Garry Oaks of Jones Island

Anthropogenic, also known as human, impact on islands areas has long caused disruption within ecosystems. But on Jones Island, these human impacts are now improving the forest ecosystem and biodiversity.

Like many other areas of North American, indigenous peoples of the San Juans once maintained the balance of ecosystems by setting small, controlled burns in order to keep the natural world healthy and thriving. On Jones Island, these controlled fires played an essential role in preserving balds, or natural openings of land that are covered in grasses and scattered trees. Among the tree species that utilize these balds, the Garry Oak (Quercus garryana) is an important species whose presence is critical to the overall health of the ecosystem.

Now that there are campsites and infrastructure on the island, fire suppression is encouraged; therefore, the balds have often become overgrown and more competitive species have moved in upon areas that were normally dominated by Garry Oak. The Douglas Fir is a species of tree that may have always been present within the Garry Oak ecosystem, but now that there are not regularly set fires suppressing Fir saplings, the species has begun to outcompete the Oaks. This disturbance in the delicate ecosystem balance can have long lasting impacts on all the species who also belong to the system. Threatened species on Jones Island can be further endangered by changes in the ecosystem, like the Douglas Fir outcompeting Garry Oak.

To prevent the Douglas Fir from becoming too prevalent within the island ecosystem, balds need to be protected and regulated. Washington State Parks is working to restore these balds by completing controlled burns, girdling fir trees, and cutting back any vegetation encroaching upon the space. Additionally, areas of bald have been fenced off to protect the Garry Oak saplings from the deer, which also pose a threat to the ecosystem when their population numbers begin to get too high. By preserving and maintaining these balds, the Garry Oak can continue to thrive and the Douglas Fir population will be contained to the heavily forested areas, where they can compete with other tree species evolved for such competition.

Though this project is ongoing, the long-term impacts these efforts will preserve the natural balance of Jones Island and the Garry Oak.