How can we determine nutrient uptake length (Sw) and nutrient uptake rate (U) and nutrient uptake velocity (Vf)? What are these measures indicators of?

Sw is basicly how far the nutrients travel before taken up. grows with nutrient aailability. Sw is an indicator of retention efficiency. If length is shorter its more limited and better at retaining nutrients. Sw is influenced by discharge. The uptake rate (black line) if theres a lot of nutrients aailable the uptake rate increases. Its an indicator of uptake capacity because it has a max where more nutrients doesnt mean a higher uptake. Uptake velocity (red line) how fast an atom is mooving towards an uptake site. It shows demand/availability. If you have high demand vf is high or if you have high availability Vf is low.