The Coral Gardening Concept and the Use of Underwater Nurseries: Lessons Learned from Silvics and Silviculture

The types and numbers of tree species within a forest, as coral colonies in a coral reef, create unique ecosystems by generating biological diversities, formulating the habitats’ three-dimensional structures, and changing local biological and environmental conditions. Resulting from intensive anthropogenic pressure, both ecosystems have lost their resilience, their ability to recover and to self-rehabilitate naturally without active human intervention. However, while forestry practices (silviculture) have been developed and tested worldwide for nearly two centuries, the discipline of active reef restoration is less than a decade old. Nevertheless, even though silviculture actions and concepts have long been subjected to rigorous scientific testing, its applications are still elusive. The situation in the field of reef restoration is even more undefined because the concepts and basic protocols have not yet been well studied. Here, one of the novel tools for coral reef restoration, the “gardening coral reefs” concept, where planned underwater nurseries present forestry principles, is discussed, bearing in mind the lessons learned from silvics and silviculture projects. Furthermore, the recently developed approach of a mid-water floating nursery is explained. In the future, as coral reef restoration may become the dominant conservation approach, there would be the need not only to develop improved protocols and defined conceptual bases, but also to adapt ideas, established expertise, and knowledge from silvicultural experience and science.