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Novel Ecosystems

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Today, most ecosystems on islands are novel, i.e. characterised by a history of intensive human disturbances and composed of mixtures of alien and native species. Therefore restoring pristine, pre-human ecosystems is often not a viable option anymore. Most conservation scientists agree that current conservation goals and standards of success should be reassessed, but there is no consensus about which road to take. In Seychelles, we explore strategies that aim at integrating different conservation approaches that are often considered conflicting (Kueffer & Kaiser-Bunbury 2014; Kueffer, Beaver & Mougal 2013). We are convinced that only landscape-scale mosaics of strictly protected areas, designed artificial biodiversity habitats, novel ecosystems, and biodiversity-rich cultural landscapes will maintain rare species, ecological interactions, and ecosystem services in heavily disturbed island landscapes (see Figure above, for explanations consult Kueffer & Kaiser-Bunbury 2014).

Reconciling conflicting biodiversity conservation strategies

Restoring habitat and essential ecosystem processes is a complex process with multifaceted trajectories. Most importantly, there is no singly path to take, and restoration is the process of initiating a sequence of successional changes along a desired path. There are two key elements to this statement: firstly, restoration is a long process and not a one-off management activity, and secondly, the outcome of any restoration efforts rarely resembles an original, pre-human or even pristine state. Restoration nowadays often resembles more a practice of designing artificial habitat for the purpose of biodiversity conservation.

Bearing this in mind, we initiated several ecosystem restoration projects in the Seychelles. One collaboration with North Island Resort aimed at restoring native biodiversity through major and continuous management interventions on a relatively small island, which houses a luxury hotel (project updates in Kapisen: Issue 4, Issue 6 (p. 16-27), Issue 7 (p. 18-19), Issue 9, Issue 12).

A second project was launched in 2009 with the aim of removing invasive alien plant species from ecologically-sensitive inselberg sites, which provide a refuge for many endangered mid- to high-altitude endemics in Seychelles. The work was initiated as part of an extensive research project focusing on the impact of human disturbance on mutualistic plant-animal interactions (see Plant-Animal Interactions), and is now being continued by the project partners Seychelles National Parks Authorities (SNPA) and Plant Conservation Action group (PCA) who aim to maintain the restored sites. To obtain long-term sustainability of the restored sites and allow the endemic vegetation to recover from the disturbance, the project partners develop a novel guardianship scheme to engage the local community in maintaining the restored inselberg plant communities (funded by GEF/Small Grant Programme).

Designed artificial biodiversity habitats


For mid-elevation forests dominated by the alien tree, Cinnamomum verum, we proposed a habitat restoration strategy that integrates patches of restored native vegetation into an alien Cinnamon-dominated matrix forest (Valentin et al. 2008, Simara et al. 2008). The hope is that strong belowground root competition of adult Cinnamon trees (Kueffer et al. 2007) serves as a barrier that protects native species from invasion of other invasive alien species from the surrounding disturbed land, while Cinnamon seems to be a rather weak invader of established native vegetation patches (Kueffer et al. 2010). Cinnamon also provides other ecosystem services such as erosion control, and fruits of Cinnamon seem to be an important food source for endemic frugivorous birds (Kueffer et al. Oikos 2009). With time, restored patches of native vegetation might serve as a native fruit source and re-seed the Cinnamon-matrix forest with the help of native birds, eventually leading to a novel biodiverse forest with native species intermixed with Cinnamon.

Maintaining rare species in novel ecosystems


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