Cold Water Springs Research Articles

Hydrogeochemical signatures of spring water in geologically diverse terrains: a case study of Southern Western Ghats, India.

Out of 5 million Indian spring water systems, a few were characterised for hydrochemistry and freshwater potential. The present study focuses on analysing the hydrochemistry, discharge, and drinking/irrigation water quality of both cold and thermal spring clusters namely Southern Kerala Springs (SKS) and Dakshina Kannada Springs (DKS) of Southern Western Ghats, India. Currently, eleven springs from SKS and ten from DKS including one thermal spring (TS) with temperature ranges from 34 to 37°C were considered. The study revealed that cold springs (CS) of SKS are Na-Cl type, while the thermal and cold-water springs in DKS are Na-HCO3 and mixing water type, respectively. Two distinct mechanisms predominantly define the hydro-chemical composition of the springs-SKS are influenced by precipitation, whereas DKS is likely by chemical weathering processes. While comparing the major ions and saturation indices of thermal springs (TS), it is evident that silicate minerals predominantly affect the chemical composition of water. CaCO3- is oversaturated in TS water and tends to precipitate as a scale layer. PCA showed that both geogenic and anthropogenic factors influence water chemistry. WQI categorized the CS in both the clusters are in the "Excellent" rank as compared to TS. Irrigation water quality signifies that the cold springs are only suitable for irrigation. Moreover, it is evident from the discharge that both SKS and DKS were rainfed in nature. Discharge monitoring designated that the CS could augment drinking water supplies in the nearby regions indicating the necessity of conservation and sustainable use considering future freshwater scarcity.

Širenje i značaj ijatričkih kultova u antičkom periodu sa posebnim osvrtom na Asklepijev kult i njegovo poštovanje u Naisu

Iatric cults were spread in Hellas, and in the Hellenistic period were also venerated in Roman Empire. The most famous were Asclepius and his daughter Hygeia. Asclepius was famous Greek physician whose divine nature helped to heal the patients, which is why he was very popular among people. That's why he was popular among people. Asclepius was the only Greek deity to be accepted in the Temple of Westphalia in Rome, which means that the Romans thoroughly accepted him as very important deity in the Roman religion. He was considered to be the guardian of the individuals as well as the whole families, in addition, the protector of soldiers and even emperors. Sanctuaries were built in his honor, but he was also revered in sanctuaries of other gods. The healing power of Asclepius was associated with hot and cold water springs for use of water in the healing process which was very respected since the water was used in healing processes. It is assumed that one shrine was placed in imperial villa in Mediana, due to near hot water source in Niška banja. The veneration of cult of Asclepius in Mediana is traced back to the Roman emperor Julian and his restoration to paganism. Although Julian ruled for a short period of time, the statues of Asclepius and Hygeia remained in the villa in Mediana for decoration, only to be destroyed during the Hun devastation of Nais in 378. The need to prevent and cure people form deadly infectious diseases, which took many lives, had caused the respect of the cult of Asclepius in the territory of Hellas, Asia Minor and most part of Roman Empire in the period from the 16th century BC until the 6th century AD. From ancient time, people felt the need to take care of their own health, and when there was no other way to be cured, Asclepius helped with his supernatural power. His ability and readiness to provide help to everyone who needed it, made him the most widespread and respected cult of healing.

Variations of stable oxygen and hydrogen isotope ratios in the cold and thermal springs of the Bazman volcanic area (in the southeast of Iran)

The Bazman volcanic area, which comprises thermal and cold water springs with different natural characteristics, was selected as the case study of this research. The cold springs can be divided into western and eastern groups. In total, 16 water samples were collected from the thermal and cold water springs for hydrochemical and stable isotope analyses. In the study area, the groundwater temperature ranged from 28.1 °C (in the cold water) to 43.9 °C (in the hot springs). The electrical conductivity (EC) values of the groundwater samples were 1102–10,250 µS/cm. The highest EC values belonged to the thermal springs known to have brackish water in this area. The δ18O and δ2H values in the springs ranged from − 5.06 to 0.04 ‰ and − 24.1 to − 8.6 ‰, respectively. The relationship between δ2H and δ18O values and physicochemical characteristics was investigated. In the west of the area, the isotopic composition of the cold springs was close to that of the LMWL, while the eastern cold springs had an isotopic composition highly enriched in δ2H and δ18O. In contrast, the isotopic composition of the thermal springs was almost on that of the GMWL and their deuterium isotope was more depleted than that of cold springs. The difference between the isotopic composition of the thermal springs and the LWML can be the result of hot water–rock interaction and underground evaporation. However, magma was not effective on this difference. The results showed that the groundwater of the western cold springs moved with faster velocity through the long and deep macro-pores and preferential flow channels in carbonate and igneous rocks, while in the eastern springs, groundwater originated from fine fractures with a low depth in shale and sandstone rocks.

