processes in a riparian wetland, with the aim of systematically tracing back the temporal patterns of stream water chemistry to different biogeochemical processes and antecedent hydrological boundary conditions in the wetland. The third part (Study 4 and 5) focuses on weathering processes with the goal (i) of identifying the mineralogical sources of the groundwater’s buffer capacity against acid atmospheric deposition in a forested granitic catchment and (ii) determining the mineralogical sources of the high cation loads in surface water, induced by intensive agricultural activities in two agricultural granitic catchments. To reach these aims, multivariate statistical methods of dimensionality reduction (linear Principal Component Analysis, non-linear Isometric Feature Mapping), a low-pass filtering of time-series, a Cluster analysis, and major and trace element ratios and strontium isotopes were used. A small number of biogeochemical process bundles explained 94% and 89% of the variance of the data set in Study 1 and 2, respectively. In Study 1, redox and topsoil processes, road salt and sulfate contamination were identified as predominating processes influencing water chemistry in the respective catchments. Low-pass filtered time series of component scores revealed a different long-term behavior at different sampling sites in both catchments, which could be traced back to the fraction of wetland area in the respective subcatchments as well as by the varying thickness of the regolith. Study 2 revealed that the upper 1 m topsoil layer could be considered as a biogeochemical hot spot for redox processes, acid-induced podsolization, and weathering processes along different flow paths. Up to 97% of the biogeochemical transformation of the chemical composition of soil solution, groundwater and stream water in the Lehstenbach catchment was restricted to this soil layer representing less than 2% of the catchment’s regolith. Wetland stream water, mobilized in the topsoil layer being considered a biogeochemical hot spot, showed a highly dynamic temporal pattern of component scores. Study 3 revealed four different types of wetland stream water chemical status, depending on the interplay between discharge dynamics, biological activity, and the water table position in the wetland. The sequence of different stream water types roughly followed a seasonal pattern, albeit being heavily modified by the respective hydrological boundary conditions for different years. Extended periods of low groundwater level in the second half of the growing season drastically changed the chemical boundary conditions, becoming evident in a drastic reoxidation of reduced species like sulfides and corresponding effects. Weathering processes are one of the predominating biogeochemical process bundles influencing water chemistry in forested catchments. Study 4 showed that the mineralogical sources of the groundwater’s buffer capacity against acid atmospheric deposition were dominated by the release of base cations from apatite dissolution, preferential cation release from feldspars and biotite, and feldspars weathering. In Study 5, determining the mineralogical sources of the high cation loads in surface water induced by intensive agricultural activities revealed a dominant manure contribution in the topsoil, and enhanced mineral dissolution (plagioclase and biotite) by fertilizer application in subsoils, becoming the unique source of base cations in the saprolite. Stream water chemistry differed from that of soil water, suggesting that stream water chemistry was dominated by elements issued from enhanced mineral and rock weathering. Soil acidification induced by agriculture allows the mobilization of cations stored in soil layers, enhances the rock weathering and accelerates plagioclase dissolution, which can highly influence stream water quality. Numerous biogeochemical, hydrological, and anthropogenic processes were found to interact with each other, mostly with non-linear patterns, influencing catchment water chemistry. The integral approach used in this thesis would be a useful prerequisite to develop accurate and parsimonious models commonly used for water management purposes by distinguishing between short- term and long-term shifts, reducing the number of processes to the predominating ones ultimately to be included in the model, focusing on hot spots and including spatial patterns where necessary and appropriate.
... Other studies are dealing with the management and function of forests in smaller water protection areas or the interaction between forest management and pollutant input into stream waters or reservoirs (e.g. Lorz et al., 2003). ...
... The addition of neutralising agents such as lime and dolomite to hydrological source areas has been successful in ameliorating the effects of surface water acidification across sensitive regions. Case studies in the UK ), Scandinavia (Löfgren et al., 2009), mainland Europe (Lorz et al., 2003) and North ...
... Gunn et al. (2001) did not find a clear effect of liming on groundwater quality at a study site at Sudbury, Canada, within the first year. Peters et al. (1999) and Lorz et al. (2003) did not observe any effect of liming on stream water Ca concentration in two Czech shallow soil catchments. They ascribed that to ion exchange processes in the topsoil. ...
