Trophic level index

The trophic level index (TLI) is used in New Zealand as a measure of nutrient status of lakes.[1] It is similar to the trophic state index but was proposed as alternative that suited New Zealand.[2]

The system uses four criteria, phosphorus and nitrogen concentrations, as well as visual clarity and algal biomass weighted equally.[3]

Lake typeTrophic levelChla (mg m−3)Secchi depth (m)TP (mg P m−3)TN (mg N m−3)
Ultra-microtrophic0-10.13-0.3331-240.84-1.816-34
Microtrophic1-20.33-0.8224-151.8-4.134-73
Oligotrophic2-30.82-2.015-7.84.1-9.073-157
Mesotrophic3-42.0-5.07.8-3.69.0-20157-337
Eutrophic4-55.0-123.6-1.620-43337-725
Supertrophic5-612-311.6-0.743-96725-1558
Hypertrophic6-7>31<0.7>96>1558

See also

References

  1. New Zealand Ministry for the Environment Archived 2010-05-22 at the Wayback Machine - Trophic Level Index for lakes
  2. Burns, Noel; Graham Bryers; Eddie Bowman (March 2000). Protocol for Monitoring Trophic Levels of New Zealand Lakes and Reservoirs. Retrieved 9 May 2017.
  3. Burns, Noel; McIntosh, John; Scholes, Paul (2005). "Strategies for Managing the Lakes of the Rotorua District, New Zealand". Lake and Reservoir Management. 21 (1): 61–72. doi:10.1080/07438140509354413. S2CID 86767838.


This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.