Figure 2
From: Water quality in New Zealand’s planted forests: a review
Range of nutrient concentrations in mature planted forest streams. NOx-N values have been aggregated with NO3-N as NO2-N is rapidly oxidised to NO3-N and typically comprises a small portion of oxidised-N. Similarly, Amm-N values have been aggregated with NH4-N values as NH3-N comprises a small component of Amm-N. Note the log scale on the y axis. Mean or median values derived from tables and text or estimated from figures in references (Collier and Bowman 2003; Cooper et al. 1987; Fahey and Stansfield 2006; Friberg et al. 1997; Harding and Winterbourn 1995; Macaskill et al. 1997; Matheson et al. 2011; Parkyn et al. 2006; Thompson et al. 2009; Thompson and Townsend 2004b; Townsend et al. 1997; Young et al. 2005). The wider range of NO3-N/ NOx-N concentrations compared with TN is influenced by studies that measured that measured concentrations of NO3-N at the high end of the range and either did not measure TN or measured TN at a lower sampling intensity than NO3-N.