The development of conceptual models for the functioning of geothermal systems using hydrogeological, hydrogeochemical and isotopic data: case studies from Rize (NE Turkey)

The hydrogeological and hydrogeochemical properties and isotopic composition of hot and cold water springs in the Ilicakoy and Ayder geothermal areas were investigated and a conceptual model was developed to explain their function. Characteristics of hot groundwater from the Ilicakoy area were: temperature, 63 °C; EC, 6913 µS/cm; pH, 7.2, DO content, 0.75 mg/L; and water type, Na–Ca–HCO3. Characteristics of hot groundwater from the Ayder area were: temperature, 55 °C; EC, 255 µS/cm; pH, 9.2, DO content, 1.9 mg/L; and water type, Na–Ca–CO3–SO4. Ilicakoy has acidic pH values, while those of the Ayder area are alkaline. Carbon in hot water in both areas was derived from inorganic carbon in groundwater and from CO2 in pore spaces in the unsaturated zone. SO2 in hot water was derived from Cenozoic-aged gypsum. Low tritium and high Cl contents in hot waters indicate deep circulation, and Sr was passed from granitic rocks to waters by simple dissolution. High total alpha and total beta values were obtained in the hot waters from the Ilicakoy geothermal area. Ilicakoy and Ayder geothermal spring formation occurred by infiltration of precipitation through fractures in granitic bedrock from the Kackar granitoid, which forms a regionally significant geothermal reservoir. Water of meteoric origin is heated under by a locally steep geothermal gradient, and it rises through bedrock fractures and re-emerges at the ground surface. In the Ilicakoy and Ayder geothermal fields, which are low temperature geothermal systems, the reservoir rock temperature was 80 °C and 149 °C, respectively.

HYDRO-CHEMICAL AND ISOTOPIC INVESTIGATION OF THE İSPENDERE MINERAL AND THERMAL WATER SPRINGS, MALATYA, TURKEY

The objective of this study is to determine the source, chemical characteristics and isotopic components of the İspendere mineral and thermal waters, Malatya, Turkey. There are many mineral and thermal water springs in the area with fl ow rates ranging between 0.01 – 0.4 l/s. Geochemical and isotope chemistry studies were carried out at three different thermal springs in the region as well as three different cold water springs during May-October 2011. The temperature of mineral and thermal waters were measured as between 21.1°C – 23.6°C in May 2011 and as 20.8°C in October 2011. The region was determined as a low temperature geothermal area and the reason for this is thought to be cold water mixing. The pH values of mineral and thermal spring waters were measured to be between 6.19 –6.69, EC values were measured to be between 1420 μS/cm and 2720 μS/cm, pH values of shallow and deep wells ranged between 6.04 and 7.82, whereas EC values were measured approximately between 275 μS/cm and 3300 μS/cm. The MgHCO3 water type dominates the chemistry of mineral and thermal water in study area. The results of 18 O and 2 H isotope analysis yield that the springs of mineral and thermal waters as well as cold waters are fed by meteoric rains. It was determined that the İspendere mineral and thermal waters have low tritium (³H), low Cl and high EC values. Reservoir rock temperatures have been estimated to be between 95 -132°C as a result of the quartz geo-thermometer calculations.

