Comparing cork quality from Hafir-Zarieffet mountain forest (Tlemcen, Algeria) vs. Tagus basin Montado (Benavente, Portugal)

Figures & data

Figure 1. Climatic diagrams for the study areas, Hafir-Zarieffet (in black) and Benavente (in gray).

Notes: Data from the meteorological stations of Mefrouche (Hafir-Zarieffet, ZA) 34°51′ N, 1°16′ W (1961–1990 for the precipitation and 1975–1990 for temperature) and Salvaterra de Magos (Benavente, CL) 39°02′ N, 8°44′ W (1961–1990). Precipitation (in bars) and mean temperature (in lines).

Table 1. Pore variables measured in the transverse section of the cork samples at both regions

Pore variables	Acronym	Description	Range	Po^1	Co^2
Dimension
Area	a	Area of pore (mm^2)	≥ 0	x	–
Perimeter	pe	Perimeter of pore (mm)	≥ 0	x	–
Diameter	di	Diameter of pore (mm)	≥ 0	x	–
Length	le	Length of pore (mm)	≥ 0	x	–
Width	wi	Width of pore (mm)	≥ 0	x	–
Mean area	Mpa	Average pore area (mm^2)	≥ 0	–	x
Maximum area	Maxpa	Maximum pore area (mm^2)	≥ 0	–	x
Mean perimeter	Mpe	Average pore perimeter (mm)	≥ 0	–	x
Mean diameter	Mdi	Average pore diameter (mm)	≥ 0	–	x
Mean length	Mle	Average pore length (mm)	≥ 0	–	x
Mean width	Mwi	Average pore width (mm)	≥ 0	–	x
Shape
Shape factor	sh	Perimeter-area ratio by adjusting for a circle standard	≥ 1	x	–
Aspect ratio	as	Ratio between width and length of a bouding pore rectangle	≥ 2	x	–
Fractal dimension	fr	Pore perimeter increase per unit increase in pore area	0–2	x	–
Roundness	ro	Ratio between the largest and smallest equivalent pore ellipse	≥ 1	x	–
Mean shape factor	Msp	Mean pore shape index	≥ 1	–	x
Mean aspect ratio	Mas	Mean pore aspect ratio	≥ 2	–	x
Mean fractal dimension	Mfr	Mean pore fractal dimension	0–2	–	x
Mean roundness	Mro	Mean pore roundness	≥ 1	–	x
Concentration
Number	np	Total number of pores per 100 mm^2 (#)	≥ 1	–	x
Mean nearest neighbor distance	Menn	Average distance to the nearest neighboring	> 0	–	x
Area fraction	af	Area-edge-to-edge squared distance ratio	≥ 0	–	x

¹ P_o—pore-level variable.

² C_o—cork plank-level variable.

