Table 3 Effects of the thinning treatment (T) and the tree’s competitive status (CS, dominant or suppressed) on foliar secondary metabolites. Significantly different groups (UT, un-thinned; C, corridor thinning; CC, cross-corridor thinning) are distinguished with different letters (where ‘a’ is the group with the greatest mean concentration), based on Tukey’s test
Compound | Model | Factor | Dominant trees | Suppressed trees | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
|  |  | T | CS | T × CS | UT | C | CC | UT | C | CC |
Dihydrochalcones | ||||||||||
  Trihydroxy-methoxydihydrochalcone-O-glucoside 1 | *** | ns | *** | ns | b | b | b | a | a | a |
  Trihydroxy-methoxydihydrochalcone-O-glucoside 2 | *** | ns | *** | * | c | c | c | bc | ab | a |
  Hesperetin dihydrochalcone-O-glucoside 1 | *** | * | *** | *** | b | b | b | b | a | a |
  Hesperetin dihydrochalcone-O-glucoside 2 | *** | ns | *** | *** | b | b | b | b | a | a |
Flavonoids | ||||||||||
  Catechin and epicatechin | *** | *** | *** | *** | ab | a | ab | c | b | ab |
  (Epi)gallocatechin | *** | *** | *** | * | a | a | a | b | a | a |
  Procyanidin B type | *** | *** | *** | *** | ab | a | a | c | b | a |
  Quercetin-O-pentoside 1 | *** | ** | *** | *** | abc | a | ab | d | bc | c |
  Quercetin-O-pentoside 2 | *** | ** | *** | *** | ab | a | a | c | b | ab |
  Kaempferol-3-O-galactoside | *** | ** | *** | *** | ab | a | ab | c | b | b |
  Kaempferol-3-O-glucoside | *** | * | *** | *** | ab | a | ab | c | b | ab |
  Myricetin-O-pentoside | *** | ** | *** | ** | ab | a | a | d | c | bc |
  Kaempferol-3-O-glucuronide | *** | * | * | *** | ab | a | bc | c | a | ab |
  Quercetin-3-O-galacatoside | *** | * | *** | *** | ab | a | ab | d | bc | c |
  Quercetin-3-O-glucoside | *** | * | *** | *** | ab | a | ab | c | b | ab |
  Quercetin-3-O-glucuronide | *** | ** | *** | *** | ab | a | b | c | ab | ab |
  Myricetin-3-O-galactoside | ns | - | - | - | - | - | - | - | - | - |
  Myricetin-3-O-glucoside | *** | *** | *** | ** | abc | ab | a | d | cd | bc |
  Myricetin-3-O-glucuronide | *** | *** | *** | *** | ab | a | ab | c | b | ab |
  Kaempferol-O-pentosylhexoside | *** | ns | ** | *** | ab | ab | bc | c | ab | a |
  Kaempferol-O-rhamnosylhexoside | *** | ns | ns | *** | a | ab | ab | b | ab | ab |
  Quercetin-3-O-arabinoglucoside | *** | * | *** | *** | a | a | a | b | a | a |
  Unk flavonoid 1 | *** | *** | *** | *** | ab | a | bc | c | b | bc |
  Unk flavonoid 2 | ns | - | - | - | - | - | - | - | - | - |
Hydroxycinnamates | ||||||||||
  5-p-O-coumaroylquinic acid | *** | ns | ns | *** | ab | ab | bc | c | ab | a |
  3-p-O-coumaroylquinic acid | *** | ** | *** | *** | a | a | a | b | a | a |
  cis 3-O-caffeoylquinic acid | *** | ns | *** | ** | a | a | ab | b | ab | ab |
  trans 3-O-caffeoylquinic acid | *** | ns | *** | *** | a | a | a | b | a | a |
  5-O-caffeoylquinic acid | *** | * | *** | *** | a | a | a | b | a | a |
  4-O-caffeoylquinic acid | *** | ns | *** | *** | ab | ac | ab | cd | bd | abcd |
Jasmonates | ||||||||||
  Hydroxyl-dihydrojasmonic acids | *** | ns | *** | ns | a | a | a | b | b | b |
  Hydroxyjasmonyl sulfate | *** | ns | *** | * | b | ab | ab | a | ab | ab |
  Unidentified jasmonate | ns | - | - | - | - | - | - | - | - | - |
  Hydroxyjasmonic acid glucoside | *** | ns | *** | ns | b | b | b | a | a | a |
Salicylates | ||||||||||
  Salicin | *** | ns | *** | ns | b | b | b | a | a | a |
  Salicortin | *** | ns | *** | ns | b | b | b | a | a | a |
  Grandidentatin 1 | *** | *** | *** | ** | c | bc | bc | b | a | a |
  Grandidentatin 2 | *** | * | *** | *** | c | bc | bc | b | a | a |
  Tremuloidin FA adduct | *** | ** | *** | ns | c | d | cd | a | b | ab |
  Salicortin FA adduct | *** | ns | *** | ns | b | b | b | a | a | a |
  Tremulacin | *** | ns | *** | ns | b | b | b | a | a | a |
Unknowns | ||||||||||
  Unk1 | ns | - | - | - | - | - | - | - | - | - |
  Unk2 | *** | ns | *** | ns | b | b | b | a | a | a |