The Coastal Springs of Southern Kerala, SW India – Hydrology and Water Quality Assessment

Spring water is a reliable source of potable water in many parts of the world. Uplifted coasts of the Southern Kerala host many high yielding cold water springs which emerge from the sand - clay interface of the Neogene outcrops. Lack of adequate studies on the hydrological and water quality aspects of these springs is challenging the wise use and management of these springs. Therefore, an attempt has been made to map the locations and study the water quality of the free-falling type of springs emerging from the Neogene outcrops exposed on the cliffed coasts of Southern Kerala, especially falling within the jurisdiction of Kollam and Thiruvananthapuram districts. A total of 31 springs from four distinct geomorphic settings has been located in our survey conducted in 2008–2009 period. But, our recent survey carried out in March 2017 revealed that about 10 % of the springs were dried out due to various reasons. The total spring water discharge during 2017 was about 450 liters/minute against the total discharge of 800 liters/minute in 2007–08 period. In general, the hydrochemistry of spring waters is dominated by alkali and strong acids, i.e. alkali-chloride type. Most of the hydrochemical parameters exhibit a great degree of seasonal and spatial variations and are well within the permissible limits (with the exception of pH) for all four groups of springs. The low mineral contents may be attributed to minimal weathering from silicate-rich rocks and insignificant leaching from soil due to infiltration from anthropogenic activities. The spring water quality in all the four groups of the study area is bacteriologically contaminated and therefore proper disinfection is required before human consumption. Most of the spring water samples are classified to be “excellent to good” for irrigation and is not expected to cause any salinity hazard.

Groundwater contamination and land drainage induce divergent responses in boreal spring ecosystems

Degradation of freshwater ecosystems has engendered legislative mandates for the protection and management of surface waters while groundwater-dependent ecosystems (GDEs) have received much less attention. This is so despite biodiversity and functioning of GDEs are currently threatened by several anthropogenic stressors, particularly intensified land use and groundwater contamination. We assessed the impacts of land drainage (increased input of dissolved organic carbon, DOC, from peatland drainage) and impaired groundwater chemical quality (NO3−-N enrichment from agricultural or urban land use) on biodiversity and ecosystem functioning in 20 southern Finnish cold-water springs using several taxonomic and functional measures. Groundwater contamination decreased macroinvertebrate and bacterial diversity and altered their community composition. Changes in macroinvertebrate and bacterial communities along the gradient of water-quality impairment were caused by the replacement of native with new taxa rather than by mere disappearance of some of the original taxa. Also species richness of habitat specialist (but not headwater generalist) bryophytes decreased due to impaired groundwater quality. Periphyton accrual rate showed a subsidy-stress response to elevated nitrate concentrations, with peak values at around 2500 μg L−1, while drainage-induced spring water brownification (increased DOC) reduced both periphyton accrual and leaf decomposition rates already at very low concentrations. Our results highlight the underutilized potential of ecosystem-level functional measures in GDE bioassessment as they seem to respond to the first signs of spring ecosystem impairment, at least for the anthropogenic stressors studied by us.

Population Structure and Habitat Use of the Endangered Watercress Darter

AbstractDespite Alabama's exceptionally diverse freshwater fish fauna, many of its fish species face extinction. Some of the state's most imperiled species dwell within coldwater springs, but a deficit of knowledge about their ecology hampers protection efforts. The watercress darter Etheostoma nuchale is a species confined to five springs in the greater Birmingham metropolitan area. Roebuck Spring likely harbors the largest population. Its pool has been surveyed occasionally, but there had been no survey of its run, a shallow stream flowing from the pool. We investigated the darter's use of the run, its habitat preferences, and characteristics of the habitats where it is most abundant. We quantified the abundance of stream microhabitats, then estimated darter density in the stream's five most common habitats using a throw trap, a high-walled metal frame dropped in the habitat. We found darters at densities vastly exceeding typical estimates derived using seine nets. We estimated the run harbored 116,932 (79,358–155,965) darters, two-thirds of which were juveniles. The most preferred habitat was coontail Ceratophyllum demersum, a submergent plant not previously known to provide darter habitat. Coontail grew prolifically in swift currents, which was surprising given that darter habitats described previously had little to no current. Coontail provided a more structurally complex habitat than the plants of the other microhabitats studied. Our results suggest that spring runs can support substantial densities of the watercress darter if dense submergent vegetation is present.

Climate-induced warming imposes a threat to north European spring ecosystems.

