Up to a point.In BTS you will want to save most forests for maths.
Hammers now are (often) better than hammers later. If you're building a settler to grab a prime position, or an early game wonder (The Great Lighthouse, Oracle, Huge Stack of Axemen) chopping without waiting for Mathematics might make the difference between success or failure. Or The Great Lighthouse or say chopping out a library might boost your economy more now than the extra hammers you'd get if you waited would.
Also, if you're working a forested hill you'll quickly earn more hammers if you mine it immediately than if you leave it.