Skip to main content
Article
Holocene Dynamics of Temperate Rainforests in West-Central Patagonia
Frontiers in Ecology and the Environment
  • Virginia Iglesias, Montana State University-Bozeman
  • Simon G. Haberle, Australian National University
  • Andrés Holz, Portland State University
  • Cathy Whitlock, Montana State University-Bozeman
Document Type
Article
Publication Date
1-26-2018
Subjects
  • Climatic changes -- Effect of human beings on,
  • Charcoal -- Analysis,
  • Climate -- Patagonia -- Holocene,
  • Paleoclimatology -- Holocene,
  • Ecological disturbances
Abstract

Analyses of long-term ecosystem dynamics offer insights into the conditions that have led to stability vs. rapid change in the past and the importance of disturbance in regulating community composition. In this study, we (1) used lithology, pollen, and charcoal data from Mallín Casanova (47°S) to reconstruct the wetland, vegetation, and fire history of west-central Patagonia; and (2) compared the records with independent paleoenvironmental and archeological information to assess the effects of past climate and human activity on ecosystem dynamics. Pollen data indicate that Nothofagus-Pilgerodendronforests were established by 9,000 cal yr BP. Although the biodiversity of the understory increased between 8,480 and 5,630 cal yr BP, forests remained relatively unchanged from 9,000 to 2,000 cal yr BP. The charcoal record registers high fire-episode frequency in the early Holocene followed by low biomass burning between 6,500 and 2,000 cal yr BP. Covarying trends in charcoal, bog development, and Neoglacial advances suggest that climate was the primary driver of these changes. After 2,000 cal yr BP, the proxy data indicate (a) increased fire-episode frequency; (b) centennial-scale shifts in bog and forest composition; (c) the emergence of vegetation-fire linkages not recorded in previous times; and (d) paludification in the last 500 years possibly associated with forest loss. Our results therefore suggest that Nothofagus-Pilgerodendrondominance was maintained through much of the Holocene despite long-term changes in climate and fire. Unparalleled fluctuations in local ecosystems during the last two millennia were governed by disturbance-vegetation-hydrology feedbacks likely triggered by greater climate variability and deforestation.

Description

© The Ecological Society of America. This is the publisher's final. Article appears in Frontiers in Ecology and the Environment and can be found online at: https://doi.org/10.3389/fevo.2017.00177

DOI
10.3389/fevo.2017.00177
Persistent Identifier
http://archives.pdx.edu/ds/psu/23501
Citation Information
Iglesias, V., Haberle, S., Holz, A., and Whitlock, C. (2018). Holocene Dynamics of Temperate Rainforests in West-Central Patagonia. Frontiers in Ecology and the Environment.