scholarly journals Drainage Impact on Plant Cover and Hydrology of Aukštumala Raised Bog (Western Lithuania)

2015 ◽  
Vol 20 (2) ◽  
pp. 109-120 ◽  
Author(s):  
Leonas Jarašius ◽  
Dalytė Matulevičiūtė ◽  
Romas Pakalnis ◽  
Juratė Sendžikaitė ◽  
Vaidotas Lygis
Keyword(s):  
Electrical Conductivity ◽  
Water Level ◽  
Plant Cover ◽  
Burned Area ◽  
Habitat Types ◽  
Raised Bog ◽  
Burnt Area ◽  
Raised Bogs ◽  
Peat Mining ◽  
Bog Water

AbstractOne-third of the former Aukstumala raised bog (western Lithuania) has been preserved as Telmological Reserve since 1995, while the remaining territory is still under active industrial peat mining or are abandoned peat harvesting fields. The present study was carried out in 2013 and aimed to assess long-term human impact on the structure of plant cover and hydrology of Aukstumala raised bog. On the basis of vegetation assessment (Twinspan analysis), four habitat types were identified: i) active raised bog, ii) degraded raised bog drained by ditches, iii) contact zone of the bog and the peat mining fields and iv) recently burnt areas. The largest anthropogenic impact on vegetation cover was found in the degraded raised bog drained by the ditches and in the burnt area, where the proportion of plant species atypical to ombrotrophic raised bogs was the highest. Water electrical conductivity negatively correlated (r = -0.57) with bog water level, whereas correlation between pH and bog water level was weaker (r = -0.38). Water level in the active raised bog was significantly higher than in the rest three habitat types. Electrical conductivity values in the active raised bog were significantly lower compared to the degraded raised bog and burned area habitats. In order to recreate favourable conditions for peat accumulation and natural functioning of bog ecosystem, mean bog water level should be raised at least up to -32 cm (the optimum water level assigned for most of the typical ombrotrophic species fell into the range of -20 - -32 cm).

scholarly journals How to Assess the Ecological Status of Highly Humic Lakes? Development of a New Method Based on Benthic Invertebrates

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 223
Author(s):  
Dāvis Ozoliņš ◽  
Agnija Skuja ◽  
Jolanta Jēkabsone ◽  
Ilga Kokorite ◽  
Andris Avotins ◽  
...  
Keyword(s):  
Ecological Status ◽  
Working Party ◽  
Nutrient Content ◽  
Humic Lakes ◽  
Raised Bog ◽  
Raised Bogs ◽  
Taxa Richness ◽  
Bog Lakes ◽  
Status Assessment

Highly humic lakes are typical for the boreal zone. These unique ecosystems are characterised as relatively undisturbed habitats with brown water, high acidity, low nutrient content and lack of macrophytes. Current lake assessment methods are not appropriate for ecological assessment of highly humic lakes because of their unique properties and differing human pressures acting on these ecosystems. This study proposes a new approach suitable for the ecological status assessment of highly humic lakes impacted by hydrological modifications. Altogether, 52 macroinvertebrate samples from 15 raised bog lakes were used to develop the method. The studied lakes are located in the raised bogs at the central and eastern parts of Latvia. Altered water level was found as the main threat to the humic lake habitats since no other pressures were established. A multimetric index based on macroinvertebrate abundance, littoral and profundal preferences, Coleoptera taxa richness and the Biological Monitoring Working Party (BMWP) Score is suggested as the most suitable tool to assess the ecological quality of the highly humic lakes.

scholarly journals Evaluation of short-term changes of hydrological response in mountainous basins of the Vitim Plateau (Russia) after forest fires based on data analysis and hydrological modelling

2015 ◽  
Vol 371 ◽  
pp. 157-162 ◽  
Author(s):  
O. M. Semenova ◽  
L. S. Lebedeva ◽  
N. V. Nesterova ◽  
T. A. Vinogradova
Keyword(s):  
Forest Fires ◽  
Model Performance ◽  
Burned Area ◽  
Model Parameters ◽  
Hydrological Response ◽  
Short Term ◽  
Burnt Area ◽  
Area Product ◽  
Induced Changes ◽  
Fire Impact