The role of different minerals in base cation release and thus the increase of buffering capacity of groundwater against acid deposition is controversially discussed in the literature. The ⁸⁷Sr/⁸⁶Sr ratios and base cation concentration were investigated in whole rock leachates, mineral separates, precipitation, soil solution, groundwater and stream water samples in the Lehstenbach catchment (Germany) to identify the weathering sequence of the granite bedrock. Three different approaches were followed in parallel. It was assumed that the contribution of different minerals to base cation supply of the groundwater with increasing weathering intensity would be observed by investigating (1) unweathered rock leachates, deep groundwater and shallow groundwater, (2) groundwater samples from new groundwater wells, reflecting the initial weathering of the drilled bedrock, and groundwater from wells that were drilled in 1988, (3) stream water during baseflow, dominated by deep groundwater, and stream water during high flow, being predominantly shallow groundwater. Whereas the first approach yielded consistent patterns, there was some evidence that groundwater from the new wells initially reflected contamination by the filter gravel rather than cation release in an initial stage of weathering. Time series samples of stream water and groundwater solute concentrations and isotope ratios turned out to reflect varying fractions of soil water and precipitation water at baseflow and high flow conditions rather than varying contributions of different minerals that prevail at different stages of granite weathering.
... Studies in which no ameliorative effects of catchment liming on surface waters were found are also known, however. Lorz et al. (2003) repeatedly limed a forest catchment in the Ore Mountains (Germany) over a period of 7 years and found only a small increase in pH and decreasing concentrations of Ca 2+ and Mg 2+ . Possibly, groundwater discharge from humic forest soils is more difficult to ameliorate due to their high (potential) CEC, whereas sod-cut heathland soils are predominantly mineral. ...
Current restoration measures of degraded, acidified heathland ecosystems have not always been successful in the Netherlands. Positive effects of a restored hydrology are often counteracted by acidification of the soil and the local groundwater system. Liming of the heathlands in the catchment of moorland pools might contribute to the restoration of both habitats. Experimental catchment liming was carried out in two degraded Dutch heathlands, with doses varying between 2 and 6 tons/ha. Catchment liming resulted in increased pH and base cation concentrations in the highest elevated limed parts, as well as in the lower situated, nonlimed heath areas and moorland pools. Generally, catchment liming created suitable conditions for the return of heathland target species, and the positive effects lasted for at least 6 years. The response of the heathland vegetation to the liming has, however, been slow because only a small number of endangered plant species increased in abundance. In contrast, four Red List soft-water macrophytes strongly increased in abundance in the moorland pool. Our results show that, even with the slow return of Red List plant species, catchment liming can be a successful management tool for the restoration of the acidified heathland landscape.
... Studies in which no ameliorative effects of catchment liming on surface waters were found, are also known, however. Lorz et al. (2003) repeatedly limed a forest catchment in the Ore Mountains (Germany) over a period of 7 years and found only a small increase in pH and decreasing concentrations of Ca 2+ and Mg 2+ . Possibly, groundwater discharge from humic forest soils is more difficult to ameliorate due to their high (potential) cation exchange capacity (CEC), whereas heathland soils are predominantly mineral. ...
... The examples published in this special issue show how these data are contributing to the detection of environmental problems and their solution. Issues being addressed include: climate change (Hawkins et al., 2003; Hejzlar et al., 2003; Knights, 2003; Reading, 2003), atmospheric pollution (Forsius et al., 2003; Hirst and Storvik, 2003; Lorz et al., 2003; McCartney et al., 2003), land managementyland use change (Eldridge and Koen, 2003; Foy et al., 2003; Tibby, 2003); catchment management (Burt, 2003; Foy et al., 2003; Folster et al., 2003; Harriman et al., 2003; Sear and Newson, 2003), marine ecosystems (Hawkins et al., 2003; Knights, 2003), water quality (Edmunds et al., 2003; Mitikka and Ekholm, 2003; Raike et al., 2003; Vrba et al., ¨ 2003), fisheries management (Knights, 2003; McCartney et al., 2003; Vrba et al., 2003) and biodiversity protection (Greenwood, 2003; Ling, 2003; Purvis et al., 2003). ...
Widespread concern over the state of the environment and the impacts of anthropogenic activities on ecosystem services and functions has highlighted the need for high-quality, long-term datasets for detecting and understanding environmental change. In July 2001, an international conference reviewed progress in the field of long-term ecosystem research and monitoring (LTERM). Examples are given which demonstrate the need for long-term environmental monitoring and research, for palaeoecological reconstructions of past environments and for applied use of historical records that inform us of past environmental conditions. LTERM approaches are needed to provide measures of baseline conditions and for informing decisions on ecosystem management and environmental policy formulation. They are also valuable in aiding the understanding of the processes of environmental change, including the integrated effects of natural and anthropogenic drivers and pressures, recovery from stress and resilience of species, populations, communities and ecosystems. The authors argue that, in order to realise the full potential of LTERM approaches, progress must be made in four key areas: (i) increase the number, variety and scope of LTERM activities to help define the operational range of ecosystems; (ii) greater integration of research, monitoring, modelling, palaeoecological reconstruction and remote sensing to create a broad-scale early warning system of environmental change; (iii) development of inter-disciplinary approaches which draw upon social and environmental science expertise to understand the factors determining the vulnerability and resilience of the nature-society system to change; and (iv) more and better use of LTERM data and information to inform the public and policymakers and to provide guidance on sustainable development.
