Abstract

Pre-industrial forests are largely absent from environments long modified by humans, such as the Mediterranean region of central Chile. Around the capital, Santiago (33° S), the dominant vegetation is the “matorral,” characterised by shrubs, small trees, and succulents. However, colonial records indicate the presence of forests in this area. Here, we document for the first time the age, composition, and diameter distribution of a small remnant patch of primeval forest within the Río Clarillo National Park (RCNP), 45 km from Santiago. In this patch and in five surrounding matorral areas, we established 50 × 20 m plots, where we measured all trees with the diameter at breast height (DBH) > 5 cm. In the forest plot, we aged 36 trees using increment borers. The DBH showed an inverted J-distribution, dominated by the shade-tolerant Cryptocarya alba and Persea lingue (both Lauraceae) with individuals up to 1 m dbh and between 15 and 20 m tall. The basal area was 64 m2/ha, with 1140 trees/ha, and minimum ages ranged from 75 to 145 years. The matorral plots' trees were concentrated in smaller diameter classes (< 30 cm DBH), with an average basal area of 16.7 m2 ± 6.5 m2. The forest exhibited characteristics of late-successional stands and differed markedly from the surrounding matorral. The RCNP was first logged for charcoal in the mid-20th century, much more recently than many other areas of central Chile. The physiognomy of this patch resembles descriptions from 19th and early 20th century scholars. We hypothesise that forests like this were once much more common in the landscape than previously thought, and that present-day matorral represents an early successional forest maintained by recurrent human use. This patch represents a biological legacy from the past, provides a reference for long-term ecological restoration, and is unique, irreplaceable, and of immense value for conservation. © 2025 Ecological Society of Australia.