scholarly journals Nutrient Dynamics in Partially Drained Arctic Thaw Lakes

2018 ◽  
Vol 123 (2) ◽  
pp. 440-452 ◽  
Author(s):  
J. C. Koch ◽  
T. F. Fondell ◽  
S. Laske ◽  
J. A. Schmutz
Keyword(s):  
Nutrient Dynamics ◽  
Thaw Lakes

Focus on Thermokarst Lakes in Indian Himalaya: Inception and Implication under Warming Climate

2020 ◽  
Vol 6 (2) ◽  
pp. 59-69
Author(s):  
Pratima Pandey ◽  
S. Nawaz Ali ◽  
Vikram Sharma ◽  
Prashant K. Champati Ray
Keyword(s):  
Western Himalaya ◽  
High Mountain ◽  
Thermokarst Lakes ◽  
Glacial Environments ◽  
Global Warming Scenario ◽  
Scientific Attention ◽  
Topographic Depressions ◽  
Permafrost Thawing ◽  
The Impact ◽  
Thaw Lakes

Thermokarst (Thaw) lakes are landforms found in topographic depressions created by thawing ground ice in permafrost zones. They play an important role in the regulation of climatic functions. These lakes are a manifestation of warming surface temperatures that accelerates the ice-rich permafrost to degrade by creating marshy hollows/ponds. In the current global warming scenario, the thermokarst lakes in the high mountain regions (Himalaya) are expected to grow further. This accelerate permafrost thawing which will affect the carbon cycle, hydrology and local ecosystems. This phenomenon has attracted huge scientific attention because it has led to a rapid mass change of glaciers in the region, including extensive changes occurring on peri-glacial environments. The most striking fact is the release of an enormous amount of greenhouse gases, including methane, carbon dioxide and nitrous oxide that is locked in these lakes. The present study delves into the thermokarst lakes in the upper reaches of Chandra Valley and Western Himalaya. The study also aims at designating the impact of their changes on the ecosystem, particularly their influence on the atmospheric greenhouse gas concentrations.

scholarly journals Microbial Respiration and Enzyme Activity Downstream from a Phosphorus Source in the Everglades, Florida, USA

Land ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 696
Author(s):  
Sanku Dattamudi ◽  
Saoli Chanda ◽  
Leonard J. Scinto
Keyword(s):  
Nutrient Dynamics ◽  
Microbial Respiration ◽  
Organic Matter Content ◽  
Physicochemical Analysis ◽  
Matter Content ◽  
Enzyme Assays ◽  
Co2 Efflux ◽  
Soil Organic Matter Content ◽  
Phosphorus Source ◽  
P Distribution

Northeast Shark River Slough (NESS), lying at the northeastern perimeter of Everglades National Park (ENP), Florida, USA, has been subjected to years of hydrologic modifications. Construction of the Tamiami Trail (US 41) in 1928 connected the east and west coasts of SE Florida and essentially created a hydrological barrier to southern sheet flow into ENP. Recently, a series of bridges were constructed to elevate a portion of Tamiami Trail, allow more water to flow under the bridges, and attempt to restore the ecological balance in the NESS and ENP. This project was conducted to determine aspects of soil physiochemistry and microbial dynamics in the NESS. We evaluated microbial respiration and enzyme assays as indicators of nutrient dynamics in NESS soils. Soil cores were collected from sites at certain distances from the inflow (near canal, NC (0–150 m); midway, M (150–600 m); and far from canal, FC (600–1200 m)). Soil slurries were incubated and assayed for CO2 emission and β-glucoside (MUFC) or phosphatase (MUFP) activity in concert with physicochemical analysis. Significantly higher TP contents at NC (2.45 times) and M (1.52 times) sites than FC sites indicated an uneven P distribution downstream from the source canal. The highest soil organic matter content (84%) contents were observed at M sites, which was due to higher vegetation biomass observed at those sites. Consequently, CO2 efflux was greater at M sites (average 2.72 µmoles g dw−1 h−1) than the other two sites. We also found that amendments of glucose increased CO2 efflux from all soils, whereas the addition of phosphorus did not. The results indicate that microbial respiration downstream of inflows in the NESS is not limited by P, but more so by the availability of labile C.

