Congratulations to new BC3 PhD graduate Gonzalo Morcillo
HiriZAIN, osasuna eta ekintza klimatikoa hiri-plangintzan txertatzeko tresna
New BC3 research reveals the secret to restoring the Galapagos Islands
A new study of BC3 in the Galapagos Islands shows that saving an endangered forest requires much more than just saving its trees. It requires rebuilding the complex “living network” that sustains forest life, including those thriving high up in the canopy.
“Restoring a forest is like rebuilding a city after a major collapse. It is not enough to reconstruct the buildings; you also need to restore the connections, relationships, and infrastructure that allow the city to function”, highlights Isabel Donoso, researcher from BC3 and author of the scientific work published in the journal Proceedings of the Royal Society B.
In a forest, trees provide the living framework -like the buildings of a city-, while smaller plants that grow entirely on their branches, known as epiphytes, such as ferns and orchids, form another layer of living infrastructure. These tree-dwelling plants are vital: they regulate the temperature, hold water like sponges, and provide homes for a huge variety of insects and microbes. However, until now, scientists did not know if these complex canopy networks could actually recover after a forest had been damaged by invasive species.
The latest research of BC3 focused on the critically endangered Scalesia forest on Santa Cruz Island in the Galapagos. Known for its giant daisy trees (Scalesia pedunculata), this unique ecosystem has been devastated by farming and aggressive invasive plants, especially the blackberry (Rubus niveus). Today, a mere 3% of the original forest remains.
To find out if conservation and restoration efforts were working, researchers spent time in the field inspecting the treetops using binoculars and ladders. They compared forest plots that were completely overgrown by invasive plants against plots where the Galapagos National Park has been carefully removing invasive species for the last 11 years.
The findings bring good news: clearing out invasive plants works. After 11 years of restoration, the forests hosted a much richer and more diverse community of canopy plants.
However, the researchers discovered that this recovery wasn’t simply a direct result of removing invasive plants. Instead, the return of these canopy plants also depended on having large, healthy, moss-covered trees to call home.
The undisputed hero of this story is the endemic giant daisy tree, which acts as the central “hub” of the forest city, supporting much of the ecosystem’s plant diversity on its branches. Invasive trees, on the other hand, proved to be terrible hosts, offering almost no support to canopy plants.
Despite the positive results in the restored areas, the study issued a stark warning. In the heavily invaded parts of the forest, the crucial giant daisy trees are not reproducing. The dense layer of invasive blackberry is choking out their seedlings. Because these daisy trees only have a natural lifespan of about 15 years, the lack of new baby trees means the entire “city” could eventually collapse, taking all the dependent canopy plants down with it.
The results from this BC3-backed study provide a crucial lesson for global conservation: when evaluating if a restoration project is successful, we can’t just count the number of trees or look at how much green covers the ground. We have to make sure the specific, life-sustaining relationships between species are actually bouncing back.
This research, available here, is part of BC3’s Ecosystems and Global Change research line. It was heavily supported by Ikerbasque (the RESTART project), with additional support from collaboration through the ERC-funded IslandLife project. The study was carried out in tight collaboration with the University of Coimbra, IMEDEA (CSIC-UIB), and the Charles Darwin Foundation, with logistical support from the Galápagos National Park Directorate.
