The amount required, even in the heyday of production, could have been continuously supplied by an area of woodland about 50 km2 in area, yet the heath covers over 7000 km2.
Nõutava hulga, isegi tootmise õitseajal, oleks saanud pideval kasutamisel umbes 50 km² metsaalalt, kuid nõmm hõlmab üle 7000 km².