Uruk-hai Scout and "fellowship's current site"

[bibfortuna25]

Anytime an effect modifies a value, that modification will remain on the affected value until the phase ends or you reach the time specified. If multiple effects alter the same value, you apply all modifiers together. The only caveat here is that the final value may not fall below 0.

Here's a scenario:

It is the archery phase. Shadow has no minion archers in play,but he does have Last Days.

FP plays Lightfootedness.
FP uses Greenleaf to pick off a minion.
Last Days triggers and Shadow player plays Archer of Harad from hand (Ringbearer has 2 burdens)

The minion archery total is now 1. You take into account the 2 points of archery from the Archer of Harad and subtract 1 from Lightfootedness.

Another example. FP has 8 events in discard. Círdan is skirmishing a 14 strength minion. Círdan uses his ability once to make the minion 6, and then again to make him -2, reset to 0. If the Shadow player then plays a +2 pump, the minion is still 0 because you must take all modifiers into account. If the Shadow player plays a +3 pump instead, the minion's strength is now 1.