Important aspects of the phosphorus cycle in a Mediterranean coastal system: the Pagassitikos Gulf, Greece

2002 ◽  
Author(s):  
A Koliou
Keyword(s):  
Phosphorus Cycle ◽  
Coastal System ◽  
Pagassitikos Gulf

ASSESSMENT OF GRAY FOREST SOIL ENZYMATIC ACTIVITY IN AGRICULTURAL SYSTEMS

2019 ◽  
Keyword(s):  
Enzymatic Activity ◽  
Environmental Sustainability ◽  
Hydrolytic Enzymes ◽  
Invertase Activity ◽  
Phosphorus Cycle ◽  
Soil Enzymatic Activity ◽  
Urease Enzyme ◽  
Natural Analogues ◽  
Activity Of Enzymes ◽  
The Impact

On the grey forest medium-loamy soil of Vladimir Opolye region we have studied the impact of various methods of basic cultivation and fertilizer systems on the activity of redox and hydrolytic enzymes: ure-ase (nitrogen cycle), invertase (carbon cycle), phosphatase (phosphorus cycle), and catalase, involved in the cycle of carbon in the soil. The second humus horizon with capacity of 19-24cm was found at the depth of 20 - 21 cm on the experimental field. We have studied three modes of basic soil cultivation: an-nual shallow flat plowing (6-8 cm), annual deep flat plowing (20-22 cm), and annual moldboard plowing (20-22 cm) with normal and intensive application of fertilizers. The most enzymatically active layer is 0-20 cm. No relevant difference has been found in the level of enzymes activity between variants of basic soil treatment. Activity of enzymes increases with application of fertilizers on the intensive background. In agrogenic soils, soil enzymatic activity is lower on average by 16-22% compared to the soil of the res-ervoir. The biggest negative transformation of activity has been observed at the urease enzyme (up to 50%). With annual moldboard plowing on the intensive backgroung, enzyme activity has been close to the natural level – 98.4%. Catalise and invertase activity in this case were found to be higher (105 and 116% respectively) than that of natural analogues. Activity of enzymes increases with intensive application of fertilizers as compared with normal background. This is particularly evident with 6-8cm deep beardless plowing and 20-22cm deep moldboard plowing. In general, the obtained biochemical indicators charac-terize the highest environmental sustainability of this variation within our research.

DEFINING THE RESPONSE OF A LOW GRADIENT COASTAL SYSTEM TO RAPID SEA-LEVEL CHANGE DURING THE LATE PLEISTOCENE

2019 ◽  
Author(s):  
Amy W. Cressman ◽  
◽  
David J. Mallinson ◽  
Stephen J. Culver ◽  
Regina DeWitt ◽  
...  
Keyword(s):  
Sea Level ◽  
Late Pleistocene ◽  
Sea Level Change ◽  
Coastal System ◽  
Level Change

LATE QUATERNARY EVOLUTION OF THE CONTINENTAL SHELF AND COASTAL SYSTEM OF THE DELMARVA PENINSULA

2019 ◽  
Author(s):  
Laura Brothers ◽  
◽  
David S. Foster ◽  
Elizabeth A. Pendleton ◽  
Wayne E. Baldwin ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Late Quaternary ◽  
Delmarva Peninsula ◽  
Coastal System

scholarly journals Hydrological droughts in the southern Andes (40–45°S) from an ensemble experiment using CMIP5 and CMIP6 models

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rodrigo Aguayo ◽  
Jorge León-Muñoz ◽  
René Garreaud ◽  
Aldo Montecinos
Keyword(s):  
Climate Models ◽  
Physicochemical Characteristics ◽  
Climate Impact ◽  
Economic Consequences ◽  
Cmip5 Models ◽  
Southern Andes ◽  
Weap Model ◽  
Coastal System ◽  
Hydrological Droughts ◽  
Impacts Of Climate Change

AbstractThe decrease in freshwater input to the coastal system of the Southern Andes (40–45°S) during the last decades has altered the physicochemical characteristics of the coastal water column, causing significant environmental, social and economic consequences. Considering these impacts, the objectives were to analyze historical severe droughts and their climate drivers, and to evaluate the hydrological impacts of climate change in the intermediate future (2040–2070). Hydrological modelling was performed in the Puelo River basin (41°S) using the Water Evaluation and Planning (WEAP) model. The hydrological response and its uncertainty were compared using different combinations of CMIP projects (n = 2), climate models (n = 5), scenarios (n = 3) and univariate statistical downscaling methods (n = 3). The 90 scenarios projected increases in the duration, hydrological deficit and frequency of severe droughts of varying duration (1 to 6 months). The three downscaling methodologies converged to similar results, with no significant differences between them. In contrast, the hydroclimatic projections obtained with the CMIP6 and CMIP5 models found significant climatic (greater trends in summer and autumn) and hydrological (longer droughts) differences. It is recommended that future climate impact assessments adapt the new simulations as more CMIP6 models become available.

scholarly journals Topological and Morphological Controls on Morphodynamics of Salt Marsh Interiors

2021 ◽  
Vol 9 (3) ◽  
pp. 311
Author(s):  
Ben R. Evans ◽  
Iris Möller ◽  
Tom Spencer
Keyword(s):  
Salt Marsh ◽  
Salt Marshes ◽  
East Coast ◽  
Marsh Surface ◽  
Coastal Environments ◽  
Coastal System ◽  
Morphological Segmentation ◽  
The Usa ◽  
The Uk ◽  
Over Time

