Azores temperate mixed forests
The Azores temperate mixed forests, primarily characterized by the evergreen broadleaved forests known as laurisilva, represent a unique and historically significant ecosystem located in the Atlantic Ocean. Once part of a larger forest biome that extended across Europe and Africa, these forests now mainly exist on the Azores archipelago, which consists of nine islands. Historically, these islands were heavily forested, with native laurel forests covering around 90% of the landscape before human settlement in the 15th century led to significant deforestation.
Today, remnants of the laurisilva can still be found at higher elevations, where a variety of endemic species, including Azores laurel and juniper, thrive. However, invasive species like the Australian cheesewood have been introduced, threatening the delicate balance of the native flora. The biodiversity of the Azores is further enriched by its bird populations, including several endemic and endangered species such as the Azores bullfinch. Conservation efforts have been initiated to protect these unique ecosystems, with reserves established across the islands, although challenges remain due to climate change and human impact. The Azores temperate mixed forests are not only vital for the local ecology but also hold significant cultural and historical value, making them a focus for both scientific research and eco-tourism initiatives.
Azores temperate mixed forests
- Category: Forest Biomes.
- Geographic Location: Atlantic Ocean.
- Summary: The evergreen broadleaved forests, or laurisilva, of the Azores archipelago are remnants of a broader historical forest ecosystem that once spanned parts of Europe and Africa.
Before human settlement, forests covered 90 percent of the surface of the Azores volcanic archipelago. The chain of nine islands contains unique endemic (uniquely evolved to fit a local biome niche) species, but deforestation and the introduction of foreign biota prompted degradation of native flora and fauna.
Stretching across approximately 373 miles (600 kilometers) of the Atlantic Ocean, the Azores are part of the Macaronesian region—a collection of archipelagos including Madeira, the Savage Islands, the Canary Islands, and the Cape Verde Islands. Situated 2,423 miles (3,900 kilometers) from North America and 932 miles (1,500 kilometers) from Portugal, the Azores are considered to be the westernmost point of Europe, although two of the islands (Flores and Corvo) actually rest on the North American plate.
Laurisilva
The evergreen forest, or laurisilva, is regarded as the most characteristic indigenous flora of the Azores. The native evergreens were once part of a much larger forest biome that covered portions of Europe and Africa nearly 2.75 million years ago, during the late Tertiary era. Scientists estimate that the Azores' cool, oceanic climate significantly contributed to laurisilva survival on the islands, in contrast to the continental climate extremes that fueled the extinction of European and African counterparts. Settlement, agriculture, and livestock domestication led to deforestation of the original laurel forest cover—a humid, evergreen broadleaf variety specific to the Azores—although somewhat similar species have been found on Madeira and the Canary Islands. Close to 98 percent of the native forests were decimated by human activity after initial settlement in the 15th century.
As a result of 20th-century conservation enlightenment and in response to the potential of tourism to drive sustainable economic growth, the Azorean government simultaneously helped and hindered the laurisilva. The majority of the native forests are now protected in 26 Recreational Forest Reserves; the Regional Directorate for Forest Resources established reserves on eight of the nine islands. To satisfy an agenda of Azorean beautification for tourism, however, and also to reduce erosion, produce timber, and minimize water loss, exotic species were imported. Subsequently, a series of plantations now grow foreign biota to replace the diminished native broadleaved evergreens. Two species in particular—the coniferous Japanese cedar (Cryptomeria japonica) and the Australian cheesewood (Pittosporum undulatum)—dominate the Azorean landscape. Although Azorean heath (Erica azorica) and fire tree (Myrica faya), both endemic species, have flourished where agricultural cultivation has been abandoned, the highly invasive Pittosporum undulatum, introduced from Australia during the 19th century, threatens the more fragile endemic flora.
Unprotected remnants of indigenous evergreens have survived at elevations above 1,640 feet (500 meters). At this elevation, Azores laurel (Laurus azorica), Azores juniper (Juniperus brevifolia), and Azores heath compose the dense canopy of native evergreen forest.
Endemic Vegetation
Despite remaining portions of laurisilva at high altitudes and those found in reserves, the endemic Azores evergreen forests remain relatively unexplored and marginally researched. There are, however, some 30 known endemic vegetation that appear exclusively within the Azores laurisilva. Several of these endemisms derive substantial significance as survivors of geologic time, or living fossils. They are peculiar to the Azores and offer evidence of vegetation that once existed on the continents, as well.
Bird Life
Faunal biodiversity, primarily a bird population consisting of 36 reported species, has been historically minimal due to the geographic isolation of the Azores. In particular, the Azores bullfinch (Pyrrhula murina), which resides in high-altitude forests, was listed as an endangered species by the International Union for Conservation of Nature. However, habitat restoration, providing the birds with various sources of food, resulted in the species being downgraded to vulnerable in 2016. At that time, there were nearly 1,000 bullfinches. Several other rare birds live in the Azores. The Monteiro’s storm petrel (Oceanodroma monteiroi) is one of the rarest seabirds in Europe and endemic to the Azores. Similarly, the Atlantic canary (Serinus canaria,), Chaffinch (Fringilla coelebs moreletti), and the the Azores woodpigeon (Columba palumbus azorica) all dwell in the Azores.
Conservation and Preservation
With its history of relatively dramatic ecosystem changes that have resulted from human activity and invasive species, the Azores and its mother country, Portugal, host a scientific community that is keen to establish protections against a range of contemporary threats that include ocean temperature warming, seawater acidification, climate change, and species genetic jeopardy. These often interconnected vectors have been under study for years; various mitigation initiatives are in the planning stages. With the unifying goal of encouraging and sustaining biological diversity, the Azores is seen as an ideal location for habitat reserves, eco-tourism, and related efforts in this campaign.
Bibliography
Morton, Brian and Joseph C. Britton. “The Origins of the Coastal and Marine Flora and Fauna of the Azores.” Oceanography and Marine Biology 38, no. 1 (2000).
Raposeiro, Pedro M., et al. “Late Holocene Climate Dynamics in the Azores Archipelago.” Quaternary Science Reviews, vol. 331, May 2024, p. N.PAG. EBSCOhost, doi.org/10.1016/j.quascirev.2024.108617. Accessed 4 Nov. 2024.
Santos Guerra, Arnoldo. Evergreen Forests in the Macaronesian Region. Strasbourg, France: Council of Europe, 1990.
Subramanian, Meera. "The Encouraging Comeback of the Azares Bullfinch." Audubon, 4 Jan. 2022, www.audubon.org/news/the-encouraging-comeback-azores-bullfinch. Accessed 4 Nov. 2024.
Tarantino, Elisa, et al. “First Finding of Sophonia Orientalis (Matsumura) in the Azores.” EPPO Bulletin, vol. 52, no. 1, Apr. 2022, pp. 190–91. EBSCOhost, doi.org/10.1111/epp.12812. Accessed 4 Nov. 2024.