scholarly journals Land Cover Effects on Selected Nutrient Compounds in Small Lowland Agricultural Catchments

Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 182
Author(s):  
Maksym Łaszewski ◽  
Michał Fedorczyk ◽  
Sylwia Gołaszewska ◽  
Zuzanna Kieliszek ◽  
Paulina Maciejewska ◽  
...  
Keyword(s):  
Land Cover ◽  
Nutrient Dynamics ◽  
Agricultural Landscape ◽  
Predictive Performance ◽  
Special Focus ◽  
Spatial And Temporal Variability ◽  
Buffer Zones ◽  
Agricultural Catchments ◽  
Landscape Water ◽  
Seasonal Impact

The influence of landscape on nutrient dynamics in rivers constitutes an important research issue because of its significance with regard to water and land management. In the current study spatial and temporal variability of N-NO3 and P-PO4 concentrations and their landscape dependence was documented in the Świder River catchment in central Poland. From April 2019 to March 2020, water samples were collected from fourteen streams in the monthly timescale and the concentrations of N-NO3 and P-PO4 were correlated with land cover metrics based on the Corine Land Cover 2018 and Sentinel 2 Global Land Cover datasets. It was documented that agricultural lands and forests have a clear seasonal impact on N-NO3 concentrations, whereas the effect of meadows was weak and its direction was dependent on the dataset. The application of buffer zones metrics increased the correlation performance, whereas Euclidean distance scaling improved correlation mainly for forest datasets. The concentration of P-PO4 was not significantly related with land cover metrics, as their dynamics were driven mainly by hydrological conditions. The obtained results provided a new insight into landscape–water quality relationships in lowland agricultural landscape, with a special focus on evaluating the predictive performance of different land cover metrics and datasets.

Effect of livestock manure on soil microbial and nutrient dynamics in Zaï cropping systems of the Sahel

2021 ◽  
Author(s):  
Salifou Traoré ◽  
Pauline Ouédraogo ◽  
Philippe Bayen ◽  
Babou André Bationo ◽  
Nathan Lee ◽  
...  
Keyword(s):  
Nutrient Dynamics ◽  
Cropping Systems ◽  
Livestock Manure ◽  
Soil Microbial

scholarly journals Detecting Climate Driven Changes in Chlorophyll-a in Deep Subalpine Lakes Using Long Term Satellite Data

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 866
Author(s):  
Gary Free ◽  
Mariano Bresciani ◽  
Monica Pinardi ◽  
Nicola Ghirardi ◽  
Giulia Luciani ◽  
...  
Keyword(s):  
Climate Change ◽  
Chlorophyll A ◽  
Nutrient Dynamics ◽  
Cascading Effects ◽  
The North ◽  
Subalpine Lakes ◽  
Winter Temperatures ◽  
Decadal Climate ◽  
The North Atlantic Oscillation ◽  
Traditional Pattern

Climate change has increased the temperature and altered the mixing regime of high-value lakes in the subalpine region of Northern Italy. Remote sensing of chlorophyll-a can help provide a time series to allow an assessment of the ecological implications of this. Non-parametric multiplicative regression (NPMR) was used to visualize and understand the changes that have occurred between 2003–2018 in Lakes Garda, Como, Iseo, and Maggiore. In all four deep subalpine lakes, there has been a disruption from a traditional pattern of a significant spring chlorophyll-a peak followed by a clear water phase and summer/autumn peaks. This was replaced after 2010–2012, with lower spring peaks and a tendency for annual maxima to occur in summer. There was a tendency for this switch to be interspersed by a two-year period of low chlorophyll-a. Variables that were significant in NPMR included time, air temperature, total phosphorus, winter temperature, and winter values for the North Atlantic Oscillation. The change from spring to summer chlorophyll-a maxima, relatively sudden in an ecological context, could be interpreted as a regime shift. The cause was probably cascading effects from increased winter temperatures, reduced winter mixing, and altered nutrient dynamics. Future trends will depend on climate change and inter-decadal climate drivers.

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