The natural environment is subject to constant transformation and change as a result of natural factors and human activity. Understanding these mechanisms, as well as identifying the multidirectional trends underlying these environmental changesis of great theoretical and practical importance. The changes taking place in the natural environment are not only local and regional, but also global. Although they proceed slowly, they often lead to disastrous consequences. It is necessary, therefore, to know the mechanisms of the natural environment. This knowledge should be based on a solid understanding of how nature developed in the past, a diagnosing of its current condition, and the ability to identify future trends.
The aim of this research was to analyse the functioning of three geoecosystems located within low mountains and foothills, and affected by various human pressure factors, including alkaline emissions and acidification, both of a local type. The study was conducted over roughly a decade from 2002–2011 in geoecosystems located on the border of the Low Beskids and Carpathian Foothills (Szymbark), and in the region of the Świętokrzyskie Mountains (Święty Krzyż, Malik). The studies were conducted on experimental plots in stands of deciduous and coniferous trees. At Święty Krzyż, the study was conducted in forests of Dentario glandulosae-Fagetum, in Szymbark in a lime-oak-hornbeam forest (Tilio-Carpinetum), and in Malik in a pine forest (Dicrano-Pinion). The research methods used were consistent with those employed in Integrated Environmental Monitoring. In addition, observations were made of the assimilation organs of fir, spruce, and pine using a Quanta 250 scanning electron microscope (SEM). Differentiation in the studied geoecosystems’ location, elevation above sea level, meteorological conditions, and forest species composition affected the size and source of the incoming air pollution, which in turn determined their functioning. The study showed that in conditions of varying types and intensity of human impact on the geoecosystems, their reaction depended on the location of emission sources, terrain orography, weather conditions, and the systems’ general sensitivity to change.
The functioning of the selected geoecosystems wassignificantly influenced by local, regional and remote SO2 and NO2 emissions, the level of which varied depending on meteorological conditions and the period in which they occurred. Another influencing factor was cross-border pollution, reaching the Świętokrzyskie Mountains from the Czech Republic and Slovakia, and the Low Beskids and Carpathian Mountains from Slovakia, as well as pollution originating in the Upper Silesian Industrial Region. Local emissions related primarily to the municipal sector, while in the south-western part of the Świętokrzyskie Mountains (Malik) there was additional influence from the cement and lime industry. Because the geoecosystem located in the central part of the Świętokrzyskie Mountains (Święty Krzyż) is distinctly elevated above the surrounding region, it is exposed to increased human pressure. The ten-year average value of SO2 concentrations was respectively 1.6 and 2.5 times higher in comparison with the geoecosystem of Malik and Szymbark. In the Świętokrzyskie Mountains’ geoecosystems, horizontal sediments play a significant role in affecting the amount of precipitation reaching the soil. This phenomenon was most clearly marked in the central part of the coniferous stands and occurred mainly during autumn and winter months. This phenomenon was not observed in the Bystrzanka catchment (Szymbark).
When evaluating the chemical denudation of a geoecosystem, the deposition of elements in atmospheric precipitation and their transformation in trees plays a crucial role, providing a significant source of the matter circulating in the water catchments. In addition to wet deposition, dry deposition also has a significant impact on the matter balance sheet. Within the forest ecosystem, depending on species composition, the amount of precipitation reaching the forest floor in the form of throughfall and stemflow varies substantially – both being higher in deciduous forests. The factors affecting the amount of precipitation reaching the forest floor include the amount of bulk precipitation, relative humidity and air temperature, the structure and density of tree crowns, seasonal changes, distance from the tree trunk, circumference of the trunk, Summary 150 and roughness of the bark. When passing through tree crowns, water coming from bulk precipitation becomes significantly more acidic or alkaline, depending on the type of human pressure factors present, thus increasing the amount of elements deposited in the soil. This, in turn, affects the rate at which components leach from the soil. It was found that in the studied geoecosystems, an increase in conductivity occurred in the following order: bulk precipitation> throughfall within deciduous stands> stemflow within deciduous stands > throughfall within coniferous stands> stemflow within coniferous stands.
Bulk precipitation deposition in the tested systems displayed the following diversity:
– Malik: SO42– > NO3– > Ca2+ > Cl– > Mg2+ > Na+ > K+> NH4+ ,
– Święty Krzyż: SO42 – > NO3– > Ca2+ > Cl – > Mg2+ >NH4+ > Na+ > K+ ,
– Szymbark: NO3– > SO42– > NH4+ > Ca2+> Cl– > Na+ > K+ > Mg2+.
