Nutrient dynamics in a hyporheic zone in response to a severe and prolonged dry period in a semi-arid river (Tafna wadi)

Abstract. Stream and riparian groundwater hydrology has been studied in a small intermittent stream draining a forested catchment for a system representative of a Mediterranean climate. The relationship between precipitation and stream runoff and the interactions between stream water and the surrounding riparian groundwater have been analysed under a wide spectrum of meteorological conditions. The hypothesis that the hydrological condition of the near-stream groundwater compartment can regulate the runoff generation during precipitation events was tested. Stream runoff is characterised by a summer dry period, and precipitation input explained only 25% of runoff variability over the study period (r2 =0.25, d.f.=51, p<0.001). The variability of precipitation v. stream runoff is explained partly by the hydrogeological properties of the riparian near-stream zone. This zone is characterised by high hydrological conductivity values and abrupt changes in groundwater level in summer. The summer dry period begins with a rapid decrease in near-stream groundwater level, and ends just after the first autumnal rain when the original groundwater level recovers suddenly. Within this period, storms do not cause major stream runoff since water infiltrates rapidly into the riparian compartment until it is refilled during the subsequent winter and spring; then the precipitation explains the 80% of the stream runoff variability (r2=0.80, d.f.=34, p<0.001). These results suggest that the hydrological interaction between the riparian groundwater compartment and the stream channel is important in elucidating the hydrological responses during drought periods in small Mediterranean streams. Keywords: riparian zone, groundwater hydrology, runoff, intermittent stream, Mediterranean climate

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Nutrient Dynamics in Bottom Sediment of a Reservoir in the Semi-Arid Region

Journal of Experimental Agriculture International ◽

10.9734/jeai/2018/42944 ◽

2018 ◽

Vol 25 (1) ◽

pp. 1-9

Author(s):

Aldênia Almeida ◽

Fernando Lopes ◽

Eunice Andrade ◽

Cicero Almeida ◽

Leilson Oliveira

Keyword(s):

Bottom Sediment ◽

Arid Region ◽

Nutrient Dynamics ◽

Semi Arid Region ◽

Semi Arid

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Potential for nutrient contribution from litter in a seasonally dry forest

Revista Agro mbiente On-line ◽

10.18227/1982-8470ragro.v11i4.4563 ◽

2017 ◽

Vol 11 (4) ◽

pp. 269 ◽

Cited By ~ 1

Author(s):

José Fredson Bezerra Lopes ◽

Eunice Maia Andrade ◽

Lindbergue Araújo Crisóstomo ◽

Meilla Marielle Araújo Rodrigues

Keyword(s):

Nutrient Dynamics ◽

Tropical Dry Forest ◽

Essential Elements ◽

Dry Forest ◽

Seasonally Dry ◽

Time Variations ◽

The Mean ◽

Semi Arid Region ◽

Seasonally Dry Forest ◽

Semi Arid

Litter is the most important way of transferring essential elements from vegetation to the soil. This is due to nutrient cycling, a process by which decomposition of the litter adds nutrients to the soil. An understanding of this process goes beyond the need for knowledge of nutrient dynamics, since it is a question of understanding the way in which ecosystems function in the search for a correct use of natural resources. The aim of this study was to quantify the average concentrations of the following nutrients: Nitrogen (N), phosphorus (P), Potassium (K), and Organic Carbon (C) in litter remaining in an area of tropical dry forest - Caatinga. The work was carried out on the Elias Andrade Private Natural Heritage Reserve (PNHR) of the Irmãos Andrade Farm, located in the semi-arid region of the State of Ceará. In February 2009, 48 nylon litter bags were randomly distributed, each containing 30 g of litter collected in the area of the Reserve. Every two months, from February 2009 to January 2011, four bags were randomly collected. Over time, variations were seen in the average levels of N, P and K for the litter in the nylon bags. The nutrient with the greatest contribution to the system from the litter was Nitrogen, followed by K and P. The highest N content occurred at the beginning of the experiment. The C content decreased over the study period. The mean C to N ratio of the litter was 21, which was in the borderline range between the processes of mineralisation and immobilisation.

