An early evaluation of translocation actions for endangered plant species on Mediterranean islands

Abstract

In situ conservation is widely considered a primary conservation strategy. Plant translocation, specifically, represents an important tool for reducing the extinction risk of threatened species. However, thus far, few documented translocations have been carried out in the Mediterranean islands. The Care-Mediflora project, carried out on six Mediterranean islands, tackles both short- and long-term needs for the insular endangered plants through in situ and ex situ conservation actions. The project approach is based on using ex situ activities as a tool to improve in situ conservation of threatened plant species. Fifty island plants (representing 45 taxa) were selected for translocations using common criteria. During the translocations, several approaches were used, which differed in site selection method, origin of genetic material, type of propagative material, planting method, and more. Although only preliminary data are available, some general lessons can be learned from the experience of the Care-Mediflora project. Among the factors restricting the implementation of translocations, limited financial resources appear to be the most important. Specific preliminary management actions, sometimes to be reiterated after translocation, increase the overall cost, but often are necessary for translocation success. Translocation using juvenile/reproductive plants produces better results over the short term, although seeds may provide good results over the long run (to be assessed in the future). Regardless, plant translocation success can only be detected over long periods; therefore, proper evaluation of plant translocations requires a long-term monitoring protocol. Care-Mediflora project represents the first attempt to combine the existing approaches in a common plant conservation strategy specifically focusing on the Mediterranean islands.

A Common Approach to the Conservation of Threatened Island Vascular Plants: First Results in the Mediterranean Basin

“…One of the main outputs of CARE-MEDIFLORA responds precisely to this need; it is represented by several in situ conservation actions that are implemented, which also exploit the knowledge acquired in ex situ conservation. In fact, all conservation translocations were carried out by introducing ex situ propagated material using different protocols, which varied in their type of translocation, locality selection process, provenance of the genetic material, type of material (seeds or cuttings) and/or planting method [18]. Preliminary data on translocation performance was highly variable between plant life forms and outplant type, as previously highlighted [9,17].…”

“…Although great efforts have been made in recent years to take concrete conservation actions and develop the structures dealing with ex situ conservation, in situ conservation actions are minimal when compared to the huge number of threatened plant species. In general, there are several constraints that may hamper the realization of in situ conservation measures, such as the significant economic and time costs, the availability of optimal sites, the difficulties (or more likely impossibility) of implementing these activities on private localities, and the great uncertainty of success chiefly related to natural stochastic events [12,18,22,34,63]. These limitations are common to a wide spectrum of human-mediated conservation actions, from those that are extremely complicated, such as translocations, to less demanding ones, such as fencing (to avoid or reduce grazing and protect the most critical life-cycle step for the population survival), removing/eradicating invasive alien plants or controlling pest plants.…”

“…Generally, translocations are recognized as time-consuming activities, as they need much preparatory analysis, a constant commitment to propagate the outplants, realization control of the activities and an extended monitoring plan to check their efficacy; also, translocations are intended as economically costly activities, due to the relevant costs of the pre-and post-management actions. The factors that made translocation challenging, as well as stimulating, included limited human resources and the availability of adequate sites, administrative difficulties encountered by working on both private and public lands, and the high uncertainty of success due to stochastic events [18].…”

“…Optimistically, ex situ conservation could reach significant levels in forthcoming years (at least in some territories worldwide), and with accessions representative of the natural variability. Conversely, in situ conservation practices-which are commonly recognized as the main and most relevant approach to preserve biodiversity, since they are centered on populations in their natural habitats-remain far from being widely achieved, for a large number of reasons [12][13][14][15][16][17][18].…”

“…Plant translocation is one of the most recently developed in situ activities, and it represents a relevant tool for lessening extinction risks for endangered species and to ameliorate their conservation status [12,[17][18][19][20]. The importance of conservation translocations, including reintroduction and population reinforcement, is notably considerable when it is part of a combined ex situ and in situ conservation strategy; the tight connection between the in situ and ex situ conservation approaches is the emerging instrument in the preservation of plant diversity [18,21,22].…”