In temperate forest ecosystems affected by acidic pollutants, the volume of potassium leaching from trees occurs in the following order: autumn (the largest)> summer> spring> winter. The intensity of this process is affected by species composition, the volume of acid deposition, seasonal changes, and the physical-chemical composition (pH) of the precipitation. Rainwater running down tree trunks become acidic regardless of the type of pollutants and tree species. Acidic water reaching the forest floor causes the highest level of soil acidification near the tree trunks, affecting the spatial variability of the rates of soil leaching. Acidification decreases with distance from the tree trunk. The amount of elements present in the surface layer of the soil surrounding deciduous trees decreases with the distance from the trunk; and increases in the case of conifers. The study of pH spatial distribution affected by distance from the trunks of the trees indicates that the greatest acidification occurs within 10 cm of the trunk. In Szymbark, acidification levels reached the silicate buffer range (4.2≥pH>3.8), as well as the aluminum and iron range (3.8≥pH>3.2); in the Święty Krzyż geoecosystem, it was iron (pH <3.2); in Malik – calcium carbonate (pH> 6.3). Among the metals studied, lead was of the greatest importance from the point of view of anthropogenic soil stress in geoecosystems. The highest average lead content in soil samples was found in Święty Krzyż – 77.8 μg∙g–1 d.m., then in Malik – 38.7 μg∙g–1 d.m., and, finally, in Szymbark – 30.0 μg∙g–1 d.m. These values exceed the geochemical baseline. The factor most affecting the surface waters in the studied geoecosystems was calcium of anthropogenic origin. The lowest average calcium concentration levels in soil samples were measured at 287.9 μg∙g–1 d.m. in the Święty Krzyż geoecosystem, in the central part of the Świętokrzyskie Mountains. Values higher by a factor of at least 1.6 were recorded in Szymbark (462.8 μg∙g–1 d.m.), while the measurements in Malik, in the south-western part of the Świętokrzyskie Mountains, indicated a 14-fold increase in calcium (4156.3 μg∙g–1 d.m.). The results can be extrapolated to other areas of lower mountains in Europe in an analysis of the morphogenetic processes and geochemical cycles occurring within catchment areas.
The acidification of stream water affects the water quality in smaller drinking water reservoirs of the upper western Ore Mountains since the 1960's considerably. In the last decade the reduction of emissions - e.g. in scope of the Gothenburg Protocol - and the effect of liming caused the recovery of these surface waters. The stream water chemistry with special regard to liming is the main interest of this study in a catchment in the upper Western Ore mountains. Data from monitoring are analyzed to show the trends of acidification related compounds, as sulfate, nitrate, aluminum, dissolved organic carbon (DOC), and base cations. The interpretation of time series supports the idea of a low effect of liming carried out in the catchment.
Since the 60s the water quality of smaller stream waters in forested hydrological catchments in Central Europe is considerably affected by acidification processes. The observed recovery during the last decade is related to the reduction of emissions - e.g. in scope of the Gothenburg protocol - and the terrestrial liming. Subject of the contribution is t he comparison of the water chemistry of stream waters in two catchments in the upper elevations of the Westerzgebirge (Western Ore Mts.), SE Germany and of the Łysogóry massif in the Gory Świetokrzyskie (Holy Cross Mts.), SE Poland. Therefore, data from current monitoring programs are analyzed in order to show trends for acidification related compounds such as sulfate, nitrate, aluminum, and base cations. The aim of the comparison is the prognosis of the future development of water quality in small mountain stream waters against the background of the EU Water Framework Directive.
AbstRAct Lorz, C.; kowaLkowski, a.; Jóźwiak, M.; kozłowski, r.; sChneider, B.: The recovery of acidified stream waters – A comparative case study from the Western Ore Mts. (Erzgebirge) and the Holy Cross Mts. (Świętokrzyskie Mts.). – Hercynia N.F. 38 (2005): 41 – 58. Since the 60s the water quality of smaller stream waters in forested hydrological catchments in Central Europe is considerably affected by acidification processes. The observed recovery during the last decade is related to the reduction of emissions -e.g. in scope of the Gothenburg protocol – and the terrestrial liming. Subject of the contribution is the comparison of the water chemistry of stream waters in two catchments in the upper elevations of the Westerzgebirge (Western Ore Mts.), SE Germany and of the Łysogóry massif in the Gory Świętokrzyskie (Holy Cross Mts.), SE Poland. Therefore, data from current monitor-ing programs are analyzed in order to show trends for acidification related compounds such as sulfate, nitrate, aluminum, and base cations. The aim of the comparison is the prognosis of the future devel-opment of water quality in small mountain stream waters against the background of the EU Water Framework Directive.
