This mostly comes up when there are multiple maluses at once or when a single malus is -2 or more. For example, if the land is under the effect of "All Things Weaken" (-1 Health), "Depleted Soil" (-1 Health in lands with Towns/Cities), and "Anchor the Land's Resilience" (+8 Health in Sacred Sites of Vital Strength of the Earth's Resilience Aspect), the final total is 2−1−1+8=8 Health for the land, even though applying the penalties "first" made the Health 0 in the middle of the computation.
Tags: Health, Durable, All Things Weaken, The Land's Bounty Exhausted, 19 more...