Interest in climate change effects on groundwater has increased dramatically during the last decade. The mechanisms of climate-related groundwater depletion have been thoroughly reviewed, but the influence of global warming on groundwater-dependent ecosystems (GDEs) remains poorly known. Here we report long-term water temperature trends in 66 northern European cold-water springs. A vast majority of the springs (82%) exhibited a significant increase in water temperature during 1968-2012. Mean spring water temperatures were closely related to regional air temperature and global radiative forcing of the corresponding year. Based on three alternative climate scenarios representing low (RCP2.6), intermediate (RCP6) and high-emission scenarios (RCP8.5), we estimate that increase in mean spring water temperature in the region is likely to range from 0.67°C (RCP2.6) to 5.94°C (RCP8.5) by 2086. According to the worst-case scenario, water temperature of these originally cold-water ecosystems (regional mean in the late 1970s: 4.7°C) may exceed 12°C by the end of this century. We used bryophyte and macroinvertebrate species data from Finnish springs and spring-fed streams to assess ecological impacts of the predicted warming. An increase in spring water temperature by several degrees will likely have substantial biodiversity impacts, causing regional extinction of native, cold-stenothermal spring specialists, whereas species diversity of headwater generalists is likely to increase. Even a slight (by 1°C) increase in water temperature may eliminate endemic spring species, thus altering bryophyte and macroinvertebrate assemblages of spring-fed streams. Climate change-induced warming of northern regions may thus alter species composition of the spring biota and cause regional homogenization of biodiversity in headwater ecosystems.

The temperature dimension of the seed germination niche in fen wetlands

The seed germination niche partly determines adaptation, ecological breadth and geographic range in plant species. In temperate wetlands, environmental temperature is the chief regulator of germination timing, but the ecological significance of high and low temperatures during dormancy break and germination is still poorly understood. Our aim was to characterize the temperature dimension of the germination niche in mountain base-rich fens, determining (1) the effect of different temperatures on dormancy break and germination, and (2) whether different germination strategies may be identified at the species level. We conducted laboratory germination experiments with seeds of 15 species from these habitats, collected in 18 fen sites in the Cantabrian Mountains (Spain) for two consecutive years. In all the species, the seeds were totally or conditionally dormant at dispersal and stratification produced a significant increase of germination. In most cases, there was not an obligatory requirement for cold temperatures during dormancy break, since warm stratification promoted germination as well. Although the optimal germination thermoperiod was generally high (30/20 °C), most species could also germinate at lower temperatures after cold-stratification. We also identified a group of species associated to cold-water springs that germinated only at low temperatures. Our results demonstrate that dormancy break in mountain base-rich fens does not obligatorily depend on cold temperatures during overwintering. Furthermore, germination at cool temperatures may be more widespread in wetland habitats than previously thought. The existence of two distinctive germination strategies, ‘warm’ and ‘cool’, can potentially give rise to divergent species responses to climate change.

Arctic microbial ecosystems and impacts of extreme warming during the International Polar Year

As a contribution to the International Polar Year program MERGE (Microbiological and Ecological Responses to Global Environmental change in polar regions), studies were conducted on the terrestrial and aquatic microbial ecosystems of northern Canada (details at: http://www.cen.ulaval.ca/merge/). The habitats included permafrost soils, saline coldwater springs, supraglacial lakes on ice shelves, epishelf lakes in fjords, deep meromictic lakes, and shallow lakes, ponds and streams. Microbiological samples from each habitat were analysed by HPLC pigment assays, light and fluorescence microscopy, and DNA sequencing. The results show a remarkably diverse microflora of viruses, Archaea (including ammonium oxidisers and methanotrophs), Bacteria (including filamentous sulfur-oxidisers in a saline spring and benthic mats of Cyanobacteria in many waterbodies), and protists (including microbial eukaryotes in snowbanks and ciliates in ice-dammed lakes). In summer 2008, we recorded extreme warming at Ward Hunt Island and vicinity, the northern limit of the Canadian high Arctic, with air temperatures up to 20.5 °C. This was accompanied by pronounced changes in microbial habitats: deepening of the permafrost active layer; loss of perennial lake ice and sea ice; loss of ice-dammed freshwater lakes; and 23% loss of total ice shelf area, including complete break-up and loss of the Markham Ice Shelf cryo-ecosystem. These observations underscore the vulnerability of Arctic microbial ecosystems to ongoing climate change.