Lake Store Hovvatn and the adjacent Lake Lille Hovvatn (Norway) are acidified owing to long-term deposition of S and N. By 1974, pH was 4.46 and acid-neutralizing capacity was 42 µequiv.·L1. Following a lake SO4 reduction from 92 to 33 µequiv.·L1, pH had increased to 4.8 and acid-neutralizing capacity had increased to 8 µequiv.·L1 by 2003. The acidification history is well reconstructed using the dynamic model MAGIC. The model predicts that the lakes will not, however, recover to conditions adequate to support a self-reproducing brown trout (Salmo trutta) population. Lake Store Hovvatn was first limed in 1981 and subsequently annually or biannually until 1999, at which time the entire catchment was limed. Liming increased pH to above target levels of 6.0 and reduced inorganic Al to below 5 µequiv.·L1 in the main water body. Only after the terrestrial liming in 1999, however, was pH potentially adequate for egg survival in the lake during winter, as pH at shallow depths below the ice stayed above 5.5. The results indicate that even the dramatic reduction in acid deposition in Europe will be insufficient to provide water quality adequate for fish populations; such lakes will require some sort of liming for many decades to come.
Strongly decreasing atmospheric emissions and acidic deposition during the 1990s have initiated chemical reversal from acidification
in several drinking-water reservoirs of the Erzgebirge, SE Germany. We studied responses of phytoplankton, zooplankton and
fish stocks in five reservoirs and at enclosure scale after experimental neutralization of 1,200m3 of lake water. About 4months after this treatment, diatoms and cryptomonads replaced the predominating chrysophytes and
dinoflagellates. The colonization by acid-sensitive species of green algae, cryptomonads, rotifers and Cladocera (e.g. Bosmina longirostris) is explained by the occurrence of dormant stages or by survival of individuals in very low abundances. Analogous to the
enclosure experiment, three reservoirs showed significantly (p < 0.01) falling trends of chlorophyll a and phytoplankton biovolume, mainly due to the decline of dinoflagellates. Picoplankton and diatoms increased slightly in
two reservoirs. The zooplankton communities were dominated by rotifers and small Cladocera. Representatives of the genus Daphnia were lacking. Two reservoirs were re-colonized by zooplanktivorous fish populations of either perch (Perca fluviatilis) or sunbleak (Leucaspius delineatus). The latter exhibited extremely high fluctuating abundance and biomass and even suffered from a population crash. This natural
mortality was caused by a limited food supply. Hence, severe top-down control may delay the recovery of larger zooplankton
species like daphnids. Fishery management comprising the introduction of predatory fishes can help to control zooplanktivorous
fish populations and to prevent their mass mortality.
This paper emphasizes the need of an improved consideration of the spatial distribution and functionality of forests in river basin management. The review of relevant papers has shown that forests, despite their frequent occurrence in temperate zones, play presently only a minor role in river basin management. In general, most of the studies highlight the positive effect of forests on water and nutrient fluxes in river basins. But hydrologists have also reported consistently flood events in or originating from forested areas. In context of the discussion on forest ecology and water quality it became obvious, that forest ecosystems can be sources depending on system properties, time and atmogenic pollution.The simulation of land use changes on water yield in forested river basins has been carried out in a great number of research projects, but mostly without considering the spatial distributed function of forests. The objective of our work is thus to improve the consideration of spatial distribution of forests in river basins and its effect on water yield and water quality. The most promising approaches in the future are either spatial explicit models or integrated models with both improved forest modules and landscape positioning. The efficiency of these models could be proved by using virtual catchments. As a first conceptual approach towards the base concept of a virtual catchment, we propose a five-units-model (FUM), representing cross-sections with typical land use sequences. The basic idea of our model is to identify major process units and to implement them in the river basin modeling and management.
In two Czech catchments covered by Norway spruce forests, the MAGIC model was used to simulate annual stream water and soil chemistry for the period 1851-2030. These two sites represent geochemical end-members of ecosystem sensitivity to acidification (acid-sensitive granitic Lysina catchment vs. acid-resistant serpentinitic Pluhuv Bor catchment). Although the total deposition of sulphur to the catchments declined by 75% between 1990 and 2002, the recovery of stream water pH was relatively small over this period. At Lysina, the annual discharge-weighted mean pH of stream water increased only from 3.92 to 4.01. although SO4 concentration declined very sharply from 570 μeq L-1 in 1990 to 150 μeq L-1 in 2002. Stream water buffering was caused mainly by dissociation of organic acids. At Pluhuv Bor, the annual mean pH varied inversely with the annual discharge. Stream water concentrations of SO4 declined dramatically at Pluhuv Bor, from 1040 μeq L-1 in 1992 to 220 μeq L-1 in 2002. Using atmospheric deposition as specified in the Gothenburg Protocol, the model predicts that, at Lysina, stream water pH will increase to 4.3 and soil base saturation will increase to 6.0% by 2030 (from 5.6% in 2002): corresponding pre-industrial stream water pH was simulated to be 5.5 and soil base saturation to be 25%. At Pluhuv Bor, the pre-industrial pH was estimated to be 7.2 and the corresponding base saturation was 94%. Large anthropogenic acidification in the 20th century caused only a small decline in pH (to 6.9) and base saturation (to 88%). Simulations in accordance with the Gothenburg Protocol predict that the pH should increase by 0.2 pH units and the base saturation by 1% by 2030. Under this protocol, critical loads of atmospheric deposition for SO4 and NO3 will not be exceeded at Pluhuv Bor but will be exceeded at Lysina.
