Managing successional trajectories in alien-dominated, novel ecosystems by facilitating seedling regeneration: A case study

Kueffer, C; Schumacher, E; Dietz, H; et al. BIOLOGICAL CONSERVATION, 143 (7): 1792-1802 JUL 2010

Invasion of cinnamon in the Seychelles has resulted in a novel ecosystem dominated by cinnamon but in which native tree species persist. Seed limitation restricts the regeneration of these native species, however, and without direct intervention their populations will decline. Previous interventions that removed large tracts of cinnamon were unsuccessful in promoting native species because other, faster-growing invasive species colonized instead. Kueffer et al. compared growth of native and exotic tree species when seeded and transplanted to the understory of cinnamon-dominated forests and to gaps created in those forests. All species grew slowly in the understory, but native species performed well on the edges of artificially created gaps, leading Kueffer et al. to conclude that planting native seedlings small, artificially-created gaps is a promising restoration strategy.

This paper is a nice example of how the novel ecosystem concept informs management choices. The authors both acknowledge the impossibility of completely removing cinnamon and also note positive ways in which cinnamon has been incorporated in the ecosystem (as a food source for native birds). Then, to further their goal of preserving native tree species, they use a scientific framework to explore effective ways to achieve this goal. The paper would benefit from discussion of whether and how a novel system that sustained native species would persist. Given the prevalence of cinnamon, would cutting gaps in which to plant native species be a practice that must carry on indefinitely? The authors note that native species currently are found in patches. Would future native regeneration be more likely if managers concentrated on restoring larger patches of native species then on interspersing native trees throughout the cinnamon-dominated forest?

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