Assessing the impact of reforestation on the diversity of Mediterranean terrestrial Gastropoda

Abstract

In the Mediterranean basin, pine tree reforestation has been the most common management tool in restoring degraded and burnt areas, as well as for economic purposes. However, the quality of the biodiversity of these habitats has undergone little assessment. Terrestrial gastropods are suitable indicators of forest quality and long-term stability because of their strict dependence on microhabitat conditions and their slow dispersal rate. We sampled the gastropod population in a protected Mediterranean area in order to compare the species richness in seven main habitats. Holm oak wood and mixed-pine forests were the habitats with the lowest species density, and areas with a high level of heterogeneity exhibited the richest communities. In recent decades however, land abandonment and pine reforestation are leading to landscape homogeneity, which is perhaps the cause of the extinction of six open-habitat gastropod species in the Park. These results provide park authorities with insights into how to adapt management plans to enhance habitat quality for land snail and slug assemblages. More specifically, our results stress the Communicated by R. H. Cowie. Electronic supplementary materialThe online version of this article (

Uncovering the environmental factors that influence diversity patterns of Mediterranean terrestrial Gastropod communities: a useful tool for conservation

“…The effect of fire seems unimportant in Collserola when compared to close natural reserves (Santos et al 2009Santos and Poquet 2010). In contrast, habitat-mediated uses such as pine plantations has negatively affected snail composition and has probably caused local extinction of some mollusc species (Torre et al 2014).…”

“…In fact, they are islands that consist of natural vegetation and are affected by landscape processes such as habitat uses in the surrounding edges (Pino and Marull 2012). In Collserola, urbanisation and forestry are the main pressures on biodiversity (Basnou et al 2013) with there being emphasis on the loss of open habitats for the terrestrial mollusc community (Torre et al 2014). Studies that uncover environmental factors that influence diversity patterns are useful tools for biodiversity conservation, especially for species with low mobility patterns such as snails.…”

“…Although acid substrates are likely to support a lower species diversity and abundance of individuals than limestone areas, acidophilic communities can also have a varied and interesting wildlife (Nekola 2010). Likewise, landscape composition and heterogeneity (i.e., the number of different vegetation units) are amongst the most frequently referred environmental factors that influence the composition of Gastropoda communities (Ondina and Mato 2001;Torre et al 2014). Elevation gradients also drive the distribution and composition of Gastropoda communities at a local scale, since these gradients can be considered as surrogates for many environmental variables that have covariates with elevation (e.g.…”

“…For example, human-induced landscape changes (i.e. land abandonment and urbanisation) may be responsible for species extinction and the decline of diversity (Torre et al 2014). In such cases, a correct assessment of the factors driving species diversity and composition of Gastropoda communities may be a necessary tool in terms of proceeding with active landscape conservation planning and management.…”

“…The study area is the Collserola Natural Park, where active forestry and land abandonment during the last century, as well as proximity to a very populated area, have had a number of impacts for land snails. Previous studies were carried out in this reserve, aimed at discovering the composition and distribution of terrestrial snails (Bros 2004(Bros , 2009Torre et al 2014). Uncovering the ecological factors that are responsible for the species composition and distribution will be an important element for planning the conservation of Gastropoda biodiversity in this protected area.…”