This study evaluates chemical trends of seven acidified reservoirs and 22 tributaries in the Erzgebirge from 1993 to 2003. About 85% of these waters showed significantly (p < 0.05) declining concentrations of protons (-69%), nitrate (-41%), sulfate (-27%), and reactive aluminum (-50% on average). This reversal is attributed to the intense reduction of industrial SO2 and NOx emissions from formerly high levels, which declined by 99% and 82% in the German-Czech border region between 1993 and 1999. The deposition rates of protons and sulfur decreased by 70-90%. Since 1993, the dry deposition of total inorganic nitrogen diminished to a minor degree, but the wet deposition remained unchanged. The surface waters reflect a substantial decrease in Al exchange processes, a release of sulfur previously stored in soils, and an uptake of nitrate by forest vegetation. The latter effect may be supported by soil protection liming which contributed to the chemical reversal in almost 20% of the study waters.
The effects of the ameliorative liming of a whole catchment on soil chemistry, soil solution, streamwater, and nutrition of the trees were studied at Steile Bramke, Harz mountains, Germany. Nine years after liming most of the added Ca and Mg are stored in the organic layer. Only in the top mineral soil substantial higher pools of Ca and Mg can be observed. In soil solution improved conditions for tree roots occurred within the main rooting zone. Streamwater has been nearly unaffected until present. The nutrition of the trees with Mg, Ca and P has been improved significantly. Long-term simulations suggest a duration of the liming effects of about 150 years.
Ecosystem modeling is confronted with complex biological systems and changing environmental conditions. A model which describes ecosystem behavior under all conditions has not been found yet and there does not exist one `true' model for a specific ecosystem. Often ecosystem models describe the measured data more or less well, but most judging criteria for model performance are rather subjective. Furthermore, from a mathematical view point the calibrations of ecosystem models are hardly ever unique. The aim of this study was to develop and use criteria which permit an objective comparison of different models to the observed field data and to each other. A given model which describes a specific system significantly better will be declared the `valid' model while the other will be rejected. The term `valid' is used here in a sense that any model that could not be proven invalid would be a valid model for the system. We used the biogeochemical soil models MAGIC (Cosby, B.J., Hornberger, G.M., Wright, R.F., 1985. Modelling the effects of acid deposition: assessment of a lumped-parameter model of soil water and stream water chemistry. Water Resour. Res. 21, 51–63) and the SO-Model (derived from the Batch Equilibrium Model (BEM; Prenzel, J., 1991. Introduction to BEM (Batch Equilibrium Model), vol 28. Berichte des Forschungszentrums Waldökosysteme/Waldsterben, Göttingen, 51 pp.). The data set used was the soil solution chemistry in a forest ecosystem of the Solling area (North-West Germany). To test the performance of the models four criteria were used: the efficiency (Martinec, J., Rango, A., 1989. Merits of statistical criteria for the performance of hydrologic models. Water Resour. Bull. 25 (2), 421–432; Hinzman, L.D., Kane, D.L., 1991. Snow hydrology of a headwater artic basin; 2. Conceptual analysis and computer modelling. Water Resour. Res. 27, 1111–1121), the Normalized Mean Absolute Error (NMAE, given by Janssen, P.H.M., Heuberger, P.S.C., 1995. Calibration of process orientated models. In: van Grinvsen, J.J.M. (Ed.), Modelling Water, Carbon and Nutrient Cycles in Forests: Application of 16 Simulation Models to a Spruce Stand at Solling, Germany. Ecological Modelling, vol. 83, pp. 55–66), the confidence interval test (CIT, developed in this study) and the model rejection criteria (Sun, N.Z., 1994. Inverse Problems in Groundwater Modelling. Dordrecht, 337 pp.). Whereas the efficiency and NMAE are related to the averaged data, the CIT and the model rejection criteria include the spatial heterogeneity at every time step. When evaluated visually, both model results might be accepted. From the application of the model performance criteria we selected the MAGIC model as the `valid' model for our system.
