We prove first order differential Harnack estimates for positive solutions of the heat
equation (in the sense of distributions) under closed Finsler–Ricci flows. We assume
suitable Ricci curvature bounds throughout the flow and also assume that the
-curvature
vanishes along the flow. One of the key tools we use is the Bochner identity
for Finsler structures proved by Ohta and Sturm (Adv. Math.252 (2014),
429–448).