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This work studies the influence of two mulching treatments on soil properties and the field performance of afforested holm-oak seedlings (Quercus ilex L. subsp. ballota (Desf.) Samp.) nine years after outplanting. Mulching treatments composed of stones, forest debris, and an untreated control were randomly applied to 180 seedlings (n = 60) in January 2001 at the bed level (1 × 1 m) in an abandoned agricultural field in SE Spain. Survival, growth measured by means of leaf area, and nutrient concentrations in leaves and soil were measured. Both mulches provided higher survival and greater leaf-area growth than the control, but did not differ in leaf-nutrient concentration. Most of the analysed soil variables were not affected by the mulching treatments at the end of the study period, and, therefore, the soil properties changes by mulching might be slower than expected under semi-arid conditions.

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Forest restoration is currently a primary objective in environmental management policies at a global scale, to the extent that impressive initiatives and commitments have been launched to plant billions of trees. However, resources are limited and the success of any restoration effort should be maximized. Thus, restoration programs should seek to guarantee that what is planted today will become an adult tree in the future, a simple fact that, however, usually receives little attention. Here, we advocate for the need to focus restoration efforts on an individual plant level to increase establishment success while reducing negative side effects by using an approach that we term “precision forest restoration” (PFR). The objective of PFR will be to ensure that planted seedlings or sowed seeds will become adult trees with the appropriate landscape configuration to create functional and self‐regulating forest ecosystems while reducing the negative impacts of traditional massive reforestation actions. PFR can take advantage of ecological knowledge together with technologies and methodologies from the landscape scale to the individual‐plant scale, and from the more traditional, low‐tech approaches to the latest high‐tech ones. PFR may be more expensive at the level of individual plants, but will be more cost‐effective in the long term if it allows for the creation of resilient forests able to provide multiple ecosystem services. PFR was not feasible a few years ago due to the high cost and low precision of the available technologies, but it is currently an alternative that might reformulate a wide spectrum of ecosystem restoration activities.

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-This paper evaluates the effectiveness of several soil preparation procedures in forestation establishment and development in localized farmland, within a territory in ombroclimatic transition between dry and semi-arid, located in Granada, southeastern Spain. An experiment in the forestation of Holm oak (Quercus rotundifolia Lam.) and Aleppo pine (Pinus halepensis Mill.) was set up, in which 8 different soil preparation techniques were used. The survival, total height and basal diameter of the plantation was monitored over a 5-year period (1996)(1997)(1998)(1999)(2000). The statistical analysis of these parameters evidenced highly significant differences in the overall behaviour of the two sample forest species, related to changes in the prevailing environmental conditions in these territories and the type of soil preparation procedure applied. The overall results obtained for the three parameters analysed show the effectiveness of using backhoes for pit planting and linear rippering with a hydraulic structure to captures runoffs, in comparison to other preparations. Areal soil preparations, in particular, are not recommended. (1996)(1997)(1998)(1999)(2000). Les analyses statistiques ont mis en relief des différences significatives du comportement général des deux essences forestières testées et en relation avec les changements des conditions de milieu et des techniques de préparation du sol. Les résultats obtenus pour les trois paramètres analysés montrent l'efficacité des trous effectués à la pelle rétroexcavatrice et des sous-solages en ligne asssociés à une structure hydraulique qui récolte les écoulements, par rapport à d'autres types de préparation, notamment le travail du sol en plein dont l'utilisation est déconseillée.reboisement / semi-aride / préparation du sol

In the 20th century, in the Mediterranean area, many extensive afforestation efforts were made with the primary objective of protecting soils from erosion and improving their fertility. This study evaluates the effects of the afforestation undertaken in the Guadalentín basin (SE Spain) with respect to the organic and inorganic soil constituents and physico-chemical soil properties. Given the phytoclimatic environments in the basin (sclerophyllous and hyperxerophyllous), paired samples were taken beneath the tree canopy of the pine plantations and in nearby open zones. With the same methodology, samples were taken from areas considered to be native forest. The data were submitted to different multivariate analyses of variance (two-way MANOVAs) in order to compare the effects and interactions of the factors CANOPY (with and without trees), PHYTOCLIMATE (sclerophyllous and hyperxerophyllous), and TYPE OF FOREST (afforested or native) on the dependent variables measured (soil variables). Significant differences were found at 0-10 cm in soil depth under pine afforestations in relation to adjacent open areas. Below this depth, differences were found only between phytoclimatic environments. No significant interactions were found between the variables analysed at any of the depths, indicating that the effects of the afforestations on the soil characteristics were independent of the phytoclimatic environment. The afforestation in the Guadalentín basin, in the two phytoclimatic environments considered increased the soil fertility. Nevertheless, the native forests presented the highest soil organic-carbon contents, mainly in the sclerophyllous phytoclimate type (Quercus ilex subsp. ballota forests). Therefore, although the afforestations improved the soil fertility in relation to the open areas, the maximum potential has probably not been reached in relation to that observed in the native forests. The effects that forest development (age, basal area) over time exerts on soil properties remain to be verified by further research.