Fig. 1. Localization of the study area, climatic and geomorphologic context, and localization of plots sampled. View larger in new window/tab.
Fig. 2. Dynamics of prickly pear orchards: a) on-going prickly pear planting in an abandoned cereal field; b) 10-year-old prickly pear orchard; c) 25-year-old prickly pear orchard with argan tree regeneration (dark green patches); c) old prickly pear orchard (>50 years) with substantial argan tree regeneration.
Fig. 3. Vegetation physiognomic diagrams associated with land use changes during the 20th century in the hinterland of Sidi Ifni (Morocco).
Fig. 4. Number of argan tree regeneration A) by zone (degree of continentality); B) by age class. Significant differences are marked with different letters at p < 0.01 (Student-Newman-Keuls test).
Fig. 5. Regression curves between age of prickly pear orchard and argan tree regeneration. View larger in new window/tab.
| Table 1. Effect of distance to the Atlantic Ocean and the age of prickly pear orchard on the Organic Matter content of soil (%). Values in brackets correspond to standard error (SE). Means with different superscript letters are statistically different at p < 0.01 in ANOVA (Student-Newman-Keuls test). | |||||
| Zone | |||||
| 1 Coastal | 2 Intermediary | 3 Pre-mountain | Mean | ||
| Age of prickly pear orchard (years) | Control | 0.51 (0.07) | 0.79 (0.14) | 0.83 (0.27) | 0.71a (0.10) |
| 10–25 | 0.70 (0.23) | 1.13 (0.11) | 1.00 (0.11) | 0.95b (0.09) | |
| >40 | 1.26 (0.27) | 1.15 (0.19) | 1.64 (0.26) | 1.35c (0.14) | |
| Mean (SE) | 0.82a (0.13) | 1.03b (0.09) | 1.16b (0.14) | ||
| Table 2. Effects of age of prickly pear orchard on the total number of arbuscular mycorrhizal fungi spores in rhizosphere soil of O. ficus-indica (number of spores/100 g soil, and standard error (SE)). Means with different superscript letters are statistically different at p < 0.05 in ANOVA (Student-Newman-Keuls test). | |||||
| Zone | |||||
| 1 Coastal | 2 Intermediary | 3 Pre-mountain | Mean | ||
| Age of prickly pear orchard (years) | Bare soil | 878 (206) | 935 (163) | 726 (45) | 835a (87) |
| 10–25 | 534 (66) | 543 (33) | 497 (93) | 522b (42) | |
| >40 | 592 (85) | 633 (90) | 453 (51) | 550b (44) | |
| Mean (SE) | 668a (80) | 704a (72) | 559a (44) | ||
Fig. 6. Interactions between prickly pear orchards and argan tree regeneration: a) prickly pear as a plant nurse?; b) the future of regional landscape?: double-purpose agroforestry parkland composed of prickly pears and thinned argan trees for nut production.