Lacustrine

Lacustrine – Outputs

 

The conceptual models were compiled by researchers in collaboration with a wide range of stakeholders from Natural Resource Management groups, universities and government agencies and based on available scientific information[2].

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• Overview
• Inputs
• Processes
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• Effects
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• Links and References

Outputs of nitrogen (N) from lacustrine wetlands (lakes) are due to surface water flows, groundwater flows, floodwater, gas, sediment, and animals.

Air

Denitrification

Denitrification could be high in some locations within lakes, especially at the edge, where macrophyte cover is high[2]. Sediment may also alternate between aerobic and anaerobic conditions, which can affect the denitrification process, particlularly at the bottom of lakes[8].

N₂O production

Export of nitrogen as N₂O is likely to occur as a result of incomplete denitrification and nitrification. Less than 1% of denitrified N is converted to N₂O[3].

Water

Surface and groundwater

During the dry season, outputs of nitrogen from lakes are more likely through groundwater flows. In the wet season, large and sporadic pulses of floodwater will transport dissolved and particulate nutrients out of the wetland[5][7]. Outputs from groundwater and floodwater are likely to be lower than inputs in most lakes due to processes inside wetlands, i.e. denitrification, sedimentation and vegetation uptake. However, in some lakes with low water/soil ratios, and low macrophyte cover, the outputs could be similar to the inputs[7].  

Weed export

Macrophytes can be flushed out of lakes during flooding or strong rainfall events[4][6][1].

References

1. ^ Adame, M, Pettit, N, Valdez, D, Ward, D, Burford, M & Bunn, S (2017), 'The contribution of epiphyton to the primary production of tropical floodplain wetlands', Biotropica, vol. 49, pp. 461-471.
2. ^ Adame, MF, Waltham, NJ, Iram, N, Farahani, BS, Salinas, C, Burford, M & Ronan, M (8 July 2021), 'Denitrification within the sediments and epiphyton of tropical macrophyte stands', Inland Waters. [online], pp. 1-10. Available at: https://www.tandfonline.com/doi/full/10.1080/20442041.2021.1902214 [Accessed 31 July 2021].
3. ^ Beaulieu, JJ, Tank, JL, Hamilton, SK, Wollheim, WM, Hall, RO, Mulholland, PJ, Peterson, BJ, Ashkenas, LR, Cooper, LW, Dahm, CN, Dodds, WK, Grimm, NB, Johnson, SL, McDowell, WH, Poole, GC, Valett, HM, Arango, CP, Bernot, MJ, Burgin, AJ, Crenshaw, CL, Helton, AM, Johnson, LT, O'Brien, JM, Potter, JD, Sheibley, RW, Sobota, DJ & Thomas, SM (2011), 'Nitrous oxide emission from denitrification in stream and river networks', Proceedings of the National Academy of Sciences. [online], vol. 108, no. 1, pp. 214-219. Available at: http://www.pnas.org/cgi/doi/10.1073/pnas.1011464108.
4. ^ Bunn, SE, Thoms, MC & Capon, SJ (2006), 'Flow variability in dryland rivers: Boom, bust and the bits in between', River Research and Applications, vol. 22, p. 179.
5. ^ Davis, AM, Pearson, RG, Brodie, JE & Butler, B (2016), 'Review and conceptual models of agricultural impacts and water quality in waterways of the Great Barrier Reef catchment area', Marine and Freshwater Research, vol. 68, pp. 1-19.
6. ^ Houston, WA & Duivenvoorden, LJ (2002), 'Replacement of littoral native vegetation with the ponded pasture grass Hymenachne amplexicaulis: effect on plant, macroinvertebrate and fish biodiversity of backwater in the Fitzroy River, Central Queensland, Australia', Marine and Freshwater Research, vol. 53, pp. 1235-1244.
7. ^ a b Mcjannet, D, Wallace, J, Keen, R, Hawdon, A & Kemei, J (2012), 'The filtering capacity of a tropical riverine wetland: I. Water balance', Hydrological Processes. [online], vol. 26, no. May 2011, pp. 40-52. Available at: Scopus.
8. ^ Seitzinger, S, Harrison, JA, Bohlke, JK, Bouwman, AF, Lowrance, R, Peterson, B, Tobias, C & Vand, D (2006), 'Denitrification across landscapes and waterscapes: A synthesis', Ecological Applications, vol. 16, no. 6, pp. 2064-2090.

Last updated: 31 July 2021