RestoringQuercus pyrenaicaforests using pioneer shrubs as nurse plants

Abstract

Question: How to improve reforestation success of Quercus pyrenaica. Location: 1800 m a.s.l., southern Spain. Methods: One-year-old Quercus pyrenaica seedlings were planted using two treatments: (1) bare soil, using a 30-cm diameter augur bit (conventional technique) and (2) under the canopy of a pioneer shrub, Salvia lavandulifolia, using a 12-cm diameter augur bit. Survival and growth were monitored for six years. Our hypothesis is that the use of shrubs as nurse plants is an alternative technique of reforestation with higher success than traditional techniques, in which pre-existing vegetation is usually considered a source of competition. The rationale for the study was that for environments with a dry season, pre-existing vegetation buffers summer drought stress, ameliorates the water status of seedlings and thus usually increases seedling recruitment. Results: Quercus survival was 6.3 × higher when planted under individuals of the pioneer shrub as compared to open areas. Quercus seedlings under shrubs also had shoots 1.8 × longer, while the number of shoots per plant did not differ among treatments. The first summer was the period with the highest mortality (49.1% of seedlings). Summer drought was the main cause of mortality. Conclusions: The use of shrubs as nurse plants for Q. pyrenaica reforestation is a viable technique to increase establishment success. The technique could be similarly useful in other environments with a dry period and for other Quercus species. In addition, this technique offers the advantage of following natural succession, thus minimizing the impact in the community.

Bioclimatology, Structure, and Conservation Perspectives of Quercus pyrenaica, Acer opalus subsp. Granatensis, and Corylus avellana Deciduous Forests on Mediterranean Bioclimate in the South-Central Part of the Iberian Peninsula

“…latifolia, Viburnum tinus, and Rhamnus alaternus subsp. alaternus in the stratum 2 behave as nurse species to the typical taxa in the dynamic stages of the deciduous forest that grow or are typical in stratum 3, comprising a mixture of shrubs or microphanerophytes and thorny shrubs (Rhamno catharticae-Prunetea spinosae) [21,30,88,89].…”

Colonization Pattern of Abandoned Croplands by Quercus pyrenaica in a Mediterranean Mountain Region

“…Another factor to consider is the presence of shrubs which can act as nurse plants. Facilitation by nurse plants has been reported as an essential process for the regeneration of some tree species [93,94]. The survival of Q. pyrenaica substantially increases when it is under individual pioneer shrubs [93,95].…”

“…Facilitation by nurse plants has been reported as an essential process for the regeneration of some tree species [93,94]. The survival of Q. pyrenaica substantially increases when it is under individual pioneer shrubs [93,95]. Shrubs may protect Q. pyrenaica seedlings from the browsing and trampling of vertebrate herbivores.…”

Restoration of a degraded oak forest in Mexico City by introducing tree native species

“…and Pinus halepensis Mill. (Castro et al 2006, Ariza-Mateos et al 2008. The difficulty of plants of P. serotina to cope with the environment is clearly shown in the survival curves of this species in both sites.…”