Natural tracers for identifying the origin of the thermal fluids emerging along the Aegean Volcanic arc (Greece): Evidence of Arc-Type Magmatic Water (ATMW) participation

The Aegean volcanic arc is the result of a lithosphere subduction process during the Quaternary time. Starting from the Soussaki area, from west to east, the arc proceeds through the islands of Egina, Methana, Milos, Santorini, the Columbus Bank, Kos and Nisyros. Volcano-tectonic activities are still pronounced at Santorini and Nisyros in form of seismic activity, craters of hydrothermal explosions, hot fumaroles and thermal springs. A significant number of cold water springs emerge in the vicinity of hot waters on these islands. Chemical and isotopic analyses were applied on water and fumaroles samples collected in different areas of the volcanic arc in order to attempt the assessment of these fluids. Stable isotopes of water and carbon have been used to evaluate the origin of cold and thermal water and CO 2. Chemical solute concentrations and isotopic contents of waters show that the fluids emerging in Egina, Soussaki, Methana and Kos areas represent geothermal systems in their waning stage, while the fluids from Milos, Santorini and Nisyros proceed from active geothermal systems. The δ 2H–δ 18O–Cl − relationships suggest that the parent hydrothermal liquids of Nisyros and Milos are produced through mixing of seawater and Arc-Type Magmatic Water (ATMW), with negligible to nil contribution of local ground waters and with very high participation of the magmatic component, which is close to 70% in both sites. A very high magmatic contribution to the deep geothermal system could occur at Santorini as well, perhaps with a percentage similar to Nisyros and Milos, but it cannot be calculated because of steam condensation heavily affecting the fumarolic fluids of Nea Kameni before the surface discharge. The parent hydrothermal liquid at Methana originates through mixing of local groundwaters, seawater and ATMW, with a magmatic participation close to 19%. All in all, the contribution of ATMW is higher in the central–eastern part of the Aegean volcanic arc than in the western sector. This difference, which is spotted in the variable isotopic composition of the sampled fluids from west to east along the arc, is probably due to several causes, including the tectonic regime, the depth of the deep reservoir below sea level, the age of volcanic activity and in general the geomorphologic state of each island.

Spatial patterns in insect community composition in coldwater springs

The insects living in 27 coldwater springs in southern Ontario, Canada were analyzed using several permutation and ordination methods, in order to detect patterns in the composition of their communities. These patterns were compared against simulations using artificial landscapes. A Moving Window Mantel Correlogram indicated the presence of both a strong local spatial aggregation and a global trend toward higher dissimilarity of sites with increasing geographical distance, especially beyond 50 km. Ordination plots showed a clear global gradient from a southern group of springs to a northern group (likely related to temperature and pH), which dominated the global, total, and local plots in both a SCA (Spatial CA) and a SPCA (Spatial PCA) analysis. However, the results of the local analysis differed markedly between the two methods: while the local plot for the SCA analysis indicated considerable variation among sites belonging to the same spatial group (thought to be related to discharge and random colonization episodes) and showed a pattern that was different from both the global and total analysis plots, the local SPCA plot showed little within-group variation and resembled the global and total plots.

Interaction Between Bacteria, Nannobacteria, and Mineral Precipitation in Hot Springs of Central Italy

