The structural parameters of Q. robur leave of trees. adenotes significant differences in the parameters in tree No. 1 (shading) and No. 3 (without shading) (P ≤ 0.05); bdenotes significant differences in the parameters in the tree No. 2 (shading) and No. 3 (without shading) (P ≤ 0.05); cdenotes significant differences in the parameters in the tree No. 1 (shading) and No.4 (without shading) (P ≤ 0.05); ddenotes significant differences in the parameters in the tree Nr 2 (shading) and No.4 (without shading) (P ≤ 0.05).

Table 3: The structural parameters of Q. robur leave of trees. ^adenotes significant differences in the parameters in tree No. 1 (shading) and No. 3 (without shading) (P ≤ 0.05); ^bdenotes significant differences in the parameters in the tree No. 2 (shading) and No. 3 (without shading) (P ≤ 0.05); ^cdenotes significant differences in the parameters in the tree No. 1 (shading) and No.4 (without shading) (P ≤ 0.05); ^ddenotes significant differences in the parameters in the tree Nr 2 (shading) and No.4 (without shading) (P ≤ 0.05).

Parameter	Oak tree number
	Tree No. 1	Tree No. 2	Tree No. 3	Tree No. 4
Adaxial epidermis
Size of pavement cell, μm
Long axis	23 ± 1.3	21 ± 1.3	25 ± 1.2	26 ± 1.2
Short axis	20 ± 1.2	18 ± 1.1	24 ± 1.7	23 ± 1.3
Abaxial epidermis
Size of pavement cell, μm	Not determined^*	Not determined^*	Not determined^*	Not determined^*
Stomata:
Density, number per mm² area	350 ± 21	380 ± 27	531 ± 37^a,b	429 ± 47^c,d
Long axis of guard cell , μm	29 ± 1.2	23 ± 1.7	28 ± 1.3	30 ± 1.1
Short axis of guard cell, μm	11 ± 0.4	10 ± 0.4	10 ± 0.1	12 ± 0.7
Trichome:
Density, number per mm² area	78 ± 8.9	71 ± 7.0	87 ± 7.3^a,b	86 ± 7.9^c,d
Long axis, μm	98 ± 7.1	82 ± 7.3	72 ± 8.9	76 ± 9.5
Short axis in the base, μm	20 ± 1.5	13.6 ± 1.3	21 ± 1.2	20 ± 1.5
Short axis in the middle, μm	8.3 ± 0.1	7.3 ± 0.1	7.3 ± 0.7	8.0 ± 0.3

*The surface of the pavement cells of the lower epidermis is covered with a ontinuous layer of lamellar rystalline structures, so the boundaries of the pavement cells of the lower epidermis are not visible and their sizes are not determined.