What causes a species to out-compete others in nutrients?

Question

If Species A and B are algae, and both have the same limiting nutrient. When does one out-compete the other?

Answer 1

One is more efficient at obtaining the nutrient than the other.

Since both are algae and need sunlight, one may grow at higher levels and shade the other one.

One can produce allopathic (toxic) chemicals to reduce the growth or kill the other one.

Lots of other ways, but these are things I could think of (that actually happen) at the moment.


ADDITION:

Differences in growth rate or reproductive rate.

One may be preferred by herbivores over the other.

Differences for tolerance levels of other environmental characteristics (temperature, pH, water movement, oxygen/CO2 content).

All it takes is for one to have any survival advantage over the other. It's rare to find two organisms that share a "niche" without competing in some way.

Answer 2

Another advantage: sym,biotic relationships with local micro-organisms that allow more efficient extraction and exploitation of the local soils.