Coral reef systems are declining at an alarming rate with grave implications for biodiversity and ecosystem services. Can reforestation guidelines give us the answers to restore these delicate ecosystems?
Based on knowledge accumulated by trial and error, and local and indigenous experience, Di Sacco and Hardwood et al. (2021)formulated 10 rules for reforestation. In our previous article, we outlined the first five golden
rules for coral reef conservation. Here are Di Sacco and Harwood’s remaining rules.
6. Select species to maximise functional diversity
In forest restoration, the framework species approach encourages mutualistic interactions where all species that are involved profit. Corals also engineer habitats in which many other species thrive, and restoration should also include
species that promote mutualistic relations and coexistence.
Just as there are tree species known for their capacity to foster functional biodiversity, we can see the emergence of coral species selection guidelines aiming to create a similar framework that can be adapted to particular landscapes and
local species’ ecology.
7. Use resilient genetic material, with appropriate genetic variability and provenance
The resilient and varied genetic material naturally found in the restored regions is necessary to avoid inbreeding and ensure evolutionary potential. Within the same species, many different genes can influence the trees’ resistance to
various environmental pressures, such as drought tolerance or susceptibility to disease. Planted forests lacking genetic diversity are considerably more vulnerable to both biotic and abiotic hazards and are less able to support pollinators
One of the best ways to ensure resilient, varied new trees is to use seeds from a large, randomly selected population of parents. Moreover, a long-term perspective allows the selection of seeds from regions that mimic the predicted climate
of the area—a procedure called predictive provenancing.
In corals, predictive provenancing is particularly important as heat tolerance can vary significantly within the same species. With a warming climate, selecting genetic material with naturally high heat tolerance will ensure the best
resilience for the restored reefs.
8. Plan for infrastructure, capacity and seed supply
Logistics is vital for the execution of any project. From the collection of seeds to the planting of saplings and the maintenance of the area, logistical needs can quickly become overwhelming, especially when resources are not readily
Using and developing existing infrastructure can create jobs, ensure compliance and generate community support. Installing locally run, low-cost seed-storage facilities (seed banks) can greatly reduce costs and allow for a stable supply.
However, due to the slow reproduction of coral, having an adequate supply can prove challenging. While fragments from other colonies can serve as growing stock in the short term, for restoration purposes natural generation is too slow, and
therefore financially and technically challenging.
The best way to increase supply is by investing in sexual reproduction. Though under natural conditions, this is limited by the annual spawning cycle. Laboratories can overcome this supply bottleneck by rearing corals in controlled
environments, generating out-of-season spawning and cryo-preserving gametes for future use. Moreover, this makes it easier to identify and support heat-tolerant genetic variants.
9. Learn by doing, using an adaptive management approach
When it comes to restoration, field trials take a long time to yield results, resulting in significant scientific knowledge gaps. It is therefore also just as important to implement the use of traditional and indigenous knowledge that has
been preserved over generations. The best approach to reforestation uses international standards for guidance while also aiming to incorporate the experience of local stakeholders.
Small-scale trials should precede wider applications, especially when unique, site-specific issues such as degraded soils, competitive weeds or high fire risk must be overcome. These trials also allow the testing of indigenous techniques to
verify their usefulness.
Similarly, there are decades, if not centuries, of indigenous knowledge regarding the management of coral reefs and their attached fisheries. As most coral restoration attempts are poorly documented, this information can provide vital
insight into the best approaches available, as well as provide examples of mistakes to be avoided. Constructive communication with locals builds transparency and provides priceless opportunities for sustainable development.
10. Make it pay by ensuring the economic sustainability of the project
The last step needed for a successful reforestation project is economic sustainability. This is especially relevant for projects that are either at odds with the economic interests of locals or for projects that will need constant input and
thus require a stream of funding.
The best way to ensure that projects do not negatively affect local economies and are self-sustaining financially is by developing diverse income streams for all involved stakeholders. These can take a variety of forms, from carbon credits
to ecotourism and sustainable foraging opportunities.
Numerous schemes, such as REDD+, attempt to monetize the ecosystem services provided by forests, whether as carbon sinks or as water purifiers. However, the potential profits are often overstated, with a high initial investment needed to
bring these income streams to fruition, especially when it comes to ecotourism due to the need to build tourist accommodations.
‘The last step needed for a successful reforestation project is economic sustainability.’
This is why a realistic view and precise economic assessment are just as important for reforestation projects as the science and experience driving them.
Novel schemes are needed to monetize the value of coral reefs. While forests can be worked into carbon budgets and monetized as carbon credits, coral reefs do not represent significant carbon sinks. New funding schemes are needed to
monetize the benefits of healthy coral reefs (such as flood risk reduction, fisheries, and tourism) and to drive public and private investment.
There is also a need to prove that coral restoration can be economically sustainable. This can be done by increasing cost effectiveness, community engagement and scalability through both the previous rules and a new generation of successful
These rules show that much of our environmental management experience is transferable, allowing us to quickly develop new functional frameworks for ecosystem restoration using pre-existing techniques.
As we are undergoing a mass extinction event, methods such as these will be crucial to saving time, and species, without sacrificing quality.
Featured Image: The Ocean Agency | Ocean Image Bank
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