Abstract. Twelve mountainous basins of the Vitim Plateau (Eastern Siberia, Russia) with areas ranging from 967 to 18 200 km2 affected by extensive fires in 2003 (from 13 to 78% of burnt area) were delineated based on MODIS Burned Area Product. The studied area is characterized by scarcity of hydrometeorological observations and complex hydrological processes. Combined analysis of monthly series of flow and precipitation was conducted to detect short-term fire impact on hydrological response of the basins. The idea of basin-analogues which have significant correlation of flow with "burnt" watersheds in stationary (pre-fire) period with the assumption that fire impact produced an outlier of established dependence was applied. Available data allowed for qualitative detection of fire-induced changes at two basins from twelve studied. Summer flow at the Amalat and Vitimkan Rivers (22 and 78% proportion of burnt area in 2003, respectively) increased by 40–50% following the fire.The impact of fire on flow from the other basins was not detectable.The hydrological model Hydrograph was applied to simulate runoff formation processes for stationary pre-fire and non-stationary post-fire conditions. It was assumed that landscape properties changed after the fire suggest a flow increase. These changes were used to assess the model parameters which allowed for better model performance in the post-fire period.

scholarly journals Karst hydrogeology of Lamprechtsofen (Leoganger Steinberge, Salzburg)

2019 ◽  
Vol 112 (1) ◽  
pp. 50-61 ◽  
Author(s):  
Katharina Gröbner ◽  
Wolfgang Gadermayr ◽  
Giorgio Höfer-Öllinger ◽  
Harald Huemer ◽  
Christoph Spötl
Keyword(s):  
Electrical Conductivity ◽  
Water Temperature ◽  
Water Level ◽  
Stream Water ◽  
Tracer Tests ◽  
Karst Water ◽  
Stream Flows ◽  
Surface Precipitation ◽  
Mineralized Water ◽  
Show Cave

AbstractThe Leoganger Steinberge are a heavily karstified massif largely composed of Dachstein dolomite and limestone hosting the deepest through-trip cave in the world, Lamprechtsofen, whose frontal parts are developed as a show cave. Many parts of this 60 km-long and 1724 m-deep system are hydrologically active. 1.5 km behind the lower cave entrance Grüntopf stream and Kneippklamm stream merge to form the main cave stream. Another underground stream, Stainerhallen stream, flows through the eponymous hall of the show cave. Since 2007 water temperature, electrical conductivity and water level have been monitored in the Grüntopf and Kneippklamm stream. Water temperature and water level in the Stainerhallen and main cave stream have been measured since 2016.The long-term dataset (2013–2017) shows that the water temperature of the cave streams (Grüntopf stream: 3.7–5.2°C; Kneippklamm stream: 5.1–5.9°C) is largely invariant, but the electrical conductivity varies strongly (Grüntopf stream: 107–210 µS/cm; Kneippklamm stream: 131–248 µS/cm) in response to snowmelt and precipitation events. The event water of the Kneippklamm stream is characterized by a low electrical conductivity and is then followed by slightly warmer and higher mineralized water derived from the phreatic zone. This dual flow pattern also explains the asymmetrical changes of the water level during snowmelt: the fast event water flows directly through vadose pathways to the measurement site, whereas the hydraulic (phreatic) response is delayed. The Grüntopf stream reacts to precipitation and snowmelt events by changes in the karst-water table, which can be explained by a piston flow-model. The Kneippklamm stream reveals evidence of a lifter system.The altitude of the catchments was calculated using δ18O values of water samples from the underground streams and from surface precipitation. The Grüntopf stream shows the highest mean catchment (2280 m a.s.l.), which is in agreement with its daily fluctuations of the water level until August caused by long-lasting snowmelt. The Stainerhallen stream has the lowest catchment (average 1400 m a.s.l.). The catchments of the other two streams are at intermediate elevations (1770–1920 m a.s.l.). The integration of the catchment analyses and observations from tracer tests conducted in the 1970s showed that the latter reflected only one aspect of the karst water regime in this massif. During times of high recharge the water level rises, new flow paths are activated and the karst watershed shifts.

Investigating Seepage Paths at Golfaraj Earthen Dam, Northwest Iran

2021 ◽  
pp. qjegh2021-053
Author(s):  
Sadegh Saberi Mehr ◽  
Malcolm S. Field
Keyword(s):  
Electrical Conductivity ◽  
Water Level ◽  
Engineering Geology ◽  
Cutoff Wall ◽  
Earthen Dam ◽  
The West ◽  
Reservoir Water ◽  
West Side ◽  
Study Results ◽  
Northwest Iran

