Table 1. Physicochemical parameters.

Results from soil physicochemical analyses (mean ± standard deviation) of the four studied quadrats within Churince System in the Cuatro Cienegas Basin (Mexico).

Variable	Quadrat				Overall mean
	A	B	C	D
Total C (mg g−1)	2.4 ± 0.8	2.4 ± 0.4	2.6 ± 0.4	2.8 ± 0.6	2.6 ± 0.6
Total N (mg g−1)	0.57 ± 0.13	0.48 ± 0.18	0.59 ± 0.1	0.60 ± 0.18	0.56 ± 0.15
Soil C:N	4.6 ± 2.3	6.1 ± 4	4.6 ± 0.7	5.0 ± 1.3	5.1 ± 2.4
Total P (mg g−1)	0.03 ± 0.01	0.03 ± 0.01	0.04 ± 0.01	0.04 ± 0.02	0.04 ± 0.01
NH${}_4^{+}$ (µg g−1)	4.0 ± 0.6	4.2 ± 0.8	4.0 ± 0.6	3.6 ± 1	4.0 ± 0.7
NO${}_3^{-}$ (µg g−1)	1.8 ± 1.9	1.5 ± 1.5	1.6 ± 1.7	2.3 ± 1.5	1.7 ± 1.6
Dissolved organic C (µg g−1)	97.3 ± 27.8	75.8 ± 30	83.0 ± 33	124 ± 21.3	95.1 ± 33.2
Dissolved organic N (µg g−1)	14.6 ± 3.4	18.1 ± 12.3	17.9 ± 8.7	19.6 ± 9.2	17.6 ± 8.7
Dissolved organic C:N	7 ± 2.9	6.4 ± 4.8	5.2 ± 2.4	7.9 ± 3.9	6.4 ± 3.5
Dissolved organic P (µg g−1)	4.3 ± 3.6	5.6 ± 2.1	2.6 ± 3.5	3.3 ± 3.7	3.9 ± 3.3
pH	8.6 ± 0.1	8.7 ± 0.1	8.7 ± 0.1	8.8 ± 0.1	8.7 ± 0.1
Electrical conductivity (dSm−1)	1.4 ± 0.1	1.4 ± 0.3	1.6 ± 0.2	1.4 ± 0.4	1.4 ± 0.3
Mg2+ (cmol kg−1)	27.1 ± 5.2	28 ± 6.3	35.2 ± 4.3	36.5 ± 4.5	31.7 ± 6.5
Ca2+ (cmol kg−1)*	0.56 ± 0.03a	0.55 ± 0.02a	0.64 ± 0.07ab	0.65 ± 0.07b	0.59 ± 0.07
Na+ (cmol kg−1)	140 ± 15.9	127 ± 16.1	166 ± 38.1	157 ± 28.4	147 ± 29.1
K+ (cmol kg−1)*	0.95 ± 0.14a	0.82 ± 0.19a	1.27 ± 0.14b	1.33 ± 0.25b	1.09 ± 0.28
HCO${}_3^{-}$ (cmol kg−1)*	2.8 ± 0.2b	2.3 ± 0.6b	1.2 ± 0.2a	1.3 ± 0.3a	1.9 ± 0.8
Cl− (cmol kg−1)*	2.8 ±0.2b	2.5 ± 0.3b	1.1 ± 0.4a	1.3 ± 0.3a	1.9 ± 0.8
SO${}_4^{2-}$ (cmol kg−1)*	15.1 ± 2.2b	16.4 ± 2.5b	7.6 ± 0.8a	7.2 ± 0.9a	11.6 ± 4.6

Notes.

Variable acronyms: C, carbon; N, nitrogen; P, phosphorous.

^*Significant difference among quadrants (p < 0.05).

Different letters indicate that means are significantly different among quadrats.