Tom Sterling

The proposed network begins at the western entrance of the Túnel das Sete Cidades—a piece of water infrastructure opened in the 1930s to moderate water level in Lagoa Azul and Lagoa Verde. The entrance area expands the existing mouth of the tunnel to create a welcoming and dramatic entrance to the trail, while a small parking area is constructed on a regraded, existing pile of rubble from the tunnel’s construction. This minimizes the material movement and waste needed to construct necessary trail infrastructure. 

Local materials like volcanic stone and the existing, well-draining volcanic soil mean that most of the materials can be sourced directly from the construction site. Volcanic stone crosswalks demarcate a clear, safe point to cross streets, help to calm passing traffic, and define boundary edges in high-traffic areas like the trail’s entrance. 

The Muro das Nove Janelas, or ‘Wall of Nine Windows,’ establishes a large larusilva nursery on a pasture in the wind shadow of a massive stone aqueduct. The aqueduct, constructed in the 17th century and decommissioned in 1888, is made an essential part of the trail experience. The aqueduct provides a substantial wind break—a vital component of growing saplings at a relatively high altitude (800m) while the thermal mass of the thick stone walls reduces the impact of temperature swings. 

The aqueduct becomes a dramatic crossing point along the trail and provides dramatic views across the nursery and to the coast, while modern water infrastructure built into the aqueduct sustains the laurisilva saplings. The central role of this disused infrastructure in the project highlights the impact of human intervention has had on the landscape (even hundreds of years ago) and inextricably ties the preservation of the island’s important cultural landscape to the restoration of its natural one.

Cyptomeria japonica was introduced to provide timber and later found success as a tall, fast-growing, and dense windbreak for the island’s pastures and farms. While essential to the island’s timber industry, the trees rapidly spread by seed and over the last 200 years have easily established themselves along the island’s hundreds of watercourses.

 

This segment of the trail continues along the path of the abandoned aqueduct and large stream through a self-seeded stand of Cryptomeria japonica trees. The invasive pine are incrementally culled and replaced with native saplings from the nursery. The roots and stumps of the removed trees help to stabilize the soil and reduce erosion while the new forest is established.  Incremental forestry management ensures that the shelter provided by the invasive trees for native invertebrates and birds is not threatened while the native flora matures in its shadow.4 As with elsewhere along the trail, timber from the culled trees is used in the construction of trail infrastructure or sold to help fund further construction. 

The trail concludes at the Ribeira Grande Geothermal Power Station. Here, as a reward for completing their trip across the island as agents of ecological restoration, visitors can enjoy thermal baths powered by geothermal exhaust. Geothermal exhaust and the network of pipes and ponds that support it mimic the island’s natural volcanic vents and provide a space to cultivate the unique, highly specialized flora that grow around them.