Table 2. Cork porosity of the transverse section of cork samples

Variables	Hafir-Zarieffet (ZA)					Benavente (CL)
	AOI	Outer cork	Middle cork	Inner cork	Yearly	AOI	Outer cork	Middle cork	Inner cork	Yearly
Dimension
Mpa	4.5 ± 4.02	3.2 ± 2.55	5.9 ± 7.30	5.6 ± 5.62	3.5 ± 5.17	5.3 ± 3.17	3.7 ± 2.67	17.7 ± 26.12	4.0 ± 1.64	3.1 ± 3.17
Maxpa	29.2 ± 37.70	9.6 ± 10.24	19.9 ± 30.39	20.4 ± 34.16	8.8 ± 16.08	47.6 ± 45.52	16.8 ± 12.57	39.7 ± 48.57	17.2 ± 9.40	11.4 ± 15.94
Mpe	14.6 ± 6.01	10.7 ± 3.39	19.0 ± 14.91	16.7 ± 8.35	11.1 ± 6.46	14.2 ± 4.42	11.1 ± 4.35	32.8 ± 35.47	12.6 ± 3.37	9.2 ± 4.62
Mdi	2.2 ± 0.74	1.8 ± 0.54	2.5 ± 1.43	2.3 ± 1.08	1.9 ± 0.90	2.1 ± 0.36	2.0 ± 0.57	3.3 ± 1.69	2.0 ± 0.46	1.7 ± 0.53
Mle	6.2 ± 2.65	4.5 ± 1.44	8.5 ± 6.75	7.3 ± 3.56	4.4 ± 2.04	4.9 ± 1.01	4.1 ± 1.41	9.9 ± 7.90	4.4 ± 1.45	3.1 ± 1.64
Mwi	1.1 ± 0.47	1.1 ± 0.44	1.0 ± 0.58	0.9 ± 0.56	1.0 ± 0.80	1.5 ± 0.38	1.4 ± 0.47	2.4 ± 1.75	1.5 ± 0.40	1.2 ± 0.21
Shape
Msp	37.5 ± 29.05	22.0 ± 14.30	33.4 ± 26.08	34.0 ± 25.89	22.9 ± 20.02	21.5 ± 7.76	18.9 ± 13.68	40.9 ± 35.54	16.8 ± 6.49	15.3 ± 12.75
Mas	6.2 ± 2.24	4.7 ± 1.27	7.8 ± 3.37	6.9 ± 4.11	5.8 ± 2.68	4.7 ± 1.15	4.2 ± 1.71	7.4 ± 4.09	4.5 ± 1.22	3.4 ± 1.25
Mfr	1.1 ± 0.02	1.1 ± 0.02	1.1 ± 0.03	1.0 ± 0.36	1.1 ± 0.02	1.1 ± 0.02	1.1 ± 0.02	1.1 ± 0.04	1.1 ± 0.03	1.1 ± 0.02
Mro	8.9 ± 3.60	6.6 ± 2.25	12.5 ± 6.53	9.9 ± 5.62	7.8 ± 4.92	4.6 ± 1.63	4.6 ± 2.27	6.3 ± 2.74	4.1 ± 1.74	3.0 ± 1.27
Concentration
np	280 ± 116	468 ± 299	165 ± 87	188 ± 135	334 ± 188	250 ± 79	330 ± 149	140 ± 61	230 ± 100	420 ± 143
Menn	3.2 ± 0.78	2.6 ± 0.66	4.3 ± 1.12	3.5 ± 1.69	3.1 ± 0.97	3.3 ± 0.47	2.9 ± 0.58	4.6 ± 1.21	3.7 ± 1.17	2.5 ± 0.42
af	9.2 ± 4.48	11.4 ± 5.84	7.7 ± 8.96	9.2 ± 7.26	7.6 ± 7.45	13.2 ± 8.23	13.9 ± 14.04	16.6 ± 19.69	9.3 ± 5.23	12.7 ± 11.65

Notes: Mean values (mean ± standard deviation) for the study areas, Hafir-Zarieffet (ZA) and Benavente (CL). Range of mean values for all the AOI and along a virtual radial transect across the transverse section, from the outer (older) to the inner (younger) layers of the cork plank.

Figure 2. Histogram for the pore area feature in all cork samples from Hafir-Zarieffet (ZA) and Benavente (CL).

Note: In bars is the frequency distribution of the number of pores and in lines is the curve for the cumulative percentage of pores.

Figure 3. Representation of pore centroids in a XY-scatter plot for all cork samplers at Hafir-Zarieffet (ZA) and Benavente (CL).

Note: Circle diameter is proportional to pore area located from cork back (minimum Y-value) to cork belly (maximum Y-value).

Table 3. Eigenvalues, canonical correlation coefficients, and variance explained by the first two discriminant functions (F1 and F2)

Variables	F1	F2
Lenght	0.698	0.497
Perimeter	0.444	0.727
Roundness	0.694	0.677
Eigenvalue	0.212	0.057
Variance (%)	77.5	20.7
Cannonical correlation	0.618	0.331

Notes: Significant variables at pore level for the cork planks porosity by SDA, for the study areas, Hafir-Zarieffet (ZA) and Benavente (CL): pore length, pore perimeter and pore roundness.