| Crown shyness is the empty space between crowns in fully-stocked stands. I measured canopy closure (CC) (i.e., the inverse of crown shyness), effective leaf area index (LAIe), crown radius (CR) and length (CL), and green litterfall in stands of various height (HT) and relative density (RD); site factors including site index (SI) were also evaluated. LAIe and CCH were measured using four hemispherical photographs; CCL was also measured using line intercepts. CCL and LAIe decreased with HT and increased with index SI and RD. Litterfall increased with HT and RD. CR and CL reached a plateau by 8--10 m height. Crown abrasion likely contributes to crown shyness, but the empty spaces between trees may also relate to the small upper limit of CR even in wide spacing. CL did not respond to changes in CCL. Canopy closures estimated by hemispherical photography (CCH) were nearly double that of CCL. |