An investigation of seepage was conducted at Golfaraj Reservoir Dam with a particular emphasis on determining the seepage areas based on regional and site-specific hydrogeological studies. The primary goal of the investigation was to develop strategies intended to minimize dam and reservoir seepage. Leakage from the reservoir is a serious problem and of considerable concern to the local populace. Substantial reduction of seepage from Golfaraj Reservoir Dam is the ultimate goal of the investigations conducted. Golfaraj Reservoir Dam, located in East Azerbaijan province, northwest Iran, was built to provide water for agricultural and industrial needs in Golfaraj plain and neighboring lands. The Golfaraj Reservoir was constructed through the Miocene Upper Red Formation, which consists of sequences of sandstone, mudstone, conglomerate, and gypsiferous marl. Following reservoir filling, seepage of water into adjacent formations was found to occur at an estimated rate of 70 L/s. After reservoir impoundment groundwater levels in Shahmar village, 2 km downstream and just north of the dam axis, rose and land surfaces became abnormally wet. Lugeon values in some boreholes drilled around Golfaraj Dam before and after dam construction were high enough to indicate that the dam base has sufficient permeability to allow water to escape by underflow. Twenty-four Casagrande piezometers installed around the dam axis at four sectors provided additional information on seepage pathways through the dam body and underneath or through the cutoff wall. Water-level variations in the Casagrande piezometers confirmed the seepage routes. Study results showed that reservoir water likely seeps through the reservoir bottom and beneath and through the cutoff wall. The west side of the dam and near the reservoir reflected water-level rises in accordance with the rise in reservoir-water level. Seepage in this area is probably due to its proximity to Golfaraj Reservoir. Hydrogeochemical analyses further suggest that the water source of Shahmar Drain, ~ 1800 m north of Golfaraj Dam cannot be from the east or west embankments of the dam because the electrical conductivity in Shahmar Drain water approximates the electrical conductivity of Golfaraj Reservoir water and is lower than the electrical conductivity of groundwater in some of boreholes. Potential future seepage mitigation measures will focus on methods to seal the reservoir floor and cutoff wall sections I2-I2 and I3-I3, although some efforts may be directed at the west side of the dam. Such measures could take the form of installation of a geomembrane barrier over the west side of the dam, concrete cutoff walls downstream of the dam, and pumping wells to intercept seepage.Thematic collection: This article is part of the Sustainability in engineering geology and hydrogeology collection available at: https://www.lyellcollection.org/cc/sustainability-in-engineering-geology-and-hydrogeology

scholarly journals Estimating carbon emissions from African wildfires

2009 ◽  
Vol 6 (3) ◽  
pp. 349-360 ◽  
Author(s):  
V. Lehsten ◽  
K. Tansey ◽  
H. Balzter ◽  
K. Thonicke ◽  
A. Spessa ◽  
...  
Keyword(s):  
Carbon Emissions ◽  
Net Primary Productivity ◽  
Fire Regime ◽  
Climatic Conditions ◽  
Burned Area ◽  
Similar Response ◽  
Response Patterns ◽  
Model Framework ◽  
Burnt Area ◽  
In Fire

Abstract. We developed a technique for studying seasonal and interannual variation in pyrogenic carbon emissions from Africa using a modelling approach that scales burned area estimates from L3JRC, a map recently generated from remote sensing of burn scars instead of active fires. Carbon fluxes were calculated by the novel fire model SPITFIRE embedded within the dynamic vegetation model framework LPJ-GUESS, using daily climate input. For the time period from 2001 to 2005 an average area of 195.5±24×104 km2 was burned annually, releasing an average of 723±70 Tg C to the atmosphere; these estimates for the biomass burned are within the range of previously published estimates. Despite the fact that the majority of wildfires are ignited by humans, strong relationships between climatic conditions (particularly precipitation), net primary productivity and overall biomass burnt emerged. Our investigation of the relationships between burnt area and carbon emissions and their potential drivers available litter and precipitation revealed uni-modal responses to annual precipitation, with a maximum around 1000 mm for burned area and emissions, or 1200 mm for litter availability. Similar response patterns identified in savannahs worldwide point to precipitation as a chief determinant for short-term variation in fire regime. A considerable variability that cannot be explained by fire-precipitation relationships alone indicates the existence of additional factors that must be taken into account.

scholarly journals Mice and Habitat Complexity Attract Carnivorans to Recently Burnt Forests

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 855
Author(s):  
Roger Puig-Gironès ◽  
Pere Pons
Keyword(s):  
Small Mammal ◽  
Resource Availability ◽  
Habitat Structure ◽  
Red Fox ◽  
Plant Cover ◽  
Fleshy Fruit ◽  
Frequency Of Occurrence ◽  
Stone Marten ◽  
Burnt Area ◽  
Fruit Availability

