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　(a)　is　a　crucial　parameter　in　converting　the　plant　area　index　estimates　of　forest　plots　obtained　by　opticalmethods　into　LAI.　Although　opticalmethods　for　estimating　the　a　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　a　of　L.　gmelinii　forest　plots　was　evaluated　by　using　the　reference　α　of　the　selected　forest　plots.　The　reference　a　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　a　of　the　selected　forest　plots　(ranging　from　0%　to　56%).　These　α　were　also　highly　correlated　with　the　site　conditions　and　management　activities　in　these　plots.　The　effective　α　(αe)　or　α　estimated　using　the　leaf-on　and　leaf-off　periodsMCI　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　a　in　the　five　plots.　The　overestimation　of　α　or　αe　wasmainly　caused　by　the　preferential　shading　ofwoody　components　by　the　shoots　in　the　leaf-on　canopy.　Accurate　a　estimates　for　the　L.　gmelinii　forest　plots　with　errors　of　less　than　20%　can　be　obtained　fromMCI　when　the　clumping　effects　of　canopy　element　and　woody　components　are　considered　in　the　estimation.　©　2018　by　the　authors.