Simulated warming does not impair seedling survival and growth of Nothofagus pumilio in the southern Andes

Published Date
Perspectives in Plant Ecology, Evolution and Systematics
20 April 2013, Vol.15(2):97–105, doi:10.1016/j.ppees.2013.02.003
Research article

• Author 

• Frida I. Piper ^a,c,,
• Alex Fajardo ^a
• Lohengrin A. Cavieres ^b,c

• aCentro de Investigación en Ecosistemas de la Patagonia (CIEP) Conicyt – Regional R10C1003, Universidad Austral de Chile, Ignacio Serrano 509, Coyhaique 5951601, Chile
• bDepartamento de Botánica, Universidad de Concepción, Concepción, Chile
• cInstituto de Ecología y Biodiversidad – IEB, Santiago, Chile

Received 26 September 2012. Revised 11 February 2013. Accepted 12 February 2013. Available online 8 March 2013.

Abstract

It has been predicted that subalpine forests will be negatively affected by global warming; however, direct responses to experimental warming have been scarcely examined in these systems. In this study we evaluated the effects of higher temperatures with and without water addition on the survival and growth of recently emerged (small) and large seedlings of the widely distributed species Nothofagus pumilio in subalpine forests of the southern Chilean Andes. We also examined the variations in seedling traits related to carbon balance in order to infer the causal mechanisms of survival and growth responses. Treatments of open top chambers (OTCs) were combined with watering in two locations with differing climates: Antillanca (40°S, humid) and Cerro Castillo (46°S, drier). OTCs increased mean and maximum air temperatures by 0.6 °C and 2–3 °C, respectively, and decreased soil humidity by 56% in Antillanca and 30% in Cerro Castillo, fulfilling methodological expectations and climate model predictions. After two complete growing seasons, the survival, relative growth rate (RGR), biomass, and a suite of seedling traits were measured and analyzed using mixed-effects models. Warming and warming in combination with watering significantly increased large seedling survival in Cerro Castillo. In Antillanca, warmer conditions increased the height, biomass, and leaf area of small seedlings, and the RGR of large seedlings. In this location, warming also caused lower leaf carbon isotopic composition in both age classes and higher specific leaf area in small seedlings, suggesting whole-plant carbon gain improvements; warming did not produce any drought effects. Our results indicate that warming produces positive effects on the seedling establishment of N. pumilio in the southern Andes, highlighting the importance of site-specific effects in response to climate change in widespread species. Site-specific effects can most likely explain the discrepancies between the results of this study and the predictions outlined by previous studies for these forests.

Keywords

Climate change

iWUE

Nothofagus pumilio

Open top chambers

Patagonia

SLA

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  Corresponding author at: Centro de Investigación en Ecosistemas de la Patagonia (CIEP) Conicyt Regional R10C1003, Universidad Austral de Chile, Ignacio Serrano 509, Coyhaique 5951601, Chile. Tel.: +56 67 247824; fax: +56 67 244501.

Copyright © 2013 Perspectives in Plant Ecology, Evolution and Systematics. Published by Elsevier GmbH All rights reserved.

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