Faunal responses to wildfire depend on the fire effects on direct mortality, habitat structure, and resource availability for animals. Despite the importance of large predators in terrestrial trophic webs, little is still known about how fire affects carnivorans (the mammalian order Carnivora). To evaluate the responses of the carnivoran community to fire, we studied three recently burnt forest areas in the western Mediterranean basin. Line transects were used to quantify evidence of carnivorans (mainly feces) and to measure environmental variables and resources (small mammal abundance, fleshy fruit availability, and plant cover). Throughout the study, we found 212 carnivoran field signs, 93% of them produced by red fox and stone marten. Immediately after fire, carnivoran occurrence was more frequent close to the perimeter of the burnt area, where fire severity was low, and in places with greater small mammal abundance. Small mammal abundance and plant cover had the greatest effect on the frequency of occurrence of red fox in the burnt area surroundings, and this increased with time-since-fire in the burnt area. Furthermore, the presence of red fox did not affect stone marten occurrence. Stone martens were found around the burnt area perimeter, probably because of their preference for high plant cover, and they were not significantly affected by small mammal abundance. The scat frequency of occurrence of both species was not significantly related to fleshy fruit availability. Accordingly, rodents and carnivorans were more abundant where the habitat was more complex. Our results show that the responses of some carnivorans to fire are influenced, directly and indirectly, by habitat structure and resource availability.

Winter peatland habitat selection by woodland caribou in northeastern Alberta

1995 ◽  
Vol 73 (8) ◽  
pp. 1567-1574 ◽  
Author(s):  
Corey J. A. Bradshaw ◽  
Stan Boutin ◽  
Daryll M. Hebert ◽  
A. Blair Rippin
Keyword(s):  
Spatial Scales ◽  
Feeding Activity ◽  
Habitat Diversity ◽  
Woodland Caribou ◽  
Raised Bog ◽  
Very High Frequency ◽  
Winter Habitat ◽  
Raised Bogs ◽  
Discontinuous Permafrost ◽  
Northeastern Alberta

Woodland caribou in northeastern Alberta are relatively sedentary, occur at low densities, and are classed as endangered in Alberta. Increasing encroachment of the forest and petroleum industries into the southern regions of the boreal woodland caribou range has highlighted the need for detailed habitat analysis for this species. We obtained approximately 1000 locations of 47 woodland caribou fitted with very high frequency telemetry collars, providing data on winter habitat use from 1991 to 1994. Telemetry data were combined with digital peatland coverages that best represented lowland habitat diversity. Woodland caribou selected forested fen peatland complexes at both the population and individual spatial scales. Woodland caribou concentrated feeding activity in forested, raised bog islands. The raised bogs provide more xeric substrate for increased lichen biomass, possibly a key factor in their selection during winter. The hypothesized connection between discontinuous permafrost and the maintenance of raised bog islands in terms of caribou forage distribution and availability is discussed.

scholarly journals Hydro-Sedimentary Study of a Tidal River: Case Study of the Arvand River in Iran

2021 ◽  
Vol 11 (1) ◽  
pp. 9-16
Author(s):  
M. Bakhtiari ◽  
A. Ashtari Larki ◽  
A. Samer
Keyword(s):  
Electrical Conductivity ◽  
Field Study ◽  
Water Level ◽  
Neap Tide ◽  
Spring Tide ◽  
Suspended Sediments ◽  
Tidal River ◽  
Deep Distribution ◽  
Suspended Sediments Concentration

Abstract The present field study investigated hydraulic and sediment in tidal conditions. Measurements were made for two stations at neap tide and spring tide for 13-hour periods at no-dimensional depths of 0.2, 0.6 and 0.8 of the water level each time. In these measurements, the parameters of velocity, direction of flow, electrical conductivity, temperature and depth were measured directly, and to determine the amount of suspended sediments per hour, 3 samples of one litre from the mentioned depths were measured by the instantaneous vertical sampler and taken to a laboratory. An examination of the depth charts of the suspended sediments concentration for all stations, and in both the neap tide and the spring tide, showed that, in general the suspended sediments concentration increased with increasing depth. Moreover, the deep distribution of sediments concentration showed that the values obtained in the laboratory corresponded well with the values calculated from the Rouse equation, and as the depth increases, the sediments concentration usually increases.

scholarly journals Annual greenhouse gas budget for a bog ecosystem undergoing restoration by rewetting

