Restoration for increasing biodiversity in areas intended for sustainable use faces several challenges. One major challenge is developing strategies that minimize restoration costs while increasing effectiveness, being at the same time culturally acceptable for those implementing them.
The current research focused on restoration of diverse pine forests in abandoned agricultural fields being reforested for sustainable timber extraction. The effect of Lupinus elegans patches on understory plant species richness was tested at two different scales, the patch scale and the site scale. Lupinus elegans was chosen because is a successional legume species that traditionally is recognized for its soil improvement capabilities.
At the patch scale, species richness was higher at patch borders (20 ± 1 species), than within patches (17 ± 1 species) or control plots (18 ± 1 species). At the site scale, our restoration site had the highest number of understory species after two years with 57 species, in contrast neighboring sites had only 12 species and 19 species. The closest forest remnant had 36 species. In our restoration site several species were present that were absent in neighboring reforestation sites in particular bird dispersed species, such as Solanum spp and Crataegus pubescens. Spontaneous recruitment tree species also occurred (Pinus pseudostrobus and Crataegus pubescens). Soil nitrogen increased within Lupinus elegans patches (59 kg/ha) and control patches (55.7 kg/ha) in comparison with initial soil concentrations (42.7 Kg/ha).
Our results suggest that use of species that play relevant ecological and cultural roles in restorations are an efficient strategy for increasing diversity.
