Restoration of a Limestone Quarry: Effect of Soil Amendments on the Establishment of Native Mediterranean Sclerophyllous Shrubs

Abstract

Limestone quarries are spread over the Mediterranean Basin and have a strong environmental impact on the landscape, causing vegetation losses and soil losses. A reclamation project was conducted in a limestone quarry, situated in Arrábida Natural Park (southwest Portugal), that is dominated by mediterranean vegetation. Revegetation was conducted using three evergreen sclerophyllous shrub species (Ceratonia siliqua, Olea europaea, and Pistacia lentiscus), and new techniques were assayed to improve plant water status and nutrient status during the first phases after plantation. A water-holding polymer (gel), fertilizer, and mycorrhiza inoculum were applied in a factorial experiment in a randomized complete block design. The success of these techniques was evaluated during 1.5 years, through monitoring of growth and ecophysiology of plants. Plant survival was high, the lowest values (95%) being recorded in C. siliqua. There were species-specific responses to the treatments applied. Ceratonia siliqua showed the highest growth rates and was the only species with growth stimulated by fertilizer application. However, the application of fertilizer induced changes in leaf characteristics of the other two species, increasing chlorophyll and nitrogen contents. Mycorrhiza inoculum had no effect on plant response. The addition of the water-holding polymer induced higher midday plant water potentials in C. siliqua, O. europaea, and P. lentiscus, but in the latter two species the simultaneous addition of gel and fertilizer induced the lowest water potentials. The addition of fertilizer and gel is recommended in future revegetation programs but not the combination of both when revegetating with O. europaea and P. lentiscus. The results of this experiment indicate that the use of these mediterranean species, adapted to nutrient and water stress, can circumvent harsh conditions of the quarry.

Reduction in Water Stress for Tree Saplings Using Hydrogels in Soil

“…However, the concentration of hydrogel was positively correlated with SPAD readings (chlorophyll content) in the maples (hydrogel = 1%, r = 0.62, p < 0.01, Figure 3(b)). The different responses of the two tree species are consistent with their coping strategies in the face of water stress [18] [43]. In general, silver maples grow in wet, poorly drained soils as in floodplains or stream banks [44] [45].…”

Erosion control blankets, organic amendments and site variability influenced the initial plant community at a limestone quarry in the Canadian Rocky Mountains

“…Limestone mining creates large disturbances that significantly impact soil, vegetation and fauna and result in habitat fragmentation and loss (Sort and Alcañiz, 1996;Clemente et al, 2004;Moreno-Peñaranda et al, 2004). Reclamation of limestone quarries, despite being an environmental necessity and mandatory in many countries, has had limited success (Bonifazi et al, 2003;Allen et al, 2005), particularly when the goal is to achieve predisturbance conditions (Wunderle, 1997).…”

Promoting seedling physiological performance and early establishment in degraded Mediterranean-type ecosystems

“…The addition of nutrients is known to enhance the growth of particular species in a restoration context; in degraded eucalypt woodlands in Western Australia (Ruthrof et al 2010;Ruthrof et al 2013a), in reforestation of Pinus halepensis and Acacia salicina in southeastern Spain (Oliet et al 2005;Oliet et al 2009), and under post mining conditions in Portugal (Clemente et al 2004) and Western Australia (Koch and Samsa 2007;Ruthrof 1997). In the current study, the addition of nutrients (in either form) clearly enhanced the height, crown health, shoot and root biomass and root length of seedlings.…”