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Social and Productive Indicators of Forage Palm and the Survival of Livestock Activity in the Semi-arid Region of Northeastern Brazil

Asian Journal of Advances in Agricultural Research ◽

10.9734/ajaar/2019/v10i130018 ◽

2019 ◽

pp. 1-12

Author(s):

Hermes Alves de Almeida ◽

Elthon Rondinelli de Almeida Soares ◽

José Antonio dos Santos Neto ◽

Ivandro de Oliveira Pinto

Keyword(s):

Arid Region ◽

Geographic Region ◽

Google Earth ◽

Northeastern Brazil ◽

Statistical Distributions ◽

Dry Period ◽

New Varieties ◽

Semi Arid Region ◽

The One ◽

Semi Arid

The importance of the cultivation of forage palm (Opuntia fícus indica Mill) for the agriculturalists of the semi-arid region of Northeast of Brazil, in particular the one of the State of Paraiba, is due to its adaptability to the environmental conditions, especially, in the dry period, since it is the only alternative to feed the herd in most of the localities of this region. The plague of carmine cochineal (Dactylopius opuntiae) has been decimating the planting of this important forage in the intermediate geographic region of Campina Grande, Paraiba, Brazil. In view of this, it was necessary to carry out a quantitative and/or qualitative diagnosis of the areas cultivated with the traditional palm (giant cultivar) and its revitalization, with the introduction of new varieties resistant to this pest, in four localities of this region, these determinations being the main objectives. The territorial cut included about fifty farms in the four localities, being geo referenced using GPS and satellite imagery from Google Earth. The diagnosis consisted of the application of structured and semi-structured questionnaires, interviews and in loco observations. Data analyzes were performed using statistical distributions of measures of central, dispersion and frequency trends. The main results indicated that forage palm in the semi-arid state of Paraiba, Brazil, is the main or only source of food for ruminants. Carmine cochineal (Dactylopius opuntiae) decimated traditional palm varieties and the only alternative was to discard part of the herd and reduce livestock activity. The levels of infestation of carmine cochineal and destruction of palms are of the order of 90%. The program of revitalization of traditional palm cultivation by clams resistant to carmine cochineal has been the alternative for the continuity of livestock activity in this region, although there is a contribution of drought.

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Bolivar Wastewater Treatment Plant provides an important habitat for South Australian ducks and waders

10.20938/afo37190199 ◽

2020 ◽

Vol 37 ◽

pp. 190-199

Author(s):

William Breed ◽

◽

John Hatch ◽

Colin Rogers ◽

William Brooker ◽

...

Keyword(s):

Wastewater Treatment ◽

Northern Hemisphere ◽

Wastewater Treatment Plant ◽

Treatment Plant ◽

Arid Zones ◽

Dry Period ◽

South Eastern ◽

Eastern Australia ◽

Semi Arid ◽

Important Habitat

The populations of South Australian duck and wader species have recently decreased considerably, but their abundance at Bolivar Wastewater Treatment Plant in metropolitan Adelaide is poorly known. To help assess the importance of this site for ducks and waders, we made 25 trips to Bolivar between December 2018 and July 2020, during most of which time south-eastern Australia was experiencing a long dry period. On each trip, we observed between 11 and 26 species of ducks and waders, with a mean total of 9804 (range 2437–15,653) individuals per trip. At times, we observed several thousand Pink-eared Ducks Malacorhynchus membranaceus, Grey Teal Anas gracilis, and Australian Shelducks Tadorna tadornoides, with occasionally up to 1200 Blue-billed Ducks Oxyura australis and 2000 Hardheads Aythya australis. Several wader species that largely breed in Australia’s semi-arid and arid zones were also observed, including occasionally >1000 Red-necked Avocets Recurvirostra novaehollandiae. Five species of waders that breed in the Northern Hemisphere were also recorded fairly regularly in the summer of both 2018–2019 and 2019–2020, including up to ~2000 Sharp-tailed Sandpipers Calidris acuminata, 2000 Red-necked Stints C. ruficollis and 150 Curlew Sandpipers C. ferruginea. These observations indicate that this wastewater treatment plant is a critically important refuge site for several species of ducks and waders. Every effort should thus be made to maintain this site for the conservation of these species in the future.

