The ancient forests of La Gomera, Canary Islands, and their sensitivity to environmental change

Abstract

Summary1. Garajonay National Park in La Gomera (Canary Islands) contains one of the largest remnant areas of a forest formation once widespread throughout Europe and North Africa. Here, we aim to address the long-term dynamics (the last 9600 cal. years) of the monteverde forest (laurel forest and Morella-Erica heath) located close to the summit of the National Park (1487 m a.s.l.) and determine past environmental and human impacts. 2. We used palaeoecological (fossil pollen, microscopic and macroscopic charcoal) and multivariate ecological techniques to identify compositional change in the monteverde forest in relation to potential climatic and human influences, based on the analysis of a core site at 1250-m elevation. 3. The regional mid-Holocene change towards drier conditions was matched in this system by a fairly rapid shift in representation of key forest elements, with declines in Canarian palm tree (Phoenix canariensis), Canarian willow (Salix canariensis) and certain laurel forest taxa and an increase in representation of the Morella-Erica woody heath. 4. Charcoal data suggest that humans arrived on the island between about 3000 and 1800 years ago, a period of minimal vegetation change. Levels of burning over the last 800 years are among the lowest of the entire 9600 years. 5. Synthesis. A rapid climatic-induced shift of forest taxa occurred 5500 years ago, with a decrease in hygrophilous species in the pollen record. In contrast, we found no evidence of a significant response to human colonization. These findings support the idea that Garajonay National Park is protecting a truly ancient relict, comprising a largely natural rather than cultural legacy.

Holocene environmental history of a small Mediterranean island in response to sea-level changes, climate and human impact

“…3100 and 1800 cal. years ago (Nogué et al, 2013). This raises the question of the potential vegetation at low and medium altitudes in Corsica and Sardinia before human impacts, and if Erica arborea also formed forests as suggested by palynological studies (Beffa et al, 2015;Reille, 1992a;Reille et al, 1999), or tall scrublands.…”

Understanding long-term post-fire regeneration of a fire-resistant pine species

“…Charcoal palaeorecords reveal how fire regimes have been modified since humans first arrived on the Canary Islands (de Nascimento et al 2009;Nogué et al 2013). At present, forest fire frequency has significantly increased over the last few decades in the Mediterranean region (Camia et al 2008).…”

Applying an integrated landscape characterization and evaluation tool to small islands (Pico, Azores, Portugal)

“…It is also relevant because this is an area of refuge of wet subtropical vegetation formation (Laurisilvae) that built the Mediterranean basin vegetation during the Tethyan-Tertiary period (Sjögren, 2000;Dias 2001;Vargas, 2007;Rodríguez-Sánchez & Arroyo, 2008;de Nascimento et al, 2009;Rodríguez-Sánchez et al, 2009;Schirone et al, 2010;Fernández-Palacios et al, 2011;Nogué et al, 2013). This fact, according to some authors (e.g.…”