A complex of inorganic and organic factors controls precipitation of carbonates in hot springs of Lazio, central Italy. A plot of data from this area shows that the main /norganic controls are temperature and Mg/Ca ratio of the spring waters. Virtually all springs with waters hotter than 400C precipitate aragonite, and cooler ones form calcite. Furthermore, even cold-water springs precipitate aragonite if the Mg/Ca ratio exceeds 1:1, except in two cases. To what extent is the precipitation of travertine inorganic vs. biochemical? Surely, conditions in diverse localities can vary between both end-points, but Le Zitelle springs, at the north flank of the caldera of Viterbo, provide a biochemical extreme. Waters are hot (600C), with Mg/Ca of .2, and are highly sulfurous. Carbonate precipitation rates can exceed 2 mm/day. /Vonetched samples of carbonate crusts, only minutes to a few hours old, exhibit aragonite, calcite, and 1- to 5- (im euhedral rhombs of probable dolomite. Aragonite forms spherical "pincushions" of radial needles, each needle tipped with a nannobacterial body of the same diameter as the needles, 0.1 to 0.4 jim. Each nannobacterium precipitated its own needle, and was propelled outward by needle growth. As little or no later "fattening" of the needle occurred, inorganic precipitation must have been insignificant here. fVonetched calcite crystals are composed of 0.05 (xm nannobacterial spheres that were incorporated into each layer of the crystal as it grew. No evidence of bacteria was found on the ?dolomite rhomb surfaces. Ironically, aragonite, calcite, and euhedral ?dolomite rhombs all grew within minutes to an hour of each other in the same solution under the same conditions, savaging all the rules exposed at the beginning they remain a baffling problem unresolved by chemistry, physics, or microbiology.

Management and conservation strategies for coldwater springs

1. Direct and indirect utilization of coldwater springs produces a wide variety of benefits to human societies around the world, but this resource use may also be associated with significant costs to the environment, including biodiversity loss and deterioration of water quality. Despite the importance of springs little attention has been paid to their management and conservation. 2. This review article draws on international literature and results from recent research on springs in New Zealand, to highlight the characteristic features of springs, identify the main human threats to their integrity, and review spring management strategies. The principal aim of the paper is to provide a management framework that can facilitate the protection, enhancement and restoration of springs. 3. A key element in the management and conservation of springs is recognition of their position at the interface of three distinct ecosystems — groundwater, surface water and terrestrial. Human impacts on all three contributing ecosystems can have significant effects on spring habitat integrity. 4. Effective management of springs must recognize the full range of environmental and societal values associated with them, understanding threats to the sustainability of these values and formulating strategies that provide a balance between potentially conflicting uses. As with any management strategy, the clear definition of management goals for springs is a precursor to effective conservation, protection and restoration. Copyright © 2007 John Wiley & Sons, Ltd.

Insect emergence in Canadian coldwater springs: spatial and temporal patterns, and species-environment relationships

Considerable spatial and temporal variability was detected in the environmental conditions in 30 coldwater springs in southern Ontario, Canada. Using standard pyramidal emergence traps, a total of 86 insect species was recorded from these springs (not including the Chironomidae). These represented nine taxonomic groups, among which the Limoniidae (Diptera) was the most diverse with 38 species. Fifty-five per cent of all species recorded had a low frequency (found at three or fewer sites), and only for very few of these rare species were more than 10 individuals m -2 collected. Interannual differences were also apparent. Continuous sampling over time showed that emergence records from a single year, on average, contained only around 50% of the total number of species obtained during the entire study. Species-environment relationships analyzed by Canonical Correspondence Analysis indicated that temperature and discharge correlated most strongly with insect community similarity among spring sites. The prospects for developing regional typologies of coldwater springs, based on their environmental conditions, and the implications of species loss to the continuity of function of coldwater spring ecosystems are discussed.

Conceptual hydrodynamic model of the Pamukkale hydrothermal field, southwestern Turkey, based on hydrochemical and isotopic data

The results of study on the hydrochemical and isotope characteristics of shallow and deep waters at Pamukkale hydrothermal field Turkey are described in order to obtain a better understanding of the hydrological circulation. The field can be grouped into two groundwater sub-systems; cold water springs of Ca–HCO3 type (10–12 °C), and CO2-rich thermal waters of Ca–HCO3–SO4 type (25–58 °C). The occurrence of these water types is closely related to the morphology of the region, where intense tectonism formed horst and graben structures. Hence, two hydrogeological systems were defined: a deep geothermal system which is related to extensive and deep circulation of meteoric water in the regional flow system, and a shallow system which is related to local groundwater flow through sedimentary strata. The meteoric water falling at higher elevations percolates to the local groundwater system at a shallow level and flows to the deep geothermal system. During a deep convection cycle from a recharge to discharge area, the cold water attains heat from the asthenospheric intrusions, causing it to ascend. Variations of chemical and isotopic composition of thermal waters result from their mixing with cool groundwater in a shallow aquifer during their ascent to the surface.

