Community‐level restoration profiles in Mediterranean vegetation: nurse‐based vs. traditional reforestation

Abstract

Summary1. Many restoration projects aim to transform degraded vegetation into mature native plant communities. The recovery of the structure and properties of reference native plant communities is acknowledged as a landmark of restoration, and the success of restoration practices is measured in terms of community metrics. Nurse-assisted planting has been proposed as a promising technique for the restoration of Mediterranean and arid vegetation based on its success at seedling establishment rather than on the recovery of reference community properties. We investigate the adequacy of this restoration practice by shifting the focus of restoration from the species to the community level. 2. In contrast to previous studies in the Mediterranean region, we assessed the efficacy of several management techniques, including nurse-based planting, in the recovery of the structure and properties of mature native reference communities. In a burned area of southern Spain, we applied widely used community analysis tools (rarefaction and species accumulation curves, Chao 2 richness estimator, species evenness and beta diversity) to compare the profiles of a reference native community and the community achieved through different management practices: traditional planting, nurse-based planting and controls where natural regeneration was allowed to occur. 3. Our results showed that post-fire establishment of planted seedlings was higher under the canopy of nurses than in open ground. More importantly, nurse-based restoration increased the species richness and evenness of tall-shrubs and trees as well as the life-form diversity, with the restored community approaching the reference community in terms of both composition and structure of the bank of juveniles. 4. Synthesis and applications. We conclude that in contrast to traditional reforestation, where diversity is constrained by the elimination of pioneer and regenerated tall-shrubs, nurse-based restoration contributes to accelerated recovery of important community structure and properties. Thus, it should be used preferentially over traditional reforestation in Mediterranean mountains where restoration of native communities, and not merely tree establishment, is dictated under current habitat directives.

Importance of irrigation and plant size in the establishment success of different native species in a degraded ecosystem of central Chile

“…Among semiarid ecosystems (e.g., Rey et al 2009, Padilla and Pugnaire 2009), including central Chile (Armesto and Pickett 1985, Fuentes et al 1986), establishment of most native tree species is facilitated by nurse pioneer shrubs, especially in more xeric conditions. This has been attributed primarily to higher soil moisture beneath the shrub canopy, compared to open areas (Fuentes et al 1986, Del Pozo et al 1989, Becerra et al 2011.…”

Recovering Quercus species on reclaimed coal wastes using native shrubs as restoration nurse plants

“…It is well known that in Mediterranean ecosystems, forest species regeneration suffers from two major constrains: (i) summer drought (Pugnaire et al, 2011), being increased in reclaimed mined sites by a lack of soil structure such as in forest systems (Alday et al, 2012), and (ii) herbivory, which can occur through trampling and browsing by livestock and wild ungulates, but also by means of acorn predation for Quercus species (see Gómez et al, 2003;Smit et al, 2008). In order to overcome these two constraints, facilitation mediated by shrubs has been proposed for the reforestation of Mediterranean systems (Castro et al, 2006;Gómez-Aparicio et al, 2004;Rey et al, 2009), which could also be implemented for mining sites (see Alday et al, 2014). Facilitation mediated by shrubs can help to reduce summer drought stress (Smit et al, 2008), improving soil properties (Pugnaire et al, 2004), and providing protection against herbivory (Smit et al, 2006).…”

Shrub biomass accumulation and growth rate models to quantify carbon stocks and fluxes for the Mediterranean region

“…Furthermore, bushes and shrubs play a vital ecological role, not only in terms of ecosystem restoration Castro et al 2004;Maestre et al 2009;Rey et al 2009), but also in soil protection (Bochet et al 2006;Pueyo et al 2013), in the nutrient and carbon cycle (Yarie 1980;Van Cleve and Alexander 1981;Chapin 1983) and in biodiversity (Noss 1990;Mangas et al 2008). Due to increasing interest in recent years with regard to determining their carbon fixation capacity (Fonseca et al 2012;Gratani et al 2013) and their potential for use in bioenergy (Viana et al 2012), there is a clear need to further our understanding with regard to the amount of biomass accumulated in Mediterranean shrubs and hence the quantity of carbon sequestered by them.…”