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Quantifying nutrient fluxes with a new hyporheic passive flux meter (HPFM)

Biogeosciences ◽

10.5194/bg-14-631-2017 ◽

2017 ◽

Vol 14 (3) ◽

pp. 631-649 ◽

Cited By ~ 4

Author(s):

Julia Vanessa Kunz ◽

Michael D. Annable ◽

Jaehyun Cho ◽

Wolf von Tümpling ◽

Kirk Hatfield ◽

...

Keyword(s):

Pore Water ◽

Nutrient Dynamics ◽

Hyporheic Zone ◽

Sampling Site ◽

Nutrient Fluxes ◽

Running Waters ◽

Grab Sampling ◽

Biofilm Growth ◽

Hyporheic Zones ◽

Passive Flux Meter

Abstract. The hyporheic zone is a hotspot of biogeochemical turnover and nutrient removal in running waters. However, nutrient fluxes through the hyporheic zone are highly variable in time and locally heterogeneous. Resulting from the lack of adequate methodologies to obtain representative long-term measurements, our quantitative knowledge on transport and turnover in this important transition zone is still limited.In groundwater systems passive flux meters, devices which simultaneously detect horizontal water and solute flow through a screen well in the subsurface, are valuable tools for measuring fluxes of target solutes and water through those ecosystems. Their functioning is based on accumulation of target substances on a sorbent and concurrent displacement of a resident tracer which is previously loaded on the sorbent.Here we evaluate the applicability of this methodology for investigating water and nutrient fluxes in hyporheic zones. Based on laboratory experiments we developed hyporheic passive flux meters (HPFMs) with a length of 50 cm which were separated in 5–7 segments allowing for vertical resolution of horizontal nutrient and water transport. The HPFMs were tested in a 7 day field campaign including simultaneous measurements of oxygen and temperature profiles and manual sampling of pore water. The results highlighted the advantages of the novel method: with HPFMs, cumulative values for the average N and P flux during the complete deployment time could be captured. Thereby the two major deficits of existing methods are overcome: first, flux rates are measured within one device instead of being calculated from separate measurements of water flow and pore-water concentrations; second, time-integrated measurements are insensitive to short-term fluctuations and therefore deliver more representable values for overall hyporheic nutrient fluxes at the sampling site than snapshots from grab sampling. A remaining limitation to the HPFM is the potential susceptibility to biofilm growth on the resin, an issue which was not considered in previous passive flux meter applications. Potential techniques to inhibit biofouling are discussed based on the results of the presented work. Finally, we exemplarily demonstrate how HPFM measurements can be used to explore hyporheic nutrient dynamics, specifically nitrate uptake rates, based on the measurements from our field test. Being low in costs and labour effective, many flux meters can be installed in order to capture larger areas of river beds. This novel technique has therefore the potential to deliver quantitative data which are required to answer unsolved questions about transport and turnover of nutrients in hyporheic zones.

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Nutrient Concentrations in Seven Irrigation Reservoirs (Lake Karla Watershed Thessaly Greece)

Proceedings ◽

10.3390/proceedings2110656 ◽

2018 ◽

Vol 2 (11) ◽

pp. 656

Author(s):

Maria Chamoglou ◽

Ioannis Vergos ◽

Pantelis Sidiropoulos ◽

Ifigenia Kagalou

Keyword(s):

Agricultural Production ◽

Catchment Area ◽

Freshwater Ecosystems ◽

Nutrient Concentrations ◽

Agricultural Activities ◽

Dry Period ◽

The World ◽

Artificial Ecosystems ◽

Semi Arid ◽

Lake Karla

The construction of irrigation reservoirs is a technical global solution for enhancing the agricultural production especially in arid and semi-arid areas. These water bodies are treated as technical projects and not as freshwater ecosystems. Eutrophication in new reservoirs becomes a hot issue in the world. The aim of the present study is to present the assessment of the key-eutrophication parameters in seven reservoirs located in the catchment area of Lake Karla. We suggest that the studied artificial ecosystems are sensitive in nutrients concentrations especially in the warm-dry period, influenced mainly by agricultural activities in the watershed.

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