The main objective of this study was to investigate long-term streamwater patterns in two catchments exhibiting different geology. The catchments are situated in the Slavkov Forest, in the western Czech Republic. The 27-ha Lysina catchment is under- lain by base-poor leucogranite and the 22-ha Pluhův Bor catchment is underlain by Mg- rich serpentinite. They are forested by Norway spruce (Picea abies) plantations and they are located 7 km apart. Lysina exhibited incomplete neutralization of mineral acids and it showed low streamwater pH and elevated concentrations of Al. Pluhův Bor exhibited efficient neutralization of acids by weathering of Mg-rich silicates. It showed near neutral streamwater pH (Krám et al., 1997). The strong decline in atmospheric deposition of sulfur in the study area in the 1990s (Hruška et al., 2002) resulted in changes of streamwater chemistry in the study catchments. Time series of streamwater concentrations showed a significant decrease of SO4 at Lysina and Pluhův Bor over the periods 1989-2001 and 1991-2001, respectively. SO4 declined at mean rates of 28 µeq L-1 yr-1 (Lysina) and 50 µeq L-1 yr-1 (Pluhův Bor). Annual volume-weighted mean SO4 declined from 568 µeq L-1 in 1990 to 232 µeq L-1 in 2000 at Lysina. Pluhův Bor experienced extremely large decline of SO4 from 1035 µeq L -1 in 1992 to 332 µeq L-1 in 2000. These declines corresponded with very slight changes of pH (Fig. 1). At the acidic Lysina catchment, pH increased at a mean rate of 0.02 pH units yr-1. Despite the large decrease in SO4 concentrations, pH did not change appreciably at Pluhův Bor (Fig. 1) probably because the concentration of organic acids increased. Marked decreases in concentrations of the base cations (Ca, Mg, K, Na) were not observed at Pluhův Bor. At Lysina the decline of SO4 was accompanied by a decrease of base cations at a mean rate of 16 µeq L-1 yr-1.
Quantitative predictions of the effects of acid deposition onterrestrial
and aquatic systems require physically based, process-oriented models of
catchment soil water and streamwater chemistry. A desirable
characteristic of such models is that they include terms to describe the
important phenomena controlling a system's chemical response to acidic
deposition, yet be restricted in complexity so that they can be
implemented on diverse systems with a minimum of a priori data. We
present an assessment of a conceptual model of soil water and
streamwater chemistry based on soil cation exchange, dissolution of
aluminum hydroxide, and solution of carbon dioxide, all processes that
occur in catchment soils and that have rapid equilibration times. The
model is constructed using an "average" or lumped representation of
these spatially distributed catchment processes. The adequacy of the
model is assessed by applying it to 3 years of soil water and
streamwater chemistry data from White Oak Run, Virginia, a second-order
stream in the Shenandoah National Park. Soil properties predicted by the
model are in good agreement with presently available measurements of
those soil properties. The success of the model suggests that lumped
representations of complex and spatially distributed chemical reactions
in soils can efficiently describe the gross chemical behavior of whole
catchments (e.g., pH, alkalinity, and major ionic concentrations in
surface waters). Further assessment of the adequacy of this conceptual
approach will require more detailed empirical knowledge of the soil
processes being modeled, particularly soil cation exchange and the
variability of soil CO2 partial pressures.
In June 1983 a whole-catchment liming experiment was conducted at Tjønnstrond, southernmost Norway, to test the utility of terrestrial liming as a technique to restore fish populations in remote lakes with short water-retention times. Tjønnstrond consists of 2 small ponds of 3.0 and 1.5 ha in area which drain a 25-ha catchment. The area is located at about 650–700 meters above sea-level in sparse and unproductive forests of spruce, pine and birch with abundant peatlands. A dose of 3 ton/ha of powdered limestone were spread by helicopter to the terrestrial area. No limestone was added to the ponds themselves. The ponds were subsequently stocked with brown and brook trout.
Liming caused large and immediate changes in surface water chemistry; pH increased from 4.5 to 7.0, Ca increased from 40 to 200μeq/L, ANC increased from −30 to +70μeq/L, and reactive-Al decreased from about 10 to 3μmol/L. During the subsequent 11 years the chemical composition of runoff has decreased gradually back towards the acidic pre-treatment situation. The major trends in concentrations of runoff Ca, ANC, pH, Al and NO3 in runoff are all well simulated by the acidification model MAGIC. Neither the measured data nor the MAGIC simulations indicate significant changes in any other major ion as a result of liming.
The soils at Tjønnstrond in 1992 contained significantly higher amounts of exchangeable Ca relative to those at the untreated reference catchment Storgama. In 1992 about 75% of the added Ca remains in the soil as exchangeable Ca, 15% has been lost in runoff, and 10% is unaccounted for.
The whole-catchment liming experiment at Tjønnstrond clearly demonstrates that this liming technique produces a long-term stable and favourable water quality for fish. Brown trout in both ponds in 1994 have good condition factors, which indicate that the fish are not stressed by marginal water quality due to re-acidification. The water quality is still adequate after 11 years and >20 water renewals. Concentrations of H+ and inorganic Al have gradually increased and approach levels toxic to trout, but the toxicity of these are offset by the continued elevated Ca concentrations. Reduced sulphate deposition during the last 4 years (1990–94) has also helped to slow and even reverse the rate of reacidification. The experiment at Tjønnstrond demonstrates that for this type of upland, remote terrain typical of large areas of southern Norway, terrestrial liming offers a suitable mitigation technique for treating acidified surface waters with short retention times.
