Lecture 18

May 28, 2008

Control of Cyanobacteria
by Nutrient Loading Restrictions

 

1. P loading vs. Chlorophyll

P required to support C productivity

100 mol C : 1 mol P

loading (1200 g C m^-2 y^-1 productivity) / (30 g P m^-2 y^-1)

biome productivity

figure

correlation

P-Chla-correlation

 

2. P budget and sources

land use

farming - fertilizer

erosion

table 1 from Walker

comparison to N loading

number of humans in a lake basin X protein they eat

 

3. Controlling P input

Total Daily Maximum Load

goal is not to exceed Chla or pH a certain % of the time

distribution

long-term, basin-wide, equilibrium outcome

model - Walker

 

4. residence times and biological recycling are crucial

residence times of different lake basins

Carpenter 2006

ppt slide: scale-sci-manag/esr-seminar....

biological recycling

AFA sink, pick up P, float

reduces burial rate substantially

positive feedback that maintains the "turbid" condition

 

5. Threshold rather than linear relationship

compare cartoon graph (factoria..

management and resilience

mss with resilience

 

6. Path and alternative management strategies