Dross–Montassier–Pinlou conjecture on feedback vertex sets in large-girth planar graphs

Let $G$ be a planar graph of girth at least $g$, and let $e(G)$ be its number of edges. Let $\mathrm{fvs}(G)$ denote the minimum size of a feedback vertex set of $G$, that is, a vertex set whose deletion leaves a forest.

Dross–Montassier–Pinlou conjecture. Every planar graph $G$ of girth at least $g$ satisfies

$$\mathrm{fvs}(G)\leq \frac{e(G)}{g}.$$

The abstract states that this conjecture is confirmed in the paper, so it is solved.