The results from two whole-catchment manipulation experiments in Norway are used to evaluate MAGIC (Model of Acidification of Groundwater In Catchments), a model of ecosystem biogeochemical response to acid deposition. MAGIC is an aggregated catchment-scale model of acidification that has been widely used in assessment activities in Europe and North America. The experiments involved artificial decrease (Reversing Acidification In Norway, RAIN) and increases (Humid Lake Acidification Experiment, HUMEX) in acidic deposition. Runoff from both sites is influenced by moderate levels of organic acids. At each site the model was calibrated to the control catchment and then applied to the manipulated catchments with only minor adjustments. The major responses in runoff chemistry to the manipulations were closely simulated by the model. Differences between simulated and observed volume-weighted annual average concentrations of all major ions were less than ±6 μequiv 1−1 for the entire 4–8 year period of prediction. Trends in response to the manipulations were correctly simulated. Most of the residual error resulted from an inability of the model to reproduce the year-to-year variability (noise) around the trends. Although such model evaluations cannot ‘prove’ the correctness of the model structure, good fits to experimental data increase confidence in model applications for assessment and management purposes. Evaluations of this sort can also identify aspects of the model that need further development. For MAGIC, these are primarily a need for improvement in the calibration of aluminium solubility and a better process basis for nitrogen dynamics.
Zugl.: Leipzig, Univ., Diss., 1999.
The geochemical model MAGIC was applied to estimate streamwater and soil chemistry between 1851 and 2030 at the Lysina catchment, an acid-sensitive granitic catchment covered by planted Norway spruce monoculture in the western Czech Republic. The total deposition of sulfur to the catchment was 164 meq m(-2) in 1991, but had declined to 52 meq m(-2) by 2000. Although SO2 emissions in the region declined by 90% compared to the 1980s, acidification recovery was small within the period 1990-2000. Stream pH increased only slightly (from 3.92 to 4.07), although SO4 concentration declined sharply from 568 microeq l(-1) (1990) to 232 microeq l(-1) (2000). Organic acids played an important role in streamwater buffering. According to the MAGIC prediction using deposition measured in 1999-2000, streamwater pH will increase to 4.3 and soil base saturation will increase to 6.2% by 2030 (from 5.7% in 2002). Pre-industrial pH was estimated to be 5.5 and soil base saturation 24.7%. The loss of base cations (Ca, Mg, Na, K) was caused predominantly by atmospheric acidity, but intensive forestry was responsible for approximately one third of the net base cation loss via accumulation in harvested biomass. Severely damaged sites, under continued pressure from forestry, will not return to a good environmental status in the near future (if ever) when the acid deposition input is only partially reduced.
Geochemical modelling of acidification and recovery in forest soils and runoff waters, IVL Report B 1323 Gothenburg: Swedish Environmental Research Institute Whole-catchment liming at Tjønnstrond, Norway: an 11-year record
- F Moldan
- O Westling
- Munthe
- Traaen Ts
- T Frogner
- A Hindar
- E Kleiven
- A Lande
- Wright
Moldan F, Westling O, Munthe J. Geochemical modelling of acidification and recovery in forest soils and runoff waters, IVL Report B 1323. Gothenburg: Swedish Environmental Research Institute, 1999. p. 1–56. Traaen TS, Frogner T, Hindar A, Kleiven E, Lande A, Wright RF. Whole-catchment liming at Tjønnstrond, Norway: an 11-year record. Water Air Soil Pollut 1997;94:163–180. ¨
Ecosystem effects after ameliorative liming of a catchment at the Harz Mountains, Germany Plant nutrition— food security and sustainability of agro-ecosystems. Dor-drecht: Kluwer
- Meiwes H Kj Meesenburg
- M Wagner
Meesenburg H, Meiwes KJ, Wagner M, Prenzel J. Ecosystem effects after ameliorative liming of a catchment at the Harz Mountains, Germany. In: Horst WJ, editor. Plant nutrition— food security and sustainability of agro-ecosystems. Dor-drecht: Kluwer, 2001. p. 914 –915.
Geochemical modelling of acidification and recovery in forest soils and runoff waters
- F Moldan
- O Westling
- Munthe
Moldan F, Westling O, Munthe J. Geochemical modelling of acidification and recovery in forest soils and runoff waters, IVL Report B 1323. Gothenburg: Swedish Environmental Research Institute, 1999. p. 1 –56.
Overview of the MAGIC model applica-´ tions in 1985– Detecting Environmental Change: Sci-ence and Society Conference Proceedings
- P Kram
- Bishop
Kram P, Bishop K. Overview of the MAGIC model applica-´ tions in 1985–2000. Detecting Environmental Change: Sci-ence and Society Conference Proceedings, University College London 2001. p. 20 –21.