Accurate　in　situ　leaf　area　index　(LAI)　estimates　of　forest　plots　are　required　to　validate　currently-used　LAI　map　products.　Woody-to-total　area　ratio　(alpha)　is　a　crucial　parameter　in　converting　the　plant　area　index　estimates　of　forest　plots　obtained　by　optical　methods　into　LAI.　Although　optical　methods　for　estimating　the　alpha　of　forest　canopy　have　been　proposed,　their　performance　has　never　been　assessed.　In　this　study,　five　Larix　gmelinii　Rupr.　forest　plots　with　contrasting　plot　characteristics　(i.e.,　tree　age,　tree　height,　management　activities,　stand　density,　and　site　conditions)　were　selected.　The　performance　of　two　commonly　used　optical　methods,　namely,　multispectral　canopy　imager　(MCI)　and　digital　hemispherical　photography　(DHP),　in　estimating　the　alpha　of　L.　gmelinii　forest　plots　was　evaluated　by　using　the　reference　alpha　of　the　selected　forest　plots.　The　reference　alpha　of　forest　plots　was　measured　via　destructive　method　by　harvesting　two　or　three　representative　trees　in　each　plot.　Large　variations　were　observed　amongst　the　reference　alpha　of　the　selected　forest　plots　(ranging　from　0%　to　56%).　These　alpha　were　also　highly　correlated　with　the　site　conditions　and　management　activities　in　these　plots.　The　effective　alpha　(alpha(e))　or　alpha　estimated　using　the　leaf-on　and　leaf-off　periods　MCI　or　DHP　images　with　or　without　consideration　of　the　clumping　effects　of　canopy　element　and　woody　components　were　1.57　to　4.63　times　the　reference　alpha　in　the　five　plots.　The　overestimation　of　alpha　or　alpha(e)　was　mainly　caused　by　the　preferential　shading　of　woody　components　by　the　shoots　in　the　leaf-on　canopy.　Accurate　alpha　estimates　for　the　L.　gmelinii　forest　plots　with　errors　of　less　than　20%　can　be　obtained　from　MCI　when　the　clumping　effects　of　canopy　element　and　woody　components　are　considered　in　the　estimation.