2016 ◽  
Author(s):  
Sung Ching Lee ◽  
Andreas Christen ◽  
Andy T. Black ◽  
Mark S. Johnson ◽  
Rachhpal S. Jassal ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Water Table ◽  
Time Horizon ◽  
Ecosystem Respiration ◽  
High Water ◽  
Co2 Uptake ◽  
Raised Bog ◽  
Peat Mining ◽  
Ch4 Emissions ◽  
Carbon Dioxide Co2

Abstract. Many peatlands have been drained and harvested for peat mining, which has turned them from carbon (C) sinks into C emitters. Rewetting of disturbed peatlands facilitates their ecological recovery, and may help them revert to carbon dioxide (CO2) sinks. However, rewetting may also cause substantial emissions of the more potent greenhouse gas (GHG) methane (CH4). Our knowledge on the exchange of CO2 and CH4 following rewetting during restoration of disturbed peatlands is currently limited. This study quantifies annual fluxes of CO2 and CH4 in a disturbed and rewetted area located in the Burns Bog Ecological Conservancy Area in Delta, BC, Canada. Burns Bog is recognized as the largest raised bog ecosystem on North America's West Coast. Burns Bog was substantially reduced in size and degraded by peat mining and agriculture. Since 2005, the bog has been declared a conservancy area, with restoration efforts focusing on rewetting disturbed ecosystems to recover Sphagnum and suppress fires. Using the eddy-covariance (EC) technique, we measured year-round (16th June 2015 to 15th June 2016) turbulent fluxes of CO2 and CH4 from a tower platform in an area rewetted for the last 8 years. The study area, dominated by sedges and Sphagnum, experienced a varying water table position that ranged between 7.7 (inundation) and −26.5 cm from the surface during the study year. The annual CO2 budget of the rewetted area was −179 g CO2-C m−2 year−1 (CO2 sink) and the annual CH4 budget was 16 g CH4-C m−2 year−1 (CH4 source). Gross ecosystem productivity (GEP) exceeded ecosystem respiration (Re) during summer months (June–August), causing a net CO2 uptake. In summer, high CH4 emissions (121 mg CH4-C m−2 day−1) were measured. In winter (December–February), while roughly equal magnitudes of GEP and Re made the study area CO2 neutral, very low CH4 emissions (9 mg CH4-C m−2 day−1) were observed. The key environmental factors controlling the seasonality of these exchanges were downwelling photosynthetically active radiation and 5-cm soil temperature. It appears that the high water table caused by ditch blocking which suppresses Re. With low temperatures in winter, CH4 emission was more suppressed than Re. Annual net GHG flux from CO2 and CH4 expressed in terms of CO2 equivalents (CO2e) during the study period totaled to −55 g CO2e m−2 year−1 (net CO2e sink) and 1147 g CO2e m−2 year−1 (net CO2e source) by using 100-year and 20-year global warming potential values, respectively. Consequently, the ecosystem was almost CO2e neutral during the study period expressed on a 100-year time horizon but was a significant CO2e source on a 20-year time horizon.

scholarly journals Selected properties of organic soils under boreal mire spruce forest in the Romincka Forest, NE Poland

2017 ◽  
Vol 68 (4) ◽  
pp. 182-188
Author(s):  
Szymon Bijak
Keyword(s):  
Soil Fertility ◽  
Site Index ◽  
Exchange Capacity ◽  
Organic Soils ◽  
Raised Bog ◽  
Base Exchange ◽  
Raised Bogs ◽  
Trophic Index ◽  
Ne Poland ◽  
Stand Productivity

Abstract The paper presents selected properties of the organic soils developed in boreal mire spruce forests (Sphagno girensohnii-Piceetum) in the Romincka Forest (NE Poland). Additionally, the relationship between soil fertility and forest stand productivity was investigated. Data from 12 soil profiles, differing in terms of peatland ecological type (raised bog, transitional bog and fen) was used. The significance of the differences in soil properties among peatland types was assessed with the Kruskal-Wallis test. Soil fertility was described using soil trophic index (SIGo), whereas stand productivity according to site index (SI) value. The properties of the analysed soils varied significantly in terms of peatland type. Soils from fens were more fertile (SIGo 25–31), less acidic (pH > 5.7), with lower total potential acidity (36–40 cmol(+)·kg−1), higher base saturation (77–79%), Ca2+ content (116–136 cmol(+)·kg−1) and base exchange capacity (123–145 cmol(+)·kg−1) than soils from transition or raised bogs. No significant effect of soil fertility on the site index of stands growing on analysed soils was observed (r = 0.385, p = 0.216).

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