Major ion chemistry of groundwater from perched-water bodies of the Azores (Portugal) volcanic archipelago

A dataset of major ion composition of 246 samples from cold-water springs discharging from perched-water bodies at volcanic islands (Azores archipelago, Portugal) reveal waters with low mineralization, which evolve due to two main geochemical processes: (1) seawater spraying and (2) dissolution of primary minerals of volcanic rocks. As a result, water facies range from Na–Cl to Na–HCO3 type waters. The relationship between alkali, alkali–earth metals and HCO3− shows differences between waters discharging from perched-water bodies in basaltic rocks comparing to more evolved rocks of trachytic nature. The use of principal component analysis shows that water-rock interaction is limited, which is compatible with the geochemical observations and with the hydrogeological environment.

Grazing Effects on Spring Ecosystem Vegetation of California's Hardwood Rangelands

Three watersheds at the University of California's Sierra Foothill Research and Extension Center (SFREC), Marysville, Calif. were selected to study cattle grazing effects on the vegeta - tion surrounding cold-water springs and their downslope creeks. Three spring-creek systems from each of 3 watersheds were ran- domly assigned to grazing treatments (9 total). Treatments were ungrazed, lightly grazed (1,500 kgha -1 residual dry matter), and moderately grazed (1,000 kgha -1 residual dry matter) based on degree of use in upland pastures encircling the spring-creek sys - tems. Total herbaceous cover at springs varied significantly among the 6 years only once (greater in 1994 than all others) covarying with previous year's rainfall. Grazing intensity did not affect total herbaceous cover at springs. A year X grazing treat - ment interaction (P<0.05) was detected for total herbaceous cover at spring-fed creeks. Three years after grazing removal, total herbaceous cover on ungrazed creek plots surpassed cover at moderately grazed and lightly grazed plots. Moderately grazed plot herbaceous cover declined steadily throughout the first 3 years, while lightly grazed cover remained relatively sta - ble. Plant community composition and stability by year and graz - ing treatment were analyzed with TWINSPAN. With few excep- tions, stable plant communities persisted on sites regardless of grazing intensity or cover changes. Total herbaceous cover was sensitive to interannual fluctuations, especially under increased grazing intensities. This attribute renders cover a more useful gauge of ecosystem health than plant composition as the latter may not provide evidence of potentially deleterious grazing X cli - mate interactions until after soil erosion or water table charac- teristics are seriously, perhaps permanently, altered.

Grazing effects on spring ecosystem vegetation of California's hardwood rangelands

Three watersheds at the University of California's Sierra Foothill Research and Extension Center (SFREC), Marysville, Calif. were selected to study cattle grazing effects on the vegetation surrounding cold-water springs and their downslope creeks. Three spring-creek systems from each of 3 watersheds were randomly assigned to grazing treatments (9 total). Treatments were ungrazed, lightly grazed (1,500 kg(.)ha(-1) residual dry matter), and moderately grazed (1,000 kg(.)ha(-1) residual dry matter) based on degree of use in upland pastures encircling the spring-creek systems. Total herbaceous cover at springs varied significantly among the 6 years only once (greater in 1994 than all others covarying with previous year's rainfall. Grazing intensity did not affect total herbaceous cover at springs. A year X grazing treatment interaction (P 0.05) was detected for total herbaceous cover at spring-fed creeks. Three years after grazing removal, total herbaceous cover on ungrazed creek plots surpassed cover at moderately grazed and lightly grazed plots. Moderately grazed plot herbaceous cover declined steadily throughout the first 3 years, while lightly grazed cover remained relatively stable. Plant community composition and stability by year and grazing treatment were analyzed with TWINSPAN. With few exceptions, stable plant communities persisted on sites regardless of grazing intensity or cover changes. Total herbaceous cover was sensitive to interannual fluctuations, especially under increased grazing intensities. This attribute renders cover a more useful gauge of ecosystem health than plant composition as the latter may not provide evidence of potentially deleterious grazing X climate interactions until after soil erosion or water table characteristics are seriously, perhaps permanently, altered.