Figure 5.

Estimated response of TN (a and b) and DIN (c and d) in mg N L⁻¹ to increasing agricultural inputs (kg N ha⁻¹ y⁻¹), across 3 levels of wetland cover (a and c) and riparian disturbance (b and d) based on multiple regression model coefficients (Table 2). The low, medium, and high values correspond to the 1^st, 2^nd, and 3^rd quartiles of wetland or riparian cover in the data set, while all other variables are set to their median values (Table 1). Agricultural N is the sum of fertilizer, cultivated biological N fixation, and manure N inputs.