June 2, 2008
Dena - periphyton
Howard - phycobilins
Whitney - K+ ratios
examples of cyanobacteria control (from straightforward to complex)
a. nutrient interception
b. competition by aquatic plants
c. biomanipulation of the food web (add big fish)
d. manipulate timing of algal growth or grazing
e. shallow lake - 2 stable states - ILP
a. regulation - potential for algae to respond
flux control - fast rates both direction
- O2 build-up, feedback regulation and dissipation (dissipation)
potential pathways
- low light capture ability (phycobilins, especially phycoerythrin)
- N2 fixation
- AlkPase
understanding regulatory linkages
- Fe limitation and oxidative stress
- nitrogen limitation on chlorophyll synthesis
- others
b. shifts in community structure
claim: systems that are away from equilibrium may tend to get order through fluctuation
example - predator-prey pulses
near chaos state as a "pre-adaption" for rapid changes in many potential directions
demonstration of model that shows pulsing and how to interpret it with a limit cycle
- courses/models/pred-prey-v8-b.stm
<!-- not done in class -->
- pushing this farther
- fluctuations that drive a system determined by the logistic equation into chaos
- variation in K or in period of K while r < 2.65
- courses/models/logistic-near-chaos.stm
a. tied to hydrodynamics of lake and bouyant particles
compare satelllite image of Chla distrbution to Tammy Wood's negatively sinking AFA
algae/ukl2007/PSU_USGS .... report
b. spatial pattern of blooms (and subsequent crashes)
spreading from a starting "seed" bloom
- no competition or depletion
- neighboring regions increase after center
- may be a positive feedback such as (but has not been shown) between bloom and sediment P production that helps spread the bloom
bloom starts and decays and neighboring cells also blink
- could be caused by
- consumption of nutrients to depletion
- following bloom of zooplankton which then move to nearest cells
- very different spatial pattern than "seed" bloom example