In terms of restoration planning, the analysis of natural regeneration processes represents a valuable starting point for the selection of suitable species to be used. This paper aims to identify colonizing key species among the pioneer vegetation of limestone quarries in Lebanon, to identify potential restoration strategies in terms of reconstitution of the pre-mining vegetation cover. Characteristics of the major ground colonizers after disturbance were identified in a representative quarry in the thermo-Mediterranean biozone. The floristic inventories resulted in a matrix of cover values of 107 species × 14 plots. Correspondence analyses were used to pinpoint similarities in the distribution of key species among the different environmental characteristics of sites. The main results reveal a heterogeneous floristic composition along the regeneration gradient, where annual R-strategy taxa such as Inula viscosa and Ainsworthia cordata dominate on very perturbed and degraded sites. Less degraded areas within the quarry were rich in herbaceous perennial or shrub species such as Geranium dissectum, Stachys distans, Salvia triloba and Ptilostemon chamaepeuce. On relatively non-degraded areas woody and shrub perennials such as Pinus brutia, Pistacia palaestina and Quercus calliprinos dominate, along with less stress tolerant taxa such as Arbutus andrachne and Cistus creticus. Species to be used in restoration projects should be chosen from among the local vegetation, according to frequency of occurrence during the whole succession process which will reflect their adaptability to local conditions and their relevance to restoration objectives.

Nomenclature: Mouterde (1966).