Benefits of Using Shrubs as Nurse Plants for Reforestation in Mediterranean Mountains: A 4‐Year Study

By J. Castro, Regino Zamora, J. Hódar, J. Gómez, L. Gómez‐Aparicio. 2004

287 citations recorded by the source corpus.

Shrubs are commonly considered competitors of planted seedlings in reforestation programs. However, shrubs can facilitate the establishment of understory seedlings in environments that, like Mediterranean‐type ecosystems, are characterized by harsh environmental conditions. In 1997, an experiment was set up in the Sierra Nevada mountains (southeast Spain) to test the use of shrubs as nurse plants for an alternative reforestation technique. Two‐year‐old seedlings of Pinus sylvestris and Pinus nigra were planted in four microhabitats: (1) open interspaces without vegetation (which is the usual method employed in reforestation programs), (2) under individuals of the shrub Salvia lavandulifolia, (3) under the north side of spiny shrubs, and (4) under the south side of spiny shrubs. Seedlings were also distributed in plots with and without ungulates to test the effect of herbivore damage. We report here the results of survival and growth after four growing seasons, a time span long enough to draw robust conclusions concerning the suitability of this technique. Pine survival was remarkably higher when planted under individuals of S. lavandulifolia as compared with open areas (2.6 times for P. sylvestris and 1.8 for P. nigra). The survival of both pine species was also higher when planted on the north side of spiny shrubs, while mortality on the south side was similar to that found in open areas. The reduction of solar radiation by the canopy of shrubs was likely the main factor determining shrub facilitation. The growth of the pines differed among years. However, growth was not inhibited when planted with shrubs as compared with open areas in any of the years. Herbivore damage was low but was mostly concentrated in the leader shoot, exacerbating the deleterious effect of ungulate herbivores on pine growth. We conclude that the use of shrubs as nurse plants for reforestation is a viable technique to increase establishment success of reforestation in Mediterranean‐type ecosystems and that it might be similarly useful in other water‐stressed environments. In addition, this technique offers the advantage of following natural succession, thus minimizing the impact in the community.

Subfields: Nature and Landscape Conservation

View Paper: https://www.semanticscholar.org/paper/2ab739f8b249cd25664c96b3153a163e50c28d06

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In Nature and Landscape Conservation

Citations in the corpus

Facilitation of Quercus ilex recruitment by shrubs in Mediterranean open woodlands (2008, background): “Seedlings of many tree species profit from the presence of various nurse shrubs in Mediterranean forests (Castro et al. 2002, 2004; Gómez-Aparicio et al. 2004; Pulido & Díaz 2005), despite variation in the magnitude of facilitative effects between species.”
Priority effects and ecological restoration (2020, background): “At more geographic or landscape scales, theory indicates that a need for facilitators might be more common in abiotically harsh conditions such as arid or alpine ecosystems (see Castro et al. 2004).”
Increase in size and nitrogen concentration enhances seedling survival in Mediterranean plantations. Insights from an ecophysiological conceptual model of plant survival (2012, background): “This suggests that the ecophysiological processes and functional attributes relevant for early seedling survival in Mediterranean climate must be reconsidered.”
Direct and indirect effects of tree canopy facilitation in the recruitment of Mediterranean oaks (2014, methodology): “In the Mediterranean Basin, evergreen Quercus woodlands occupy c. 2 5 million ha and have high conservation and socio-economic value (Bugalho et al. 2011).”
Seedling establishment of a boreal tree species (Pinus sylvestris) at its southernmost distribution limit: consequences of being in a marginal Mediterranean habitat (2004, methodology): “On the contrary, the Mediterranean southern boundary is marked by a harsh summer drought and is therefore a stressful environment liable to facilitative interactions (see also Pugnaire et al. 1996; Castro et al. 2002a, 2004; Gomez et al. 2004).”
The role of nurse plants in the restoration of degraded environments (2006, background): “Differences were still present after four growing seasons (Castro et al. 2004); survival rates were 1.8 to 2.6 times higher under sage than in gaps.”
Restoring Quercus pyrenaica forests using pioneer shrubs as nurse plants (2006, unknown): “…as other reforested trees in the Mediterranean area (García-Salmerón 1995; Vallejo et al. 2003; Castro et al. 2002, 2004a; Gómez-Aparicio et al. 2004), are caused mostly by heavy mortality during the first growing season (Vallejo et al. 2003; Castro et al. 2002, 2004a; Gómez-Aparicio et al. 2004).”
Restoration of Dry Afromontane Forest Using Pioneer Shrubs as Nurse‐Plants for Olea europaea ssp. cuspidata (2007, background): “Planted trees may help restore previous levels of indigenous functional biodiversity (Cusack & Montagnini 2004) and thus complement and accelerate natural regeneration of forest ecosystems, for example, by improving the habitat for seed-dispersing birds (Hardwick et al. 1997; Martı́nez-Garza & Howe…”
Spatial patterns of recruitment in Mediterranean plant species: linking the fate of seeds, seedlings and saplings in heterogeneous landscapes at different scales (2008, background): “The limited nurse capacity of spiny deciduous shrubs has been reported elsewhere for seedling survival (Castro et al. 2004a; Gómez-Aparicio et al. 2004, 2005c), and results shown here suggest that it also applies to the overall early recruitment cycle.”
Interactions between growth, demography and biotic interactions in determining species range limits in a warming world: the case of Pinus sylvestris (2012, background): “The recent changes in precipitation and temperature are increasing the already limiting conditions of dry and warm summers for Scots pine at its southernmost limit (Castro et al., 2004a).”
Cambial activity, wood formation and sapling survival of Pinus halepensis exposed to different irrigation regimes (2011, background): “…dynamics and summer drought is commonly found to be a major limiting factor both for seedlings and sapling survival, currently observed limitations on regeneration in Mediterranean forests may be exacerbated (Castro et al., 2004; de Luis et al., 2008; Mendoza et al., 2009; Urbieta et al., 2011).”
Facilitation in plant communities: the past, the present, and the future (2007, background): “Such results directly contradict traditional reforestation management practice, where shrubs are removed prior to tree planting due to their presumed competitive effects on tree seedlings (see also Castro et al. 2004).”
Conditional outcomes in plant/herbivore interactions: neighbours matter (2006, background): “Secondly, studies analysing spatial patterns of woody-plant establishment in Mediterranean ecosystems found that many woody species typically regenerate under pre-established vegetation (Herrera et al. 1994, Rey and Alcántara 2000, Castro et al. 2004, Gómez-Aparicio et al. 2004).”