Salt marshes are important coastal environments and provide multiple benefits to society. They are considered to be declining in extent globally, including on the UK east coast. The dynamics and characteristics of interior parts of salt marsh systems are spatially variable and can fundamentally affect biotic distributions and the way in which the landscape delivers ecosystem services. It is therefore important to understand, and be able to predict, how these landscape configurations may evolve over time and where the greatest dynamism will occur. This study estimates morphodynamic changes in salt marsh areas for a regional domain over a multi-decadal timescale. We demonstrate at a landscape scale that relationships exist between the topology and morphology of a salt marsh and changes in its condition over time. We present an inherently scalable satellite-derived measure of change in marsh platform integrity that allows the monitoring of changes in marsh condition. We then demonstrate that easily derived geospatial and morphometric parameters can be used to determine the probability of marsh degradation. We draw comparisons with previous work conducted on the east coast of the USA, finding differences in marsh responses according to their position within the wider coastal system between the two regions, but relatively consistent in relation to the within-marsh situation. We describe the sub-pixel-scale marsh morphometry using a morphological segmentation algorithm applied to 25 cm-resolution maps of vegetated marsh surface. We also find strong relationships between morphometric indices and change in marsh platform integrity which allow for the inference of past dynamism but also suggest that current morphology may be predictive of future change. We thus provide insight into the factors governing marsh degradation that will assist the anticipation of adverse changes to the attributes and functions of these critical coastal environments and inform ongoing ecogeomorphic modelling developments.

scholarly journals Global phosphorus dynamics in terms of phosphine

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Wanyi Fu ◽  
Xihui Zhang
Keyword(s):  
Wastewater Treatment ◽  
Human Activities ◽  
Wastewater Treatment Plants ◽  
Global Climate ◽  
Global Scale ◽  
Phosphorus Cycle ◽  
Natural Ecosystems ◽  
Driving Cycles ◽  
Global Cycles ◽  
Urban Wastewater Treatment

AbstractSince the detection of phosphine in the wastewater treatment plants in 1988, more and more investigations revealed that phosphine is closely related to ecological activities on a global scale. Here, we present perspectives on the whole dynamic cycles of phosphorus, particularly in terms of phosphine and its interactions with natural ecosystems, as well as the impacts from human activities. It may conclude that the phosphine-driving cycles of phosphorus depend on the coordination of human activities with natural ecosystems. Most importantly, the extensive recovery of phosphorus in numerous urban wastewater treatment plants may seriously obstruct its global cycles to catch up with the ecological needs in natural ecosystems. Phosphine gas plays an important role in the biogeochemical phosphorus cycle. Phosphorus might be one of the important elements participating in the global climate change together with carbon and nitrogen.

scholarly journals Functional Metagenomics Reveals an Overlooked Diversity and Novel Features of Soil-Derived Bacterial Phosphatases and Phytases

mBio ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. e01966-18 ◽  
Author(s):  
Genis Andrés Castillo Villamizar ◽  
Heiko Nacke ◽  
Marc Boehning ◽  
Kristin Herz ◽  
Rolf Daniel
Keyword(s):  
Phosphatase Activity ◽  
High Performance ◽  
Cell Metabolism ◽  
Screening Method ◽  
Phosphorus Cycle ◽  
Functional Metagenomics ◽  
Phosphorus Pollution ◽  
Metagenome Analysis ◽  
Genes Encoding ◽  
Novel Target

ABSTRACTPhosphatases, including phytases, play a major role in cell metabolism, phosphorus cycle, biotechnology, and pathogenic processes. Nevertheless, their discovery by functional metagenomics is challenging. Here, soil metagenomic libraries were successfully screened for genes encoding phosphatase activity. In this context, we report the largest number and diversity of phosphatase genes derived from functional metagenome analysis. Two of the detected gene products carry domains which have never been associated with phosphatase activity before. One of these domains, the SNARE-associated domain DedA, harbors a so-far-overlooked motif present in numerous bacterial SNARE-associated proteins. Our analysis revealed a previously unreported phytase activity of the alkaline phosphatase and sulfatase superfamily (cl23718) and of purple acid phosphatases from nonvegetal origin. This suggests that the classical concept comprising four classes of phytases should be modified and indicates high performance of our screening method for retrieving novel types of phosphatases/phytases hidden in metagenomes of complex environments.IMPORTANCEPhosphorus (P) is a key element involved in numerous cellular processes and essential to meet global food demand. Phosphatases play a major role in cell metabolism and contribute to control the release of P from phosphorylated organic compounds, including phytate. Apart from the relationship with pathogenesis and the enormous economic relevance, phosphatases/phytases are also important for reduction of phosphorus pollution. Almost all known functional phosphatases/phytases are derived from cultured individual microorganisms. We demonstrate here for the first time the potential of functional metagenomics to exploit the phosphatase/phytase pools hidden in environmental soil samples. The recovered diversity of phosphatases/phytases comprises new types and proteins exhibiting largely unknown characteristics, demonstrating the potential of the screening method for retrieving novel target enzymes. The insights gained into the unknown diversity of genes involved in the P cycle highlight the power of function-based metagenomic screening strategies to study Earth’s phosphatase pools.

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